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SPIRV-Cross-Vulnerable/spirv_glsl.cpp
Hans-Kristian Arntzen 1bc5b70752 Add exhaustive image query to HLSL. 
Need to strip this down somehow ...
2017-09-20 10:00:13 +02:00

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/*
* Copyright 2015-2017 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "spirv_glsl.hpp"
#include "GLSL.std.450.h"
#include <algorithm>
#include <assert.h>
#include <utility>
using namespace spv;
using namespace spirv_cross;
using namespace std;
// Sanitizes underscores for GLSL where multiple underscores in a row are not allowed.
static string sanitize_underscores(const string &str)
{
string res;
res.reserve(str.size());
bool last_underscore = false;
for (auto c : str)
{
if (c == '_')
{
if (last_underscore)
continue;
res += c;
last_underscore = true;
}
else
{
res += c;
last_underscore = false;
}
}
return res;
}
// Returns true if an arithmetic operation does not change behavior depending on signedness.
static bool opcode_is_sign_invariant(Op opcode)
{
switch (opcode)
{
case OpIEqual:
case OpINotEqual:
case OpISub:
case OpIAdd:
case OpIMul:
case OpShiftLeftLogical:
case OpBitwiseOr:
case OpBitwiseXor:
case OpBitwiseAnd:
return true;
default:
return false;
}
}
static const char *to_pls_layout(PlsFormat format)
{
switch (format)
{
case PlsR11FG11FB10F:
return "layout(r11f_g11f_b10f) ";
case PlsR32F:
return "layout(r32f) ";
case PlsRG16F:
return "layout(rg16f) ";
case PlsRGB10A2:
return "layout(rgb10_a2) ";
case PlsRGBA8:
return "layout(rgba8) ";
case PlsRG16:
return "layout(rg16) ";
case PlsRGBA8I:
return "layout(rgba8i)";
case PlsRG16I:
return "layout(rg16i) ";
case PlsRGB10A2UI:
return "layout(rgb10_a2ui) ";
case PlsRGBA8UI:
return "layout(rgba8ui) ";
case PlsRG16UI:
return "layout(rg16ui) ";
case PlsR32UI:
return "layout(r32ui) ";
default:
return "";
}
}
static SPIRType::BaseType pls_format_to_basetype(PlsFormat format)
{
switch (format)
{
default:
case PlsR11FG11FB10F:
case PlsR32F:
case PlsRG16F:
case PlsRGB10A2:
case PlsRGBA8:
case PlsRG16:
return SPIRType::Float;
case PlsRGBA8I:
case PlsRG16I:
return SPIRType::Int;
case PlsRGB10A2UI:
case PlsRGBA8UI:
case PlsRG16UI:
case PlsR32UI:
return SPIRType::UInt;
}
}
static uint32_t pls_format_to_components(PlsFormat format)
{
switch (format)
{
default:
case PlsR32F:
case PlsR32UI:
return 1;
case PlsRG16F:
case PlsRG16:
case PlsRG16UI:
case PlsRG16I:
return 2;
case PlsR11FG11FB10F:
return 3;
case PlsRGB10A2:
case PlsRGBA8:
case PlsRGBA8I:
case PlsRGB10A2UI:
case PlsRGBA8UI:
return 4;
}
}
static const char *vector_swizzle(int vecsize, int index)
{
static const char *swizzle[4][4] = {
{ ".x", ".y", ".z", ".w" }, { ".xy", ".yz", ".zw" }, { ".xyz", ".yzw" }, { "" }
};
assert(vecsize >= 1 && vecsize <= 4);
assert(index >= 0 && index < 4);
assert(swizzle[vecsize - 1][index]);
return swizzle[vecsize - 1][index];
}
void CompilerGLSL::reset()
{
// We do some speculative optimizations which should pretty much always work out,
// but just in case the SPIR-V is rather weird, recompile until it's happy.
// This typically only means one extra pass.
force_recompile = false;
// Clear invalid expression tracking.
invalid_expressions.clear();
current_function = nullptr;
// Clear temporary usage tracking.
expression_usage_counts.clear();
forwarded_temporaries.clear();
resource_names.clear();
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
// Clear unflushed dependees.
id.get<SPIRVariable>().dependees.clear();
}
else if (id.get_type() == TypeExpression)
{
// And remove all expressions.
id.reset();
}
else if (id.get_type() == TypeFunction)
{
// Reset active state for all functions.
id.get<SPIRFunction>().active = false;
id.get<SPIRFunction>().flush_undeclared = true;
}
}
statement_count = 0;
indent = 0;
}
void CompilerGLSL::remap_pls_variables()
{
for (auto &input : pls_inputs)
{
auto &var = get<SPIRVariable>(input.id);
bool input_is_target = false;
if (var.storage == StorageClassUniformConstant)
{
auto &type = get<SPIRType>(var.basetype);
input_is_target = type.image.dim == DimSubpassData;
}
if (var.storage != StorageClassInput && !input_is_target)
SPIRV_CROSS_THROW("Can only use in and target variables for PLS inputs.");
var.remapped_variable = true;
}
for (auto &output : pls_outputs)
{
auto &var = get<SPIRVariable>(output.id);
if (var.storage != StorageClassOutput)
SPIRV_CROSS_THROW("Can only use out variables for PLS outputs.");
var.remapped_variable = true;
}
}
void CompilerGLSL::find_static_extensions()
{
for (auto &id : ids)
{
if (id.get_type() == TypeType)
{
auto &type = id.get<SPIRType>();
if (type.basetype == SPIRType::Double)
{
if (options.es)
SPIRV_CROSS_THROW("FP64 not supported in ES profile.");
if (!options.es && options.version < 400)
require_extension("GL_ARB_gpu_shader_fp64");
}
if (type.basetype == SPIRType::Int64 || type.basetype == SPIRType::UInt64)
{
if (options.es)
SPIRV_CROSS_THROW("64-bit integers not supported in ES profile.");
if (!options.es)
require_extension("GL_ARB_gpu_shader_int64");
}
}
}
auto &execution = get_entry_point();
switch (execution.model)
{
case ExecutionModelGLCompute:
if (!options.es && options.version < 430)
require_extension("GL_ARB_compute_shader");
if (options.es && options.version < 310)
SPIRV_CROSS_THROW("At least ESSL 3.10 required for compute shaders.");
break;
case ExecutionModelGeometry:
if (options.es && options.version < 320)
require_extension("GL_EXT_geometry_shader");
if (!options.es && options.version < 150)
require_extension("GL_ARB_geometry_shader4");
if ((execution.flags & (1ull << ExecutionModeInvocations)) && execution.invocations != 1)
{
// Instanced GS is part of 400 core or this extension.
if (!options.es && options.version < 400)
require_extension("GL_ARB_gpu_shader5");
}
break;
case ExecutionModelTessellationEvaluation:
case ExecutionModelTessellationControl:
if (options.es && options.version < 320)
require_extension("GL_EXT_tessellation_shader");
if (!options.es && options.version < 400)
require_extension("GL_ARB_tessellation_shader");
break;
default:
break;
}
if (!pls_inputs.empty() || !pls_outputs.empty())
require_extension("GL_EXT_shader_pixel_local_storage");
if (options.separate_shader_objects && !options.es && options.version < 410)
require_extension("GL_ARB_separate_shader_objects");
}
string CompilerGLSL::compile()
{
// Force a classic "C" locale, reverts when function returns
ClassicLocale classic_locale;
// Scan the SPIR-V to find trivial uses of extensions.
find_static_extensions();
fixup_image_load_store_access();
update_active_builtins();
analyze_sampler_comparison_states();
uint32_t pass_count = 0;
do
{
if (pass_count >= 3)
SPIRV_CROSS_THROW("Over 3 compilation loops detected. Must be a bug!");
reset();
// Move constructor for this type is broken on GCC 4.9 ...
buffer = unique_ptr<ostringstream>(new ostringstream());
emit_header();
emit_resources();
emit_function(get<SPIRFunction>(entry_point), 0);
pass_count++;
} while (force_recompile);
return buffer->str();
}
std::string CompilerGLSL::get_partial_source()
{
return buffer ? buffer->str() : "No compiled source available yet.";
}
void CompilerGLSL::emit_header()
{
auto &execution = get_entry_point();
statement("#version ", options.version, options.es && options.version > 100 ? " es" : "");
// Needed for binding = # on UBOs, etc.
if (!options.es && options.version < 420 && options.enable_420pack_extension)
{
statement("#ifdef GL_ARB_shading_language_420pack");
statement("#extension GL_ARB_shading_language_420pack : require");
statement("#endif");
}
for (auto &ext : forced_extensions)
statement("#extension ", ext, " : require");
for (auto &header : header_lines)
statement(header);
vector<string> inputs;
vector<string> outputs;
switch (execution.model)
{
case ExecutionModelGeometry:
outputs.push_back(join("max_vertices = ", execution.output_vertices));
if ((execution.flags & (1ull << ExecutionModeInvocations)) && execution.invocations != 1)
inputs.push_back(join("invocations = ", execution.invocations));
if (execution.flags & (1ull << ExecutionModeInputPoints))
inputs.push_back("points");
if (execution.flags & (1ull << ExecutionModeInputLines))
inputs.push_back("lines");
if (execution.flags & (1ull << ExecutionModeInputLinesAdjacency))
inputs.push_back("lines_adjacency");
if (execution.flags & (1ull << ExecutionModeTriangles))
inputs.push_back("triangles");
if (execution.flags & (1ull << ExecutionModeInputTrianglesAdjacency))
inputs.push_back("triangles_adjacency");
if (execution.flags & (1ull << ExecutionModeOutputTriangleStrip))
outputs.push_back("triangle_strip");
if (execution.flags & (1ull << ExecutionModeOutputPoints))
outputs.push_back("points");
if (execution.flags & (1ull << ExecutionModeOutputLineStrip))
outputs.push_back("line_strip");
break;
case ExecutionModelTessellationControl:
if (execution.flags & (1ull << ExecutionModeOutputVertices))
outputs.push_back(join("vertices = ", execution.output_vertices));
break;
case ExecutionModelTessellationEvaluation:
if (execution.flags & (1ull << ExecutionModeQuads))
inputs.push_back("quads");
if (execution.flags & (1ull << ExecutionModeTriangles))
inputs.push_back("triangles");
if (execution.flags & (1ull << ExecutionModeIsolines))
inputs.push_back("isolines");
if (execution.flags & (1ull << ExecutionModePointMode))
inputs.push_back("point_mode");
if ((execution.flags & (1ull << ExecutionModeIsolines)) == 0)
{
if (execution.flags & (1ull << ExecutionModeVertexOrderCw))
inputs.push_back("cw");
if (execution.flags & (1ull << ExecutionModeVertexOrderCcw))
inputs.push_back("ccw");
}
if (execution.flags & (1ull << ExecutionModeSpacingFractionalEven))
inputs.push_back("fractional_even_spacing");
if (execution.flags & (1ull << ExecutionModeSpacingFractionalOdd))
inputs.push_back("fractional_odd_spacing");
if (execution.flags & (1ull << ExecutionModeSpacingEqual))
inputs.push_back("equal_spacing");
break;
case ExecutionModelGLCompute:
inputs.push_back(join("local_size_x = ", execution.workgroup_size.x));
inputs.push_back(join("local_size_y = ", execution.workgroup_size.y));
inputs.push_back(join("local_size_z = ", execution.workgroup_size.z));
break;
case ExecutionModelFragment:
if (options.es)
{
switch (options.fragment.default_float_precision)
{
case Options::Lowp:
statement("precision lowp float;");
break;
case Options::Mediump:
statement("precision mediump float;");
break;
case Options::Highp:
statement("precision highp float;");
break;
default:
break;
}
switch (options.fragment.default_int_precision)
{
case Options::Lowp:
statement("precision lowp int;");
break;
case Options::Mediump:
statement("precision mediump int;");
break;
case Options::Highp:
statement("precision highp int;");
break;
default:
break;
}
}
if (execution.flags & (1ull << ExecutionModeEarlyFragmentTests))
inputs.push_back("early_fragment_tests");
if (execution.flags & (1ull << ExecutionModeDepthGreater))
inputs.push_back("depth_greater");
if (execution.flags & (1ull << ExecutionModeDepthLess))
inputs.push_back("depth_less");
break;
default:
break;
}
if (!inputs.empty())
statement("layout(", merge(inputs), ") in;");
if (!outputs.empty())
statement("layout(", merge(outputs), ") out;");
statement("");
}
bool CompilerGLSL::type_is_empty(const SPIRType &type)
{
return type.basetype == SPIRType::Struct && type.member_types.empty();
}
void CompilerGLSL::emit_struct(SPIRType &type)
{
// Struct types can be stamped out multiple times
// with just different offsets, matrix layouts, etc ...
// Type-punning with these types is legal, which complicates things
// when we are storing struct and array types in an SSBO for example.
if (type.type_alias != 0)
return;
// Don't declare empty structs in GLSL, this is not allowed.
// Empty structs is a corner case of HLSL output, and only sensible thing to do is avoiding to declare
// these types.
if (type_is_empty(type))
return;
add_resource_name(type.self);
auto name = type_to_glsl(type);
statement(!backend.explicit_struct_type ? "struct " : "", name);
begin_scope();
type.member_name_cache.clear();
uint32_t i = 0;
bool emitted = false;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
emitted = true;
}
end_scope_decl();
if (emitted)
statement("");
}
uint64_t CompilerGLSL::combined_decoration_for_member(const SPIRType &type, uint32_t index)
{
uint64_t flags = 0;
auto &memb = meta[type.self].members;
if (index >= memb.size())
return 0;
auto &dec = memb[index];
// If our type is a struct, traverse all the members as well recursively.
flags |= dec.decoration_flags;
for (uint32_t i = 0; i < type.member_types.size(); i++)
flags |= combined_decoration_for_member(get<SPIRType>(type.member_types[i]), i);
return flags;
}
string CompilerGLSL::to_interpolation_qualifiers(uint64_t flags)
{
string res;
//if (flags & (1ull << DecorationSmooth))
// res += "smooth ";
if (flags & (1ull << DecorationFlat))
res += "flat ";
if (flags & (1ull << DecorationNoPerspective))
res += "noperspective ";
if (flags & (1ull << DecorationCentroid))
res += "centroid ";
if (flags & (1ull << DecorationPatch))
res += "patch ";
if (flags & (1ull << DecorationSample))
res += "sample ";
if (flags & (1ull << DecorationInvariant))
res += "invariant ";
return res;
}
string CompilerGLSL::layout_for_member(const SPIRType &type, uint32_t index)
{
if (is_legacy())
return "";
bool is_block = (meta[type.self].decoration.decoration_flags &
((1ull << DecorationBlock) | (1ull << DecorationBufferBlock))) != 0;
if (!is_block)
return "";
auto &memb = meta[type.self].members;
if (index >= memb.size())
return "";
auto &dec = memb[index];
vector<string> attr;
// We can only apply layouts on members in block interfaces.
// This is a bit problematic because in SPIR-V decorations are applied on the struct types directly.
// This is not supported on GLSL, so we have to make the assumption that if a struct within our buffer block struct
// has a decoration, it was originally caused by a top-level layout() qualifier in GLSL.
//
// We would like to go from (SPIR-V style):
//
// struct Foo { layout(row_major) mat4 matrix; };
// buffer UBO { Foo foo; };
//
// to
//
// struct Foo { mat4 matrix; }; // GLSL doesn't support any layout shenanigans in raw struct declarations.
// buffer UBO { layout(row_major) Foo foo; }; // Apply the layout on top-level.
auto flags = combined_decoration_for_member(type, index);
if (flags & (1ull << DecorationRowMajor))
attr.push_back("row_major");
// We don't emit any global layouts, so column_major is default.
//if (flags & (1ull << DecorationColMajor))
// attr.push_back("column_major");
if (dec.decoration_flags & (1ull << DecorationLocation))
attr.push_back(join("location = ", dec.location));
if (attr.empty())
return "";
string res = "layout(";
res += merge(attr);
res += ") ";
return res;
}
const char *CompilerGLSL::format_to_glsl(spv::ImageFormat format)
{
auto check_desktop = [this] {
if (options.es)
SPIRV_CROSS_THROW("Attempting to use image format not supported in ES profile.");
};
switch (format)
{
case ImageFormatRgba32f:
return "rgba32f";
case ImageFormatRgba16f:
return "rgba16f";
case ImageFormatR32f:
return "r32f";
case ImageFormatRgba8:
return "rgba8";
case ImageFormatRgba8Snorm:
return "rgba8_snorm";
case ImageFormatRg32f:
return "rg32f";
case ImageFormatRg16f:
return "rg16f";
case ImageFormatRgba32i:
return "rgba32i";
case ImageFormatRgba16i:
return "rgba16i";
case ImageFormatR32i:
return "r32i";
case ImageFormatRgba8i:
return "rgba8i";
case ImageFormatRg32i:
return "rg32i";
case ImageFormatRg16i:
return "rg16i";
case ImageFormatRgba32ui:
return "rgba32ui";
case ImageFormatRgba16ui:
return "rgba16ui";
case ImageFormatR32ui:
return "r32ui";
case ImageFormatRgba8ui:
return "rgba8ui";
case ImageFormatRg32ui:
return "rg32ui";
case ImageFormatRg16ui:
return "rg16ui";
// Desktop-only formats
case ImageFormatR11fG11fB10f:
check_desktop();
return "r11f_g11f_b10f";
case ImageFormatR16f:
check_desktop();
return "r16f";
case ImageFormatRgb10A2:
check_desktop();
return "rgb10_a2";
case ImageFormatR8:
check_desktop();
return "r8";
case ImageFormatRg8:
check_desktop();
return "rg8";
case ImageFormatR16:
check_desktop();
return "r16";
case ImageFormatRg16:
check_desktop();
return "rg16";
case ImageFormatRgba16:
check_desktop();
return "rgba16";
case ImageFormatR16Snorm:
check_desktop();
return "r16_snorm";
case ImageFormatRg16Snorm:
check_desktop();
return "rg16_snorm";
case ImageFormatRgba16Snorm:
check_desktop();
return "rgba16_snorm";
case ImageFormatR8Snorm:
check_desktop();
return "r8_snorm";
case ImageFormatRg8Snorm:
check_desktop();
return "rg8_snorm";
case ImageFormatR8ui:
check_desktop();
return "r8ui";
case ImageFormatRg8ui:
check_desktop();
return "rg8ui";
case ImageFormatR16ui:
check_desktop();
return "r16ui";
case ImageFormatRgb10a2ui:
check_desktop();
return "rgb10_a2ui";
case ImageFormatR8i:
check_desktop();
return "r8i";
case ImageFormatRg8i:
check_desktop();
return "rg8i";
case ImageFormatR16i:
check_desktop();
return "r16i";
default:
case ImageFormatUnknown:
return nullptr;
}
}
uint32_t CompilerGLSL::type_to_std430_base_size(const SPIRType &type)
{
switch (type.basetype)
{
case SPIRType::Double:
case SPIRType::Int64:
case SPIRType::UInt64:
return 8;
default:
return 4;
}
}
uint32_t CompilerGLSL::type_to_std430_alignment(const SPIRType &type, uint64_t flags)
{
const uint32_t base_alignment = type_to_std430_base_size(type);
if (type.basetype == SPIRType::Struct)
{
// Rule 9. Structs alignments are maximum alignment of its members.
uint32_t alignment = 0;
for (uint32_t i = 0; i < type.member_types.size(); i++)
{
auto member_flags = meta[type.self].members.at(i).decoration_flags;
alignment = max(alignment, type_to_std430_alignment(get<SPIRType>(type.member_types[i]), member_flags));
}
return alignment;
}
else
{
// From 7.6.2.2 in GL 4.5 core spec.
// Rule 1
if (type.vecsize == 1 && type.columns == 1)
return base_alignment;
// Rule 2
if ((type.vecsize == 2 || type.vecsize == 4) && type.columns == 1)
return type.vecsize * base_alignment;
// Rule 3
if (type.vecsize == 3 && type.columns == 1)
return 4 * base_alignment;
// Rule 4 implied. Alignment does not change in std430.
// Rule 5. Column-major matrices are stored as arrays of
// vectors.
if ((flags & (1ull << DecorationColMajor)) && type.columns > 1)
{
if (type.vecsize == 3)
return 4 * base_alignment;
else
return type.vecsize * base_alignment;
}
// Rule 6 implied.
// Rule 7.
if ((flags & (1ull << DecorationRowMajor)) && type.vecsize > 1)
{
if (type.columns == 3)
return 4 * base_alignment;
else
return type.columns * base_alignment;
}
// Rule 8 implied.
}
SPIRV_CROSS_THROW("Did not find suitable std430 rule for type. Bogus decorations?");
}
uint32_t CompilerGLSL::type_to_std430_array_stride(const SPIRType &type, uint64_t flags)
{
// Array stride is equal to aligned size of the underlying type.
SPIRType tmp = type;
tmp.array.pop_back();
tmp.array_size_literal.pop_back();
uint32_t size = type_to_std430_size(tmp, flags);
uint32_t alignment = type_to_std430_alignment(tmp, flags);
return (size + alignment - 1) & ~(alignment - 1);
}
uint32_t CompilerGLSL::type_to_std430_size(const SPIRType &type, uint64_t flags)
{
if (!type.array.empty())
return to_array_size_literal(type, uint32_t(type.array.size()) - 1) * type_to_std430_array_stride(type, flags);
const uint32_t base_alignment = type_to_std430_base_size(type);
uint32_t size = 0;
if (type.basetype == SPIRType::Struct)
{
uint32_t pad_alignment = 1;
for (uint32_t i = 0; i < type.member_types.size(); i++)
{
auto member_flags = meta[type.self].members.at(i).decoration_flags;
auto &member_type = get<SPIRType>(type.member_types[i]);
uint32_t std430_alignment = type_to_std430_alignment(member_type, member_flags);
uint32_t alignment = max(std430_alignment, pad_alignment);
// The next member following a struct member is aligned to the base alignment of the struct that came before.
// GL 4.5 spec, 7.6.2.2.
if (member_type.basetype == SPIRType::Struct)
pad_alignment = std430_alignment;
else
pad_alignment = 1;
size = (size + alignment - 1) & ~(alignment - 1);
size += type_to_std430_size(member_type, member_flags);
}
}
else
{
if (type.columns == 1)
size = type.vecsize * base_alignment;
if ((flags & (1ull << DecorationColMajor)) && type.columns > 1)
{
if (type.vecsize == 3)
size = type.columns * 4 * base_alignment;
else
size = type.columns * type.vecsize * base_alignment;
}
if ((flags & (1ull << DecorationRowMajor)) && type.vecsize > 1)
{
if (type.columns == 3)
size = type.vecsize * 4 * base_alignment;
else
size = type.vecsize * type.columns * base_alignment;
}
}
return size;
}
bool CompilerGLSL::ssbo_is_std430_packing(const SPIRType &type)
{
// This is very tricky and error prone, but try to be exhaustive and correct here.
// SPIR-V doesn't directly say if we're using std430 or std140.
// SPIR-V communicates this using Offset and ArrayStride decorations (which is what really matters),
// so we have to try to infer whether or not the original GLSL source was std140 or std430 based on this information.
// We do not have to consider shared or packed since these layouts are not allowed in Vulkan SPIR-V (they are useless anyways, and custom offsets would do the same thing).
//
// It is almost certain that we're using std430, but it gets tricky with arrays in particular.
// We will assume std430, but infer std140 if we can prove the struct is not compliant with std430.
//
// The only two differences between std140 and std430 are related to padding alignment/array stride
// in arrays and structs. In std140 they take minimum vec4 alignment.
// std430 only removes the vec4 requirement.
uint32_t offset = 0;
uint32_t pad_alignment = 1;
for (uint32_t i = 0; i < type.member_types.size(); i++)
{
auto &memb_type = get<SPIRType>(type.member_types[i]);
auto member_flags = meta[type.self].members.at(i).decoration_flags;
// Verify alignment rules.
uint32_t std430_alignment = type_to_std430_alignment(memb_type, member_flags);
uint32_t alignment = max(std430_alignment, pad_alignment);
offset = (offset + alignment - 1) & ~(alignment - 1);
// The next member following a struct member is aligned to the base alignment of the struct that came before.
// GL 4.5 spec, 7.6.2.2.
if (memb_type.basetype == SPIRType::Struct)
pad_alignment = std430_alignment;
else
pad_alignment = 1;
uint32_t actual_offset = type_struct_member_offset(type, i);
if (actual_offset != offset) // This cannot be std430.
return false;
// Verify array stride rules.
if (!memb_type.array.empty() &&
type_to_std430_array_stride(memb_type, member_flags) != type_struct_member_array_stride(type, i))
return false;
// Verify that sub-structs also follow std430 rules.
if (!memb_type.member_types.empty() && !ssbo_is_std430_packing(memb_type))
return false;
// Bump size.
offset += type_to_std430_size(memb_type, member_flags);
}
return true;
}
string CompilerGLSL::layout_for_variable(const SPIRVariable &var)
{
// FIXME: Come up with a better solution for when to disable layouts.
// Having layouts depend on extensions as well as which types
// of layouts are used. For now, the simple solution is to just disable
// layouts for legacy versions.
if (is_legacy())
return "";
vector<string> attr;
auto &dec = meta[var.self].decoration;
auto &type = get<SPIRType>(var.basetype);
auto flags = dec.decoration_flags;
auto typeflags = meta[type.self].decoration.decoration_flags;
if (options.vulkan_semantics && var.storage == StorageClassPushConstant)
attr.push_back("push_constant");
if (flags & (1ull << DecorationRowMajor))
attr.push_back("row_major");
if (flags & (1ull << DecorationColMajor))
attr.push_back("column_major");
if (options.vulkan_semantics)
{
if (flags & (1ull << DecorationInputAttachmentIndex))
attr.push_back(join("input_attachment_index = ", dec.input_attachment));
}
if (flags & (1ull << DecorationLocation))
{
bool can_use_varying_location = true;
// Location specifiers are must have in SPIR-V, but they aren't really supported in earlier versions of GLSL.
// Be very explicit here about how to solve the issue.
if ((get_execution_model() != ExecutionModelVertex && var.storage == StorageClassInput) ||
(get_execution_model() != ExecutionModelFragment && var.storage == StorageClassOutput))
{
if (!options.es && options.version < 410 && !options.separate_shader_objects)
can_use_varying_location = false;
else if (options.es && options.version < 310)
can_use_varying_location = false;
}
if (can_use_varying_location)
{
uint64_t combined_decoration = 0;
for (uint32_t i = 0; i < meta[type.self].members.size(); i++)
combined_decoration |= combined_decoration_for_member(type, i);
// If our members have location decorations, we don't need to
// emit location decorations at the top as well (looks weird).
if ((combined_decoration & (1ull << DecorationLocation)) == 0)
attr.push_back(join("location = ", dec.location));
}
}
// set = 0 is the default. Do not emit set = decoration in regular GLSL output, but
// we should preserve it in Vulkan GLSL mode.
if (var.storage != StorageClassPushConstant)
{
if ((flags & (1ull << DecorationDescriptorSet)) && (dec.set != 0 || options.vulkan_semantics))
attr.push_back(join("set = ", dec.set));
}
bool can_use_binding;
if (options.es)
can_use_binding = options.version >= 310;
else
can_use_binding = options.enable_420pack_extension || (options.version >= 420);
if (can_use_binding && (flags & (1ull << DecorationBinding)))
attr.push_back(join("binding = ", dec.binding));
if (flags & (1ull << DecorationOffset))
attr.push_back(join("offset = ", dec.offset));
// Instead of adding explicit offsets for every element here, just assume we're using std140 or std430.
// If SPIR-V does not comply with either layout, we cannot really work around it.
if (var.storage == StorageClassUniform && (typeflags & (1ull << DecorationBlock)))
attr.push_back("std140");
else if (var.storage == StorageClassUniform && (typeflags & (1ull << DecorationBufferBlock)))
attr.push_back(ssbo_is_std430_packing(type) ? "std430" : "std140");
else if (options.vulkan_semantics && var.storage == StorageClassPushConstant)
attr.push_back(ssbo_is_std430_packing(type) ? "std430" : "std140");
// For images, the type itself adds a layout qualifer.
// Only emit the format for storage images.
if (type.basetype == SPIRType::Image && type.image.sampled == 2)
{
const char *fmt = format_to_glsl(type.image.format);
if (fmt)
attr.push_back(fmt);
}
if (attr.empty())
return "";
string res = "layout(";
res += merge(attr);
res += ") ";
return res;
}
void CompilerGLSL::emit_push_constant_block(const SPIRVariable &var)
{
if (flattened_buffer_blocks.count(var.self))
emit_buffer_block_flattened(var);
else if (options.vulkan_semantics)
emit_push_constant_block_vulkan(var);
else
emit_push_constant_block_glsl(var);
}
void CompilerGLSL::emit_push_constant_block_vulkan(const SPIRVariable &var)
{
emit_buffer_block(var);
}
void CompilerGLSL::emit_push_constant_block_glsl(const SPIRVariable &var)
{
// OpenGL has no concept of push constant blocks, implement it as a uniform struct.
auto &type = get<SPIRType>(var.basetype);
auto &flags = meta[var.self].decoration.decoration_flags;
flags &= ~((1ull << DecorationBinding) | (1ull << DecorationDescriptorSet));
#if 0
if (flags & ((1ull << DecorationBinding) | (1ull << DecorationDescriptorSet)))
SPIRV_CROSS_THROW("Push constant blocks cannot be compiled to GLSL with Binding or Set syntax. "
"Remap to location with reflection API first or disable these decorations.");
#endif
// We're emitting the push constant block as a regular struct, so disable the block qualifier temporarily.
// Otherwise, we will end up emitting layout() qualifiers on naked structs which is not allowed.
auto &block_flags = meta[type.self].decoration.decoration_flags;
uint64_t block_flag = block_flags & (1ull << DecorationBlock);
block_flags &= ~block_flag;
emit_struct(type);
block_flags |= block_flag;
emit_uniform(var);
statement("");
}
void CompilerGLSL::emit_buffer_block(const SPIRVariable &var)
{
if (flattened_buffer_blocks.count(var.self))
emit_buffer_block_flattened(var);
else if (is_legacy())
emit_buffer_block_legacy(var);
else
emit_buffer_block_native(var);
}
void CompilerGLSL::emit_buffer_block_legacy(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
bool ssbo = (meta[type.self].decoration.decoration_flags & (1ull << DecorationBufferBlock)) != 0;
if (ssbo)
SPIRV_CROSS_THROW("SSBOs not supported in legacy targets.");
// We're emitting the push constant block as a regular struct, so disable the block qualifier temporarily.
// Otherwise, we will end up emitting layout() qualifiers on naked structs which is not allowed.
auto &block_flags = meta[type.self].decoration.decoration_flags;
uint64_t block_flag = block_flags & (1ull << DecorationBlock);
block_flags &= ~block_flag;
emit_struct(type);
block_flags |= block_flag;
emit_uniform(var);
statement("");
}
void CompilerGLSL::emit_buffer_block_native(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
uint64_t flags = get_buffer_block_flags(var);
bool ssbo = (meta[type.self].decoration.decoration_flags & (1ull << DecorationBufferBlock)) != 0;
bool is_restrict = ssbo && (flags & (1ull << DecorationRestrict)) != 0;
bool is_writeonly = ssbo && (flags & (1ull << DecorationNonReadable)) != 0;
bool is_readonly = ssbo && (flags & (1ull << DecorationNonWritable)) != 0;
bool is_coherent = ssbo && (flags & (1ull << DecorationCoherent)) != 0;
add_resource_name(var.self);
// Block names should never alias.
auto buffer_name = to_name(type.self, false);
// Shaders never use the block by interface name, so we don't
// have to track this other than updating name caches.
if (resource_names.find(buffer_name) != end(resource_names))
buffer_name = get_fallback_name(type.self);
else
resource_names.insert(buffer_name);
statement(layout_for_variable(var), is_coherent ? "coherent " : "", is_restrict ? "restrict " : "",
is_writeonly ? "writeonly " : "", is_readonly ? "readonly " : "", ssbo ? "buffer " : "uniform ",
buffer_name);
begin_scope();
type.member_name_cache.clear();
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
}
end_scope_decl(to_name(var.self) + type_to_array_glsl(type));
statement("");
}
void CompilerGLSL::emit_buffer_block_flattened(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
// Block names should never alias.
auto buffer_name = to_name(type.self, false);
size_t buffer_size = (get_declared_struct_size(type) + 15) / 16;
SPIRType::BaseType basic_type;
if (get_common_basic_type(type, basic_type))
{
SPIRType tmp;
tmp.basetype = basic_type;
tmp.vecsize = 4;
if (basic_type != SPIRType::Float && basic_type != SPIRType::Int && basic_type != SPIRType::UInt)
SPIRV_CROSS_THROW("Basic types in a flattened UBO must be float, int or uint.");
auto flags = get_buffer_block_flags(var);
statement("uniform ", flags_to_precision_qualifiers_glsl(tmp, flags), type_to_glsl(tmp), " ", buffer_name, "[",
buffer_size, "];");
}
else
SPIRV_CROSS_THROW("All basic types in a flattened block must be the same.");
}
const char *CompilerGLSL::to_storage_qualifiers_glsl(const SPIRVariable &var)
{
auto &execution = get_entry_point();
if (var.storage == StorageClassInput || var.storage == StorageClassOutput)
{
if (is_legacy() && execution.model == ExecutionModelVertex)
return var.storage == StorageClassInput ? "attribute " : "varying ";
else if (is_legacy() && execution.model == ExecutionModelFragment)
return "varying "; // Fragment outputs are renamed so they never hit this case.
else
return var.storage == StorageClassInput ? "in " : "out ";
}
else if (var.storage == StorageClassUniformConstant || var.storage == StorageClassUniform ||
var.storage == StorageClassPushConstant)
{
return "uniform ";
}
return "";
}
void CompilerGLSL::emit_flattened_io_block(const SPIRVariable &var, const char *qual)
{
auto &type = get<SPIRType>(var.basetype);
if (!type.array.empty())
SPIRV_CROSS_THROW("Array of varying structs cannot be flattened to legacy-compatible varyings.");
// Block names should never alias.
auto block_name = to_name(type.self, false);
// Shaders never use the block by interface name, so we don't
// have to track this other than updating name caches.
if (resource_names.find(block_name) != end(resource_names))
block_name = get_fallback_name(type.self);
else
resource_names.insert(block_name);
auto old_flags = meta[type.self].decoration.decoration_flags;
// Emit the members as if they are part of a block to get all qualifiers.
meta[type.self].decoration.decoration_flags |= 1ull << DecorationBlock;
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
auto &membertype = get<SPIRType>(member);
if (membertype.basetype == SPIRType::Struct)
SPIRV_CROSS_THROW("Cannot flatten struct inside structs in I/O variables.");
// Pass in the varying qualifier here so it will appear in the correct declaration order.
// Replace member name while emitting it so it encodes both struct name and member name.
// Sanitize underscores because joining the two identifiers might create more than 1 underscore in a row,
// which is not allowed.
auto member_name = get_member_name(type.self, i);
set_member_name(type.self, i, sanitize_underscores(join(to_name(type.self), "_", member_name)));
emit_struct_member(type, member, i, qual);
// Restore member name.
set_member_name(type.self, i, member_name);
i++;
}
meta[type.self].decoration.decoration_flags = old_flags;
// Treat this variable as flattened from now on.
flattened_structs.insert(var.self);
}
void CompilerGLSL::emit_interface_block(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
// Either make it plain in/out or in/out blocks depending on what shader is doing ...
bool block = (meta[type.self].decoration.decoration_flags & (1ull << DecorationBlock)) != 0;
const char *qual = to_storage_qualifiers_glsl(var);
if (block)
{
// ESSL earlier than 310 and GLSL earlier than 150 did not support
// I/O variables which are struct types.
// To support this, flatten the struct into separate varyings instead.
if ((options.es && options.version < 310) || (!options.es && options.version < 150))
{
// I/O blocks on ES require version 310 with Android Extension Pack extensions, or core version 320.
// On desktop, I/O blocks were introduced with geometry shaders in GL 3.2 (GLSL 150).
emit_flattened_io_block(var, qual);
}
else
{
if (options.es && options.version < 320)
{
// Geometry and tessellation extensions imply this extension.
if (!forced_extensions.count("GL_EXT_geometry_shader") &&
!forced_extensions.count("GL_EXT_tessellation_shader"))
require_extension("GL_EXT_shader_io_blocks");
}
add_resource_name(var.self);
// Block names should never alias.
auto block_name = to_name(type.self, false);
// Shaders never use the block by interface name, so we don't
// have to track this other than updating name caches.
if (resource_names.find(block_name) != end(resource_names))
block_name = get_fallback_name(type.self);
else
resource_names.insert(block_name);
statement(layout_for_variable(var), qual, block_name);
begin_scope();
type.member_name_cache.clear();
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
}
end_scope_decl(join(to_name(var.self), type_to_array_glsl(type)));
statement("");
}
}
else
{
// ESSL earlier than 310 and GLSL earlier than 150 did not support
// I/O variables which are struct types.
// To support this, flatten the struct into separate varyings instead.
if (type.basetype == SPIRType::Struct &&
((options.es && options.version < 310) || (!options.es && options.version < 150)))
{
emit_flattened_io_block(var, qual);
}
else
{
add_resource_name(var.self);
statement(layout_for_variable(var), variable_decl(var), ";");
}
}
}
void CompilerGLSL::emit_uniform(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
if (type.basetype == SPIRType::Image && type.image.sampled == 2)
{
if (!options.es && options.version < 420)
require_extension("GL_ARB_shader_image_load_store");
else if (options.es && options.version < 310)
SPIRV_CROSS_THROW("At least ESSL 3.10 required for shader image load store.");
}
add_resource_name(var.self);
statement(layout_for_variable(var), variable_decl(var), ";");
}
void CompilerGLSL::emit_specialization_constant(const SPIRConstant &constant)
{
auto &type = get<SPIRType>(constant.constant_type);
auto name = to_name(constant.self);
statement("layout(constant_id = ", get_decoration(constant.self, DecorationSpecId), ") const ",
variable_decl(type, name), " = ", constant_expression(constant), ";");
}
void CompilerGLSL::replace_illegal_names()
{
// clang-format off
static const unordered_set<string> keywords = {
"active", "asm", "atomic_uint", "attribute", "bool", "break",
"bvec2", "bvec3", "bvec4", "case", "cast", "centroid", "class", "coherent", "common", "const", "continue", "default", "discard",
"dmat2", "dmat2x2", "dmat2x3", "dmat2x4", "dmat3", "dmat3x2", "dmat3x3", "dmat3x4", "dmat4", "dmat4x2", "dmat4x3", "dmat4x4",
"do", "double", "dvec2", "dvec3", "dvec4", "else", "enum", "extern", "external", "false", "filter", "fixed", "flat", "float",
"for", "fvec2", "fvec3", "fvec4", "goto", "half", "highp", "hvec2", "hvec3", "hvec4", "if", "iimage1D", "iimage1DArray",
"iimage2D", "iimage2DArray", "iimage2DMS", "iimage2DMSArray", "iimage2DRect", "iimage3D", "iimageBuffer", "iimageCube",
"iimageCubeArray", "image1D", "image1DArray", "image2D", "image2DArray", "image2DMS", "image2DMSArray", "image2DRect",
"image3D", "imageBuffer", "imageCube", "imageCubeArray", "in", "inline", "inout", "input", "int", "interface", "invariant",
"isampler1D", "isampler1DArray", "isampler2D", "isampler2DArray", "isampler2DMS", "isampler2DMSArray", "isampler2DRect",
"isampler3D", "isamplerBuffer", "isamplerCube", "isamplerCubeArray", "ivec2", "ivec3", "ivec4", "layout", "long", "lowp",
"mat2", "mat2x2", "mat2x3", "mat2x4", "mat3", "mat3x2", "mat3x3", "mat3x4", "mat4", "mat4x2", "mat4x3", "mat4x4", "mediump",
"namespace", "noinline", "noperspective", "out", "output", "packed", "partition", "patch", "precision", "public", "readonly",
"resource", "restrict", "return", "row_major", "sample", "sampler1D", "sampler1DArray", "sampler1DArrayShadow",
"sampler1DShadow", "sampler2D", "sampler2DArray", "sampler2DArrayShadow", "sampler2DMS", "sampler2DMSArray",
"sampler2DRect", "sampler2DRectShadow", "sampler2DShadow", "sampler3D", "sampler3DRect", "samplerBuffer",
"samplerCube", "samplerCubeArray", "samplerCubeArrayShadow", "samplerCubeShadow", "short", "sizeof", "smooth", "static",
"struct", "subroutine", "superp", "switch", "template", "this", "true", "typedef", "uimage1D", "uimage1DArray", "uimage2D",
"uimage2DArray", "uimage2DMS", "uimage2DMSArray", "uimage2DRect", "uimage3D", "uimageBuffer", "uimageCube",
"uimageCubeArray", "uint", "uniform", "union", "unsigned", "usampler1D", "usampler1DArray", "usampler2D", "usampler2DArray",
"usampler2DMS", "usampler2DMSArray", "usampler2DRect", "usampler3D", "usamplerBuffer", "usamplerCube",
"usamplerCubeArray", "using", "uvec2", "uvec3", "uvec4", "varying", "vec2", "vec3", "vec4", "void", "volatile", "volatile",
"while", "writeonly", "texture"
};
// clang-format on
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
if (!is_hidden_variable(var))
{
auto &m = meta[var.self].decoration;
if (m.alias.compare(0, 3, "gl_") == 0 || keywords.find(m.alias) != end(keywords))
m.alias = join("_", m.alias);
}
}
}
}
void CompilerGLSL::replace_fragment_output(SPIRVariable &var)
{
auto &m = meta[var.self].decoration;
uint32_t location = 0;
if (m.decoration_flags & (1ull << DecorationLocation))
location = m.location;
// If our variable is arrayed, we must not emit the array part of this as the SPIR-V will
// do the access chain part of this for us.
auto &type = get<SPIRType>(var.basetype);
if (type.array.empty())
{
// Redirect the write to a specific render target in legacy GLSL.
m.alias = join("gl_FragData[", location, "]");
if (is_legacy_es() && location != 0)
require_extension("GL_EXT_draw_buffers");
}
else if (type.array.size() == 1)
{
// If location is non-zero, we probably have to add an offset.
// This gets really tricky since we'd have to inject an offset in the access chain.
// FIXME: This seems like an extremely odd-ball case, so it's probably fine to leave it like this for now.
m.alias = "gl_FragData";
if (location != 0)
SPIRV_CROSS_THROW("Arrayed output variable used, but location is not 0. "
"This is unimplemented in SPIRV-Cross.");
if (is_legacy_es())
require_extension("GL_EXT_draw_buffers");
}
else
SPIRV_CROSS_THROW("Array-of-array output variable used. This cannot be implemented in legacy GLSL.");
var.compat_builtin = true; // We don't want to declare this variable, but use the name as-is.
}
void CompilerGLSL::replace_fragment_outputs()
{
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
if (!is_builtin_variable(var) && !var.remapped_variable && type.pointer &&
var.storage == StorageClassOutput)
replace_fragment_output(var);
}
}
}
string CompilerGLSL::remap_swizzle(uint32_t result_type, uint32_t input_components, uint32_t expr)
{
auto &out_type = get<SPIRType>(result_type);
if (out_type.vecsize == input_components)
return to_expression(expr);
else if (input_components == 1)
return join(type_to_glsl(out_type), "(", to_expression(expr), ")");
else
{
auto e = to_enclosed_expression(expr) + ".";
// Just clamp the swizzle index if we have more outputs than inputs.
for (uint32_t c = 0; c < out_type.vecsize; c++)
e += index_to_swizzle(min(c, input_components - 1));
if (backend.swizzle_is_function && out_type.vecsize > 1)
e += "()";
return e;
}
}
void CompilerGLSL::emit_pls()
{
auto &execution = get_entry_point();
if (execution.model != ExecutionModelFragment)
SPIRV_CROSS_THROW("Pixel local storage only supported in fragment shaders.");
if (!options.es)
SPIRV_CROSS_THROW("Pixel local storage only supported in OpenGL ES.");
if (options.version < 300)
SPIRV_CROSS_THROW("Pixel local storage only supported in ESSL 3.0 and above.");
if (!pls_inputs.empty())
{
statement("__pixel_local_inEXT _PLSIn");
begin_scope();
for (auto &input : pls_inputs)
statement(pls_decl(input), ";");
end_scope_decl();
statement("");
}
if (!pls_outputs.empty())
{
statement("__pixel_local_outEXT _PLSOut");
begin_scope();
for (auto &output : pls_outputs)
statement(pls_decl(output), ";");
end_scope_decl();
statement("");
}
}
void CompilerGLSL::fixup_image_load_store_access()
{
for (auto &id : ids)
{
if (id.get_type() != TypeVariable)
continue;
uint32_t var = id.get<SPIRVariable>().self;
auto &vartype = expression_type(var);
if (vartype.basetype == SPIRType::Image)
{
// Older glslangValidator does not emit required qualifiers here.
// Solve this by making the image access as restricted as possible and loosen up if we need to.
// If any no-read/no-write flags are actually set, assume that the compiler knows what it's doing.
auto &flags = meta.at(var).decoration.decoration_flags;
static const uint64_t NoWrite = 1ull << DecorationNonWritable;
static const uint64_t NoRead = 1ull << DecorationNonReadable;
if ((flags & (NoWrite | NoRead)) == 0)
flags |= NoRead | NoWrite;
}
}
}
void CompilerGLSL::emit_declared_builtin_block(StorageClass storage, ExecutionModel model)
{
bool emitted_block = false;
for (auto &id : ids)
{
if (id.get_type() != TypeVariable)
continue;
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
bool block = has_decoration(type.self, DecorationBlock);
uint64_t builtins = 0;
if (var.storage == storage && block && is_builtin_variable(var))
{
for (auto &m : meta[type.self].members)
if (m.builtin)
builtins |= 1ull << m.builtin_type;
}
if (!builtins)
continue;
if (emitted_block)
SPIRV_CROSS_THROW("Cannot use more than one builtin I/O block.");
if (storage == StorageClassOutput)
statement("out gl_PerVertex");
else
statement("in gl_PerVertex");
begin_scope();
if (builtins & (1ull << BuiltInPosition))
statement("vec4 gl_Position;");
if (builtins & (1ull << BuiltInPointSize))
statement("float gl_PointSize;");
if (builtins & (1ull << BuiltInClipDistance))
statement("float gl_ClipDistance[];"); // TODO: Do we need a fixed array size here?
if (builtins & (1ull << BuiltInCullDistance))
statement("float gl_CullDistance[];"); // TODO: Do we need a fixed array size here?
bool builtin_array = !type.array.empty();
bool tessellation = model == ExecutionModelTessellationEvaluation || model == ExecutionModelTessellationControl;
if (builtin_array)
{
// Make sure the array has a supported name in the code.
if (storage == StorageClassOutput)
set_name(var.self, "gl_out");
else if (storage == StorageClassInput)
set_name(var.self, "gl_in");
if (model == ExecutionModelTessellationControl && storage == StorageClassOutput)
end_scope_decl(join(to_name(var.self), "[", get_entry_point().output_vertices, "]"));
else
end_scope_decl(join(to_name(var.self), tessellation ? "[gl_MaxPatchVertices]" : "[]"));
}
else
end_scope_decl();
statement("");
emitted_block = true;
}
}
void CompilerGLSL::declare_undefined_values()
{
bool emitted = false;
for (auto &id : ids)
{
if (id.get_type() != TypeUndef)
continue;
auto &undef = id.get<SPIRUndef>();
statement(variable_decl(get<SPIRType>(undef.basetype), to_name(undef.self), undef.self), ";");
emitted = true;
}
if (emitted)
statement("");
}
void CompilerGLSL::emit_resources()
{
auto &execution = get_entry_point();
replace_illegal_names();
// Legacy GL uses gl_FragData[], redeclare all fragment outputs
// with builtins.
if (execution.model == ExecutionModelFragment && is_legacy())
replace_fragment_outputs();
// Emit PLS blocks if we have such variables.
if (!pls_inputs.empty() || !pls_outputs.empty())
emit_pls();
// Emit custom gl_PerVertex for SSO compatibility.
if (options.separate_shader_objects && !options.es)
{
switch (execution.model)
{
case ExecutionModelGeometry:
case ExecutionModelTessellationControl:
case ExecutionModelTessellationEvaluation:
emit_declared_builtin_block(StorageClassInput, execution.model);
emit_declared_builtin_block(StorageClassOutput, execution.model);
break;
case ExecutionModelVertex:
emit_declared_builtin_block(StorageClassOutput, execution.model);
break;
default:
break;
}
}
bool emitted = false;
// If emitted Vulkan GLSL,
// emit specialization constants as actual floats,
// spec op expressions will redirect to the constant name.
//
// TODO: If we have the fringe case that we create a spec constant which depends on a struct type,
// we'll have to deal with that, but there's currently no known way to express that.
if (options.vulkan_semantics)
{
for (auto &id : ids)
{
if (id.get_type() == TypeConstant)
{
auto &c = id.get<SPIRConstant>();
if (!c.specialization)
continue;
emit_specialization_constant(c);
emitted = true;
}
}
}
if (emitted)
statement("");
emitted = false;
// Output all basic struct types which are not Block or BufferBlock as these are declared inplace
// when such variables are instantiated.
for (auto &id : ids)
{
if (id.get_type() == TypeType)
{
auto &type = id.get<SPIRType>();
if (type.basetype == SPIRType::Struct && type.array.empty() && !type.pointer &&
(meta[type.self].decoration.decoration_flags &
((1ull << DecorationBlock) | (1ull << DecorationBufferBlock))) == 0)
{
emit_struct(type);
}
}
}
// Output UBOs and SSBOs
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
if (var.storage != StorageClassFunction && type.pointer && type.storage == StorageClassUniform &&
!is_hidden_variable(var) && (meta[type.self].decoration.decoration_flags &
((1ull << DecorationBlock) | (1ull << DecorationBufferBlock))))
{
emit_buffer_block(var);
}
}
}
// Output push constant blocks
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
if (var.storage != StorageClassFunction && type.pointer && type.storage == StorageClassPushConstant &&
!is_hidden_variable(var))
{
emit_push_constant_block(var);
}
}
}
bool skip_separate_image_sampler = !combined_image_samplers.empty() || !options.vulkan_semantics;
// Output Uniform Constants (values, samplers, images, etc).
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
// If we're remapping separate samplers and images, only emit the combined samplers.
if (skip_separate_image_sampler)
{
// Sampler buffers are always used without a sampler, and they will also work in regular GL.
bool sampler_buffer = type.basetype == SPIRType::Image && type.image.dim == DimBuffer;
bool separate_image = type.basetype == SPIRType::Image && type.image.sampled == 1;
bool separate_sampler = type.basetype == SPIRType::Sampler;
if (!sampler_buffer && (separate_image || separate_sampler))
continue;
}
if (var.storage != StorageClassFunction && type.pointer &&
(type.storage == StorageClassUniformConstant || type.storage == StorageClassAtomicCounter) &&
!is_hidden_variable(var))
{
emit_uniform(var);
emitted = true;
}
}
}
if (emitted)
statement("");
emitted = false;
// Output in/out interfaces.
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
// HLSL output from glslang may emit interface variables which are "empty".
// Just avoid declaring them.
if (type_is_empty(type))
continue;
if (var.storage != StorageClassFunction && type.pointer &&
(var.storage == StorageClassInput || var.storage == StorageClassOutput) &&
interface_variable_exists_in_entry_point(var.self) && !is_hidden_variable(var))
{
emit_interface_block(var);
emitted = true;
}
else if (is_builtin_variable(var))
{
// For gl_InstanceIndex emulation on GLES, the API user needs to
// supply this uniform.
if (meta[var.self].decoration.builtin_type == BuiltInInstanceIndex && !options.vulkan_semantics)
{
statement("uniform int SPIRV_Cross_BaseInstance;");
emitted = true;
}
}
}
}
// Global variables.
for (auto global : global_variables)
{
auto &var = get<SPIRVariable>(global);
if (var.storage != StorageClassOutput)
{
add_resource_name(var.self);
statement(variable_decl(var), ";");
emitted = true;
}
}
if (emitted)
statement("");
declare_undefined_values();
}
// Returns a string representation of the ID, usable as a function arg.
// Default is to simply return the expression representation fo the arg ID.
// Subclasses may override to modify the return value.
string CompilerGLSL::to_func_call_arg(uint32_t id)
{
return to_expression(id);
}
void CompilerGLSL::handle_invalid_expression(uint32_t id)
{
// We tried to read an invalidated expression.
// This means we need another pass at compilation, but next time, force temporary variables so that they cannot be invalidated.
forced_temporaries.insert(id);
force_recompile = true;
}
// Converts the format of the current expression from packed to unpacked,
// by wrapping the expression in a constructor of the appropriate type.
// GLSL does not support packed formats, so simply return the expression.
// Subclasses that do will override
string CompilerGLSL::unpack_expression_type(string expr_str, const SPIRType &)
{
return expr_str;
}
// Sometimes we proactively enclosed an expression where it turns out we might have not needed it after all.
void CompilerGLSL::strip_enclosed_expression(string &expr)
{
if (expr.size() < 2 || expr.front() != '(' || expr.back() != ')')
return;
// Have to make sure that our first and last parens actually enclose everything inside it.
uint32_t paren_count = 0;
for (auto &c : expr)
{
if (c == '(')
paren_count++;
else if (c == ')')
{
paren_count--;
// If we hit 0 and this is not the final char, our first and final parens actually don't
// enclose the expression, and we cannot strip, e.g.: (a + b) * (c + d).
if (paren_count == 0 && &c != &expr.back())
return;
}
}
expr.erase(expr.size() - 1, 1);
expr.erase(begin(expr));
}
string CompilerGLSL::enclose_expression(const string &expr)
{
bool need_parens = false;
// If the expression starts with a unary we need to enclose to deal with cases where we have back-to-back
// unary expressions.
if (!expr.empty())
{
auto c = expr.front();
if (c == '-' || c == '+' || c == '!' || c == '~')
need_parens = true;
}
if (!need_parens)
{
uint32_t paren_count = 0;
for (auto c : expr)
{
if (c == '(')
paren_count++;
else if (c == ')')
{
assert(paren_count);
paren_count--;
}
else if (c == ' ' && paren_count == 0)
{
need_parens = true;
break;
}
}
assert(paren_count == 0);
}
// If this expression contains any spaces which are not enclosed by parentheses,
// we need to enclose it so we can treat the whole string as an expression.
// This happens when two expressions have been part of a binary op earlier.
if (need_parens)
return join('(', expr, ')');
else
return expr;
}
// Just like to_expression except that we enclose the expression inside parentheses if needed.
string CompilerGLSL::to_enclosed_expression(uint32_t id)
{
return enclose_expression(to_expression(id));
}
string CompilerGLSL::to_expression(uint32_t id)
{
auto itr = invalid_expressions.find(id);
if (itr != end(invalid_expressions))
handle_invalid_expression(id);
if (ids[id].get_type() == TypeExpression)
{
// We might have a more complex chain of dependencies.
// A possible scenario is that we
//
// %1 = OpLoad
// %2 = OpDoSomething %1 %1. here %2 will have a dependency on %1.
// %3 = OpDoSomethingAgain %2 %2. Here %3 will lose the link to %1 since we don't propagate the dependencies like that.
// OpStore %1 %foo // Here we can invalidate %1, and hence all expressions which depend on %1. Only %2 will know since it's part of invalid_expressions.
// %4 = OpDoSomethingAnotherTime %3 %3 // If we forward all expressions we will see %1 expression after store, not before.
//
// However, we can propagate up a list of depended expressions when we used %2, so we can check if %2 is invalid when reading %3 after the store,
// and see that we should not forward reads of the original variable.
auto &expr = get<SPIRExpression>(id);
for (uint32_t dep : expr.expression_dependencies)
if (invalid_expressions.find(dep) != end(invalid_expressions))
handle_invalid_expression(dep);
}
track_expression_read(id);
switch (ids[id].get_type())
{
case TypeExpression:
{
auto &e = get<SPIRExpression>(id);
if (e.base_expression)
return to_enclosed_expression(e.base_expression) + e.expression;
else if (e.need_transpose)
return convert_row_major_matrix(e.expression);
else
return e.expression;
}
case TypeConstant:
{
auto &c = get<SPIRConstant>(id);
if (c.specialization && options.vulkan_semantics)
return to_name(id);
else
return constant_expression(c);
}
case TypeConstantOp:
return constant_op_expression(get<SPIRConstantOp>(id));
case TypeVariable:
{
auto &var = get<SPIRVariable>(id);
// If we try to use a loop variable before the loop header, we have to redirect it to the static expression,
// the variable has not been declared yet.
if (var.statically_assigned || (var.loop_variable && !var.loop_variable_enable))
return to_expression(var.static_expression);
else if (var.deferred_declaration)
{
var.deferred_declaration = false;
return variable_decl(var);
}
else if (flattened_structs.count(id))
{
return load_flattened_struct(var);
}
else
{
auto &dec = meta[var.self].decoration;
if (dec.builtin)
return builtin_to_glsl(dec.builtin_type, var.storage);
else
return to_name(id);
}
}
case TypeCombinedImageSampler:
// This type should never be taken the expression of directly.
// The intention is that texture sampling functions will extract the image and samplers
// separately and take their expressions as needed.
// GLSL does not use this type because OpSampledImage immediately creates a combined image sampler
// expression ala sampler2D(texture, sampler).
SPIRV_CROSS_THROW("Combined image samplers have no default expression representation.");
case TypeAccessChain:
// We cannot express this type. They only have meaning in other OpAccessChains, OpStore or OpLoad.
SPIRV_CROSS_THROW("Access chains have no default expression representation.");
default:
return to_name(id);
}
}
string CompilerGLSL::constant_op_expression(const SPIRConstantOp &cop)
{
auto &type = get<SPIRType>(cop.basetype);
bool binary = false;
bool unary = false;
string op;
// TODO: Find a clean way to reuse emit_instruction.
switch (cop.opcode)
{
case OpSConvert:
case OpUConvert:
case OpFConvert:
op = type_to_glsl_constructor(type);
break;
#define BOP(opname, x) \
case Op##opname: \
binary = true; \
op = x; \
break
#define UOP(opname, x) \
case Op##opname: \
unary = true; \
op = x; \
break
UOP(SNegate, "-");
UOP(Not, "~");
BOP(IAdd, "+");
BOP(ISub, "-");
BOP(IMul, "*");
BOP(SDiv, "/");
BOP(UDiv, "/");
BOP(UMod, "%");
BOP(SMod, "%");
BOP(ShiftRightLogical, ">>");
BOP(ShiftRightArithmetic, ">>");
BOP(ShiftLeftLogical, "<<");
BOP(BitwiseOr, "|");
BOP(BitwiseXor, "^");
BOP(BitwiseAnd, "&");
BOP(LogicalOr, "||");
BOP(LogicalAnd, "&&");
UOP(LogicalNot, "!");
BOP(LogicalEqual, "==");
BOP(LogicalNotEqual, "!=");
BOP(IEqual, "==");
BOP(INotEqual, "!=");
BOP(ULessThan, "<");
BOP(SLessThan, "<");
BOP(ULessThanEqual, "<=");
BOP(SLessThanEqual, "<=");
BOP(UGreaterThan, ">");
BOP(SGreaterThan, ">");
BOP(UGreaterThanEqual, ">=");
BOP(SGreaterThanEqual, ">=");
case OpSelect:
{
if (cop.arguments.size() < 3)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
// This one is pretty annoying. It's triggered from
// uint(bool), int(bool) from spec constants.
// In order to preserve its compile-time constness in Vulkan GLSL,
// we need to reduce the OpSelect expression back to this simplified model.
// If we cannot, fail.
if (!to_trivial_mix_op(type, op, cop.arguments[2], cop.arguments[1], cop.arguments[0]))
{
SPIRV_CROSS_THROW(
"Cannot implement specialization constant op OpSelect. "
"Need trivial select implementation which can be resolved to a simple cast from boolean.");
}
break;
}
default:
// Some opcodes are unimplemented here, these are currently not possible to test from glslang.
SPIRV_CROSS_THROW("Unimplemented spec constant op.");
}
SPIRType::BaseType input_type;
bool skip_cast_if_equal_type = opcode_is_sign_invariant(cop.opcode);
switch (cop.opcode)
{
case OpIEqual:
case OpINotEqual:
input_type = SPIRType::Int;
break;
default:
input_type = type.basetype;
break;
}
#undef BOP
#undef UOP
if (binary)
{
if (cop.arguments.size() < 2)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
string cast_op0;
string cast_op1;
auto expected_type = binary_op_bitcast_helper(cast_op0, cast_op1, input_type, cop.arguments[0],
cop.arguments[1], skip_cast_if_equal_type);
if (type.basetype != input_type && type.basetype != SPIRType::Boolean)
{
expected_type.basetype = input_type;
auto expr = bitcast_glsl_op(type, expected_type);
expr += '(';
expr += join(cast_op0, " ", op, " ", cast_op1);
expr += ')';
return expr;
}
else
return join("(", cast_op0, " ", op, " ", cast_op1, ")");
}
else if (unary)
{
if (cop.arguments.size() < 1)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
// Auto-bitcast to result type as needed.
// Works around various casting scenarios in glslang as there is no OpBitcast for specialization constants.
return join("(", op, bitcast_glsl(type, cop.arguments[0]), ")");
}
else
{
if (cop.arguments.size() < 1)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
return join(op, "(", to_expression(cop.arguments[0]), ")");
}
}
string CompilerGLSL::constant_expression(const SPIRConstant &c)
{
if (!c.subconstants.empty())
{
// Handles Arrays and structures.
string res;
if (backend.use_initializer_list)
res = "{ ";
else
res = type_to_glsl_constructor(get<SPIRType>(c.constant_type)) + "(";
for (auto &elem : c.subconstants)
{
auto &subc = get<SPIRConstant>(elem);
if (subc.specialization && options.vulkan_semantics)
res += to_name(elem);
else
res += constant_expression(subc);
if (&elem != &c.subconstants.back())
res += ", ";
}
res += backend.use_initializer_list ? " }" : ")";
return res;
}
else if (c.columns() == 1)
{
return constant_expression_vector(c, 0);
}
else
{
string res = type_to_glsl(get<SPIRType>(c.constant_type)) + "(";
for (uint32_t col = 0; col < c.columns(); col++)
{
res += constant_expression_vector(c, col);
if (col + 1 < c.columns())
res += ", ";
}
res += ")";
return res;
}
}
string CompilerGLSL::constant_expression_vector(const SPIRConstant &c, uint32_t vector)
{
auto type = get<SPIRType>(c.constant_type);
type.columns = 1;
string res;
if (c.vector_size() > 1)
res += type_to_glsl(type) + "(";
bool splat = backend.use_constructor_splatting && c.vector_size() > 1;
if (splat)
{
if (type_to_std430_base_size(type) == 8)
{
uint64_t ident = c.scalar_u64(vector, 0);
for (uint32_t i = 1; i < c.vector_size(); i++)
if (ident != c.scalar_u64(vector, i))
splat = false;
}
else
{
uint32_t ident = c.scalar(vector, 0);
for (uint32_t i = 1; i < c.vector_size(); i++)
if (ident != c.scalar(vector, i))
splat = false;
}
}
switch (type.basetype)
{
case SPIRType::Float:
if (splat)
{
res += convert_to_string(c.scalar_f32(vector, 0));
if (backend.float_literal_suffix)
res += "f";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += convert_to_string(c.scalar_f32(vector, i));
if (backend.float_literal_suffix)
res += "f";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Double:
if (splat)
{
res += convert_to_string(c.scalar_f64(vector, 0));
if (backend.double_literal_suffix)
res += "lf";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += convert_to_string(c.scalar_f64(vector, i));
if (backend.double_literal_suffix)
res += "lf";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Int64:
if (splat)
{
res += convert_to_string(c.scalar_i64(vector, 0));
if (backend.long_long_literal_suffix)
res += "ll";
else
res += "l";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += convert_to_string(c.scalar_i64(vector, i));
if (backend.long_long_literal_suffix)
res += "ll";
else
res += "l";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::UInt64:
if (splat)
{
res += convert_to_string(c.scalar_u64(vector, 0));
if (backend.long_long_literal_suffix)
res += "ull";
else
res += "ul";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += convert_to_string(c.scalar_u64(vector, i));
if (backend.long_long_literal_suffix)
res += "ull";
else
res += "ul";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::UInt:
if (splat)
{
res += convert_to_string(c.scalar(vector, 0));
if (backend.uint32_t_literal_suffix)
res += "u";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += convert_to_string(c.scalar(vector, i));
if (backend.uint32_t_literal_suffix)
res += "u";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Int:
if (splat)
res += convert_to_string(c.scalar_i32(vector, 0));
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += convert_to_string(c.scalar_i32(vector, i));
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Boolean:
if (splat)
res += c.scalar(vector, 0) ? "true" : "false";
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
res += c.scalar(vector, i) ? "true" : "false";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
default:
SPIRV_CROSS_THROW("Invalid constant expression basetype.");
}
if (c.vector_size() > 1)
res += ")";
return res;
}
string CompilerGLSL::declare_temporary(uint32_t result_type, uint32_t result_id)
{
auto &type = get<SPIRType>(result_type);
auto flags = meta[result_id].decoration.decoration_flags;
// If we're declaring temporaries inside continue blocks,
// we must declare the temporary in the loop header so that the continue block can avoid declaring new variables.
if (current_continue_block)
{
auto &header = get<SPIRBlock>(current_continue_block->loop_dominator);
if (find_if(begin(header.declare_temporary), end(header.declare_temporary),
[result_type, result_id](const pair<uint32_t, uint32_t> &tmp) {
return tmp.first == result_type && tmp.second == result_id;
}) == end(header.declare_temporary))
{
header.declare_temporary.emplace_back(result_type, result_id);
force_recompile = true;
}
return join(to_name(result_id), " = ");
}
else
{
// The result_id has not been made into an expression yet, so use flags interface.
return join(flags_to_precision_qualifiers_glsl(type, flags), variable_decl(type, to_name(result_id)), " = ");
}
}
bool CompilerGLSL::expression_is_forwarded(uint32_t id)
{
return forwarded_temporaries.find(id) != end(forwarded_temporaries);
}
SPIRExpression &CompilerGLSL::emit_op(uint32_t result_type, uint32_t result_id, const string &rhs, bool forwarding,
bool suppress_usage_tracking)
{
if (forwarding && (forced_temporaries.find(result_id) == end(forced_temporaries)))
{
// Just forward it without temporary.
// If the forward is trivial, we do not force flushing to temporary for this expression.
if (!suppress_usage_tracking)
forwarded_temporaries.insert(result_id);
return set<SPIRExpression>(result_id, rhs, result_type, true);
}
else
{
// If expression isn't immutable, bind it to a temporary and make the new temporary immutable (they always are).
statement(declare_temporary(result_type, result_id), rhs, ";");
return set<SPIRExpression>(result_id, to_name(result_id), result_type, true);
}
}
void CompilerGLSL::emit_unary_op(uint32_t result_type, uint32_t result_id, uint32_t op0, const char *op)
{
bool forward = should_forward(op0);
emit_op(result_type, result_id, join(op, to_enclosed_expression(op0)), forward);
inherit_expression_dependencies(result_id, op0);
}
void CompilerGLSL::emit_binary_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1, const char *op)
{
bool forward = should_forward(op0) && should_forward(op1);
emit_op(result_type, result_id, join(to_enclosed_expression(op0), " ", op, " ", to_enclosed_expression(op1)),
forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
void CompilerGLSL::emit_unrolled_unary_op(uint32_t result_type, uint32_t result_id, uint32_t operand, const char *op)
{
auto &type = get<SPIRType>(result_type);
auto expr = type_to_glsl_constructor(type);
expr += '(';
for (uint32_t i = 0; i < type.vecsize; i++)
{
// Make sure to call to_expression multiple times to ensure
// that these expressions are properly flushed to temporaries if needed.
expr += op;
expr += to_enclosed_expression(operand);
expr += '.';
expr += index_to_swizzle(i);
if (i + 1 < type.vecsize)
expr += ", ";
}
expr += ')';
emit_op(result_type, result_id, expr, should_forward(operand));
inherit_expression_dependencies(result_id, operand);
}
void CompilerGLSL::emit_unrolled_binary_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op)
{
auto &type = get<SPIRType>(result_type);
auto expr = type_to_glsl_constructor(type);
expr += '(';
for (uint32_t i = 0; i < type.vecsize; i++)
{
// Make sure to call to_expression multiple times to ensure
// that these expressions are properly flushed to temporaries if needed.
expr += to_enclosed_expression(op0);
expr += '.';
expr += index_to_swizzle(i);
expr += ' ';
expr += op;
expr += ' ';
expr += to_enclosed_expression(op1);
expr += '.';
expr += index_to_swizzle(i);
if (i + 1 < type.vecsize)
expr += ", ";
}
expr += ')';
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1));
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
SPIRType CompilerGLSL::binary_op_bitcast_helper(string &cast_op0, string &cast_op1, SPIRType::BaseType &input_type,
uint32_t op0, uint32_t op1, bool skip_cast_if_equal_type)
{
auto &type0 = expression_type(op0);
auto &type1 = expression_type(op1);
// We have to bitcast if our inputs are of different type, or if our types are not equal to expected inputs.
// For some functions like OpIEqual and INotEqual, we don't care if inputs are of different types than expected
// since equality test is exactly the same.
bool cast = (type0.basetype != type1.basetype) || (!skip_cast_if_equal_type && type0.basetype != input_type);
// Create a fake type so we can bitcast to it.
// We only deal with regular arithmetic types here like int, uints and so on.
SPIRType expected_type;
expected_type.basetype = input_type;
expected_type.vecsize = type0.vecsize;
expected_type.columns = type0.columns;
expected_type.width = type0.width;
if (cast)
{
cast_op0 = bitcast_glsl(expected_type, op0);
cast_op1 = bitcast_glsl(expected_type, op1);
}
else
{
// If we don't cast, our actual input type is that of the first (or second) argument.
cast_op0 = to_enclosed_expression(op0);
cast_op1 = to_enclosed_expression(op1);
input_type = type0.basetype;
}
return expected_type;
}
void CompilerGLSL::emit_binary_op_cast(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op, SPIRType::BaseType input_type, bool skip_cast_if_equal_type)
{
string cast_op0, cast_op1;
auto expected_type = binary_op_bitcast_helper(cast_op0, cast_op1, input_type, op0, op1, skip_cast_if_equal_type);
auto &out_type = get<SPIRType>(result_type);
// We might have casted away from the result type, so bitcast again.
// For example, arithmetic right shift with uint inputs.
// Special case boolean outputs since relational opcodes output booleans instead of int/uint.
string expr;
if (out_type.basetype != input_type && out_type.basetype != SPIRType::Boolean)
{
expected_type.basetype = input_type;
expr = bitcast_glsl_op(out_type, expected_type);
expr += '(';
expr += join(cast_op0, " ", op, " ", cast_op1);
expr += ')';
}
else
expr += join(cast_op0, " ", op, " ", cast_op1);
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1));
}
void CompilerGLSL::emit_unary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, const char *op)
{
bool forward = should_forward(op0);
emit_op(result_type, result_id, join(op, "(", to_expression(op0), ")"), forward);
inherit_expression_dependencies(result_id, op0);
}
void CompilerGLSL::emit_binary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op)
{
bool forward = should_forward(op0) && should_forward(op1);
emit_op(result_type, result_id, join(op, "(", to_expression(op0), ", ", to_expression(op1), ")"), forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
void CompilerGLSL::emit_binary_func_op_cast(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op, SPIRType::BaseType input_type, bool skip_cast_if_equal_type)
{
string cast_op0, cast_op1;
auto expected_type = binary_op_bitcast_helper(cast_op0, cast_op1, input_type, op0, op1, skip_cast_if_equal_type);
auto &out_type = get<SPIRType>(result_type);
// Special case boolean outputs since relational opcodes output booleans instead of int/uint.
string expr;
if (out_type.basetype != input_type && out_type.basetype != SPIRType::Boolean)
{
expected_type.basetype = input_type;
expr = bitcast_glsl_op(out_type, expected_type);
expr += '(';
expr += join(op, "(", cast_op0, ", ", cast_op1, ")");
expr += ')';
}
else
{
expr += join(op, "(", cast_op0, ", ", cast_op1, ")");
}
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1));
}
void CompilerGLSL::emit_trinary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
uint32_t op2, const char *op)
{
bool forward = should_forward(op0) && should_forward(op1) && should_forward(op2);
emit_op(result_type, result_id,
join(op, "(", to_expression(op0), ", ", to_expression(op1), ", ", to_expression(op2), ")"), forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
inherit_expression_dependencies(result_id, op2);
}
void CompilerGLSL::emit_quaternary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
uint32_t op2, uint32_t op3, const char *op)
{
bool forward = should_forward(op0) && should_forward(op1) && should_forward(op2) && should_forward(op3);
emit_op(result_type, result_id, join(op, "(", to_expression(op0), ", ", to_expression(op1), ", ",
to_expression(op2), ", ", to_expression(op3), ")"),
forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
inherit_expression_dependencies(result_id, op2);
inherit_expression_dependencies(result_id, op3);
}
// EXT_shader_texture_lod only concerns fragment shaders so lod tex functions
// are not allowed in ES 2 vertex shaders. But SPIR-V only supports lod tex
// functions in vertex shaders so we revert those back to plain calls when
// the lod is a constant value of zero.
bool CompilerGLSL::check_explicit_lod_allowed(uint32_t lod)
{
auto &execution = get_entry_point();
bool allowed = !is_legacy_es() || execution.model == ExecutionModelFragment;
if (!allowed && lod != 0)
{
auto *lod_constant = maybe_get<SPIRConstant>(lod);
if (!lod_constant || lod_constant->scalar_f32() != 0.0f)
{
SPIRV_CROSS_THROW("Explicit lod not allowed in legacy ES non-fragment shaders.");
}
}
return allowed;
}
string CompilerGLSL::legacy_tex_op(const std::string &op, const SPIRType &imgtype, uint32_t lod)
{
const char *type;
switch (imgtype.image.dim)
{
case spv::Dim1D:
type = (imgtype.image.arrayed && !options.es) ? "1DArray" : "1D";
break;
case spv::Dim2D:
type = (imgtype.image.arrayed && !options.es) ? "2DArray" : "2D";
break;
case spv::Dim3D:
type = "3D";
break;
case spv::DimCube:
type = "Cube";
break;
case spv::DimBuffer:
type = "Buffer";
break;
case spv::DimSubpassData:
type = "2D";
break;
default:
type = "";
break;
}
bool use_explicit_lod = check_explicit_lod_allowed(lod);
if (op == "textureLod" || op == "textureProjLod")
{
if (is_legacy_es())
{
if (use_explicit_lod)
require_extension("GL_EXT_shader_texture_lod");
}
else if (is_legacy())
require_extension("GL_ARB_shader_texture_lod");
}
if (op == "texture")
return join("texture", type);
else if (op == "textureLod")
{
if (use_explicit_lod)
return join("texture", type, is_legacy_es() ? "LodEXT" : "Lod");
else
return join("texture", type);
}
else if (op == "textureProj")
return join("texture", type, "Proj");
else if (op == "textureProjLod")
{
if (use_explicit_lod)
return join("texture", type, is_legacy_es() ? "ProjLodEXT" : "ProjLod");
else
return join("texture", type);
}
else
{
SPIRV_CROSS_THROW(join("Unsupported legacy texture op: ", op));
}
}
bool CompilerGLSL::to_trivial_mix_op(const SPIRType &type, string &op, uint32_t left, uint32_t right, uint32_t lerp)
{
auto *cleft = maybe_get<SPIRConstant>(left);
auto *cright = maybe_get<SPIRConstant>(right);
auto &lerptype = expression_type(lerp);
// If our targets aren't constants, we cannot use construction.
if (!cleft || !cright)
return false;
// If our targets are spec constants, we cannot use construction.
if (cleft->specialization || cright->specialization)
return false;
// We can only use trivial construction if we have a scalar
// (should be possible to do it for vectors as well, but that is overkill for now).
if (lerptype.basetype != SPIRType::Boolean || lerptype.vecsize > 1)
return false;
// If our bool selects between 0 and 1, we can cast from bool instead, making our trivial constructor.
bool ret = false;
switch (type.basetype)
{
case SPIRType::Int:
case SPIRType::UInt:
ret = cleft->scalar() == 0 && cright->scalar() == 1;
break;
case SPIRType::Float:
ret = cleft->scalar_f32() == 0.0f && cright->scalar_f32() == 1.0f;
break;
case SPIRType::Double:
ret = cleft->scalar_f64() == 0.0 && cright->scalar_f64() == 1.0;
break;
case SPIRType::Int64:
case SPIRType::UInt64:
ret = cleft->scalar_u64() == 0 && cright->scalar_u64() == 1;
break;
default:
break;
}
if (ret)
op = type_to_glsl_constructor(type);
return ret;
}
void CompilerGLSL::emit_mix_op(uint32_t result_type, uint32_t id, uint32_t left, uint32_t right, uint32_t lerp)
{
auto &lerptype = expression_type(lerp);
auto &restype = get<SPIRType>(result_type);
string mix_op;
bool has_boolean_mix = backend.boolean_mix_support &&
((options.es && options.version >= 310) || (!options.es && options.version >= 450));
bool trivial_mix = to_trivial_mix_op(restype, mix_op, left, right, lerp);
// Cannot use boolean mix when the lerp argument is just one boolean,
// fall back to regular trinary statements.
if (lerptype.vecsize == 1)
has_boolean_mix = false;
// If we can reduce the mix to a simple cast, do so.
// This helps for cases like int(bool), uint(bool) which is implemented with
// OpSelect bool 1 0.
if (trivial_mix)
{
emit_unary_func_op(result_type, id, lerp, mix_op.c_str());
}
else if (!has_boolean_mix && lerptype.basetype == SPIRType::Boolean)
{
// Boolean mix not supported on desktop without extension.
// Was added in OpenGL 4.5 with ES 3.1 compat.
//
// Could use GL_EXT_shader_integer_mix on desktop at least,
// but Apple doesn't support it. :(
// Just implement it as ternary expressions.
string expr;
if (lerptype.vecsize == 1)
expr = join(to_enclosed_expression(lerp), " ? ", to_enclosed_expression(right), " : ",
to_enclosed_expression(left));
else
{
auto swiz = [this](uint32_t expression, uint32_t i) {
return join(to_enclosed_expression(expression), ".", index_to_swizzle(i));
};
expr = type_to_glsl_constructor(restype);
expr += "(";
for (uint32_t i = 0; i < restype.vecsize; i++)
{
expr += swiz(lerp, i);
expr += " ? ";
expr += swiz(right, i);
expr += " : ";
expr += swiz(left, i);
if (i + 1 < restype.vecsize)
expr += ", ";
}
expr += ")";
}
emit_op(result_type, id, expr, should_forward(left) && should_forward(right) && should_forward(lerp));
}
else
emit_trinary_func_op(result_type, id, left, right, lerp, "mix");
}
string CompilerGLSL::to_combined_image_sampler(uint32_t image_id, uint32_t samp_id)
{
auto &args = current_function->arguments;
// For GLSL and ESSL targets, we must enumerate all possible combinations for sampler2D(texture2D, sampler) and redirect
// all possible combinations into new sampler2D uniforms.
auto *image = maybe_get_backing_variable(image_id);
auto *samp = maybe_get_backing_variable(samp_id);
if (image)
image_id = image->self;
if (samp)
samp_id = samp->self;
auto image_itr = find_if(begin(args), end(args),
[image_id](const SPIRFunction::Parameter &param) { return param.id == image_id; });
auto sampler_itr = find_if(begin(args), end(args),
[samp_id](const SPIRFunction::Parameter &param) { return param.id == samp_id; });
if (image_itr != end(args) || sampler_itr != end(args))
{
// If any parameter originates from a parameter, we will find it in our argument list.
bool global_image = image_itr == end(args);
bool global_sampler = sampler_itr == end(args);
uint32_t iid = global_image ? image_id : uint32_t(image_itr - begin(args));
uint32_t sid = global_sampler ? samp_id : uint32_t(sampler_itr - begin(args));
auto &combined = current_function->combined_parameters;
auto itr = find_if(begin(combined), end(combined), [=](const SPIRFunction::CombinedImageSamplerParameter &p) {
return p.global_image == global_image && p.global_sampler == global_sampler && p.image_id == iid &&
p.sampler_id == sid;
});
if (itr != end(combined))
return to_expression(itr->id);
else
{
SPIRV_CROSS_THROW(
"Cannot find mapping for combined sampler parameter, was build_combined_image_samplers() used "
"before compile() was called?");
}
}
else
{
// For global sampler2D, look directly at the global remapping table.
auto &mapping = combined_image_samplers;
auto itr = find_if(begin(mapping), end(mapping), [image_id, samp_id](const CombinedImageSampler &combined) {
return combined.image_id == image_id && combined.sampler_id == samp_id;
});
if (itr != end(combined_image_samplers))
return to_expression(itr->combined_id);
else
{
SPIRV_CROSS_THROW("Cannot find mapping for combined sampler, was build_combined_image_samplers() used "
"before compile() was called?");
}
}
}
void CompilerGLSL::emit_sampled_image_op(uint32_t result_type, uint32_t result_id, uint32_t image_id, uint32_t samp_id)
{
if (options.vulkan_semantics && combined_image_samplers.empty())
{
emit_binary_func_op(result_type, result_id, image_id, samp_id,
type_to_glsl(get<SPIRType>(result_type)).c_str());
}
else
emit_op(result_type, result_id, to_combined_image_sampler(image_id, samp_id), true);
}
void CompilerGLSL::emit_texture_op(const Instruction &i)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
uint32_t length = i.length;
if (i.offset + length > spirv.size())
SPIRV_CROSS_THROW("Compiler::parse() opcode out of range.");
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t img = ops[2];
uint32_t coord = ops[3];
uint32_t dref = 0;
uint32_t comp = 0;
bool gather = false;
bool proj = false;
bool fetch = false;
const uint32_t *opt = nullptr;
switch (op)
{
case OpImageSampleDrefImplicitLod:
case OpImageSampleDrefExplicitLod:
dref = ops[4];
opt = &ops[5];
length -= 5;
break;
case OpImageSampleProjDrefImplicitLod:
case OpImageSampleProjDrefExplicitLod:
dref = ops[4];
opt = &ops[5];
length -= 5;
proj = true;
break;
case OpImageDrefGather:
dref = ops[4];
opt = &ops[5];
length -= 5;
gather = true;
break;
case OpImageGather:
comp = ops[4];
opt = &ops[5];
length -= 5;
gather = true;
break;
case OpImageFetch:
case OpImageRead: // Reads == fetches in Metal (other langs will not get here)
opt = &ops[4];
length -= 4;
fetch = true;
break;
case OpImageSampleProjImplicitLod:
case OpImageSampleProjExplicitLod:
opt = &ops[4];
length -= 4;
proj = true;
break;
default:
opt = &ops[4];
length -= 4;
break;
}
// Bypass pointers because we need the real image struct
auto &type = expression_type(img);
auto &imgtype = get<SPIRType>(type.self);
uint32_t coord_components = 0;
switch (imgtype.image.dim)
{
case spv::Dim1D:
coord_components = 1;
break;
case spv::Dim2D:
coord_components = 2;
break;
case spv::Dim3D:
coord_components = 3;
break;
case spv::DimCube:
coord_components = 3;
break;
case spv::DimBuffer:
coord_components = 1;
break;
default:
coord_components = 2;
break;
}
if (proj)
coord_components++;
if (imgtype.image.arrayed)
coord_components++;
uint32_t bias = 0;
uint32_t lod = 0;
uint32_t grad_x = 0;
uint32_t grad_y = 0;
uint32_t coffset = 0;
uint32_t offset = 0;
uint32_t coffsets = 0;
uint32_t sample = 0;
uint32_t flags = 0;
if (length)
{
flags = *opt++;
length--;
}
auto test = [&](uint32_t &v, uint32_t flag) {
if (length && (flags & flag))
{
v = *opt++;
length--;
}
};
test(bias, ImageOperandsBiasMask);
test(lod, ImageOperandsLodMask);
test(grad_x, ImageOperandsGradMask);
test(grad_y, ImageOperandsGradMask);
test(coffset, ImageOperandsConstOffsetMask);
test(offset, ImageOperandsOffsetMask);
test(coffsets, ImageOperandsConstOffsetsMask);
test(sample, ImageOperandsSampleMask);
string expr;
bool forward = false;
expr += to_function_name(img, imgtype, !!fetch, !!gather, !!proj, !!coffsets, (!!coffset || !!offset),
(!!grad_x || !!grad_y), !!dref, lod);
expr += "(";
expr += to_function_args(img, imgtype, fetch, gather, proj, coord, coord_components, dref, grad_x, grad_y, lod,
coffset, offset, bias, comp, sample, &forward);
expr += ")";
emit_op(result_type, id, expr, forward);
}
// Returns the function name for a texture sampling function for the specified image and sampling characteristics.
// For some subclasses, the function is a method on the specified image.
string CompilerGLSL::to_function_name(uint32_t, const SPIRType &imgtype, bool is_fetch, bool is_gather, bool is_proj,
bool has_array_offsets, bool has_offset, bool has_grad, bool, uint32_t lod)
{
string fname;
// textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL for some reason.
// To emulate this, we will have to use textureGrad with a constant gradient of 0.
// The workaround will assert that the LOD is in fact constant 0, or we cannot emit correct code.
// This happens for HLSL SampleCmpLevelZero on Texture2DArray and TextureCube.
bool workaround_lod_array_shadow_as_grad = false;
if (((imgtype.image.arrayed && imgtype.image.dim == Dim2D) || imgtype.image.dim == DimCube) &&
imgtype.image.depth && lod)
{
auto *constant_lod = maybe_get<SPIRConstant>(lod);
if (!constant_lod || constant_lod->scalar_f32() != 0.0f)
SPIRV_CROSS_THROW(
"textureLod on sampler2DArrayShadow is not constant 0.0. This cannot be expressed in GLSL.");
workaround_lod_array_shadow_as_grad = true;
}
if (is_fetch)
fname += "texelFetch";
else
{
fname += "texture";
if (is_gather)
fname += "Gather";
if (has_array_offsets)
fname += "Offsets";
if (is_proj)
fname += "Proj";
if (has_grad || workaround_lod_array_shadow_as_grad)
fname += "Grad";
if (!!lod && !workaround_lod_array_shadow_as_grad)
fname += "Lod";
}
if (has_offset)
fname += "Offset";
return is_legacy() ? legacy_tex_op(fname, imgtype, lod) : fname;
}
// Returns the function args for a texture sampling function for the specified image and sampling characteristics.
string CompilerGLSL::to_function_args(uint32_t img, const SPIRType &imgtype, bool, bool, bool is_proj, uint32_t coord,
uint32_t coord_components, uint32_t dref, uint32_t grad_x, uint32_t grad_y,
uint32_t lod, uint32_t coffset, uint32_t offset, uint32_t bias, uint32_t comp,
uint32_t sample, bool *p_forward)
{
string farg_str = to_expression(img);
bool swizz_func = backend.swizzle_is_function;
auto swizzle = [swizz_func](uint32_t comps, uint32_t in_comps) -> const char * {
if (comps == in_comps)
return "";
switch (comps)
{
case 1:
return ".x";
case 2:
return swizz_func ? ".xy()" : ".xy";
case 3:
return swizz_func ? ".xyz()" : ".xyz";
default:
return "";
}
};
bool forward = should_forward(coord);
// The IR can give us more components than we need, so chop them off as needed.
auto swizzle_expr = swizzle(coord_components, expression_type(coord).vecsize);
// Only enclose the UV expression if needed.
auto coord_expr = (*swizzle_expr == '\0') ? to_expression(coord) : (to_enclosed_expression(coord) + swizzle_expr);
// textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL for some reason.
// To emulate this, we will have to use textureGrad with a constant gradient of 0.
// The workaround will assert that the LOD is in fact constant 0, or we cannot emit correct code.
// This happens for HLSL SampleCmpLevelZero on Texture2DArray and TextureCube.
bool workaround_lod_array_shadow_as_grad =
((imgtype.image.arrayed && imgtype.image.dim == Dim2D) || imgtype.image.dim == DimCube) &&
imgtype.image.depth && lod;
if (dref)
{
forward = forward && should_forward(dref);
// SPIR-V splits dref and coordinate.
if (coord_components == 4) // GLSL also splits the arguments in two.
{
farg_str += ", ";
farg_str += to_expression(coord);
farg_str += ", ";
farg_str += to_expression(dref);
}
else if (is_proj)
{
// Have to reshuffle so we get vec4(coord, dref, proj), special case.
// Other shading languages splits up the arguments for coord and compare value like SPIR-V.
// The coordinate type for textureProj shadow is always vec4 even for sampler1DShadow.
farg_str += ", vec4(";
if (imgtype.image.dim == Dim1D)
{
// Could reuse coord_expr, but we will mess up the temporary usage checking.
farg_str += to_enclosed_expression(coord) + ".x";
farg_str += ", ";
farg_str += "0.0, ";
farg_str += to_expression(dref);
farg_str += ", ";
farg_str += to_enclosed_expression(coord) + ".y)";
}
else if (imgtype.image.dim == Dim2D)
{
// Could reuse coord_expr, but we will mess up the temporary usage checking.
farg_str += to_enclosed_expression(coord) + (swizz_func ? ".xy()" : ".xy");
farg_str += ", ";
farg_str += to_expression(dref);
farg_str += ", ";
farg_str += to_enclosed_expression(coord) + ".z)";
}
else
SPIRV_CROSS_THROW("Invalid type for textureProj with shadow.");
}
else
{
// Create a composite which merges coord/dref into a single vector.
auto type = expression_type(coord);
type.vecsize = coord_components + 1;
farg_str += ", ";
farg_str += type_to_glsl_constructor(type);
farg_str += "(";
farg_str += coord_expr;
farg_str += ", ";
farg_str += to_expression(dref);
farg_str += ")";
}
}
else
{
farg_str += ", ";
farg_str += coord_expr;
}
if (grad_x || grad_y)
{
forward = forward && should_forward(grad_x);
forward = forward && should_forward(grad_y);
farg_str += ", ";
farg_str += to_expression(grad_x);
farg_str += ", ";
farg_str += to_expression(grad_y);
}
if (lod)
{
if (workaround_lod_array_shadow_as_grad)
{
// Implement textureGrad() instead. LOD == 0.0 is implemented as gradient of 0.0.
// Implementing this as plain texture() is not safe on some implementations.
if (imgtype.image.dim == Dim2D)
farg_str += ", vec2(0.0), vec2(0.0)";
else if (imgtype.image.dim == DimCube)
farg_str += ", vec3(0.0), vec3(0.0)";
}
else
{
if (check_explicit_lod_allowed(lod))
{
forward = forward && should_forward(lod);
farg_str += ", ";
farg_str += to_expression(lod);
}
}
}
if (coffset)
{
forward = forward && should_forward(coffset);
farg_str += ", ";
farg_str += to_expression(coffset);
}
else if (offset)
{
forward = forward && should_forward(offset);
farg_str += ", ";
farg_str += to_expression(offset);
}
if (bias)
{
forward = forward && should_forward(bias);
farg_str += ", ";
farg_str += to_expression(bias);
}
if (comp)
{
forward = forward && should_forward(comp);
farg_str += ", ";
farg_str += to_expression(comp);
}
if (sample)
{
farg_str += ", ";
farg_str += to_expression(sample);
}
*p_forward = forward;
return farg_str;
}
// Some languages may have additional standard library functions whose names conflict
// with a function defined in the body of the shader. Subclasses can override to rename
// the function name defined in the shader to avoid conflict with the language standard
// functions (eg. MSL includes saturate()).
string CompilerGLSL::clean_func_name(string func_name)
{
return func_name;
}
void CompilerGLSL::emit_glsl_op(uint32_t result_type, uint32_t id, uint32_t eop, const uint32_t *args, uint32_t)
{
GLSLstd450 op = static_cast<GLSLstd450>(eop);
switch (op)
{
// FP fiddling
case GLSLstd450Round:
emit_unary_func_op(result_type, id, args[0], "round");
break;
case GLSLstd450RoundEven:
if ((options.es && options.version >= 300) || (!options.es && options.version >= 130))
emit_unary_func_op(result_type, id, args[0], "roundEven");
else
SPIRV_CROSS_THROW("roundEven supported only in ESSL 300 and GLSL 130 and up.");
break;
case GLSLstd450Trunc:
emit_unary_func_op(result_type, id, args[0], "trunc");
break;
case GLSLstd450SAbs:
case GLSLstd450FAbs:
emit_unary_func_op(result_type, id, args[0], "abs");
break;
case GLSLstd450SSign:
case GLSLstd450FSign:
emit_unary_func_op(result_type, id, args[0], "sign");
break;
case GLSLstd450Floor:
emit_unary_func_op(result_type, id, args[0], "floor");
break;
case GLSLstd450Ceil:
emit_unary_func_op(result_type, id, args[0], "ceil");
break;
case GLSLstd450Fract:
emit_unary_func_op(result_type, id, args[0], "fract");
break;
case GLSLstd450Radians:
emit_unary_func_op(result_type, id, args[0], "radians");
break;
case GLSLstd450Degrees:
emit_unary_func_op(result_type, id, args[0], "degrees");
break;
case GLSLstd450Fma:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "fma");
break;
case GLSLstd450Modf:
register_call_out_argument(args[1]);
forced_temporaries.insert(id);
emit_binary_func_op(result_type, id, args[0], args[1], "modf");
break;
case GLSLstd450ModfStruct:
{
forced_temporaries.insert(id);
auto &type = get<SPIRType>(result_type);
auto flags = meta[id].decoration.decoration_flags;
statement(flags_to_precision_qualifiers_glsl(type, flags), variable_decl(type, to_name(id)), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
statement(to_expression(id), ".", to_member_name(type, 0), " = ", "modf(", to_expression(args[0]), ", ",
to_expression(id), ".", to_member_name(type, 1), ");");
break;
}
// Minmax
case GLSLstd450FMin:
case GLSLstd450UMin:
case GLSLstd450SMin:
emit_binary_func_op(result_type, id, args[0], args[1], "min");
break;
case GLSLstd450FMax:
case GLSLstd450UMax:
case GLSLstd450SMax:
emit_binary_func_op(result_type, id, args[0], args[1], "max");
break;
case GLSLstd450FClamp:
case GLSLstd450UClamp:
case GLSLstd450SClamp:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "clamp");
break;
// Trig
case GLSLstd450Sin:
emit_unary_func_op(result_type, id, args[0], "sin");
break;
case GLSLstd450Cos:
emit_unary_func_op(result_type, id, args[0], "cos");
break;
case GLSLstd450Tan:
emit_unary_func_op(result_type, id, args[0], "tan");
break;
case GLSLstd450Asin:
emit_unary_func_op(result_type, id, args[0], "asin");
break;
case GLSLstd450Acos:
emit_unary_func_op(result_type, id, args[0], "acos");
break;
case GLSLstd450Atan:
emit_unary_func_op(result_type, id, args[0], "atan");
break;
case GLSLstd450Sinh:
emit_unary_func_op(result_type, id, args[0], "sinh");
break;
case GLSLstd450Cosh:
emit_unary_func_op(result_type, id, args[0], "cosh");
break;
case GLSLstd450Tanh:
emit_unary_func_op(result_type, id, args[0], "tanh");
break;
case GLSLstd450Asinh:
emit_unary_func_op(result_type, id, args[0], "asinh");
break;
case GLSLstd450Acosh:
emit_unary_func_op(result_type, id, args[0], "acosh");
break;
case GLSLstd450Atanh:
emit_unary_func_op(result_type, id, args[0], "atanh");
break;
case GLSLstd450Atan2:
emit_binary_func_op(result_type, id, args[0], args[1], "atan");
break;
// Exponentials
case GLSLstd450Pow:
emit_binary_func_op(result_type, id, args[0], args[1], "pow");
break;
case GLSLstd450Exp:
emit_unary_func_op(result_type, id, args[0], "exp");
break;
case GLSLstd450Log:
emit_unary_func_op(result_type, id, args[0], "log");
break;
case GLSLstd450Exp2:
emit_unary_func_op(result_type, id, args[0], "exp2");
break;
case GLSLstd450Log2:
emit_unary_func_op(result_type, id, args[0], "log2");
break;
case GLSLstd450Sqrt:
emit_unary_func_op(result_type, id, args[0], "sqrt");
break;
case GLSLstd450InverseSqrt:
emit_unary_func_op(result_type, id, args[0], "inversesqrt");
break;
// Matrix math
case GLSLstd450Determinant:
emit_unary_func_op(result_type, id, args[0], "determinant");
break;
case GLSLstd450MatrixInverse:
emit_unary_func_op(result_type, id, args[0], "inverse");
break;
// Lerping
case GLSLstd450FMix:
case GLSLstd450IMix:
{
emit_mix_op(result_type, id, args[0], args[1], args[2]);
break;
}
case GLSLstd450Step:
emit_binary_func_op(result_type, id, args[0], args[1], "step");
break;
case GLSLstd450SmoothStep:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "smoothstep");
break;
// Packing
case GLSLstd450Frexp:
register_call_out_argument(args[1]);
forced_temporaries.insert(id);
emit_binary_func_op(result_type, id, args[0], args[1], "frexp");
break;
case GLSLstd450FrexpStruct:
{
forced_temporaries.insert(id);
auto &type = get<SPIRType>(result_type);
auto flags = meta[id].decoration.decoration_flags;
statement(flags_to_precision_qualifiers_glsl(type, flags), variable_decl(type, to_name(id)), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
statement(to_expression(id), ".", to_member_name(type, 0), " = ", "frexp(", to_expression(args[0]), ", ",
to_expression(id), ".", to_member_name(type, 1), ");");
break;
}
case GLSLstd450Ldexp:
emit_binary_func_op(result_type, id, args[0], args[1], "ldexp");
break;
case GLSLstd450PackSnorm4x8:
emit_unary_func_op(result_type, id, args[0], "packSnorm4x8");
break;
case GLSLstd450PackUnorm4x8:
emit_unary_func_op(result_type, id, args[0], "packUnorm4x8");
break;
case GLSLstd450PackSnorm2x16:
emit_unary_func_op(result_type, id, args[0], "packSnorm2x16");
break;
case GLSLstd450PackUnorm2x16:
emit_unary_func_op(result_type, id, args[0], "packUnorm2x16");
break;
case GLSLstd450PackHalf2x16:
emit_unary_func_op(result_type, id, args[0], "packHalf2x16");
break;
case GLSLstd450UnpackSnorm4x8:
emit_unary_func_op(result_type, id, args[0], "unpackSnorm4x8");
break;
case GLSLstd450UnpackUnorm4x8:
emit_unary_func_op(result_type, id, args[0], "unpackUnorm4x8");
break;
case GLSLstd450UnpackSnorm2x16:
emit_unary_func_op(result_type, id, args[0], "unpackSnorm2x16");
break;
case GLSLstd450UnpackUnorm2x16:
emit_unary_func_op(result_type, id, args[0], "unpackUnorm2x16");
break;
case GLSLstd450UnpackHalf2x16:
emit_unary_func_op(result_type, id, args[0], "unpackHalf2x16");
break;
case GLSLstd450PackDouble2x32:
emit_unary_func_op(result_type, id, args[0], "packDouble2x32");
break;
case GLSLstd450UnpackDouble2x32:
emit_unary_func_op(result_type, id, args[0], "unpackDouble2x32");
break;
// Vector math
case GLSLstd450Length:
emit_unary_func_op(result_type, id, args[0], "length");
break;
case GLSLstd450Distance:
emit_binary_func_op(result_type, id, args[0], args[1], "distance");
break;
case GLSLstd450Cross:
emit_binary_func_op(result_type, id, args[0], args[1], "cross");
break;
case GLSLstd450Normalize:
emit_unary_func_op(result_type, id, args[0], "normalize");
break;
case GLSLstd450FaceForward:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "faceforward");
break;
case GLSLstd450Reflect:
emit_binary_func_op(result_type, id, args[0], args[1], "reflect");
break;
case GLSLstd450Refract:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "refract");
break;
// Bit-fiddling
case GLSLstd450FindILsb:
emit_unary_func_op(result_type, id, args[0], "findLSB");
break;
case GLSLstd450FindSMsb:
case GLSLstd450FindUMsb:
emit_unary_func_op(result_type, id, args[0], "findMSB");
break;
// Multisampled varying
case GLSLstd450InterpolateAtCentroid:
emit_unary_func_op(result_type, id, args[0], "interpolateAtCentroid");
break;
case GLSLstd450InterpolateAtSample:
emit_binary_func_op(result_type, id, args[0], args[1], "interpolateAtSample");
break;
case GLSLstd450InterpolateAtOffset:
emit_binary_func_op(result_type, id, args[0], args[1], "interpolateAtOffset");
break;
default:
statement("// unimplemented GLSL op ", eop);
break;
}
}
string CompilerGLSL::bitcast_glsl_op(const SPIRType &out_type, const SPIRType &in_type)
{
if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Int)
return type_to_glsl(out_type);
else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Int64)
return type_to_glsl(out_type);
else if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Float)
return "floatBitsToUint";
else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::UInt)
return type_to_glsl(out_type);
else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::UInt64)
return type_to_glsl(out_type);
else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::Float)
return "floatBitsToInt";
else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::UInt)
return "uintBitsToFloat";
else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::Int)
return "intBitsToFloat";
else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::Double)
return "doubleBitsToInt64";
else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Double)
return "doubleBitsToUint64";
else if (out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::Int64)
return "int64BitsToDouble";
else if (out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::UInt64)
return "uint64BitsToDouble";
else
return "";
}
string CompilerGLSL::bitcast_glsl(const SPIRType &result_type, uint32_t argument)
{
auto op = bitcast_glsl_op(result_type, expression_type(argument));
if (op.empty())
return to_enclosed_expression(argument);
else
return join(op, "(", to_expression(argument), ")");
}
std::string CompilerGLSL::bitcast_expression(SPIRType::BaseType target_type, uint32_t arg)
{
auto expr = to_expression(arg);
auto &src_type = expression_type(arg);
if (src_type.basetype != target_type)
{
auto target = src_type;
target.basetype = target_type;
expr = join(bitcast_glsl_op(target, src_type), "(", expr, ")");
}
return expr;
}
std::string CompilerGLSL::bitcast_expression(const SPIRType &target_type, SPIRType::BaseType expr_type,
const std::string &expr)
{
if (target_type.basetype == expr_type)
return expr;
auto src_type = target_type;
src_type.basetype = expr_type;
return join(bitcast_glsl_op(target_type, src_type), "(", expr, ")");
}
string CompilerGLSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
{
switch (builtin)
{
case BuiltInPosition:
return "gl_Position";
case BuiltInPointSize:
return "gl_PointSize";
case BuiltInClipDistance:
return "gl_ClipDistance";
case BuiltInCullDistance:
return "gl_CullDistance";
case BuiltInVertexId:
if (options.vulkan_semantics)
SPIRV_CROSS_THROW(
"Cannot implement gl_VertexID in Vulkan GLSL. This shader was created with GL semantics.");
return "gl_VertexID";
case BuiltInInstanceId:
if (options.vulkan_semantics)
SPIRV_CROSS_THROW(
"Cannot implement gl_InstanceID in Vulkan GLSL. This shader was created with GL semantics.");
return "gl_InstanceID";
case BuiltInVertexIndex:
if (options.vulkan_semantics)
return "gl_VertexIndex";
else
return "gl_VertexID"; // gl_VertexID already has the base offset applied.
case BuiltInInstanceIndex:
if (options.vulkan_semantics)
return "gl_InstanceIndex";
else
return "(gl_InstanceID + SPIRV_Cross_BaseInstance)"; // ... but not gl_InstanceID.
case BuiltInPrimitiveId:
return "gl_PrimitiveID";
case BuiltInInvocationId:
return "gl_InvocationID";
case BuiltInLayer:
return "gl_Layer";
case BuiltInTessLevelOuter:
return "gl_TessLevelOuter";
case BuiltInTessLevelInner:
return "gl_TessLevelInner";
case BuiltInTessCoord:
return "gl_TessCoord";
case BuiltInFragCoord:
return "gl_FragCoord";
case BuiltInPointCoord:
return "gl_PointCoord";
case BuiltInFrontFacing:
return "gl_FrontFacing";
case BuiltInFragDepth:
return "gl_FragDepth";
case BuiltInNumWorkgroups:
return "gl_NumWorkGroups";
case BuiltInWorkgroupSize:
return "gl_WorkGroupSize";
case BuiltInWorkgroupId:
return "gl_WorkGroupID";
case BuiltInLocalInvocationId:
return "gl_LocalInvocationID";
case BuiltInGlobalInvocationId:
return "gl_GlobalInvocationID";
case BuiltInLocalInvocationIndex:
return "gl_LocalInvocationIndex";
case BuiltInSampleId:
if (options.es && options.version < 320)
require_extension("GL_OES_sample_variables");
if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("gl_SampleID not supported before GLSL 400.");
return "gl_SampleID";
case BuiltInSampleMask:
if (options.es && options.version < 320)
require_extension("GL_OES_sample_variables");
if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("gl_SampleMask/gl_SampleMaskIn not supported before GLSL 400.");
if (storage == StorageClassInput)
return "gl_SampleMaskIn";
else
return "gl_SampleMask";
case BuiltInSamplePosition:
if (options.es && options.version < 320)
require_extension("GL_OES_sample_variables");
if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("gl_SamplePosition not supported before GLSL 400.");
return "gl_SamplePosition";
case BuiltInViewIndex:
if (options.vulkan_semantics)
{
require_extension("GL_EXT_multiview");
return "gl_ViewIndex";
}
else
{
require_extension("GL_OVR_multiview2");
return "gl_ViewID_OVR";
}
default:
return join("gl_BuiltIn_", convert_to_string(builtin));
}
}
const char *CompilerGLSL::index_to_swizzle(uint32_t index)
{
switch (index)
{
case 0:
return "x";
case 1:
return "y";
case 2:
return "z";
case 3:
return "w";
default:
SPIRV_CROSS_THROW("Swizzle index out of range");
}
}
string CompilerGLSL::access_chain_internal(uint32_t base, const uint32_t *indices, uint32_t count,
bool index_is_literal, bool chain_only, bool *need_transpose)
{
string expr;
if (!chain_only)
expr = to_enclosed_expression(base);
uint32_t type_id = expression_type_id(base);
const auto *type = &get<SPIRType>(type_id);
// Start traversing type hierarchy at the proper non-pointer types,
// but keep type_id referencing the original pointer for use below.
while (type->pointer)
{
assert(type->parent_type);
type = &get<SPIRType>(type->parent_type);
}
bool access_chain_is_arrayed = false;
bool row_major_matrix_needs_conversion = is_non_native_row_major_matrix(base);
bool pending_array_enclose = false;
bool dimension_flatten = false;
for (uint32_t i = 0; i < count; i++)
{
uint32_t index = indices[i];
// Arrays
if (!type->array.empty())
{
// If we are flattening multidimensional arrays, only create opening bracket on first
// array index.
if (options.flatten_multidimensional_arrays && !pending_array_enclose)
{
dimension_flatten = type->array.size() > 1;
pending_array_enclose = dimension_flatten;
if (pending_array_enclose)
expr += "[";
}
assert(type->parent_type);
// If we are flattening multidimensional arrays, do manual stride computation.
if (options.flatten_multidimensional_arrays && dimension_flatten)
{
auto &parent_type = get<SPIRType>(type->parent_type);
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_enclosed_expression(index);
for (auto j = uint32_t(parent_type.array.size()); j; j--)
{
expr += " * ";
expr += enclose_expression(to_array_size(parent_type, j - 1));
}
if (parent_type.array.empty())
pending_array_enclose = false;
else
expr += " + ";
}
else
{
expr += "[";
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_expression(index);
}
if (!pending_array_enclose)
expr += "]";
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
access_chain_is_arrayed = true;
}
// For structs, the index refers to a constant, which indexes into the members.
// We also check if this member is a builtin, since we then replace the entire expression with the builtin one.
else if (type->basetype == SPIRType::Struct)
{
if (!index_is_literal)
index = get<SPIRConstant>(index).scalar();
if (index >= type->member_types.size())
SPIRV_CROSS_THROW("Member index is out of bounds!");
BuiltIn builtin;
if (is_member_builtin(*type, index, &builtin))
{
// FIXME: We rely here on OpName on gl_in/gl_out to make this work properly.
// To make this properly work by omitting all OpName opcodes,
// we need to infer gl_in or gl_out based on the builtin, and stage.
if (access_chain_is_arrayed)
{
expr += ".";
expr += builtin_to_glsl(builtin, type->storage);
}
else
expr = builtin_to_glsl(builtin, type->storage);
}
else
{
// If the member has a qualified name, use it as the entire chain
string qual_mbr_name = get_member_qualified_name(type_id, index);
if (!qual_mbr_name.empty())
expr = qual_mbr_name;
else
{
expr += ".";
expr += to_member_name(*type, index);
}
}
if (member_is_packed_type(*type, index))
{
auto &membertype = get<SPIRType>(type->member_types[index]);
expr = unpack_expression_type(expr, membertype);
}
row_major_matrix_needs_conversion = member_is_non_native_row_major_matrix(*type, index);
type = &get<SPIRType>(type->member_types[index]);
}
// Matrix -> Vector
else if (type->columns > 1)
{
if (row_major_matrix_needs_conversion)
{
expr = convert_row_major_matrix(expr);
row_major_matrix_needs_conversion = false;
}
expr += "[";
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_expression(index);
expr += "]";
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
}
// Vector -> Scalar
else if (type->vecsize > 1)
{
if (index_is_literal)
{
expr += ".";
expr += index_to_swizzle(index);
}
else if (ids[index].get_type() == TypeConstant)
{
auto &c = get<SPIRConstant>(index);
expr += ".";
expr += index_to_swizzle(c.scalar());
}
else
{
expr += "[";
expr += to_expression(index);
expr += "]";
}
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
}
else
SPIRV_CROSS_THROW("Cannot subdivide a scalar value!");
}
if (pending_array_enclose)
{
SPIRV_CROSS_THROW("Flattening of multidimensional arrays were enabled, "
"but the access chain was terminated in the middle of a multidimensional array. "
"This is not supported.");
}
if (need_transpose)
*need_transpose = row_major_matrix_needs_conversion;
return expr;
}
string CompilerGLSL::to_flattened_struct_member(const SPIRType &type, uint32_t index)
{
return sanitize_underscores(join(to_name(type.self), "_", to_member_name(type, index)));
}
string CompilerGLSL::access_chain(uint32_t base, const uint32_t *indices, uint32_t count, const SPIRType &target_type,
bool *out_need_transpose)
{
if (flattened_buffer_blocks.count(base))
{
uint32_t matrix_stride;
bool need_transpose;
flattened_access_chain_offset(expression_type(base), indices, count, 0, 16, &need_transpose, &matrix_stride);
if (out_need_transpose)
*out_need_transpose = target_type.columns > 1 && need_transpose;
return flattened_access_chain(base, indices, count, target_type, 0, matrix_stride, need_transpose);
}
else if (flattened_structs.count(base) && count > 0)
{
auto chain = access_chain_internal(base, indices, count, false, true).substr(1);
auto &type = get<SPIRType>(get<SPIRVariable>(base).basetype);
if (out_need_transpose)
*out_need_transpose = false;
return sanitize_underscores(join(to_name(type.self), "_", chain));
}
else
{
return access_chain_internal(base, indices, count, false, false, out_need_transpose);
}
}
string CompilerGLSL::load_flattened_struct(SPIRVariable &var)
{
auto expr = type_to_glsl_constructor(get<SPIRType>(var.basetype));
expr += '(';
auto &type = get<SPIRType>(var.basetype);
for (uint32_t i = 0; i < uint32_t(type.member_types.size()); i++)
{
if (i)
expr += ", ";
// Flatten the varyings.
// Apply name transformation for flattened I/O blocks.
expr += to_flattened_struct_member(type, i);
}
expr += ')';
return expr;
}
void CompilerGLSL::store_flattened_struct(SPIRVariable &var, uint32_t value)
{
// We're trying to store a structure which has been flattened.
// Need to copy members one by one.
auto rhs = to_expression(value);
// Store result locally.
// Since we're declaring a variable potentially multiple times here,
// store the variable in an isolated scope.
begin_scope();
statement(variable_decl_function_local(var), " = ", rhs, ";");
auto &type = get<SPIRType>(var.basetype);
for (uint32_t i = 0; i < uint32_t(type.member_types.size()); i++)
{
// Flatten the varyings.
// Apply name transformation for flattened I/O blocks.
auto lhs = sanitize_underscores(join(to_name(type.self), "_", to_member_name(type, i)));
rhs = join(to_name(var.self), ".", to_member_name(type, i));
statement(lhs, " = ", rhs, ";");
}
end_scope();
}
std::string CompilerGLSL::flattened_access_chain(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset, uint32_t matrix_stride,
bool need_transpose)
{
if (!target_type.array.empty())
SPIRV_CROSS_THROW("Access chains that result in an array can not be flattened");
else if (target_type.basetype == SPIRType::Struct)
return flattened_access_chain_struct(base, indices, count, target_type, offset);
else if (target_type.columns > 1)
return flattened_access_chain_matrix(base, indices, count, target_type, offset, matrix_stride, need_transpose);
else
return flattened_access_chain_vector(base, indices, count, target_type, offset, matrix_stride, need_transpose);
}
std::string CompilerGLSL::flattened_access_chain_struct(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset)
{
std::string expr;
expr += type_to_glsl_constructor(target_type);
expr += "(";
for (uint32_t i = 0; i < uint32_t(target_type.member_types.size()); ++i)
{
if (i != 0)
expr += ", ";
const SPIRType &member_type = get<SPIRType>(target_type.member_types[i]);
uint32_t member_offset = type_struct_member_offset(target_type, i);
// The access chain terminates at the struct, so we need to find matrix strides and row-major information
// ahead of time.
bool need_transpose = false;
uint32_t matrix_stride = 0;
if (member_type.columns > 1)
{
need_transpose = (combined_decoration_for_member(target_type, i) & (1ull << DecorationRowMajor)) != 0;
matrix_stride = type_struct_member_matrix_stride(target_type, i);
}
auto tmp = flattened_access_chain(base, indices, count, member_type, offset + member_offset, matrix_stride,
need_transpose);
// Cannot forward transpositions, so resolve them here.
if (need_transpose)
expr += convert_row_major_matrix(tmp);
else
expr += tmp;
}
expr += ")";
return expr;
}
std::string CompilerGLSL::flattened_access_chain_matrix(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset,
uint32_t matrix_stride, bool need_transpose)
{
assert(matrix_stride);
SPIRType tmp_type = target_type;
if (need_transpose)
swap(tmp_type.vecsize, tmp_type.columns);
std::string expr;
expr += type_to_glsl_constructor(tmp_type);
expr += "(";
for (uint32_t i = 0; i < tmp_type.columns; i++)
{
if (i != 0)
expr += ", ";
expr += flattened_access_chain_vector(base, indices, count, tmp_type, offset + i * matrix_stride, matrix_stride,
/* need_transpose= */ false);
}
expr += ")";
return expr;
}
std::string CompilerGLSL::flattened_access_chain_vector(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset,
uint32_t matrix_stride, bool need_transpose)
{
auto result = flattened_access_chain_offset(expression_type(base), indices, count, offset, 16);
auto buffer_name = to_name(expression_type(base).self);
if (need_transpose)
{
std::string expr;
if (target_type.vecsize > 1)
{
expr += type_to_glsl_constructor(target_type);
expr += "(";
}
for (uint32_t i = 0; i < target_type.vecsize; ++i)
{
if (i != 0)
expr += ", ";
uint32_t component_offset = result.second + i * matrix_stride;
assert(component_offset % (target_type.width / 8) == 0);
uint32_t index = component_offset / (target_type.width / 8);
expr += buffer_name;
expr += "[";
expr += result.first; // this is a series of N1 * k1 + N2 * k2 + ... that is either empty or ends with a +
expr += convert_to_string(index / 4);
expr += "]";
expr += vector_swizzle(1, index % 4);
}
if (target_type.vecsize > 1)
{
expr += ")";
}
return expr;
}
else
{
assert(result.second % (target_type.width / 8) == 0);
uint32_t index = result.second / (target_type.width / 8);
std::string expr;
expr += buffer_name;
expr += "[";
expr += result.first; // this is a series of N1 * k1 + N2 * k2 + ... that is either empty or ends with a +
expr += convert_to_string(index / 4);
expr += "]";
expr += vector_swizzle(target_type.vecsize, index % 4);
return expr;
}
}
std::pair<std::string, uint32_t> CompilerGLSL::flattened_access_chain_offset(const SPIRType &basetype,
const uint32_t *indices, uint32_t count,
uint32_t offset, uint32_t word_stride,
bool *need_transpose,
uint32_t *out_matrix_stride)
{
const auto *type = &basetype;
// Start traversing type hierarchy at the proper non-pointer types.
while (type->pointer)
{
assert(type->parent_type);
type = &get<SPIRType>(type->parent_type);
}
// This holds the type of the current pointer which we are traversing through.
// We always start out from a struct type which is the block.
// This is primarily used to reflect the array strides and matrix strides later.
// For the first access chain index, type_id won't be needed, so just keep it as 0, it will be set
// accordingly as members of structs are accessed.
assert(type->basetype == SPIRType::Struct);
uint32_t type_id = 0;
uint32_t matrix_stride = 0;
std::string expr;
bool row_major_matrix_needs_conversion = false;
for (uint32_t i = 0; i < count; i++)
{
uint32_t index = indices[i];
// Arrays
if (!type->array.empty())
{
// Here, the type_id will be a type ID for the array type itself.
uint32_t array_stride = get_decoration(type_id, DecorationArrayStride);
if (!array_stride)
SPIRV_CROSS_THROW("SPIR-V does not define ArrayStride for buffer block.");
auto *constant = maybe_get<SPIRConstant>(index);
if (constant)
{
// Constant array access.
offset += constant->scalar() * array_stride;
}
else
{
// Dynamic array access.
if (array_stride % word_stride)
{
SPIRV_CROSS_THROW(
"Array stride for dynamic indexing must be divisible by the size of a 4-component vector. "
"Likely culprit here is a float or vec2 array inside a push constant block which is std430. "
"This cannot be flattened. Try using std140 layout instead.");
}
expr += to_enclosed_expression(index);
expr += " * ";
expr += convert_to_string(array_stride / word_stride);
expr += " + ";
}
uint32_t parent_type = type->parent_type;
type = &get<SPIRType>(parent_type);
type_id = parent_type;
// Type ID now refers to the array type with one less dimension.
}
// For structs, the index refers to a constant, which indexes into the members.
// We also check if this member is a builtin, since we then replace the entire expression with the builtin one.
else if (type->basetype == SPIRType::Struct)
{
index = get<SPIRConstant>(index).scalar();
if (index >= type->member_types.size())
SPIRV_CROSS_THROW("Member index is out of bounds!");
offset += type_struct_member_offset(*type, index);
type_id = type->member_types[index];
auto &struct_type = *type;
type = &get<SPIRType>(type->member_types[index]);
if (type->columns > 1)
{
matrix_stride = type_struct_member_matrix_stride(struct_type, index);
row_major_matrix_needs_conversion =
(combined_decoration_for_member(struct_type, index) & (1ull << DecorationRowMajor)) != 0;
}
else
row_major_matrix_needs_conversion = false;
}
// Matrix -> Vector
else if (type->columns > 1)
{
if (ids[index].get_type() != TypeConstant)
SPIRV_CROSS_THROW("Cannot flatten dynamic matrix indexing!");
index = get<SPIRConstant>(index).scalar();
offset += index * (row_major_matrix_needs_conversion ? type->width / 8 : matrix_stride);
uint32_t parent_type = type->parent_type;
type = &get<SPIRType>(type->parent_type);
type_id = parent_type;
}
// Vector -> Scalar
else if (type->vecsize > 1)
{
if (ids[index].get_type() != TypeConstant)
SPIRV_CROSS_THROW("Cannot flatten dynamic vector indexing!");
index = get<SPIRConstant>(index).scalar();
offset += index * (row_major_matrix_needs_conversion ? matrix_stride : type->width / 8);
uint32_t parent_type = type->parent_type;
type = &get<SPIRType>(type->parent_type);
type_id = parent_type;
}
else
SPIRV_CROSS_THROW("Cannot subdivide a scalar value!");
}
if (need_transpose)
*need_transpose = row_major_matrix_needs_conversion;
if (out_matrix_stride)
*out_matrix_stride = matrix_stride;
return std::make_pair(expr, offset);
}
bool CompilerGLSL::should_forward(uint32_t id)
{
// Immutable expression can always be forwarded.
// If not immutable, we can speculate about it by forwarding potentially mutable variables.
auto *var = maybe_get<SPIRVariable>(id);
bool forward = var ? var->forwardable : false;
return (is_immutable(id) || forward) && !options.force_temporary;
}
void CompilerGLSL::track_expression_read(uint32_t id)
{
// If we try to read a forwarded temporary more than once we will stamp out possibly complex code twice.
// In this case, it's better to just bind the complex expression to the temporary and read that temporary twice.
if (expression_is_forwarded(id))
{
auto &v = expression_usage_counts[id];
v++;
if (v >= 2)
{
//if (v == 2)
// fprintf(stderr, "ID %u was forced to temporary due to more than 1 expression use!\n", id);
forced_temporaries.insert(id);
// Force a recompile after this pass to avoid forwarding this variable.
force_recompile = true;
}
}
}
bool CompilerGLSL::args_will_forward(uint32_t id, const uint32_t *args, uint32_t num_args, bool pure)
{
if (forced_temporaries.find(id) != end(forced_temporaries))
return false;
for (uint32_t i = 0; i < num_args; i++)
if (!should_forward(args[i]))
return false;
// We need to forward globals as well.
if (!pure)
{
for (auto global : global_variables)
if (!should_forward(global))
return false;
for (auto aliased : aliased_variables)
if (!should_forward(aliased))
return false;
}
return true;
}
void CompilerGLSL::register_impure_function_call()
{
// Impure functions can modify globals and aliased variables, so invalidate them as well.
for (auto global : global_variables)
flush_dependees(get<SPIRVariable>(global));
for (auto aliased : aliased_variables)
flush_dependees(get<SPIRVariable>(aliased));
}
void CompilerGLSL::register_call_out_argument(uint32_t id)
{
register_write(id);
auto *var = maybe_get<SPIRVariable>(id);
if (var)
flush_variable_declaration(var->self);
}
string CompilerGLSL::variable_decl_function_local(SPIRVariable &var)
{
// These variables are always function local,
// so make sure we emit the variable without storage qualifiers.
// Some backends will inject custom variables locally in a function
// with a storage qualifier which is not function-local.
auto old_storage = var.storage;
var.storage = StorageClassFunction;
auto expr = variable_decl(var);
var.storage = old_storage;
return expr;
}
void CompilerGLSL::flush_variable_declaration(uint32_t id)
{
auto *var = maybe_get<SPIRVariable>(id);
if (var && var->deferred_declaration)
{
statement(variable_decl_function_local(*var), ";");
var->deferred_declaration = false;
}
}
bool CompilerGLSL::remove_duplicate_swizzle(string &op)
{
auto pos = op.find_last_of('.');
if (pos == string::npos || pos == 0)
return false;
string final_swiz = op.substr(pos + 1, string::npos);
if (backend.swizzle_is_function)
{
if (final_swiz.size() < 2)
return false;
if (final_swiz.substr(final_swiz.size() - 2, string::npos) == "()")
final_swiz.erase(final_swiz.size() - 2, string::npos);
else
return false;
}
// Check if final swizzle is of form .x, .xy, .xyz, .xyzw or similar.
// If so, and previous swizzle is of same length,
// we can drop the final swizzle altogether.
for (uint32_t i = 0; i < final_swiz.size(); i++)
{
static const char expected[] = { 'x', 'y', 'z', 'w' };
if (i >= 4 || final_swiz[i] != expected[i])
return false;
}
auto prevpos = op.find_last_of('.', pos - 1);
if (prevpos == string::npos)
return false;
prevpos++;
// Make sure there are only swizzles here ...
for (auto i = prevpos; i < pos; i++)
{
if (op[i] < 'w' || op[i] > 'z')
{
// If swizzles are foo.xyz() like in C++ backend for example, check for that.
if (backend.swizzle_is_function && i + 2 == pos && op[i] == '(' && op[i + 1] == ')')
break;
return false;
}
}
// If original swizzle is large enough, just carve out the components we need.
// E.g. foobar.wyx.xy will turn into foobar.wy.
if (pos - prevpos >= final_swiz.size())
{
op.erase(prevpos + final_swiz.size(), string::npos);
// Add back the function call ...
if (backend.swizzle_is_function)
op += "()";
}
return true;
}
// Optimizes away vector swizzles where we have something like
// vec3 foo;
// foo.xyz <-- swizzle expression does nothing.
// This is a very common pattern after OpCompositeCombine.
bool CompilerGLSL::remove_unity_swizzle(uint32_t base, string &op)
{
auto pos = op.find_last_of('.');
if (pos == string::npos || pos == 0)
return false;
string final_swiz = op.substr(pos + 1, string::npos);
if (backend.swizzle_is_function)
{
if (final_swiz.size() < 2)
return false;
if (final_swiz.substr(final_swiz.size() - 2, string::npos) == "()")
final_swiz.erase(final_swiz.size() - 2, string::npos);
else
return false;
}
// Check if final swizzle is of form .x, .xy, .xyz, .xyzw or similar.
// If so, and previous swizzle is of same length,
// we can drop the final swizzle altogether.
for (uint32_t i = 0; i < final_swiz.size(); i++)
{
static const char expected[] = { 'x', 'y', 'z', 'w' };
if (i >= 4 || final_swiz[i] != expected[i])
return false;
}
auto &type = expression_type(base);
// Sanity checking ...
assert(type.columns == 1 && type.array.empty());
if (type.vecsize == final_swiz.size())
op.erase(pos, string::npos);
return true;
}
string CompilerGLSL::build_composite_combiner(const uint32_t *elems, uint32_t length)
{
uint32_t base = 0;
bool swizzle_optimization = false;
string op;
string subop;
for (uint32_t i = 0; i < length; i++)
{
auto *e = maybe_get<SPIRExpression>(elems[i]);
// If we're merging another scalar which belongs to the same base
// object, just merge the swizzles to avoid triggering more than 1 expression read as much as possible!
if (e && e->base_expression && e->base_expression == base)
{
// Only supposed to be used for vector swizzle -> scalar.
assert(!e->expression.empty() && e->expression.front() == '.');
subop += e->expression.substr(1, string::npos);
swizzle_optimization = true;
}
else
{
// We'll likely end up with duplicated swizzles, e.g.
// foobar.xyz.xyz from patterns like
// OpVectorSwizzle
// OpCompositeExtract x 3
// OpCompositeConstruct 3x + other scalar.
// Just modify op in-place.
if (swizzle_optimization)
{
if (backend.swizzle_is_function)
subop += "()";
// Don't attempt to remove unity swizzling if we managed to remove duplicate swizzles.
// The base "foo" might be vec4, while foo.xyz is vec3 (OpVectorShuffle) and looks like a vec3 due to the .xyz tacked on.
// We only want to remove the swizzles if we're certain that the resulting base will be the same vecsize.
// Essentially, we can only remove one set of swizzles, since that's what we have control over ...
// Case 1:
// foo.yxz.xyz: Duplicate swizzle kicks in, giving foo.yxz, we are done.
// foo.yxz was the result of OpVectorShuffle and we don't know the type of foo.
// Case 2:
// foo.xyz: Duplicate swizzle won't kick in.
// If foo is vec3, we can remove xyz, giving just foo.
if (!remove_duplicate_swizzle(subop))
remove_unity_swizzle(base, subop);
// Strips away redundant parens if we created them during component extraction.
strip_enclosed_expression(subop);
swizzle_optimization = false;
op += subop;
}
else
op += subop;
if (i)
op += ", ";
subop = to_expression(elems[i]);
}
base = e ? e->base_expression : 0;
}
if (swizzle_optimization)
{
if (backend.swizzle_is_function)
subop += "()";
if (!remove_duplicate_swizzle(subop))
remove_unity_swizzle(base, subop);
// Strips away redundant parens if we created them during component extraction.
strip_enclosed_expression(subop);
}
op += subop;
return op;
}
bool CompilerGLSL::skip_argument(uint32_t id) const
{
if (!combined_image_samplers.empty() || !options.vulkan_semantics)
{
auto &type = expression_type(id);
if (type.basetype == SPIRType::Sampler || (type.basetype == SPIRType::Image && type.image.sampled == 1))
return true;
}
return false;
}
bool CompilerGLSL::optimize_read_modify_write(const string &lhs, const string &rhs)
{
// Do this with strings because we have a very clear pattern we can check for and it avoids
// adding lots of special cases to the code emission.
if (rhs.size() < lhs.size() + 3)
return false;
auto index = rhs.find(lhs);
if (index != 0)
return false;
// TODO: Shift operators, but it's not important for now.
auto op = rhs.find_first_of("+-/*%|&^", lhs.size() + 1);
if (op != lhs.size() + 1)
return false;
// Check that the op is followed by space. This excludes && and ||.
if (rhs[op + 1] != ' ')
return false;
char bop = rhs[op];
auto expr = rhs.substr(lhs.size() + 3);
// Try to find increments and decrements. Makes it look neater as += 1, -= 1 is fairly rare to see in real code.
// Find some common patterns which are equivalent.
if ((bop == '+' || bop == '-') && (expr == "1" || expr == "uint(1)" || expr == "1u" || expr == "int(1u)"))
statement(lhs, bop, bop, ";");
else
statement(lhs, " ", bop, "= ", expr, ";");
return true;
}
void CompilerGLSL::emit_instruction(const Instruction &instruction)
{
auto ops = stream(instruction);
auto opcode = static_cast<Op>(instruction.op);
uint32_t length = instruction.length;
#define BOP(op) emit_binary_op(ops[0], ops[1], ops[2], ops[3], #op)
#define BOP_CAST(op, type) \
emit_binary_op_cast(ops[0], ops[1], ops[2], ops[3], #op, type, opcode_is_sign_invariant(opcode))
#define UOP(op) emit_unary_op(ops[0], ops[1], ops[2], #op)
#define QFOP(op) emit_quaternary_func_op(ops[0], ops[1], ops[2], ops[3], ops[4], ops[5], #op)
#define TFOP(op) emit_trinary_func_op(ops[0], ops[1], ops[2], ops[3], ops[4], #op)
#define BFOP(op) emit_binary_func_op(ops[0], ops[1], ops[2], ops[3], #op)
#define BFOP_CAST(op, type) \
emit_binary_func_op_cast(ops[0], ops[1], ops[2], ops[3], #op, type, opcode_is_sign_invariant(opcode))
#define BFOP(op) emit_binary_func_op(ops[0], ops[1], ops[2], ops[3], #op)
#define UFOP(op) emit_unary_func_op(ops[0], ops[1], ops[2], #op)
switch (opcode)
{
// Dealing with memory
case OpLoad:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
flush_variable_declaration(ptr);
// If we're loading from memory that cannot be changed by the shader,
// just forward the expression directly to avoid needless temporaries.
// If an expression is mutable and forwardable, we speculate that it is immutable.
bool forward = should_forward(ptr) && forced_temporaries.find(id) == end(forced_temporaries);
// If loading a non-native row-major matrix, mark the expression as need_transpose.
bool need_transpose = false;
bool old_need_transpose = false;
auto *ptr_expression = maybe_get<SPIRExpression>(ptr);
if (ptr_expression && ptr_expression->need_transpose)
{
old_need_transpose = true;
ptr_expression->need_transpose = false;
need_transpose = true;
}
else if (is_non_native_row_major_matrix(ptr))
need_transpose = true;
auto expr = to_expression(ptr);
if (ptr_expression)
ptr_expression->need_transpose = old_need_transpose;
// Suppress usage tracking since using same expression multiple times does not imply any extra work.
auto &e = emit_op(result_type, id, expr, forward, true);
e.need_transpose = need_transpose;
register_read(id, ptr, forward);
break;
}
case OpInBoundsAccessChain:
case OpAccessChain:
{
auto *var = maybe_get<SPIRVariable>(ops[2]);
if (var)
flush_variable_declaration(var->self);
// If the base is immutable, the access chain pointer must also be.
// If an expression is mutable and forwardable, we speculate that it is immutable.
bool need_transpose;
auto e = access_chain(ops[2], &ops[3], length - 3, get<SPIRType>(ops[0]), &need_transpose);
auto &expr = set<SPIRExpression>(ops[1], move(e), ops[0], should_forward(ops[2]));
expr.loaded_from = ops[2];
expr.need_transpose = need_transpose;
break;
}
case OpStore:
{
auto *var = maybe_get<SPIRVariable>(ops[0]);
if (var && var->statically_assigned)
var->static_expression = ops[1];
else if (var && var->loop_variable && !var->loop_variable_enable)
var->static_expression = ops[1];
else if (var && flattened_structs.count(ops[0]))
{
store_flattened_struct(*var, ops[1]);
register_write(ops[0]);
}
else
{
auto lhs = to_expression(ops[0]);
auto rhs = to_expression(ops[1]);
// Tries to optimize assignments like "<lhs> = <lhs> op expr".
// While this is purely cosmetic, this is important for legacy ESSL where loop
// variable increments must be in either i++ or i += const-expr.
// Without this, we end up with i = i + 1, which is correct GLSL, but not correct GLES 2.0.
if (!optimize_read_modify_write(lhs, rhs))
statement(lhs, " = ", rhs, ";");
register_write(ops[0]);
}
break;
}
case OpArrayLength:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto e = access_chain_internal(ops[2], &ops[3], length - 3, true);
set<SPIRExpression>(id, e + ".length()", result_type, true);
break;
}
// Function calls
case OpFunctionCall:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t func = ops[2];
const auto *arg = &ops[3];
length -= 3;
auto &callee = get<SPIRFunction>(func);
bool pure = function_is_pure(callee);
bool callee_has_out_variables = false;
// Invalidate out variables passed to functions since they can be OpStore'd to.
for (uint32_t i = 0; i < length; i++)
{
if (callee.arguments[i].write_count)
{
register_call_out_argument(arg[i]);
callee_has_out_variables = true;
}
flush_variable_declaration(arg[i]);
}
if (!pure)
register_impure_function_call();
string funexpr;
vector<string> arglist;
funexpr += clean_func_name(to_name(func)) + "(";
for (uint32_t i = 0; i < length; i++)
{
// Do not pass in separate images or samplers if we're remapping
// to combined image samplers.
if (skip_argument(arg[i]))
continue;
arglist.push_back(to_func_call_arg(arg[i]));
}
for (auto &combined : callee.combined_parameters)
{
uint32_t image_id = combined.global_image ? combined.image_id : arg[combined.image_id];
uint32_t sampler_id = combined.global_sampler ? combined.sampler_id : arg[combined.sampler_id];
auto *image = maybe_get_backing_variable(image_id);
if (image)
image_id = image->self;
auto *samp = maybe_get_backing_variable(sampler_id);
if (samp)
sampler_id = samp->self;
arglist.push_back(to_combined_image_sampler(image_id, sampler_id));
}
append_global_func_args(callee, length, arglist);
funexpr += merge(arglist);
funexpr += ")";
// Check for function call constraints.
check_function_call_constraints(arg, length);
if (get<SPIRType>(result_type).basetype != SPIRType::Void)
{
// If the function actually writes to an out variable,
// take the conservative route and do not forward.
// The problem is that we might not read the function
// result (and emit the function) before an out variable
// is read (common case when return value is ignored!
// In order to avoid start tracking invalid variables,
// just avoid the forwarding problem altogether.
bool forward = args_will_forward(id, arg, length, pure) && !callee_has_out_variables && pure &&
(forced_temporaries.find(id) == end(forced_temporaries));
emit_op(result_type, id, funexpr, forward);
// Function calls are implicit loads from all variables in question.
// Set dependencies for them.
for (uint32_t i = 0; i < length; i++)
register_read(id, arg[i], forward);
// If we're going to forward the temporary result,
// put dependencies on every variable that must not change.
if (forward)
register_global_read_dependencies(callee, id);
}
else
statement(funexpr, ";");
break;
}
// Composite munging
case OpCompositeConstruct:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
const auto *elems = &ops[2];
length -= 2;
if (!length)
SPIRV_CROSS_THROW("Invalid input to OpCompositeConstruct.");
bool forward = true;
for (uint32_t i = 0; i < length; i++)
forward = forward && should_forward(elems[i]);
auto &in_type = expression_type(elems[0]);
auto &out_type = get<SPIRType>(result_type);
// Only splat if we have vector constructors.
// Arrays and structs must be initialized properly in full.
bool composite = !out_type.array.empty() || out_type.basetype == SPIRType::Struct;
bool splat = in_type.vecsize == 1 && in_type.columns == 1 && !composite && backend.use_constructor_splatting;
if (splat)
{
uint32_t input = elems[0];
for (uint32_t i = 0; i < length; i++)
if (input != elems[i])
splat = false;
}
string constructor_op;
if (backend.use_initializer_list && composite)
{
// Only use this path if we are building composites.
// This path cannot be used for arithmetic.
constructor_op += "{ ";
if (splat)
constructor_op += to_expression(elems[0]);
else
constructor_op += build_composite_combiner(elems, length);
constructor_op += " }";
}
else
{
constructor_op = type_to_glsl_constructor(get<SPIRType>(result_type)) + "(";
if (splat)
constructor_op += to_expression(elems[0]);
else
constructor_op += build_composite_combiner(elems, length);
constructor_op += ")";
}
emit_op(result_type, id, constructor_op, forward);
break;
}
case OpVectorInsertDynamic:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t vec = ops[2];
uint32_t comp = ops[3];
uint32_t index = ops[4];
flush_variable_declaration(vec);
// Make a copy, then use access chain to store the variable.
statement(declare_temporary(result_type, id), to_expression(vec), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
auto chain = access_chain_internal(id, &index, 1, false);
statement(chain, " = ", to_expression(comp), ";");
break;
}
case OpVectorExtractDynamic:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto expr = access_chain_internal(ops[2], &ops[3], 1, false);
emit_op(result_type, id, expr, should_forward(ops[2]));
break;
}
case OpCompositeExtract:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
length -= 3;
auto &type = get<SPIRType>(result_type);
// We can only split the expression here if our expression is forwarded as a temporary.
bool allow_base_expression = forced_temporaries.find(id) == end(forced_temporaries);
// Only apply this optimization if result is scalar.
if (allow_base_expression && should_forward(ops[2]) && type.vecsize == 1 && type.columns == 1 && length == 1)
{
// We want to split the access chain from the base.
// This is so we can later combine different CompositeExtract results
// with CompositeConstruct without emitting code like
//
// vec3 temp = texture(...).xyz
// vec4(temp.x, temp.y, temp.z, 1.0).
//
// when we actually wanted to emit this
// vec4(texture(...).xyz, 1.0).
//
// Including the base will prevent this and would trigger multiple reads
// from expression causing it to be forced to an actual temporary in GLSL.
auto expr = access_chain_internal(ops[2], &ops[3], length, true, true);
auto &e = emit_op(result_type, id, expr, true, !expression_is_forwarded(ops[2]));
e.base_expression = ops[2];
}
else
{
auto expr = access_chain_internal(ops[2], &ops[3], length, true);
emit_op(result_type, id, expr, should_forward(ops[2]), !expression_is_forwarded(ops[2]));
}
break;
}
case OpCompositeInsert:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t obj = ops[2];
uint32_t composite = ops[3];
const auto *elems = &ops[4];
length -= 4;
flush_variable_declaration(composite);
// Make a copy, then use access chain to store the variable.
statement(declare_temporary(result_type, id), to_expression(composite), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
auto chain = access_chain_internal(id, elems, length, true);
statement(chain, " = ", to_expression(obj), ";");
break;
}
case OpCopyMemory:
{
uint32_t lhs = ops[0];
uint32_t rhs = ops[1];
if (lhs != rhs)
{
flush_variable_declaration(lhs);
flush_variable_declaration(rhs);
statement(to_expression(lhs), " = ", to_expression(rhs), ";");
register_write(lhs);
}
break;
}
case OpCopyObject:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t rhs = ops[2];
bool pointer = get<SPIRType>(result_type).pointer;
if (expression_is_lvalue(rhs) && !pointer)
{
// Need a copy.
// For pointer types, we copy the pointer itself.
statement(declare_temporary(result_type, id), to_expression(rhs), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
}
else
{
// RHS expression is immutable, so just forward it.
// Copying these things really make no sense, but
// seems to be allowed anyways.
auto &e = set<SPIRExpression>(id, to_expression(rhs), result_type, true);
if (pointer)
{
auto *var = maybe_get_backing_variable(rhs);
e.loaded_from = var ? var->self : 0;
}
}
break;
}
case OpVectorShuffle:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t vec0 = ops[2];
uint32_t vec1 = ops[3];
const auto *elems = &ops[4];
length -= 4;
auto &type0 = expression_type(vec0);
bool shuffle = false;
for (uint32_t i = 0; i < length; i++)
if (elems[i] >= type0.vecsize)
shuffle = true;
string expr;
bool trivial_forward;
if (shuffle)
{
trivial_forward = !expression_is_forwarded(vec0) && !expression_is_forwarded(vec1);
// Constructor style and shuffling from two different vectors.
vector<string> args;
for (uint32_t i = 0; i < length; i++)
{
if (elems[i] >= type0.vecsize)
args.push_back(join(to_enclosed_expression(vec1), ".", index_to_swizzle(elems[i] - type0.vecsize)));
else
args.push_back(join(to_enclosed_expression(vec0), ".", index_to_swizzle(elems[i])));
}
expr += join(type_to_glsl_constructor(get<SPIRType>(result_type)), "(", merge(args), ")");
}
else
{
trivial_forward = !expression_is_forwarded(vec0);
// We only source from first vector, so can use swizzle.
expr += to_enclosed_expression(vec0);
expr += ".";
for (uint32_t i = 0; i < length; i++)
expr += index_to_swizzle(elems[i]);
if (backend.swizzle_is_function && length > 1)
expr += "()";
}
// A shuffle is trivial in that it doesn't actually *do* anything.
// We inherit the forwardedness from our arguments to avoid flushing out to temporaries when it's not really needed.
emit_op(result_type, id, expr, should_forward(vec0) && should_forward(vec1), trivial_forward);
break;
}
// ALU
case OpIsNan:
UFOP(isnan);
break;
case OpIsInf:
UFOP(isinf);
break;
case OpSNegate:
case OpFNegate:
UOP(-);
break;
case OpIAdd:
{
// For simple arith ops, prefer the output type if there's a mismatch to avoid extra bitcasts.
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST(+, type);
break;
}
case OpFAdd:
BOP(+);
break;
case OpISub:
{
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST(-, type);
break;
}
case OpFSub:
BOP(-);
break;
case OpIMul:
{
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST(*, type);
break;
}
case OpVectorTimesMatrix:
case OpMatrixTimesVector:
{
// If the matrix needs transpose, just flip the multiply order.
auto *e = maybe_get<SPIRExpression>(ops[opcode == OpMatrixTimesVector ? 2 : 3]);
if (e && e->need_transpose)
{
e->need_transpose = false;
emit_binary_op(ops[0], ops[1], ops[3], ops[2], "*");
e->need_transpose = true;
}
else
BOP(*);
break;
}
case OpFMul:
case OpMatrixTimesScalar:
case OpVectorTimesScalar:
case OpMatrixTimesMatrix:
BOP(*);
break;
case OpOuterProduct:
BFOP(outerProduct);
break;
case OpDot:
BFOP(dot);
break;
case OpTranspose:
UFOP(transpose);
break;
case OpSDiv:
BOP_CAST(/, SPIRType::Int);
break;
case OpUDiv:
BOP_CAST(/, SPIRType::UInt);
break;
case OpFDiv:
BOP(/);
break;
case OpShiftRightLogical:
BOP_CAST(>>, SPIRType::UInt);
break;
case OpShiftRightArithmetic:
BOP_CAST(>>, SPIRType::Int);
break;
case OpShiftLeftLogical:
{
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST(<<, type);
break;
}
case OpBitwiseOr:
{
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST(|, type);
break;
}
case OpBitwiseXor:
{
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST (^, type);
break;
}
case OpBitwiseAnd:
{
auto type = get<SPIRType>(ops[0]).basetype;
BOP_CAST(&, type);
break;
}
case OpNot:
UOP(~);
break;
case OpUMod:
BOP_CAST(%, SPIRType::UInt);
break;
case OpSMod:
BOP_CAST(%, SPIRType::Int);
break;
case OpFMod:
BFOP(mod);
break;
// Relational
case OpAny:
UFOP(any);
break;
case OpAll:
UFOP(all);
break;
case OpSelect:
emit_mix_op(ops[0], ops[1], ops[4], ops[3], ops[2]);
break;
case OpLogicalOr:
{
// No vector variant in GLSL for logical OR.
auto result_type = ops[0];
auto id = ops[1];
auto &type = get<SPIRType>(result_type);
if (type.vecsize > 1)
emit_unrolled_binary_op(result_type, id, ops[2], ops[3], "||");
else
BOP(||);
break;
}
case OpLogicalAnd:
{
// No vector variant in GLSL for logical AND.
auto result_type = ops[0];
auto id = ops[1];
auto &type = get<SPIRType>(result_type);
if (type.vecsize > 1)
emit_unrolled_binary_op(result_type, id, ops[2], ops[3], "&&");
else
BOP(&&);
break;
}
case OpLogicalNot:
{
auto &type = get<SPIRType>(ops[0]);
if (type.vecsize > 1)
UFOP(not);
else
UOP(!);
break;
}
case OpIEqual:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP_CAST(equal, SPIRType::Int);
else
BOP_CAST(==, SPIRType::Int);
break;
}
case OpLogicalEqual:
case OpFOrdEqual:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP(equal);
else
BOP(==);
break;
}
case OpINotEqual:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP_CAST(notEqual, SPIRType::Int);
else
BOP_CAST(!=, SPIRType::Int);
break;
}
case OpLogicalNotEqual:
case OpFOrdNotEqual:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP(notEqual);
else
BOP(!=);
break;
}
case OpUGreaterThan:
case OpSGreaterThan:
{
auto type = opcode == OpUGreaterThan ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
BFOP_CAST(greaterThan, type);
else
BOP_CAST(>, type);
break;
}
case OpFOrdGreaterThan:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP(greaterThan);
else
BOP(>);
break;
}
case OpUGreaterThanEqual:
case OpSGreaterThanEqual:
{
auto type = opcode == OpUGreaterThanEqual ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
BFOP_CAST(greaterThanEqual, type);
else
BOP_CAST(>=, type);
break;
}
case OpFOrdGreaterThanEqual:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP(greaterThanEqual);
else
BOP(>=);
break;
}
case OpULessThan:
case OpSLessThan:
{
auto type = opcode == OpULessThan ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
BFOP_CAST(lessThan, type);
else
BOP_CAST(<, type);
break;
}
case OpFOrdLessThan:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP(lessThan);
else
BOP(<);
break;
}
case OpULessThanEqual:
case OpSLessThanEqual:
{
auto type = opcode == OpULessThanEqual ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
BFOP_CAST(lessThanEqual, type);
else
BOP_CAST(<=, type);
break;
}
case OpFOrdLessThanEqual:
{
if (expression_type(ops[2]).vecsize > 1)
BFOP(lessThanEqual);
else
BOP(<=);
break;
}
// Conversion
case OpConvertFToU:
case OpConvertFToS:
case OpConvertSToF:
case OpConvertUToF:
case OpUConvert:
case OpSConvert:
case OpFConvert:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto func = type_to_glsl_constructor(get<SPIRType>(result_type));
emit_unary_func_op(result_type, id, ops[2], func.c_str());
break;
}
case OpBitcast:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t arg = ops[2];
auto op = bitcast_glsl_op(get<SPIRType>(result_type), expression_type(arg));
emit_unary_func_op(result_type, id, arg, op.c_str());
break;
}
case OpQuantizeToF16:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t arg = ops[2];
string op;
auto &type = get<SPIRType>(result_type);
switch (type.vecsize)
{
case 1:
op = join("unpackHalf2x16(packHalf2x16(vec2(", to_expression(arg), "))).x");
break;
case 2:
op = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), "))");
break;
case 3:
{
auto op0 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".xy))");
auto op1 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".zz)).x");
op = join("vec3(", op0, ", ", op1, ")");
break;
}
case 4:
{
auto op0 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".xy))");
auto op1 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".zw))");
op = join("vec4(", op0, ", ", op1, ")");
break;
}
default:
SPIRV_CROSS_THROW("Illegal argument to OpQuantizeToF16.");
}
emit_op(result_type, id, op, should_forward(arg));
break;
}
// Derivatives
case OpDPdx:
UFOP(dFdx);
if (is_legacy_es())
require_extension("GL_OES_standard_derivatives");
break;
case OpDPdy:
UFOP(dFdy);
if (is_legacy_es())
require_extension("GL_OES_standard_derivatives");
break;
case OpDPdxFine:
UFOP(dFdxFine);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension("GL_ARB_derivative_control");
break;
case OpDPdyFine:
UFOP(dFdyFine);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension("GL_ARB_derivative_control");
break;
case OpDPdxCoarse:
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
UFOP(dFdxCoarse);
if (options.version < 450)
require_extension("GL_ARB_derivative_control");
break;
case OpDPdyCoarse:
UFOP(dFdyCoarse);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension("GL_ARB_derivative_control");
break;
case OpFwidth:
UFOP(fwidth);
if (is_legacy_es())
require_extension("GL_OES_standard_derivatives");
break;
// Bitfield
case OpBitFieldInsert:
// TODO: The signedness of inputs is strict in GLSL, but not in SPIR-V, bitcast if necessary.
QFOP(bitfieldInsert);
break;
case OpBitFieldSExtract:
case OpBitFieldUExtract:
// TODO: The signedness of inputs is strict in GLSL, but not in SPIR-V, bitcast if necessary.
TFOP(bitfieldExtract);
break;
case OpBitReverse:
UFOP(bitfieldReverse);
break;
case OpBitCount:
UFOP(bitCount);
break;
// Atomics
case OpAtomicExchange:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
// Ignore semantics for now, probably only relevant to CL.
uint32_t val = ops[5];
const char *op = check_atomic_image(ptr) ? "imageAtomicExchange" : "atomicExchange";
forced_temporaries.insert(id);
emit_binary_func_op(result_type, id, ptr, val, op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicCompareExchange:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
uint32_t val = ops[6];
uint32_t comp = ops[7];
const char *op = check_atomic_image(ptr) ? "imageAtomicCompSwap" : "atomicCompSwap";
forced_temporaries.insert(id);
emit_trinary_func_op(result_type, id, ptr, comp, val, op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicLoad:
flush_all_atomic_capable_variables();
// FIXME: Image?
UFOP(atomicCounter);
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
// OpAtomicStore unimplemented. Not sure what would use that.
// OpAtomicLoad seems to only be relevant for atomic counters.
case OpAtomicIIncrement:
forced_temporaries.insert(ops[1]);
// FIXME: Image?
UFOP(atomicCounterIncrement);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
case OpAtomicIDecrement:
forced_temporaries.insert(ops[1]);
// FIXME: Image?
UFOP(atomicCounterDecrement);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
case OpAtomicIAdd:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicAdd" : "atomicAdd";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
case OpAtomicISub:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicAdd" : "atomicAdd";
forced_temporaries.insert(ops[1]);
auto expr = join(op, "(", to_expression(ops[2]), ", -", to_enclosed_expression(ops[5]), ")");
emit_op(ops[0], ops[1], expr, should_forward(ops[2]) && should_forward(ops[5]));
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
case OpAtomicSMin:
case OpAtomicUMin:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicMin" : "atomicMin";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
case OpAtomicSMax:
case OpAtomicUMax:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicMax" : "atomicMax";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
case OpAtomicAnd:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicAnd" : "atomicAnd";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
case OpAtomicOr:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicOr" : "atomicOr";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
case OpAtomicXor:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicXor" : "atomicXor";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
register_read(ops[1], ops[2], should_forward(ops[2]));
break;
}
// Geometry shaders
case OpEmitVertex:
statement("EmitVertex();");
break;
case OpEndPrimitive:
statement("EndPrimitive();");
break;
case OpEmitStreamVertex:
statement("EmitStreamVertex();");
break;
case OpEndStreamPrimitive:
statement("EndStreamPrimitive();");
break;
// Textures
case OpImageSampleExplicitLod:
case OpImageSampleProjExplicitLod:
case OpImageSampleDrefExplicitLod:
case OpImageSampleProjDrefExplicitLod:
case OpImageSampleImplicitLod:
case OpImageSampleProjImplicitLod:
case OpImageSampleDrefImplicitLod:
case OpImageSampleProjDrefImplicitLod:
case OpImageFetch:
case OpImageGather:
case OpImageDrefGather:
// Gets a bit hairy, so move this to a separate instruction.
emit_texture_op(instruction);
break;
case OpImage:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto &e = emit_op(result_type, id, to_expression(ops[2]), true);
// When using the image, we need to know which variable it is actually loaded from.
auto *var = maybe_get_backing_variable(ops[2]);
e.loaded_from = var ? var->self : 0;
break;
}
case OpImageQueryLod:
{
if (!options.es && options.version < 400)
{
require_extension("GL_ARB_texture_query_lod");
// For some reason, the ARB spec is all-caps.
BFOP(textureQueryLOD);
}
else if (options.es)
SPIRV_CROSS_THROW("textureQueryLod not supported in ES profile.");
else
BFOP(textureQueryLod);
break;
}
case OpImageQueryLevels:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
if (!options.es && options.version < 430)
require_extension("GL_ARB_texture_query_levels");
if (options.es)
SPIRV_CROSS_THROW("textureQueryLevels not supported in ES profile.");
auto expr = join("textureQueryLevels(", to_expression(ops[2]), ")");
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
break;
}
case OpImageQuerySamples:
{
auto &type = expression_type(ops[2]);
uint32_t result_type = ops[0];
uint32_t id = ops[1];
string expr;
if (type.image.sampled == 2)
expr = join("imageSamples(", to_expression(ops[2]), ")");
else
expr = join("textureSamples(", to_expression(ops[2]), ")");
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
break;
}
case OpSampledImage:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_sampled_image_op(result_type, id, ops[2], ops[3]);
break;
}
case OpImageQuerySizeLod:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto expr = join("textureSize(", to_expression(ops[2]), ", ", bitcast_expression(SPIRType::Int, ops[3]), ")");
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
break;
}
// Image load/store
case OpImageRead:
{
// We added Nonreadable speculatively to the OpImage variable due to glslangValidator
// not adding the proper qualifiers.
// If it turns out we need to read the image after all, remove the qualifier and recompile.
auto *var = maybe_get_backing_variable(ops[2]);
if (var)
{
auto &flags = meta.at(var->self).decoration.decoration_flags;
if (flags & (1ull << DecorationNonReadable))
{
flags &= ~(1ull << DecorationNonReadable);
force_recompile = true;
}
}
uint32_t result_type = ops[0];
uint32_t id = ops[1];
bool pure;
string imgexpr;
auto &type = expression_type(ops[2]);
if (var && var->remapped_variable) // Remapped input, just read as-is without any op-code
{
if (type.image.ms)
SPIRV_CROSS_THROW("Trying to remap multisampled image to variable, this is not possible.");
auto itr =
find_if(begin(pls_inputs), end(pls_inputs), [var](const PlsRemap &pls) { return pls.id == var->self; });
if (itr == end(pls_inputs))
{
// For non-PLS inputs, we rely on subpass type remapping information to get it right
// since ImageRead always returns 4-component vectors and the backing type is opaque.
if (!var->remapped_components)
SPIRV_CROSS_THROW("subpassInput was remapped, but remap_components is not set correctly.");
imgexpr = remap_swizzle(result_type, var->remapped_components, ops[2]);
}
else
{
// PLS input could have different number of components than what the SPIR expects, swizzle to
// the appropriate vector size.
uint32_t components = pls_format_to_components(itr->format);
imgexpr = remap_swizzle(result_type, components, ops[2]);
}
pure = true;
}
else if (type.image.dim == DimSubpassData)
{
if (options.vulkan_semantics)
{
// With Vulkan semantics, use the proper Vulkan GLSL construct.
if (type.image.ms)
{
uint32_t operands = ops[4];
if (operands != ImageOperandsSampleMask || length != 6)
SPIRV_CROSS_THROW(
"Multisampled image used in OpImageRead, but unexpected operand mask was used.");
uint32_t samples = ops[5];
imgexpr = join("subpassLoad(", to_expression(ops[2]), ", ", to_expression(samples), ")");
}
else
imgexpr = join("subpassLoad(", to_expression(ops[2]), ")");
}
else
{
if (type.image.ms)
{
uint32_t operands = ops[4];
if (operands != ImageOperandsSampleMask || length != 6)
SPIRV_CROSS_THROW(
"Multisampled image used in OpImageRead, but unexpected operand mask was used.");
uint32_t samples = ops[5];
imgexpr = join("texelFetch(", to_expression(ops[2]), ", ivec2(gl_FragCoord.xy), ",
to_expression(samples), ")");
}
else
{
// Implement subpass loads via texture barrier style sampling.
imgexpr = join("texelFetch(", to_expression(ops[2]), ", ivec2(gl_FragCoord.xy), 0)");
}
}
pure = true;
}
else
{
// Plain image load/store.
if (type.image.ms)
{
uint32_t operands = ops[4];
if (operands != ImageOperandsSampleMask || length != 6)
SPIRV_CROSS_THROW("Multisampled image used in OpImageRead, but unexpected operand mask was used.");
uint32_t samples = ops[5];
imgexpr = join("imageLoad(", to_expression(ops[2]), ", ", to_expression(ops[3]), ", ",
to_expression(samples), ")");
}
else
imgexpr = join("imageLoad(", to_expression(ops[2]), ", ", to_expression(ops[3]), ")");
pure = false;
}
if (var && var->forwardable)
{
auto &e = emit_op(result_type, id, imgexpr, true);
// We only need to track dependencies if we're reading from image load/store.
if (!pure)
{
e.loaded_from = var->self;
var->dependees.push_back(id);
}
}
else
emit_op(result_type, id, imgexpr, false);
break;
}
case OpImageTexelPointer:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto &e = set<SPIRExpression>(id, join(to_expression(ops[2]), ", ", to_expression(ops[3])), result_type, true);
// When using the pointer, we need to know which variable it is actually loaded from.
auto *var = maybe_get_backing_variable(ops[2]);
e.loaded_from = var ? var->self : 0;
break;
}
case OpImageWrite:
{
// We added Nonwritable speculatively to the OpImage variable due to glslangValidator
// not adding the proper qualifiers.
// If it turns out we need to write to the image after all, remove the qualifier and recompile.
auto *var = maybe_get_backing_variable(ops[0]);
if (var)
{
auto &flags = meta.at(var->self).decoration.decoration_flags;
if (flags & (1ull << DecorationNonWritable))
{
flags &= ~(1ull << DecorationNonWritable);
force_recompile = true;
}
}
auto &type = expression_type(ops[0]);
if (type.image.ms)
{
uint32_t operands = ops[3];
if (operands != ImageOperandsSampleMask || length != 5)
SPIRV_CROSS_THROW("Multisampled image used in OpImageWrite, but unexpected operand mask was used.");
uint32_t samples = ops[4];
statement("imageStore(", to_expression(ops[0]), ", ", to_expression(ops[1]), ", ", to_expression(samples),
", ", to_expression(ops[2]), ");");
}
else
statement("imageStore(", to_expression(ops[0]), ", ", to_expression(ops[1]), ", ", to_expression(ops[2]),
");");
if (var && variable_storage_is_aliased(*var))
flush_all_aliased_variables();
break;
}
case OpImageQuerySize:
{
auto &type = expression_type(ops[2]);
uint32_t result_type = ops[0];
uint32_t id = ops[1];
if (type.basetype == SPIRType::Image)
{
string expr;
if (type.image.sampled == 2)
{
// The size of an image is always constant.
expr = join("imageSize(", to_expression(ops[2]), ")");
}
else
{
// This path is hit for samplerBuffers and multisampled images which do not have LOD.
expr = join("textureSize(", to_expression(ops[2]), ")");
}
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
}
else
SPIRV_CROSS_THROW("Invalid type for OpImageQuerySize.");
break;
}
// Compute
case OpControlBarrier:
{
// Ignore execution and memory scope.
if (get_entry_point().model == ExecutionModelGLCompute)
{
uint32_t mem = get<SPIRConstant>(ops[2]).scalar();
if (mem == MemorySemanticsWorkgroupMemoryMask)
statement("memoryBarrierShared();");
else if (mem)
statement("memoryBarrier();");
}
statement("barrier();");
break;
}
case OpMemoryBarrier:
{
uint32_t mem = get<SPIRConstant>(ops[1]).scalar();
// We cannot forward any loads beyond the memory barrier.
if (mem)
flush_all_active_variables();
if (mem == MemorySemanticsWorkgroupMemoryMask)
statement("memoryBarrierShared();");
else if (mem)
statement("memoryBarrier();");
break;
}
case OpExtInst:
{
uint32_t extension_set = ops[2];
if (get<SPIRExtension>(extension_set).ext != SPIRExtension::GLSL)
{
statement("// unimplemented ext op ", instruction.op);
break;
}
emit_glsl_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
break;
}
default:
statement("// unimplemented op ", instruction.op);
break;
}
}
// Appends function arguments, mapped from global variables, beyond the specified arg index.
// This is used when a function call uses fewer arguments than the function defines.
// This situation may occur if the function signature has been dynamically modified to
// extract global variables referenced from within the function, and convert them to
// function arguments. This is necessary for shader languages that do not support global
// access to shader input content from within a function (eg. Metal). Each additional
// function args uses the name of the global variable. Function nesting will modify the
// functions and calls all the way up the nesting chain.
void CompilerGLSL::append_global_func_args(const SPIRFunction &func, uint32_t index, vector<string> &arglist)
{
auto &args = func.arguments;
uint32_t arg_cnt = uint32_t(args.size());
for (uint32_t arg_idx = index; arg_idx < arg_cnt; arg_idx++)
{
assert(args[arg_idx].alias_global_variable);
arglist.push_back(to_func_call_arg(args[arg_idx].id));
}
}
string CompilerGLSL::to_member_name(const SPIRType &type, uint32_t index)
{
auto &memb = meta[type.self].members;
if (index < memb.size() && !memb[index].alias.empty())
return memb[index].alias;
else
return join("_m", index);
}
void CompilerGLSL::add_member_name(SPIRType &type, uint32_t index)
{
auto &memb = meta[type.self].members;
if (index < memb.size() && !memb[index].alias.empty())
{
auto &name = memb[index].alias;
if (name.empty())
return;
// Reserved for temporaries.
if (name[0] == '_' && name.size() >= 2 && isdigit(name[1]))
{
name.clear();
return;
}
update_name_cache(type.member_name_cache, name);
}
}
// Checks whether the ID is a row_major matrix that requires conversion before use
bool CompilerGLSL::is_non_native_row_major_matrix(uint32_t id)
{
// Natively supported row-major matrices do not need to be converted.
// Legacy targets do not support row major.
if (backend.native_row_major_matrix && !is_legacy())
return false;
// Non-matrix or column-major matrix types do not need to be converted.
if (!(meta[id].decoration.decoration_flags & (1ull << DecorationRowMajor)))
return false;
// Only square row-major matrices can be converted at this time.
// Converting non-square matrices will require defining custom GLSL function that
// swaps matrix elements while retaining the original dimensional form of the matrix.
const auto type = expression_type(id);
if (type.columns != type.vecsize)
SPIRV_CROSS_THROW("Row-major matrices must be square on this platform.");
return true;
}
// Checks whether the member is a row_major matrix that requires conversion before use
bool CompilerGLSL::member_is_non_native_row_major_matrix(const SPIRType &type, uint32_t index)
{
// Natively supported row-major matrices do not need to be converted.
if (backend.native_row_major_matrix && !is_legacy())
return false;
// Non-matrix or column-major matrix types do not need to be converted.
if (!(combined_decoration_for_member(type, index) & (1ull << DecorationRowMajor)))
return false;
// Only square row-major matrices can be converted at this time.
// Converting non-square matrices will require defining custom GLSL function that
// swaps matrix elements while retaining the original dimensional form of the matrix.
const auto mbr_type = get<SPIRType>(type.member_types[index]);
if (mbr_type.columns != mbr_type.vecsize)
SPIRV_CROSS_THROW("Row-major matrices must be square on this platform.");
return true;
}
// Checks whether the member is in packed data type, that might need to be unpacked.
// GLSL does not define packed data types, but certain subclasses do.
bool CompilerGLSL::member_is_packed_type(const SPIRType &type, uint32_t index)
{
return has_member_decoration(type.self, index, DecorationCPacked);
}
// Wraps the expression string in a function call that converts the
// row_major matrix result of the expression to a column_major matrix.
// Base implementation uses the standard library transpose() function.
// Subclasses may override to use a different function.
string CompilerGLSL::convert_row_major_matrix(string exp_str)
{
strip_enclosed_expression(exp_str);
return join("transpose(", exp_str, ")");
}
string CompilerGLSL::variable_decl(const SPIRType &type, const string &name, uint32_t id)
{
string type_name = type_to_glsl(type, id);
remap_variable_type_name(type, name, type_name);
return join(type_name, " ", name, type_to_array_glsl(type));
}
// Emit a structure member. Subclasses may override to modify output,
// or to dynamically add a padding member if needed.
void CompilerGLSL::emit_struct_member(const SPIRType &type, uint32_t member_type_id, uint32_t index,
const string &qualifier)
{
auto &membertype = get<SPIRType>(member_type_id);
uint64_t memberflags = 0;
auto &memb = meta[type.self].members;
if (index < memb.size())
memberflags = memb[index].decoration_flags;
string qualifiers;
bool is_block = (meta[type.self].decoration.decoration_flags &
((1ull << DecorationBlock) | (1ull << DecorationBufferBlock))) != 0;
if (is_block)
qualifiers = to_interpolation_qualifiers(memberflags);
statement(layout_for_member(type, index), qualifiers, qualifier,
flags_to_precision_qualifiers_glsl(membertype, memberflags),
variable_decl(membertype, to_member_name(type, index)), ";");
}
const char *CompilerGLSL::flags_to_precision_qualifiers_glsl(const SPIRType &type, uint64_t flags)
{
if (options.es)
{
auto &execution = get_entry_point();
// Structs do not have precision qualifiers, neither do doubles (desktop only anyways, so no mediump/highp).
if (type.basetype != SPIRType::Float && type.basetype != SPIRType::Int && type.basetype != SPIRType::UInt &&
type.basetype != SPIRType::Image && type.basetype != SPIRType::SampledImage &&
type.basetype != SPIRType::Sampler)
return "";
if (flags & (1ull << DecorationRelaxedPrecision))
{
bool implied_fmediump = type.basetype == SPIRType::Float &&
options.fragment.default_float_precision == Options::Mediump &&
execution.model == ExecutionModelFragment;
bool implied_imediump = (type.basetype == SPIRType::Int || type.basetype == SPIRType::UInt) &&
options.fragment.default_int_precision == Options::Mediump &&
execution.model == ExecutionModelFragment;
return implied_fmediump || implied_imediump ? "" : "mediump ";
}
else
{
bool implied_fhighp =
type.basetype == SPIRType::Float && ((options.fragment.default_float_precision == Options::Highp &&
execution.model == ExecutionModelFragment) ||
(execution.model != ExecutionModelFragment));
bool implied_ihighp = (type.basetype == SPIRType::Int || type.basetype == SPIRType::UInt) &&
((options.fragment.default_int_precision == Options::Highp &&
execution.model == ExecutionModelFragment) ||
(execution.model != ExecutionModelFragment));
return implied_fhighp || implied_ihighp ? "" : "highp ";
}
}
else
return "";
}
const char *CompilerGLSL::to_precision_qualifiers_glsl(uint32_t id)
{
return flags_to_precision_qualifiers_glsl(expression_type(id), meta[id].decoration.decoration_flags);
}
string CompilerGLSL::to_qualifiers_glsl(uint32_t id)
{
auto flags = meta[id].decoration.decoration_flags;
string res;
auto *var = maybe_get<SPIRVariable>(id);
if (var && var->storage == StorageClassWorkgroup && !backend.shared_is_implied)
res += "shared ";
res += to_interpolation_qualifiers(flags);
if (var)
res += to_storage_qualifiers_glsl(*var);
auto &type = expression_type(id);
if (type.image.dim != DimSubpassData && type.image.sampled == 2)
{
if (flags & (1ull << DecorationCoherent))
res += "coherent ";
if (flags & (1ull << DecorationRestrict))
res += "restrict ";
if (flags & (1ull << DecorationNonWritable))
res += "readonly ";
if (flags & (1ull << DecorationNonReadable))
res += "writeonly ";
}
res += to_precision_qualifiers_glsl(id);
return res;
}
string CompilerGLSL::argument_decl(const SPIRFunction::Parameter &arg)
{
// glslangValidator seems to make all arguments pointer no matter what which is rather bizarre ...
auto &type = expression_type(arg.id);
const char *direction = "";
if (type.pointer)
{
if (arg.write_count && arg.read_count)
direction = "inout ";
else if (arg.write_count)
direction = "out ";
}
return join(direction, to_qualifiers_glsl(arg.id), variable_decl(type, to_name(arg.id), arg.id));
}
string CompilerGLSL::variable_decl(const SPIRVariable &variable)
{
// Ignore the pointer type since GLSL doesn't have pointers.
auto &type = get<SPIRType>(variable.basetype);
auto res = join(to_qualifiers_glsl(variable.self), variable_decl(type, to_name(variable.self), variable.self));
if (variable.loop_variable)
res += join(" = ", to_expression(variable.static_expression));
else if (variable.initializer)
res += join(" = ", to_expression(variable.initializer));
return res;
}
const char *CompilerGLSL::to_pls_qualifiers_glsl(const SPIRVariable &variable)
{
auto flags = meta[variable.self].decoration.decoration_flags;
if (flags & (1ull << DecorationRelaxedPrecision))
return "mediump ";
else
return "highp ";
}
string CompilerGLSL::pls_decl(const PlsRemap &var)
{
auto &variable = get<SPIRVariable>(var.id);
SPIRType type;
type.vecsize = pls_format_to_components(var.format);
type.basetype = pls_format_to_basetype(var.format);
return join(to_pls_layout(var.format), to_pls_qualifiers_glsl(variable), type_to_glsl(type), " ",
to_name(variable.self));
}
uint32_t CompilerGLSL::to_array_size_literal(const SPIRType &type, uint32_t index) const
{
assert(type.array.size() == type.array_size_literal.size());
if (!type.array_size_literal[index])
SPIRV_CROSS_THROW("The array size is not a literal, but a specialization constant or spec constant op.");
return type.array[index];
}
string CompilerGLSL::to_array_size(const SPIRType &type, uint32_t index)
{
assert(type.array.size() == type.array_size_literal.size());
auto &size = type.array[index];
if (!type.array_size_literal[index])
return to_expression(size);
else if (size)
return convert_to_string(size);
else if (!backend.flexible_member_array_supported)
{
// For runtime-sized arrays, we can work around
// lack of standard support for this by simply having
// a single element array.
//
// Runtime length arrays must always be the last element
// in an interface block.
return "1";
}
else
return "";
}
string CompilerGLSL::type_to_array_glsl(const SPIRType &type)
{
if (type.array.empty())
return "";
if (options.flatten_multidimensional_arrays)
{
string res;
res += "[";
for (auto i = uint32_t(type.array.size()); i; i--)
{
res += enclose_expression(to_array_size(type, i - 1));
if (i > 1)
res += " * ";
}
res += "]";
return res;
}
else
{
if (type.array.size() > 1)
{
if (!options.es && options.version < 430)
require_extension("GL_ARB_arrays_of_arrays");
else if (options.es && options.version < 310)
SPIRV_CROSS_THROW("Arrays of arrays not supported before ESSL version 310. "
"Try using --flatten-multidimensional-arrays or set "
"options.flatten_multidimensional_arrays to true.");
}
string res;
for (auto i = uint32_t(type.array.size()); i; i--)
{
res += "[";
res += to_array_size(type, i - 1);
res += "]";
}
return res;
}
}
string CompilerGLSL::image_type_glsl(const SPIRType &type, uint32_t /* id */)
{
auto &imagetype = get<SPIRType>(type.image.type);
string res;
switch (imagetype.basetype)
{
case SPIRType::Int:
res = "i";
break;
case SPIRType::UInt:
res = "u";
break;
default:
break;
}
if (type.basetype == SPIRType::Image && type.image.dim == DimSubpassData && options.vulkan_semantics)
return res + "subpassInput" + (type.image.ms ? "MS" : "");
// If we're emulating subpassInput with samplers, force sampler2D
// so we don't have to specify format.
if (type.basetype == SPIRType::Image && type.image.dim != DimSubpassData)
{
// Sampler buffers are always declared as samplerBuffer even though they might be separate images in the SPIR-V.
if (type.image.dim == DimBuffer && type.image.sampled == 1)
res += "sampler";
else
res += type.image.sampled == 2 ? "image" : "texture";
}
else
res += "sampler";
switch (type.image.dim)
{
case Dim1D:
res += "1D";
break;
case Dim2D:
res += "2D";
break;
case Dim3D:
res += "3D";
break;
case DimCube:
res += "Cube";
break;
case DimBuffer:
if (options.es && options.version < 320)
require_extension("GL_OES_texture_buffer");
else if (!options.es && options.version < 300)
require_extension("GL_EXT_texture_buffer_object");
res += "Buffer";
break;
case DimSubpassData:
res += "2D";
break;
default:
SPIRV_CROSS_THROW("Only 1D, 2D, 3D, Buffer, InputTarget and Cube textures supported.");
}
if (type.image.ms)
res += "MS";
if (type.image.arrayed)
{
if (is_legacy_desktop())
require_extension("GL_EXT_texture_array");
res += "Array";
}
if (type.image.depth)
res += "Shadow";
return res;
}
string CompilerGLSL::type_to_glsl_constructor(const SPIRType &type)
{
if (type.array.size() > 1)
{
if (options.flatten_multidimensional_arrays)
SPIRV_CROSS_THROW("Cannot flatten constructors of multidimensional array constructors, e.g. float[][]().");
else if (!options.es && options.version < 430)
require_extension("GL_ARB_arrays_of_arrays");
else if (options.es && options.version < 310)
SPIRV_CROSS_THROW("Arrays of arrays not supported before ESSL version 310.");
}
auto e = type_to_glsl(type);
for (uint32_t i = 0; i < type.array.size(); i++)
e += "[]";
return e;
}
// The optional id parameter indicates the object whose type we are trying
// to find the description for. It is optional. Most type descriptions do not
// depend on a specific object's use of that type.
string CompilerGLSL::type_to_glsl(const SPIRType &type, uint32_t id)
{
// Ignore the pointer type since GLSL doesn't have pointers.
switch (type.basetype)
{
case SPIRType::Struct:
// Need OpName lookup here to get a "sensible" name for a struct.
if (backend.explicit_struct_type)
return join("struct ", to_name(type.self));
else
return to_name(type.self);
case SPIRType::Image:
case SPIRType::SampledImage:
return image_type_glsl(type, id);
case SPIRType::Sampler:
// The depth field is set by calling code based on the variable ID of the sampler, effectively reintroducing
// this distinction into the type system.
return comparison_samplers.count(id) ? "samplerShadow" : "sampler";
case SPIRType::Void:
return "void";
default:
break;
}
if (type.vecsize == 1 && type.columns == 1) // Scalar builtin
{
switch (type.basetype)
{
case SPIRType::Boolean:
return "bool";
case SPIRType::Int:
return backend.basic_int_type;
case SPIRType::UInt:
return backend.basic_uint_type;
case SPIRType::AtomicCounter:
return "atomic_uint";
case SPIRType::Float:
return "float";
case SPIRType::Double:
return "double";
case SPIRType::Int64:
return "int64_t";
case SPIRType::UInt64:
return "uint64_t";
default:
return "???";
}
}
else if (type.vecsize > 1 && type.columns == 1) // Vector builtin
{
switch (type.basetype)
{
case SPIRType::Boolean:
return join("bvec", type.vecsize);
case SPIRType::Int:
return join("ivec", type.vecsize);
case SPIRType::UInt:
return join("uvec", type.vecsize);
case SPIRType::Float:
return join("vec", type.vecsize);
case SPIRType::Double:
return join("dvec", type.vecsize);
case SPIRType::Int64:
return join("i64vec", type.vecsize);
case SPIRType::UInt64:
return join("u64vec", type.vecsize);
default:
return "???";
}
}
else if (type.vecsize == type.columns) // Simple Matrix builtin
{
switch (type.basetype)
{
case SPIRType::Boolean:
return join("bmat", type.vecsize);
case SPIRType::Int:
return join("imat", type.vecsize);
case SPIRType::UInt:
return join("umat", type.vecsize);
case SPIRType::Float:
return join("mat", type.vecsize);
case SPIRType::Double:
return join("dmat", type.vecsize);
// Matrix types not supported for int64/uint64.
default:
return "???";
}
}
else
{
switch (type.basetype)
{
case SPIRType::Boolean:
return join("bmat", type.columns, "x", type.vecsize);
case SPIRType::Int:
return join("imat", type.columns, "x", type.vecsize);
case SPIRType::UInt:
return join("umat", type.columns, "x", type.vecsize);
case SPIRType::Float:
return join("mat", type.columns, "x", type.vecsize);
case SPIRType::Double:
return join("dmat", type.columns, "x", type.vecsize);
// Matrix types not supported for int64/uint64.
default:
return "???";
}
}
}
void CompilerGLSL::add_variable(unordered_set<string> &variables, uint32_t id)
{
auto &name = meta[id].decoration.alias;
if (name.empty())
return;
// Reserved for temporaries.
if (name[0] == '_' && name.size() >= 2 && isdigit(name[1]))
{
name.clear();
return;
}
update_name_cache(variables, name);
}
void CompilerGLSL::add_local_variable_name(uint32_t id)
{
add_variable(local_variable_names, id);
}
void CompilerGLSL::add_resource_name(uint32_t id)
{
add_variable(resource_names, id);
}
void CompilerGLSL::add_header_line(const std::string &line)
{
header_lines.push_back(line);
}
void CompilerGLSL::require_extension(const string &ext)
{
if (forced_extensions.find(ext) == end(forced_extensions))
{
forced_extensions.insert(ext);
force_recompile = true;
}
}
void CompilerGLSL::flatten_buffer_block(uint32_t id)
{
auto &var = get<SPIRVariable>(id);
auto &type = get<SPIRType>(var.basetype);
auto name = to_name(type.self, false);
auto flags = meta.at(type.self).decoration.decoration_flags;
if (!type.array.empty())
SPIRV_CROSS_THROW(name + " is an array of UBOs.");
if (type.basetype != SPIRType::Struct)
SPIRV_CROSS_THROW(name + " is not a struct.");
if ((flags & (1ull << DecorationBlock)) == 0)
SPIRV_CROSS_THROW(name + " is not a block.");
if (type.member_types.empty())
SPIRV_CROSS_THROW(name + " is an empty struct.");
flattened_buffer_blocks.insert(id);
}
bool CompilerGLSL::check_atomic_image(uint32_t id)
{
auto &type = expression_type(id);
if (type.storage == StorageClassImage)
{
if (options.es && options.version < 320)
require_extension("GL_OES_shader_image_atomic");
auto *var = maybe_get_backing_variable(id);
if (var)
{
auto &flags = meta.at(var->self).decoration.decoration_flags;
if (flags & ((1ull << DecorationNonWritable) | (1ull << DecorationNonReadable)))
{
flags &= ~(1ull << DecorationNonWritable);
flags &= ~(1ull << DecorationNonReadable);
force_recompile = true;
}
}
return true;
}
else
return false;
}
void CompilerGLSL::emit_function_prototype(SPIRFunction &func, uint64_t return_flags)
{
// Avoid shadow declarations.
local_variable_names = resource_names;
string decl;
auto &type = get<SPIRType>(func.return_type);
decl += flags_to_precision_qualifiers_glsl(type, return_flags);
decl += type_to_glsl(type);
decl += " ";
if (func.self == entry_point)
{
decl += clean_func_name("main");
processing_entry_point = true;
}
else
decl += clean_func_name(to_name(func.self));
decl += "(";
vector<string> arglist;
for (auto &arg : func.arguments)
{
// Do not pass in separate images or samplers if we're remapping
// to combined image samplers.
if (skip_argument(arg.id))
continue;
// Might change the variable name if it already exists in this function.
// SPIRV OpName doesn't have any semantic effect, so it's valid for an implementation
// to use same name for variables.
// Since we want to make the GLSL debuggable and somewhat sane, use fallback names for variables which are duplicates.
add_local_variable_name(arg.id);
arglist.push_back(argument_decl(arg));
// Hold a pointer to the parameter so we can invalidate the readonly field if needed.
auto *var = maybe_get<SPIRVariable>(arg.id);
if (var)
var->parameter = &arg;
}
for (auto &arg : func.shadow_arguments)
{
// Might change the variable name if it already exists in this function.
// SPIRV OpName doesn't have any semantic effect, so it's valid for an implementation
// to use same name for variables.
// Since we want to make the GLSL debuggable and somewhat sane, use fallback names for variables which are duplicates.
add_local_variable_name(arg.id);
arglist.push_back(argument_decl(arg));
// Hold a pointer to the parameter so we can invalidate the readonly field if needed.
auto *var = maybe_get<SPIRVariable>(arg.id);
if (var)
var->parameter = &arg;
}
decl += merge(arglist);
decl += ")";
statement(decl);
}
void CompilerGLSL::emit_function(SPIRFunction &func, uint64_t return_flags)
{
// Avoid potential cycles.
if (func.active)
return;
func.active = true;
// If we depend on a function, emit that function before we emit our own function.
for (auto block : func.blocks)
{
auto &b = get<SPIRBlock>(block);
for (auto &i : b.ops)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
if (op == OpFunctionCall)
{
// Recursively emit functions which are called.
uint32_t id = ops[2];
emit_function(get<SPIRFunction>(id), meta[ops[1]].decoration.decoration_flags);
}
}
}
emit_function_prototype(func, return_flags);
begin_scope();
current_function = &func;
auto &entry_block = get<SPIRBlock>(func.entry_block);
if (!func.analyzed_variable_scope)
{
if (options.cfg_analysis)
{
analyze_variable_scope(func);
// Check if we can actually use the loop variables we found in analyze_variable_scope.
// To use multiple initializers, we need the same type and qualifiers.
for (auto block : func.blocks)
{
auto &b = get<SPIRBlock>(block);
if (b.loop_variables.size() < 2)
continue;
uint64_t flags = get_decoration_mask(b.loop_variables.front());
uint32_t type = get<SPIRVariable>(b.loop_variables.front()).basetype;
bool invalid_initializers = false;
for (auto loop_variable : b.loop_variables)
{
if (flags != get_decoration_mask(loop_variable) ||
type != get<SPIRVariable>(b.loop_variables.front()).basetype)
{
invalid_initializers = true;
break;
}
}
if (invalid_initializers)
{
for (auto loop_variable : b.loop_variables)
get<SPIRVariable>(loop_variable).loop_variable = false;
b.loop_variables.clear();
}
}
}
else
entry_block.dominated_variables = func.local_variables;
func.analyzed_variable_scope = true;
}
for (auto &v : func.local_variables)
{
auto &var = get<SPIRVariable>(v);
if (expression_is_lvalue(v))
{
add_local_variable_name(var.self);
if (var.initializer)
statement(variable_decl_function_local(var), ";");
else
{
// Don't declare variable until first use to declutter the GLSL output quite a lot.
// If we don't touch the variable before first branch,
// declare it then since we need variable declaration to be in top scope.
var.deferred_declaration = true;
}
}
else
{
// HACK: SPIRV likes to use samplers and images as local variables, but GLSL does not allow this.
// For these types (non-lvalue), we enforce forwarding through a shadowed variable.
// This means that when we OpStore to these variables, we just write in the expression ID directly.
// This breaks any kind of branching, since the variable must be statically assigned.
// Branching on samplers and images would be pretty much impossible to fake in GLSL.
var.statically_assigned = true;
}
var.loop_variable_enable = false;
// Loop variables are never declared outside their for-loop, so block any implicit declaration.
if (var.loop_variable)
var.deferred_declaration = false;
}
entry_block.loop_dominator = SPIRBlock::NoDominator;
emit_block_chain(entry_block);
end_scope();
processing_entry_point = false;
statement("");
}
void CompilerGLSL::emit_fixup()
{
auto &execution = get_entry_point();
if (execution.model == ExecutionModelVertex)
{
if (options.vertex.fixup_clipspace)
{
const char *suffix = backend.float_literal_suffix ? "f" : "";
statement("gl_Position.z = 2.0", suffix, " * gl_Position.z - gl_Position.w;");
}
if (options.vertex.flip_vert_y)
statement("gl_Position.y = -gl_Position.y;");
}
}
bool CompilerGLSL::flush_phi_required(uint32_t from, uint32_t to)
{
auto &child = get<SPIRBlock>(to);
for (auto &phi : child.phi_variables)
if (phi.parent == from)
return true;
return false;
}
void CompilerGLSL::flush_phi(uint32_t from, uint32_t to)
{
auto &child = get<SPIRBlock>(to);
for (auto &phi : child.phi_variables)
if (phi.parent == from)
statement(to_expression(phi.function_variable), " = ", to_expression(phi.local_variable), ";");
}
void CompilerGLSL::branch(uint32_t from, uint32_t to)
{
flush_phi(from, to);
flush_all_active_variables();
// This is only a continue if we branch to our loop dominator.
if (loop_blocks.find(to) != end(loop_blocks) && get<SPIRBlock>(from).loop_dominator == to)
{
// This can happen if we had a complex continue block which was emitted.
// Once the continue block tries to branch to the loop header, just emit continue;
// and end the chain here.
statement("continue;");
}
else if (is_continue(to))
{
auto &to_block = get<SPIRBlock>(to);
if (to_block.complex_continue)
{
// Just emit the whole block chain as is.
auto usage_counts = expression_usage_counts;
auto invalid = invalid_expressions;
emit_block_chain(to_block);
// Expression usage counts and invalid expressions
// are moot after returning from the continue block.
// Since we emit the same block multiple times,
// we don't want to invalidate ourselves.
expression_usage_counts = usage_counts;
invalid_expressions = invalid;
}
else
{
auto &from_block = get<SPIRBlock>(from);
auto &dominator = get<SPIRBlock>(from_block.loop_dominator);
// For non-complex continue blocks, we implicitly branch to the continue block
// by having the continue block be part of the loop header in for (; ; continue-block).
bool outside_control_flow = block_is_outside_flow_control_from_block(dominator, from_block);
// Some simplification for for-loops. We always end up with a useless continue;
// statement since we branch to a loop block.
// Walk the CFG, if we uncoditionally execute the block calling continue assuming we're in the loop block,
// we can avoid writing out an explicit continue statement.
// Similar optimization to return statements if we know we're outside flow control.
if (!outside_control_flow)
statement("continue;");
}
}
else if (is_break(to))
statement("break;");
else if (!is_conditional(to))
emit_block_chain(get<SPIRBlock>(to));
}
void CompilerGLSL::branch(uint32_t from, uint32_t cond, uint32_t true_block, uint32_t false_block)
{
// If we branch directly to a selection merge target, we don't really need a code path.
bool true_sub = !is_conditional(true_block);
bool false_sub = !is_conditional(false_block);
if (true_sub)
{
statement("if (", to_expression(cond), ")");
begin_scope();
branch(from, true_block);
end_scope();
if (false_sub)
{
statement("else");
begin_scope();
branch(from, false_block);
end_scope();
}
else if (flush_phi_required(from, false_block))
{
statement("else");
begin_scope();
flush_phi(from, false_block);
end_scope();
}
}
else if (false_sub && !true_sub)
{
// Only need false path, use negative conditional.
statement("if (!", to_expression(cond), ")");
begin_scope();
branch(from, false_block);
end_scope();
if (flush_phi_required(from, true_block))
{
statement("else");
begin_scope();
flush_phi(from, true_block);
end_scope();
}
}
}
void CompilerGLSL::propagate_loop_dominators(const SPIRBlock &block)
{
// Propagate down the loop dominator block, so that dominated blocks can back trace.
if (block.merge == SPIRBlock::MergeLoop || block.loop_dominator)
{
uint32_t dominator = block.merge == SPIRBlock::MergeLoop ? block.self : block.loop_dominator;
auto set_dominator = [this](uint32_t self, uint32_t new_dominator) {
auto &dominated_block = this->get<SPIRBlock>(self);
// If we already have a loop dominator, we're trying to break out to merge targets
// which should not update the loop dominator.
if (!dominated_block.loop_dominator)
dominated_block.loop_dominator = new_dominator;
};
// After merging a loop, we inherit the loop dominator always.
if (block.merge_block)
set_dominator(block.merge_block, block.loop_dominator);
if (block.true_block)
set_dominator(block.true_block, dominator);
if (block.false_block)
set_dominator(block.false_block, dominator);
if (block.next_block)
set_dominator(block.next_block, dominator);
for (auto &c : block.cases)
set_dominator(c.block, dominator);
// In older glslang output continue_block can be == loop header.
if (block.continue_block && block.continue_block != block.self)
set_dominator(block.continue_block, dominator);
}
}
// FIXME: This currently cannot handle complex continue blocks
// as in do-while.
// This should be seen as a "trivial" continue block.
string CompilerGLSL::emit_continue_block(uint32_t continue_block)
{
auto *block = &get<SPIRBlock>(continue_block);
// While emitting the continue block, declare_temporary will check this
// if we have to emit temporaries.
current_continue_block = block;
vector<string> statements;
// Capture all statements into our list.
auto *old = redirect_statement;
redirect_statement = &statements;
// Stamp out all blocks one after each other.
while (loop_blocks.find(block->self) == end(loop_blocks))
{
propagate_loop_dominators(*block);
// Write out all instructions we have in this block.
for (auto &op : block->ops)
emit_instruction(op);
// For plain branchless for/while continue blocks.
if (block->next_block)
{
flush_phi(continue_block, block->next_block);
block = &get<SPIRBlock>(block->next_block);
}
// For do while blocks. The last block will be a select block.
else if (block->true_block)
{
flush_phi(continue_block, block->true_block);
block = &get<SPIRBlock>(block->true_block);
}
}
// Restore old pointer.
redirect_statement = old;
// Somewhat ugly, strip off the last ';' since we use ',' instead.
// Ideally, we should select this behavior in statement().
for (auto &s : statements)
{
if (!s.empty() && s.back() == ';')
s.erase(s.size() - 1, 1);
}
current_continue_block = nullptr;
return merge(statements);
}
string CompilerGLSL::emit_for_loop_initializers(const SPIRBlock &block)
{
if (block.loop_variables.empty())
return "";
if (block.loop_variables.size() == 1)
{
return variable_decl(get<SPIRVariable>(block.loop_variables.front()));
}
else
{
auto &var = get<SPIRVariable>(block.loop_variables.front());
auto &type = get<SPIRType>(var.basetype);
// Don't remap the type here as we have multiple names,
// doesn't make sense to remap types for loop variables anyways.
// It is assumed here that all relevant qualifiers are equal for all loop variables.
string expr = join(to_qualifiers_glsl(var.self), type_to_glsl(type), " ");
for (auto &loop_var : block.loop_variables)
{
auto &v = get<SPIRVariable>(loop_var);
expr += join(to_name(loop_var), " = ", to_expression(v.static_expression));
if (&loop_var != &block.loop_variables.back())
expr += ", ";
}
return expr;
}
}
bool CompilerGLSL::attempt_emit_loop_header(SPIRBlock &block, SPIRBlock::Method method)
{
SPIRBlock::ContinueBlockType continue_type = continue_block_type(get<SPIRBlock>(block.continue_block));
if (method == SPIRBlock::MergeToSelectForLoop)
{
uint32_t current_count = statement_count;
// If we're trying to create a true for loop,
// we need to make sure that all opcodes before branch statement do not actually emit any code.
// We can then take the condition expression and create a for (; cond ; ) { body; } structure instead.
for (auto &op : block.ops)
emit_instruction(op);
bool condition_is_temporary = forced_temporaries.find(block.condition) == end(forced_temporaries);
// This can work! We only did trivial things which could be forwarded in block body!
if (current_count == statement_count && condition_is_temporary)
{
switch (continue_type)
{
case SPIRBlock::ForLoop:
{
// Important that we do this in this order because
// emitting the continue block can invalidate the condition expression.
auto initializer = emit_for_loop_initializers(block);
auto condition = to_expression(block.condition);
auto continue_block = emit_continue_block(block.continue_block);
statement("for (", initializer, "; ", condition, "; ", continue_block, ")");
break;
}
case SPIRBlock::WhileLoop:
statement("while (", to_expression(block.condition), ")");
break;
default:
SPIRV_CROSS_THROW("For/while loop detected, but need while/for loop semantics.");
}
begin_scope();
return true;
}
else
{
block.disable_block_optimization = true;
force_recompile = true;
begin_scope(); // We'll see an end_scope() later.
return false;
}
}
else if (method == SPIRBlock::MergeToDirectForLoop)
{
auto &child = get<SPIRBlock>(block.next_block);
// This block may be a dominating block, so make sure we flush undeclared variables before building the for loop header.
flush_undeclared_variables(child);
uint32_t current_count = statement_count;
// If we're trying to create a true for loop,
// we need to make sure that all opcodes before branch statement do not actually emit any code.
// We can then take the condition expression and create a for (; cond ; ) { body; } structure instead.
for (auto &op : child.ops)
emit_instruction(op);
bool condition_is_temporary = forced_temporaries.find(child.condition) == end(forced_temporaries);
if (current_count == statement_count && condition_is_temporary)
{
propagate_loop_dominators(child);
switch (continue_type)
{
case SPIRBlock::ForLoop:
{
// Important that we do this in this order because
// emitting the continue block can invalidate the condition expression.
auto initializer = emit_for_loop_initializers(block);
auto condition = to_expression(child.condition);
auto continue_block = emit_continue_block(block.continue_block);
statement("for (", initializer, "; ", condition, "; ", continue_block, ")");
break;
}
case SPIRBlock::WhileLoop:
statement("while (", to_expression(child.condition), ")");
break;
default:
SPIRV_CROSS_THROW("For/while loop detected, but need while/for loop semantics.");
}
begin_scope();
branch(child.self, child.true_block);
return true;
}
else
{
block.disable_block_optimization = true;
force_recompile = true;
begin_scope(); // We'll see an end_scope() later.
return false;
}
}
else
return false;
}
void CompilerGLSL::flush_undeclared_variables(SPIRBlock &block)
{
for (auto &v : block.dominated_variables)
{
auto &var = get<SPIRVariable>(v);
if (var.deferred_declaration)
statement(variable_decl(var), ";");
var.deferred_declaration = false;
}
}
void CompilerGLSL::emit_block_chain(SPIRBlock &block)
{
propagate_loop_dominators(block);
bool select_branch_to_true_block = false;
bool skip_direct_branch = false;
bool emitted_for_loop_header = false;
// If we need to force temporaries for certain IDs due to continue blocks, do it before starting loop header.
for (auto &tmp : block.declare_temporary)
{
auto flags = meta[tmp.second].decoration.decoration_flags;
auto &type = get<SPIRType>(tmp.first);
statement(flags_to_precision_qualifiers_glsl(type, flags), variable_decl(type, to_name(tmp.second)), ";");
}
SPIRBlock::ContinueBlockType continue_type = SPIRBlock::ContinueNone;
if (block.continue_block)
continue_type = continue_block_type(get<SPIRBlock>(block.continue_block));
// If we have loop variables, stop masking out access to the variable now.
for (auto var : block.loop_variables)
get<SPIRVariable>(var).loop_variable_enable = true;
// This is the older loop behavior in glslang which branches to loop body directly from the loop header.
if (block_is_loop_candidate(block, SPIRBlock::MergeToSelectForLoop))
{
flush_undeclared_variables(block);
if (attempt_emit_loop_header(block, SPIRBlock::MergeToSelectForLoop))
{
// The body of while, is actually just the true block, so always branch there unconditionally.
select_branch_to_true_block = true;
emitted_for_loop_header = true;
}
}
// This is the newer loop behavior in glslang which branches from Loop header directly to
// a new block, which in turn has a OpBranchSelection without a selection merge.
else if (block_is_loop_candidate(block, SPIRBlock::MergeToDirectForLoop))
{
flush_undeclared_variables(block);
if (attempt_emit_loop_header(block, SPIRBlock::MergeToDirectForLoop))
{
skip_direct_branch = true;
emitted_for_loop_header = true;
}
}
else if (continue_type == SPIRBlock::DoWhileLoop)
{
statement("do");
begin_scope();
for (auto &op : block.ops)
emit_instruction(op);
}
else if (block.merge == SPIRBlock::MergeLoop)
{
flush_undeclared_variables(block);
// We have a generic loop without any distinguishable pattern like for, while or do while.
get<SPIRBlock>(block.continue_block).complex_continue = true;
continue_type = SPIRBlock::ComplexLoop;
statement("for (;;)");
begin_scope();
for (auto &op : block.ops)
emit_instruction(op);
}
else
{
for (auto &op : block.ops)
emit_instruction(op);
}
// If we didn't successfully emit a loop header and we had loop variable candidates, we have a problem
// as writes to said loop variables might have been masked out, we need a recompile.
if (!emitted_for_loop_header && !block.loop_variables.empty())
{
force_recompile = true;
for (auto var : block.loop_variables)
get<SPIRVariable>(var).loop_variable = false;
block.loop_variables.clear();
}
flush_undeclared_variables(block);
bool emit_next_block = true;
// Handle end of block.
switch (block.terminator)
{
case SPIRBlock::Direct:
// True when emitting complex continue block.
if (block.loop_dominator == block.next_block)
{
branch(block.self, block.next_block);
emit_next_block = false;
}
// True if MergeToDirectForLoop succeeded.
else if (skip_direct_branch)
emit_next_block = false;
else if (is_continue(block.next_block) || is_break(block.next_block) || is_conditional(block.next_block))
{
branch(block.self, block.next_block);
emit_next_block = false;
}
break;
case SPIRBlock::Select:
// True if MergeToSelectForLoop succeeded.
if (select_branch_to_true_block)
branch(block.self, block.true_block);
else
branch(block.self, block.condition, block.true_block, block.false_block);
break;
case SPIRBlock::MultiSelect:
{
auto &type = expression_type(block.condition);
bool uint32_t_case = type.basetype == SPIRType::UInt;
statement("switch (", to_expression(block.condition), ")");
begin_scope();
for (auto &c : block.cases)
{
auto case_value =
uint32_t_case ? convert_to_string(uint32_t(c.value)) : convert_to_string(int32_t(c.value));
statement("case ", case_value, ":");
begin_scope();
branch(block.self, c.block);
end_scope();
}
if (block.default_block != block.next_block)
{
statement("default:");
begin_scope();
if (is_break(block.default_block))
SPIRV_CROSS_THROW("Cannot break; out of a switch statement and out of a loop at the same time ...");
branch(block.self, block.default_block);
end_scope();
}
else if (flush_phi_required(block.self, block.next_block))
{
statement("default:");
begin_scope();
flush_phi(block.self, block.next_block);
statement("break;");
end_scope();
}
end_scope();
break;
}
case SPIRBlock::Return:
if (processing_entry_point)
emit_fixup();
if (block.return_value)
{
// OpReturnValue can return Undef, so don't emit anything for this case.
if (ids.at(block.return_value).get_type() != TypeUndef)
statement("return ", to_expression(block.return_value), ";");
}
// If this block is the very final block and not called from control flow,
// we do not need an explicit return which looks out of place. Just end the function here.
// In the very weird case of for(;;) { return; } executing return is unconditional,
// but we actually need a return here ...
else if (!block_is_outside_flow_control_from_block(get<SPIRBlock>(current_function->entry_block), block) ||
block.loop_dominator != SPIRBlock::NoDominator)
statement("return;");
break;
case SPIRBlock::Kill:
statement(backend.discard_literal, ";");
break;
default:
SPIRV_CROSS_THROW("Unimplemented block terminator.");
}
if (block.next_block && emit_next_block)
{
// If we hit this case, we're dealing with an unconditional branch, which means we will output
// that block after this. If we had selection merge, we already flushed phi variables.
if (block.merge != SPIRBlock::MergeSelection)
flush_phi(block.self, block.next_block);
emit_block_chain(get<SPIRBlock>(block.next_block));
}
if (block.merge == SPIRBlock::MergeLoop)
{
if (continue_type == SPIRBlock::DoWhileLoop)
{
// Make sure that we run the continue block to get the expressions set, but this
// should become an empty string.
// We have no fallbacks if we cannot forward everything to temporaries ...
auto statements = emit_continue_block(block.continue_block);
if (!statements.empty())
{
// The DoWhile block has side effects, force ComplexLoop pattern next pass.
get<SPIRBlock>(block.continue_block).complex_continue = true;
force_recompile = true;
}
end_scope_decl(join("while (", to_expression(get<SPIRBlock>(block.continue_block).condition), ")"));
}
else
end_scope();
flush_phi(block.self, block.merge_block);
emit_block_chain(get<SPIRBlock>(block.merge_block));
}
}
void CompilerGLSL::begin_scope()
{
statement("{");
indent++;
}
void CompilerGLSL::end_scope()
{
if (!indent)
SPIRV_CROSS_THROW("Popping empty indent stack.");
indent--;
statement("}");
}
void CompilerGLSL::end_scope_decl()
{
if (!indent)
SPIRV_CROSS_THROW("Popping empty indent stack.");
indent--;
statement("};");
}
void CompilerGLSL::end_scope_decl(const string &decl)
{
if (!indent)
SPIRV_CROSS_THROW("Popping empty indent stack.");
indent--;
statement("} ", decl, ";");
}
void CompilerGLSL::check_function_call_constraints(const uint32_t *args, uint32_t length)
{
// If our variable is remapped, and we rely on type-remapping information as
// well, then we cannot pass the variable as a function parameter.
// Fixing this is non-trivial without stamping out variants of the same function,
// so for now warn about this and suggest workarounds instead.
for (uint32_t i = 0; i < length; i++)
{
auto *var = maybe_get<SPIRVariable>(args[i]);
if (!var || !var->remapped_variable)
continue;
auto &type = get<SPIRType>(var->basetype);
if (type.basetype == SPIRType::Image && type.image.dim == DimSubpassData)
{
SPIRV_CROSS_THROW("Tried passing a remapped subpassInput variable to a function. "
"This will not work correctly because type-remapping information is lost. "
"To workaround, please consider not passing the subpass input as a function parameter, "
"or use in/out variables instead which do not need type remapping information.");
}
}
}
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