SPIRV-Cross/spirv_cross.cpp
Hans-Kristian Arntzen d4e470babd Analyze the CFG for temporaries as well.
Normally, temporary declaration must dominate any use of it,
so we generally did not need to analyze the CFG for these variables,
but there is an edge case where you have an inliner doing:

do {
	create_temporary;
	break;
} while(0);

use_temporary;

The inside of the loop dominates the outer scope, but we cannot emit
code like this in GLSL, so make sure we hoist these temporaries outside
the "loop".
2018-01-12 10:56:11 +01:00

3887 lines
103 KiB
C++

/*
* 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_cross.hpp"
#include "GLSL.std.450.h"
#include "spirv_cfg.hpp"
#include <algorithm>
#include <cstring>
#include <utility>
using namespace std;
using namespace spv;
using namespace spirv_cross;
#define log(...) fprintf(stderr, __VA_ARGS__)
static string ensure_valid_identifier(const string &name, bool member)
{
// Functions in glslangValidator are mangled with name(<mangled> stuff.
// Normally, we would never see '(' in any legal identifiers, so just strip them out.
auto str = name.substr(0, name.find('('));
for (uint32_t i = 0; i < str.size(); i++)
{
auto &c = str[i];
if (member)
{
// _m<num> variables are reserved by the internal implementation,
// otherwise, make sure the name is a valid identifier.
if (i == 0)
c = isalpha(c) ? c : '_';
else if (i == 2 && str[0] == '_' && str[1] == 'm')
c = isalpha(c) ? c : '_';
else
c = isalnum(c) ? c : '_';
}
else
{
// _<num> variables are reserved by the internal implementation,
// otherwise, make sure the name is a valid identifier.
if (i == 0 || (str[0] == '_' && i == 1))
c = isalpha(c) ? c : '_';
else
c = isalnum(c) ? c : '_';
}
}
return str;
}
Instruction::Instruction(const vector<uint32_t> &spirv, uint32_t &index)
{
op = spirv[index] & 0xffff;
count = (spirv[index] >> 16) & 0xffff;
if (count == 0)
SPIRV_CROSS_THROW("SPIR-V instructions cannot consume 0 words. Invalid SPIR-V file.");
offset = index + 1;
length = count - 1;
index += count;
if (index > spirv.size())
SPIRV_CROSS_THROW("SPIR-V instruction goes out of bounds.");
}
Compiler::Compiler(vector<uint32_t> ir)
: spirv(move(ir))
{
parse();
}
Compiler::Compiler(const uint32_t *ir, size_t word_count)
: spirv(ir, ir + word_count)
{
parse();
}
string Compiler::compile()
{
// Force a classic "C" locale, reverts when function returns
ClassicLocale classic_locale;
return "";
}
bool Compiler::variable_storage_is_aliased(const SPIRVariable &v)
{
auto &type = get<SPIRType>(v.basetype);
bool ssbo = v.storage == StorageClassStorageBuffer ||
((meta[type.self].decoration.decoration_flags & (1ull << DecorationBufferBlock)) != 0);
bool image = type.basetype == SPIRType::Image;
bool counter = type.basetype == SPIRType::AtomicCounter;
bool is_restrict = (meta[v.self].decoration.decoration_flags & (1ull << DecorationRestrict)) != 0;
return !is_restrict && (ssbo || image || counter);
}
bool Compiler::block_is_pure(const SPIRBlock &block)
{
for (auto &i : block.ops)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
switch (op)
{
case OpFunctionCall:
{
uint32_t func = ops[2];
if (!function_is_pure(get<SPIRFunction>(func)))
return false;
break;
}
case OpCopyMemory:
case OpStore:
{
auto &type = expression_type(ops[0]);
if (type.storage != StorageClassFunction)
return false;
break;
}
case OpImageWrite:
return false;
// Atomics are impure.
case OpAtomicLoad:
case OpAtomicStore:
case OpAtomicExchange:
case OpAtomicCompareExchange:
case OpAtomicCompareExchangeWeak:
case OpAtomicIIncrement:
case OpAtomicIDecrement:
case OpAtomicIAdd:
case OpAtomicISub:
case OpAtomicSMin:
case OpAtomicUMin:
case OpAtomicSMax:
case OpAtomicUMax:
case OpAtomicAnd:
case OpAtomicOr:
case OpAtomicXor:
return false;
// Geometry shader builtins modify global state.
case OpEndPrimitive:
case OpEmitStreamVertex:
case OpEndStreamPrimitive:
case OpEmitVertex:
return false;
// Barriers disallow any reordering, so we should treat blocks with barrier as writing.
case OpControlBarrier:
case OpMemoryBarrier:
return false;
// OpExtInst is potentially impure depending on extension, but GLSL builtins are at least pure.
default:
break;
}
}
return true;
}
string Compiler::to_name(uint32_t id, bool allow_alias) const
{
if (allow_alias && ids.at(id).get_type() == TypeType)
{
// If this type is a simple alias, emit the
// name of the original type instead.
// We don't want to override the meta alias
// as that can be overridden by the reflection APIs after parse.
auto &type = get<SPIRType>(id);
if (type.type_alias)
return to_name(type.type_alias);
}
if (meta[id].decoration.alias.empty())
return join("_", id);
else
return meta.at(id).decoration.alias;
}
bool Compiler::function_is_pure(const SPIRFunction &func)
{
for (auto block : func.blocks)
{
if (!block_is_pure(get<SPIRBlock>(block)))
{
//fprintf(stderr, "Function %s is impure!\n", to_name(func.self).c_str());
return false;
}
}
//fprintf(stderr, "Function %s is pure!\n", to_name(func.self).c_str());
return true;
}
void Compiler::register_global_read_dependencies(const SPIRBlock &block, uint32_t id)
{
for (auto &i : block.ops)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
switch (op)
{
case OpFunctionCall:
{
uint32_t func = ops[2];
register_global_read_dependencies(get<SPIRFunction>(func), id);
break;
}
case OpLoad:
case OpImageRead:
{
// If we're in a storage class which does not get invalidated, adding dependencies here is no big deal.
auto *var = maybe_get_backing_variable(ops[2]);
if (var && var->storage != StorageClassFunction)
{
auto &type = get<SPIRType>(var->basetype);
// InputTargets are immutable.
if (type.basetype != SPIRType::Image && type.image.dim != DimSubpassData)
var->dependees.push_back(id);
}
break;
}
default:
break;
}
}
}
void Compiler::register_global_read_dependencies(const SPIRFunction &func, uint32_t id)
{
for (auto block : func.blocks)
register_global_read_dependencies(get<SPIRBlock>(block), id);
}
SPIRVariable *Compiler::maybe_get_backing_variable(uint32_t chain)
{
auto *var = maybe_get<SPIRVariable>(chain);
if (!var)
{
auto *cexpr = maybe_get<SPIRExpression>(chain);
if (cexpr)
var = maybe_get<SPIRVariable>(cexpr->loaded_from);
auto *access_chain = maybe_get<SPIRAccessChain>(chain);
if (access_chain)
var = maybe_get<SPIRVariable>(access_chain->loaded_from);
}
return var;
}
void Compiler::register_read(uint32_t expr, uint32_t chain, bool forwarded)
{
auto &e = get<SPIRExpression>(expr);
auto *var = maybe_get_backing_variable(chain);
if (var)
{
e.loaded_from = var->self;
// If the backing variable is immutable, we do not need to depend on the variable.
if (forwarded && !is_immutable(var->self))
var->dependees.push_back(e.self);
// If we load from a parameter, make sure we create "inout" if we also write to the parameter.
// The default is "in" however, so we never invalidate our compilation by reading.
if (var && var->parameter)
var->parameter->read_count++;
}
}
void Compiler::register_write(uint32_t chain)
{
auto *var = maybe_get<SPIRVariable>(chain);
if (!var)
{
// If we're storing through an access chain, invalidate the backing variable instead.
auto *expr = maybe_get<SPIRExpression>(chain);
if (expr && expr->loaded_from)
var = maybe_get<SPIRVariable>(expr->loaded_from);
auto *access_chain = maybe_get<SPIRAccessChain>(chain);
if (access_chain && access_chain->loaded_from)
var = maybe_get<SPIRVariable>(access_chain->loaded_from);
}
if (var)
{
// If our variable is in a storage class which can alias with other buffers,
// invalidate all variables which depend on aliased variables.
if (variable_storage_is_aliased(*var))
flush_all_aliased_variables();
else if (var)
flush_dependees(*var);
// We tried to write to a parameter which is not marked with out qualifier, force a recompile.
if (var->parameter && var->parameter->write_count == 0)
{
var->parameter->write_count++;
force_recompile = true;
}
}
}
void Compiler::flush_dependees(SPIRVariable &var)
{
for (auto expr : var.dependees)
invalid_expressions.insert(expr);
var.dependees.clear();
}
void Compiler::flush_all_aliased_variables()
{
for (auto aliased : aliased_variables)
flush_dependees(get<SPIRVariable>(aliased));
}
void Compiler::flush_all_atomic_capable_variables()
{
for (auto global : global_variables)
flush_dependees(get<SPIRVariable>(global));
flush_all_aliased_variables();
}
void Compiler::flush_all_active_variables()
{
// Invalidate all temporaries we read from variables in this block since they were forwarded.
// Invalidate all temporaries we read from globals.
for (auto &v : current_function->local_variables)
flush_dependees(get<SPIRVariable>(v));
for (auto &arg : current_function->arguments)
flush_dependees(get<SPIRVariable>(arg.id));
for (auto global : global_variables)
flush_dependees(get<SPIRVariable>(global));
flush_all_aliased_variables();
}
uint32_t Compiler::expression_type_id(uint32_t id) const
{
switch (ids[id].get_type())
{
case TypeVariable:
return get<SPIRVariable>(id).basetype;
case TypeExpression:
return get<SPIRExpression>(id).expression_type;
case TypeConstant:
return get<SPIRConstant>(id).constant_type;
case TypeConstantOp:
return get<SPIRConstantOp>(id).basetype;
case TypeUndef:
return get<SPIRUndef>(id).basetype;
case TypeCombinedImageSampler:
return get<SPIRCombinedImageSampler>(id).combined_type;
case TypeAccessChain:
return get<SPIRAccessChain>(id).basetype;
default:
SPIRV_CROSS_THROW("Cannot resolve expression type.");
}
}
const SPIRType &Compiler::expression_type(uint32_t id) const
{
return get<SPIRType>(expression_type_id(id));
}
bool Compiler::expression_is_lvalue(uint32_t id) const
{
auto &type = expression_type(id);
switch (type.basetype)
{
case SPIRType::SampledImage:
case SPIRType::Image:
case SPIRType::Sampler:
return false;
default:
return true;
}
}
bool Compiler::is_immutable(uint32_t id) const
{
if (ids[id].get_type() == TypeVariable)
{
auto &var = get<SPIRVariable>(id);
// Anything we load from the UniformConstant address space is guaranteed to be immutable.
bool pointer_to_const = var.storage == StorageClassUniformConstant;
return pointer_to_const || var.phi_variable || !expression_is_lvalue(id);
}
else if (ids[id].get_type() == TypeAccessChain)
return get<SPIRAccessChain>(id).immutable;
else if (ids[id].get_type() == TypeExpression)
return get<SPIRExpression>(id).immutable;
else if (ids[id].get_type() == TypeConstant || ids[id].get_type() == TypeConstantOp ||
ids[id].get_type() == TypeUndef)
return true;
else
return false;
}
static inline bool storage_class_is_interface(spv::StorageClass storage)
{
switch (storage)
{
case StorageClassInput:
case StorageClassOutput:
case StorageClassUniform:
case StorageClassUniformConstant:
case StorageClassAtomicCounter:
case StorageClassPushConstant:
case StorageClassStorageBuffer:
return true;
default:
return false;
}
}
bool Compiler::is_hidden_variable(const SPIRVariable &var, bool include_builtins) const
{
if ((is_builtin_variable(var) && !include_builtins) || var.remapped_variable)
return true;
// Combined image samplers are always considered active as they are "magic" variables.
if (find_if(begin(combined_image_samplers), end(combined_image_samplers), [&var](const CombinedImageSampler &samp) {
return samp.combined_id == var.self;
}) != end(combined_image_samplers))
{
return false;
}
bool hidden = false;
if (check_active_interface_variables && storage_class_is_interface(var.storage))
hidden = active_interface_variables.find(var.self) == end(active_interface_variables);
return hidden;
}
bool Compiler::is_builtin_variable(const SPIRVariable &var) const
{
if (var.compat_builtin || meta[var.self].decoration.builtin)
return true;
// We can have builtin structs as well. If one member of a struct is builtin, the struct must also be builtin.
for (auto &m : meta[get<SPIRType>(var.basetype).self].members)
if (m.builtin)
return true;
return false;
}
bool Compiler::is_member_builtin(const SPIRType &type, uint32_t index, BuiltIn *builtin) const
{
auto &memb = meta[type.self].members;
if (index < memb.size() && memb[index].builtin)
{
if (builtin)
*builtin = memb[index].builtin_type;
return true;
}
return false;
}
bool Compiler::is_scalar(const SPIRType &type) const
{
return type.vecsize == 1 && type.columns == 1;
}
bool Compiler::is_vector(const SPIRType &type) const
{
return type.vecsize > 1 && type.columns == 1;
}
bool Compiler::is_matrix(const SPIRType &type) const
{
return type.vecsize > 1 && type.columns > 1;
}
bool Compiler::is_array(const SPIRType &type) const
{
return !type.array.empty();
}
ShaderResources Compiler::get_shader_resources() const
{
return get_shader_resources(nullptr);
}
ShaderResources Compiler::get_shader_resources(const unordered_set<uint32_t> &active_variables) const
{
return get_shader_resources(&active_variables);
}
bool Compiler::InterfaceVariableAccessHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
{
uint32_t variable = 0;
switch (opcode)
{
// Need this first, otherwise, GCC complains about unhandled switch statements.
default:
break;
case OpFunctionCall:
{
// Invalid SPIR-V.
if (length < 3)
return false;
uint32_t count = length - 3;
args += 3;
for (uint32_t i = 0; i < count; i++)
{
auto *var = compiler.maybe_get<SPIRVariable>(args[i]);
if (var && storage_class_is_interface(var->storage))
variables.insert(args[i]);
}
break;
}
case OpAtomicStore:
case OpStore:
// Invalid SPIR-V.
if (length < 1)
return false;
variable = args[0];
break;
case OpCopyMemory:
{
if (length < 2)
return false;
auto *var = compiler.maybe_get<SPIRVariable>(args[0]);
if (var && storage_class_is_interface(var->storage))
variables.insert(variable);
var = compiler.maybe_get<SPIRVariable>(args[1]);
if (var && storage_class_is_interface(var->storage))
variables.insert(variable);
break;
}
case OpExtInst:
{
if (length < 5)
return false;
uint32_t extension_set = args[2];
if (compiler.get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_AMD_shader_explicit_vertex_parameter)
{
enum AMDShaderExplicitVertexParameter
{
InterpolateAtVertexAMD = 1
};
auto op = static_cast<AMDShaderExplicitVertexParameter>(args[3]);
switch (op)
{
case InterpolateAtVertexAMD:
{
auto *var = compiler.maybe_get<SPIRVariable>(args[4]);
if (var && storage_class_is_interface(var->storage))
variables.insert(args[4]);
break;
}
default:
break;
}
}
break;
}
case OpAccessChain:
case OpInBoundsAccessChain:
case OpLoad:
case OpCopyObject:
case OpImageTexelPointer:
case OpAtomicLoad:
case OpAtomicExchange:
case OpAtomicCompareExchange:
case OpAtomicCompareExchangeWeak:
case OpAtomicIIncrement:
case OpAtomicIDecrement:
case OpAtomicIAdd:
case OpAtomicISub:
case OpAtomicSMin:
case OpAtomicUMin:
case OpAtomicSMax:
case OpAtomicUMax:
case OpAtomicAnd:
case OpAtomicOr:
case OpAtomicXor:
// Invalid SPIR-V.
if (length < 3)
return false;
variable = args[2];
break;
}
if (variable)
{
auto *var = compiler.maybe_get<SPIRVariable>(variable);
if (var && storage_class_is_interface(var->storage))
variables.insert(variable);
}
return true;
}
unordered_set<uint32_t> Compiler::get_active_interface_variables() const
{
// Traverse the call graph and find all interface variables which are in use.
unordered_set<uint32_t> variables;
InterfaceVariableAccessHandler handler(*this, variables);
traverse_all_reachable_opcodes(get<SPIRFunction>(entry_point), handler);
return variables;
}
void Compiler::set_enabled_interface_variables(std::unordered_set<uint32_t> active_variables)
{
active_interface_variables = move(active_variables);
check_active_interface_variables = true;
}
ShaderResources Compiler::get_shader_resources(const unordered_set<uint32_t> *active_variables) const
{
ShaderResources res;
for (auto &id : ids)
{
if (id.get_type() != TypeVariable)
continue;
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
// It is possible for uniform storage classes to be passed as function parameters, so detect
// that. To detect function parameters, check of StorageClass of variable is function scope.
if (var.storage == StorageClassFunction || !type.pointer || is_builtin_variable(var))
continue;
if (active_variables && active_variables->find(var.self) == end(*active_variables))
continue;
// Input
if (var.storage == StorageClassInput && interface_variable_exists_in_entry_point(var.self))
{
if (meta[type.self].decoration.decoration_flags & (1ull << DecorationBlock))
res.stage_inputs.push_back(
{ var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
else
res.stage_inputs.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Subpass inputs
else if (var.storage == StorageClassUniformConstant && type.image.dim == DimSubpassData)
{
res.subpass_inputs.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Outputs
else if (var.storage == StorageClassOutput && interface_variable_exists_in_entry_point(var.self))
{
if (meta[type.self].decoration.decoration_flags & (1ull << DecorationBlock))
res.stage_outputs.push_back(
{ var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
else
res.stage_outputs.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// UBOs
else if (type.storage == StorageClassUniform &&
(meta[type.self].decoration.decoration_flags & (1ull << DecorationBlock)))
{
res.uniform_buffers.push_back(
{ var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
}
// Old way to declare SSBOs.
else if (type.storage == StorageClassUniform &&
(meta[type.self].decoration.decoration_flags & (1ull << DecorationBufferBlock)))
{
res.storage_buffers.push_back(
{ var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
}
// Modern way to declare SSBOs.
else if (type.storage == StorageClassStorageBuffer)
{
res.storage_buffers.push_back(
{ var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
}
// Push constant blocks
else if (type.storage == StorageClassPushConstant)
{
// There can only be one push constant block, but keep the vector in case this restriction is lifted
// in the future.
res.push_constant_buffers.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Images
else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::Image &&
type.image.sampled == 2)
{
res.storage_images.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Separate images
else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::Image &&
type.image.sampled == 1)
{
res.separate_images.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Separate samplers
else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::Sampler)
{
res.separate_samplers.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Textures
else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::SampledImage)
{
res.sampled_images.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
// Atomic counters
else if (type.storage == StorageClassAtomicCounter)
{
res.atomic_counters.push_back({ var.self, var.basetype, type.self, meta[var.self].decoration.alias });
}
}
return res;
}
static inline uint32_t swap_endian(uint32_t v)
{
return ((v >> 24) & 0x000000ffu) | ((v >> 8) & 0x0000ff00u) | ((v << 8) & 0x00ff0000u) | ((v << 24) & 0xff000000u);
}
static string extract_string(const vector<uint32_t> &spirv, uint32_t offset)
{
string ret;
for (uint32_t i = offset; i < spirv.size(); i++)
{
uint32_t w = spirv[i];
for (uint32_t j = 0; j < 4; j++, w >>= 8)
{
char c = w & 0xff;
if (c == '\0')
return ret;
ret += c;
}
}
SPIRV_CROSS_THROW("String was not terminated before EOF");
}
static bool is_valid_spirv_version(uint32_t version)
{
switch (version)
{
// Allow v99 since it tends to just work.
case 99:
case 0x10000: // SPIR-V 1.0
case 0x10100: // SPIR-V 1.1
case 0x10200: // SPIR-V 1.2
return true;
default:
return false;
}
}
void Compiler::parse()
{
auto len = spirv.size();
if (len < 5)
SPIRV_CROSS_THROW("SPIRV file too small.");
auto s = spirv.data();
// Endian-swap if we need to.
if (s[0] == swap_endian(MagicNumber))
transform(begin(spirv), end(spirv), begin(spirv), [](uint32_t c) { return swap_endian(c); });
if (s[0] != MagicNumber || !is_valid_spirv_version(s[1]))
SPIRV_CROSS_THROW("Invalid SPIRV format.");
uint32_t bound = s[3];
ids.resize(bound);
meta.resize(bound);
uint32_t offset = 5;
while (offset < len)
inst.emplace_back(spirv, offset);
for (auto &i : inst)
parse(i);
if (current_function)
SPIRV_CROSS_THROW("Function was not terminated.");
if (current_block)
SPIRV_CROSS_THROW("Block was not terminated.");
// Figure out specialization constants for work group sizes.
for (auto &id : ids)
{
if (id.get_type() == TypeConstant)
{
auto &c = id.get<SPIRConstant>();
if (meta[c.self].decoration.builtin && meta[c.self].decoration.builtin_type == BuiltInWorkgroupSize)
{
// In current SPIR-V, there can be just one constant like this.
// All entry points will receive the constant value.
for (auto &entry : entry_points)
{
entry.second.workgroup_size.constant = c.self;
entry.second.workgroup_size.x = c.scalar(0, 0);
entry.second.workgroup_size.y = c.scalar(0, 1);
entry.second.workgroup_size.z = c.scalar(0, 2);
}
}
}
}
}
void Compiler::flatten_interface_block(uint32_t id)
{
auto &var = get<SPIRVariable>(id);
auto &type = get<SPIRType>(var.basetype);
auto flags = meta.at(type.self).decoration.decoration_flags;
if (!type.array.empty())
SPIRV_CROSS_THROW("Type is array of UBOs.");
if (type.basetype != SPIRType::Struct)
SPIRV_CROSS_THROW("Type is not a struct.");
if ((flags & (1ull << DecorationBlock)) == 0)
SPIRV_CROSS_THROW("Type is not a block.");
if (type.member_types.empty())
SPIRV_CROSS_THROW("Member list of struct is empty.");
uint32_t t = type.member_types[0];
for (auto &m : type.member_types)
if (t != m)
SPIRV_CROSS_THROW("Types in block differ.");
auto &mtype = get<SPIRType>(t);
if (!mtype.array.empty())
SPIRV_CROSS_THROW("Member type cannot be arrays.");
if (mtype.basetype == SPIRType::Struct)
SPIRV_CROSS_THROW("Member type cannot be struct.");
// Inherit variable name from interface block name.
meta.at(var.self).decoration.alias = meta.at(type.self).decoration.alias;
auto storage = var.storage;
if (storage == StorageClassUniform)
storage = StorageClassUniformConstant;
// Change type definition in-place into an array instead.
// Access chains will still work as-is.
uint32_t array_size = uint32_t(type.member_types.size());
type = mtype;
type.array.push_back(array_size);
type.pointer = true;
type.storage = storage;
var.storage = storage;
}
void Compiler::update_name_cache(unordered_set<string> &cache, string &name)
{
if (name.empty())
return;
if (cache.find(name) == end(cache))
{
cache.insert(name);
return;
}
uint32_t counter = 0;
auto tmpname = name;
// If there is a collision (very rare),
// keep tacking on extra identifier until it's unique.
do
{
counter++;
name = tmpname + "_" + convert_to_string(counter);
} while (cache.find(name) != end(cache));
cache.insert(name);
}
void Compiler::set_name(uint32_t id, const std::string &name)
{
auto &str = meta.at(id).decoration.alias;
str.clear();
if (name.empty())
return;
// glslang uses identifiers to pass along meaningful information
// about HLSL reflection.
auto &m = meta.at(id);
if (source.hlsl && name.size() >= 6 && name.find("@count") == name.size() - 6)
{
m.hlsl_magic_counter_buffer_candidate = true;
m.hlsl_magic_counter_buffer_name = name.substr(0, name.find("@count"));
}
else
{
m.hlsl_magic_counter_buffer_candidate = false;
m.hlsl_magic_counter_buffer_name.clear();
}
// Reserved for temporaries.
if (name[0] == '_' && name.size() >= 2 && isdigit(name[1]))
return;
str = ensure_valid_identifier(name, false);
}
const SPIRType &Compiler::get_type(uint32_t id) const
{
return get<SPIRType>(id);
}
const SPIRType &Compiler::get_type_from_variable(uint32_t id) const
{
return get<SPIRType>(get<SPIRVariable>(id).basetype);
}
void Compiler::set_member_decoration(uint32_t id, uint32_t index, Decoration decoration, uint32_t argument)
{
meta.at(id).members.resize(max(meta[id].members.size(), size_t(index) + 1));
auto &dec = meta.at(id).members[index];
dec.decoration_flags |= 1ull << decoration;
switch (decoration)
{
case DecorationBuiltIn:
dec.builtin = true;
dec.builtin_type = static_cast<BuiltIn>(argument);
break;
case DecorationLocation:
dec.location = argument;
break;
case DecorationBinding:
dec.binding = argument;
break;
case DecorationOffset:
dec.offset = argument;
break;
case DecorationSpecId:
dec.spec_id = argument;
break;
case DecorationMatrixStride:
dec.matrix_stride = argument;
break;
default:
break;
}
}
void Compiler::set_member_name(uint32_t id, uint32_t index, const std::string &name)
{
meta.at(id).members.resize(max(meta[id].members.size(), size_t(index) + 1));
auto &str = meta.at(id).members[index].alias;
str.clear();
if (name.empty())
return;
// Reserved for unnamed members.
if (name[0] == '_' && name.size() >= 3 && name[1] == 'm' && isdigit(name[2]))
return;
str = ensure_valid_identifier(name, true);
}
const std::string &Compiler::get_member_name(uint32_t id, uint32_t index) const
{
auto &m = meta.at(id);
if (index >= m.members.size())
{
static string empty;
return empty;
}
return m.members[index].alias;
}
void Compiler::set_member_qualified_name(uint32_t type_id, uint32_t index, const std::string &name)
{
meta.at(type_id).members.resize(max(meta[type_id].members.size(), size_t(index) + 1));
meta.at(type_id).members[index].qualified_alias = name;
}
const std::string &Compiler::get_member_qualified_name(uint32_t type_id, uint32_t index) const
{
const static string empty;
auto &m = meta.at(type_id);
if (index < m.members.size())
return m.members[index].qualified_alias;
else
return empty;
}
uint32_t Compiler::get_member_decoration(uint32_t id, uint32_t index, Decoration decoration) const
{
auto &m = meta.at(id);
if (index >= m.members.size())
return 0;
auto &dec = m.members[index];
if (!(dec.decoration_flags & (1ull << decoration)))
return 0;
switch (decoration)
{
case DecorationBuiltIn:
return dec.builtin_type;
case DecorationLocation:
return dec.location;
case DecorationBinding:
return dec.binding;
case DecorationOffset:
return dec.offset;
case DecorationSpecId:
return dec.spec_id;
default:
return 1;
}
}
uint64_t Compiler::get_member_decoration_mask(uint32_t id, uint32_t index) const
{
auto &m = meta.at(id);
if (index >= m.members.size())
return 0;
return m.members[index].decoration_flags;
}
bool Compiler::has_member_decoration(uint32_t id, uint32_t index, Decoration decoration) const
{
return get_member_decoration_mask(id, index) & (1ull << decoration);
}
void Compiler::unset_member_decoration(uint32_t id, uint32_t index, Decoration decoration)
{
auto &m = meta.at(id);
if (index >= m.members.size())
return;
auto &dec = m.members[index];
dec.decoration_flags &= ~(1ull << decoration);
switch (decoration)
{
case DecorationBuiltIn:
dec.builtin = false;
break;
case DecorationLocation:
dec.location = 0;
break;
case DecorationOffset:
dec.offset = 0;
break;
case DecorationSpecId:
dec.spec_id = 0;
break;
default:
break;
}
}
void Compiler::set_decoration(uint32_t id, Decoration decoration, uint32_t argument)
{
auto &dec = meta.at(id).decoration;
dec.decoration_flags |= 1ull << decoration;
switch (decoration)
{
case DecorationBuiltIn:
dec.builtin = true;
dec.builtin_type = static_cast<BuiltIn>(argument);
break;
case DecorationLocation:
dec.location = argument;
break;
case DecorationOffset:
dec.offset = argument;
break;
case DecorationArrayStride:
dec.array_stride = argument;
break;
case DecorationMatrixStride:
dec.matrix_stride = argument;
break;
case DecorationBinding:
dec.binding = argument;
break;
case DecorationDescriptorSet:
dec.set = argument;
break;
case DecorationInputAttachmentIndex:
dec.input_attachment = argument;
break;
case DecorationSpecId:
dec.spec_id = argument;
break;
default:
break;
}
}
StorageClass Compiler::get_storage_class(uint32_t id) const
{
return get<SPIRVariable>(id).storage;
}
const std::string &Compiler::get_name(uint32_t id) const
{
return meta.at(id).decoration.alias;
}
const std::string Compiler::get_fallback_name(uint32_t id) const
{
return join("_", id);
}
const std::string Compiler::get_block_fallback_name(uint32_t id) const
{
auto &var = get<SPIRVariable>(id);
if (get_name(id).empty())
return join("_", get<SPIRType>(var.basetype).self, "_", id);
else
return get_name(id);
}
uint64_t Compiler::get_decoration_mask(uint32_t id) const
{
auto &dec = meta.at(id).decoration;
return dec.decoration_flags;
}
bool Compiler::has_decoration(uint32_t id, Decoration decoration) const
{
return get_decoration_mask(id) & (1ull << decoration);
}
uint32_t Compiler::get_decoration(uint32_t id, Decoration decoration) const
{
auto &dec = meta.at(id).decoration;
if (!(dec.decoration_flags & (1ull << decoration)))
return 0;
switch (decoration)
{
case DecorationBuiltIn:
return dec.builtin_type;
case DecorationLocation:
return dec.location;
case DecorationOffset:
return dec.offset;
case DecorationBinding:
return dec.binding;
case DecorationDescriptorSet:
return dec.set;
case DecorationInputAttachmentIndex:
return dec.input_attachment;
case DecorationSpecId:
return dec.spec_id;
case DecorationArrayStride:
return dec.array_stride;
case DecorationMatrixStride:
return dec.matrix_stride;
default:
return 1;
}
}
void Compiler::unset_decoration(uint32_t id, Decoration decoration)
{
auto &dec = meta.at(id).decoration;
dec.decoration_flags &= ~(1ull << decoration);
switch (decoration)
{
case DecorationBuiltIn:
dec.builtin = false;
break;
case DecorationLocation:
dec.location = 0;
break;
case DecorationOffset:
dec.offset = 0;
break;
case DecorationBinding:
dec.binding = 0;
break;
case DecorationDescriptorSet:
dec.set = 0;
break;
case DecorationInputAttachmentIndex:
dec.input_attachment = 0;
break;
case DecorationSpecId:
dec.spec_id = 0;
break;
default:
break;
}
}
bool Compiler::get_binary_offset_for_decoration(uint32_t id, spv::Decoration decoration, uint32_t &word_offset) const
{
auto &word_offsets = meta.at(id).decoration_word_offset;
auto itr = word_offsets.find(decoration);
if (itr == end(word_offsets))
return false;
word_offset = itr->second;
return true;
}
void Compiler::parse(const Instruction &instruction)
{
auto ops = stream(instruction);
auto op = static_cast<Op>(instruction.op);
uint32_t length = instruction.length;
switch (op)
{
case OpMemoryModel:
case OpSourceExtension:
case OpNop:
case OpLine:
case OpNoLine:
case OpString:
break;
case OpSource:
{
auto lang = static_cast<SourceLanguage>(ops[0]);
switch (lang)
{
case SourceLanguageESSL:
source.es = true;
source.version = ops[1];
source.known = true;
source.hlsl = false;
break;
case SourceLanguageGLSL:
source.es = false;
source.version = ops[1];
source.known = true;
source.hlsl = false;
break;
case SourceLanguageHLSL:
// For purposes of cross-compiling, this is GLSL 450.
source.es = false;
source.version = 450;
source.known = true;
source.hlsl = true;
break;
default:
source.known = false;
break;
}
break;
}
case OpUndef:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
set<SPIRUndef>(id, result_type);
break;
}
case OpCapability:
{
uint32_t cap = ops[0];
if (cap == CapabilityKernel)
SPIRV_CROSS_THROW("Kernel capability not supported.");
declared_capabilities.push_back(static_cast<Capability>(ops[0]));
break;
}
case OpExtension:
{
auto ext = extract_string(spirv, instruction.offset);
declared_extensions.push_back(move(ext));
break;
}
case OpExtInstImport:
{
uint32_t id = ops[0];
auto ext = extract_string(spirv, instruction.offset + 1);
if (ext == "GLSL.std.450")
set<SPIRExtension>(id, SPIRExtension::GLSL);
else if (ext == "SPV_AMD_shader_ballot")
set<SPIRExtension>(id, SPIRExtension::SPV_AMD_shader_ballot);
else if (ext == "SPV_AMD_shader_explicit_vertex_parameter")
set<SPIRExtension>(id, SPIRExtension::SPV_AMD_shader_explicit_vertex_parameter);
else if (ext == "SPV_AMD_shader_trinary_minmax")
set<SPIRExtension>(id, SPIRExtension::SPV_AMD_shader_trinary_minmax);
else if (ext == "SPV_AMD_gcn_shader")
set<SPIRExtension>(id, SPIRExtension::SPV_AMD_gcn_shader);
else
set<SPIRExtension>(id, SPIRExtension::Unsupported);
// Other SPIR-V extensions currently not supported.
break;
}
case OpEntryPoint:
{
auto itr =
entry_points.insert(make_pair(ops[1], SPIREntryPoint(ops[1], static_cast<ExecutionModel>(ops[0]),
extract_string(spirv, instruction.offset + 2))));
auto &e = itr.first->second;
// Strings need nul-terminator and consume the whole word.
uint32_t strlen_words = uint32_t((e.name.size() + 1 + 3) >> 2);
e.interface_variables.insert(end(e.interface_variables), ops + strlen_words + 2, ops + instruction.length);
// Set the name of the entry point in case OpName is not provided later
set_name(ops[1], e.name);
// If we don't have an entry, make the first one our "default".
if (!entry_point)
entry_point = ops[1];
break;
}
case OpExecutionMode:
{
auto &execution = entry_points[ops[0]];
auto mode = static_cast<ExecutionMode>(ops[1]);
execution.flags |= 1ull << mode;
switch (mode)
{
case ExecutionModeInvocations:
execution.invocations = ops[2];
break;
case ExecutionModeLocalSize:
execution.workgroup_size.x = ops[2];
execution.workgroup_size.y = ops[3];
execution.workgroup_size.z = ops[4];
break;
case ExecutionModeOutputVertices:
execution.output_vertices = ops[2];
break;
default:
break;
}
break;
}
case OpName:
{
uint32_t id = ops[0];
set_name(id, extract_string(spirv, instruction.offset + 1));
break;
}
case OpMemberName:
{
uint32_t id = ops[0];
uint32_t member = ops[1];
set_member_name(id, member, extract_string(spirv, instruction.offset + 2));
break;
}
case OpDecorate:
{
uint32_t id = ops[0];
auto decoration = static_cast<Decoration>(ops[1]);
if (length >= 3)
{
meta[id].decoration_word_offset[decoration] = uint32_t(&ops[2] - spirv.data());
set_decoration(id, decoration, ops[2]);
}
else
set_decoration(id, decoration);
break;
}
case OpMemberDecorate:
{
uint32_t id = ops[0];
uint32_t member = ops[1];
auto decoration = static_cast<Decoration>(ops[2]);
if (length >= 4)
set_member_decoration(id, member, decoration, ops[3]);
else
set_member_decoration(id, member, decoration);
break;
}
// Build up basic types.
case OpTypeVoid:
{
uint32_t id = ops[0];
auto &type = set<SPIRType>(id);
type.basetype = SPIRType::Void;
break;
}
case OpTypeBool:
{
uint32_t id = ops[0];
auto &type = set<SPIRType>(id);
type.basetype = SPIRType::Boolean;
type.width = 1;
break;
}
case OpTypeFloat:
{
uint32_t id = ops[0];
uint32_t width = ops[1];
auto &type = set<SPIRType>(id);
type.basetype = width > 32 ? SPIRType::Double : SPIRType::Float;
type.width = width;
break;
}
case OpTypeInt:
{
uint32_t id = ops[0];
uint32_t width = ops[1];
auto &type = set<SPIRType>(id);
type.basetype =
ops[2] ? (width > 32 ? SPIRType::Int64 : SPIRType::Int) : (width > 32 ? SPIRType::UInt64 : SPIRType::UInt);
type.width = width;
break;
}
// Build composite types by "inheriting".
// NOTE: The self member is also copied! For pointers and array modifiers this is a good thing
// since we can refer to decorations on pointee classes which is needed for UBO/SSBO, I/O blocks in geometry/tess etc.
case OpTypeVector:
{
uint32_t id = ops[0];
uint32_t vecsize = ops[2];
auto &base = get<SPIRType>(ops[1]);
auto &vecbase = set<SPIRType>(id);
vecbase = base;
vecbase.vecsize = vecsize;
vecbase.self = id;
vecbase.parent_type = ops[1];
break;
}
case OpTypeMatrix:
{
uint32_t id = ops[0];
uint32_t colcount = ops[2];
auto &base = get<SPIRType>(ops[1]);
auto &matrixbase = set<SPIRType>(id);
matrixbase = base;
matrixbase.columns = colcount;
matrixbase.self = id;
matrixbase.parent_type = ops[1];
break;
}
case OpTypeArray:
{
uint32_t id = ops[0];
auto &arraybase = set<SPIRType>(id);
uint32_t tid = ops[1];
auto &base = get<SPIRType>(tid);
arraybase = base;
arraybase.parent_type = tid;
uint32_t cid = ops[2];
mark_used_as_array_length(cid);
auto *c = maybe_get<SPIRConstant>(cid);
bool literal = c && !c->specialization;
arraybase.array_size_literal.push_back(literal);
arraybase.array.push_back(literal ? c->scalar() : cid);
// Do NOT set arraybase.self!
break;
}
case OpTypeRuntimeArray:
{
uint32_t id = ops[0];
auto &base = get<SPIRType>(ops[1]);
auto &arraybase = set<SPIRType>(id);
arraybase = base;
arraybase.array.push_back(0);
arraybase.array_size_literal.push_back(true);
arraybase.parent_type = ops[1];
// Do NOT set arraybase.self!
break;
}
case OpTypeImage:
{
uint32_t id = ops[0];
auto &type = set<SPIRType>(id);
type.basetype = SPIRType::Image;
type.image.type = ops[1];
type.image.dim = static_cast<Dim>(ops[2]);
type.image.depth = ops[3] != 0;
type.image.arrayed = ops[4] != 0;
type.image.ms = ops[5] != 0;
type.image.sampled = ops[6];
type.image.format = static_cast<ImageFormat>(ops[7]);
type.image.access = (length >= 9) ? static_cast<AccessQualifier>(ops[8]) : AccessQualifierMax;
if (type.image.sampled == 0)
SPIRV_CROSS_THROW("OpTypeImage Sampled parameter must not be zero.");
break;
}
case OpTypeSampledImage:
{
uint32_t id = ops[0];
uint32_t imagetype = ops[1];
auto &type = set<SPIRType>(id);
type = get<SPIRType>(imagetype);
type.basetype = SPIRType::SampledImage;
type.self = id;
break;
}
case OpTypeSampler:
{
uint32_t id = ops[0];
auto &type = set<SPIRType>(id);
type.basetype = SPIRType::Sampler;
break;
}
case OpTypePointer:
{
uint32_t id = ops[0];
auto &base = get<SPIRType>(ops[2]);
auto &ptrbase = set<SPIRType>(id);
ptrbase = base;
if (ptrbase.pointer)
SPIRV_CROSS_THROW("Cannot make pointer-to-pointer type.");
ptrbase.pointer = true;
ptrbase.storage = static_cast<StorageClass>(ops[1]);
if (ptrbase.storage == StorageClassAtomicCounter)
ptrbase.basetype = SPIRType::AtomicCounter;
ptrbase.parent_type = ops[2];
// Do NOT set ptrbase.self!
break;
}
case OpTypeStruct:
{
uint32_t id = ops[0];
auto &type = set<SPIRType>(id);
type.basetype = SPIRType::Struct;
for (uint32_t i = 1; i < length; i++)
type.member_types.push_back(ops[i]);
// Check if we have seen this struct type before, with just different
// decorations.
//
// Add workaround for issue #17 as well by looking at OpName for the struct
// types, which we shouldn't normally do.
// We should not normally have to consider type aliases like this to begin with
// however ... glslang issues #304, #307 cover this.
// For stripped names, never consider struct type aliasing.
// We risk declaring the same struct multiple times, but type-punning is not allowed
// so this is safe.
bool consider_aliasing = !get_name(type.self).empty();
if (consider_aliasing)
{
for (auto &other : global_struct_cache)
{
if (get_name(type.self) == get_name(other) &&
types_are_logically_equivalent(type, get<SPIRType>(other)))
{
type.type_alias = other;
break;
}
}
if (type.type_alias == 0)
global_struct_cache.push_back(id);
}
break;
}
case OpTypeFunction:
{
uint32_t id = ops[0];
uint32_t ret = ops[1];
auto &func = set<SPIRFunctionPrototype>(id, ret);
for (uint32_t i = 2; i < length; i++)
func.parameter_types.push_back(ops[i]);
break;
}
// Variable declaration
// All variables are essentially pointers with a storage qualifier.
case OpVariable:
{
uint32_t type = ops[0];
uint32_t id = ops[1];
auto storage = static_cast<StorageClass>(ops[2]);
uint32_t initializer = length == 4 ? ops[3] : 0;
if (storage == StorageClassFunction)
{
if (!current_function)
SPIRV_CROSS_THROW("No function currently in scope");
current_function->add_local_variable(id);
}
else if (storage == StorageClassPrivate || storage == StorageClassWorkgroup || storage == StorageClassOutput)
{
global_variables.push_back(id);
}
auto &var = set<SPIRVariable>(id, type, storage, initializer);
// hlsl based shaders don't have those decorations. force them and then reset when reading/writing images
auto &ttype = get<SPIRType>(type);
if (ttype.basetype == SPIRType::BaseType::Image)
{
set_decoration(id, DecorationNonWritable);
set_decoration(id, DecorationNonReadable);
}
if (variable_storage_is_aliased(var))
aliased_variables.push_back(var.self);
break;
}
// OpPhi
// OpPhi is a fairly magical opcode.
// It selects temporary variables based on which parent block we *came from*.
// In high-level languages we can "de-SSA" by creating a function local, and flush out temporaries to this function-local
// variable to emulate SSA Phi.
case OpPhi:
{
if (!current_function)
SPIRV_CROSS_THROW("No function currently in scope");
if (!current_block)
SPIRV_CROSS_THROW("No block currently in scope");
uint32_t result_type = ops[0];
uint32_t id = ops[1];
// Instead of a temporary, create a new function-wide temporary with this ID instead.
auto &var = set<SPIRVariable>(id, result_type, spv::StorageClassFunction);
var.phi_variable = true;
current_function->add_local_variable(id);
for (uint32_t i = 2; i + 2 <= length; i += 2)
current_block->phi_variables.push_back({ ops[i], ops[i + 1], id });
break;
}
// Constants
case OpSpecConstant:
case OpConstant:
{
uint32_t id = ops[1];
auto &type = get<SPIRType>(ops[0]);
if (type.width > 32)
set<SPIRConstant>(id, ops[0], ops[2] | (uint64_t(ops[3]) << 32), op == OpSpecConstant);
else
set<SPIRConstant>(id, ops[0], ops[2], op == OpSpecConstant);
break;
}
case OpSpecConstantFalse:
case OpConstantFalse:
{
uint32_t id = ops[1];
set<SPIRConstant>(id, ops[0], uint32_t(0), op == OpSpecConstantFalse);
break;
}
case OpSpecConstantTrue:
case OpConstantTrue:
{
uint32_t id = ops[1];
set<SPIRConstant>(id, ops[0], uint32_t(1), op == OpSpecConstantTrue);
break;
}
case OpConstantNull:
{
uint32_t id = ops[1];
uint32_t type = ops[0];
make_constant_null(id, type);
break;
}
case OpSpecConstantComposite:
case OpConstantComposite:
{
uint32_t id = ops[1];
uint32_t type = ops[0];
auto &ctype = get<SPIRType>(type);
// We can have constants which are structs and arrays.
// In this case, our SPIRConstant will be a list of other SPIRConstant ids which we
// can refer to.
if (ctype.basetype == SPIRType::Struct || !ctype.array.empty())
{
set<SPIRConstant>(id, type, ops + 2, length - 2, op == OpSpecConstantComposite);
}
else
{
uint32_t elements = length - 2;
if (elements > 4)
SPIRV_CROSS_THROW("OpConstantComposite only supports 1, 2, 3 and 4 elements.");
const SPIRConstant *c[4];
for (uint32_t i = 0; i < elements; i++)
c[i] = &get<SPIRConstant>(ops[2 + i]);
set<SPIRConstant>(id, type, c, elements, op == OpSpecConstantComposite);
}
break;
}
// Functions
case OpFunction:
{
uint32_t res = ops[0];
uint32_t id = ops[1];
// Control
uint32_t type = ops[3];
if (current_function)
SPIRV_CROSS_THROW("Must end a function before starting a new one!");
current_function = &set<SPIRFunction>(id, res, type);
break;
}
case OpFunctionParameter:
{
uint32_t type = ops[0];
uint32_t id = ops[1];
if (!current_function)
SPIRV_CROSS_THROW("Must be in a function!");
current_function->add_parameter(type, id);
set<SPIRVariable>(id, type, StorageClassFunction);
break;
}
case OpFunctionEnd:
{
if (current_block)
{
// Very specific error message, but seems to come up quite often.
SPIRV_CROSS_THROW(
"Cannot end a function before ending the current block.\n"
"Likely cause: If this SPIR-V was created from glslang HLSL, make sure the entry point is valid.");
}
current_function = nullptr;
break;
}
// Blocks
case OpLabel:
{
// OpLabel always starts a block.
if (!current_function)
SPIRV_CROSS_THROW("Blocks cannot exist outside functions!");
uint32_t id = ops[0];
current_function->blocks.push_back(id);
if (!current_function->entry_block)
current_function->entry_block = id;
if (current_block)
SPIRV_CROSS_THROW("Cannot start a block before ending the current block.");
current_block = &set<SPIRBlock>(id);
break;
}
// Branch instructions end blocks.
case OpBranch:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
uint32_t target = ops[0];
current_block->terminator = SPIRBlock::Direct;
current_block->next_block = target;
current_block = nullptr;
break;
}
case OpBranchConditional:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
current_block->condition = ops[0];
current_block->true_block = ops[1];
current_block->false_block = ops[2];
current_block->terminator = SPIRBlock::Select;
current_block = nullptr;
break;
}
case OpSwitch:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
if (current_block->merge == SPIRBlock::MergeNone)
SPIRV_CROSS_THROW("Switch statement is not structured");
current_block->terminator = SPIRBlock::MultiSelect;
current_block->condition = ops[0];
current_block->default_block = ops[1];
for (uint32_t i = 2; i + 2 <= length; i += 2)
current_block->cases.push_back({ ops[i], ops[i + 1] });
// If we jump to next block, make it break instead since we're inside a switch case block at that point.
multiselect_merge_targets.insert(current_block->next_block);
current_block = nullptr;
break;
}
case OpKill:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
current_block->terminator = SPIRBlock::Kill;
current_block = nullptr;
break;
}
case OpReturn:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
current_block->terminator = SPIRBlock::Return;
current_block = nullptr;
break;
}
case OpReturnValue:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
current_block->terminator = SPIRBlock::Return;
current_block->return_value = ops[0];
current_block = nullptr;
break;
}
case OpUnreachable:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to end a non-existing block.");
current_block->terminator = SPIRBlock::Unreachable;
current_block = nullptr;
break;
}
case OpSelectionMerge:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to modify a non-existing block.");
current_block->next_block = ops[0];
current_block->merge = SPIRBlock::MergeSelection;
selection_merge_targets.insert(current_block->next_block);
break;
}
case OpLoopMerge:
{
if (!current_block)
SPIRV_CROSS_THROW("Trying to modify a non-existing block.");
current_block->merge_block = ops[0];
current_block->continue_block = ops[1];
current_block->merge = SPIRBlock::MergeLoop;
loop_blocks.insert(current_block->self);
loop_merge_targets.insert(current_block->merge_block);
continue_block_to_loop_header[current_block->continue_block] = current_block->self;
// Don't add loop headers to continue blocks,
// which would make it impossible branch into the loop header since
// they are treated as continues.
if (current_block->continue_block != current_block->self)
continue_blocks.insert(current_block->continue_block);
break;
}
case OpSpecConstantOp:
{
if (length < 3)
SPIRV_CROSS_THROW("OpSpecConstantOp not enough arguments.");
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto spec_op = static_cast<Op>(ops[2]);
set<SPIRConstantOp>(id, result_type, spec_op, ops + 3, length - 3);
break;
}
// Actual opcodes.
default:
{
if (!current_block)
SPIRV_CROSS_THROW("Currently no block to insert opcode.");
current_block->ops.push_back(instruction);
break;
}
}
}
bool Compiler::block_is_loop_candidate(const SPIRBlock &block, SPIRBlock::Method method) const
{
// Tried and failed.
if (block.disable_block_optimization || block.complex_continue)
return false;
if (method == SPIRBlock::MergeToSelectForLoop)
{
// Try to detect common for loop pattern
// which the code backend can use to create cleaner code.
// for(;;) { if (cond) { some_body; } else { break; } }
// is the pattern we're looking for.
bool ret = block.terminator == SPIRBlock::Select && block.merge == SPIRBlock::MergeLoop &&
block.true_block != block.merge_block && block.true_block != block.self &&
block.false_block == block.merge_block;
// If we have OpPhi which depends on branches which came from our own block,
// we need to flush phi variables in else block instead of a trivial break,
// so we cannot assume this is a for loop candidate.
if (ret)
{
for (auto &phi : block.phi_variables)
if (phi.parent == block.self)
return false;
auto *merge = maybe_get<SPIRBlock>(block.merge_block);
if (merge)
for (auto &phi : merge->phi_variables)
if (phi.parent == block.self)
return false;
}
return ret;
}
else if (method == SPIRBlock::MergeToDirectForLoop)
{
// Empty loop header that just sets up merge target
// and branches to loop body.
bool ret = block.terminator == SPIRBlock::Direct && block.merge == SPIRBlock::MergeLoop && block.ops.empty();
if (!ret)
return false;
auto &child = get<SPIRBlock>(block.next_block);
ret = child.terminator == SPIRBlock::Select && child.merge == SPIRBlock::MergeNone &&
child.false_block == block.merge_block && child.true_block != block.merge_block &&
child.true_block != block.self;
// If we have OpPhi which depends on branches which came from our own block,
// we need to flush phi variables in else block instead of a trivial break,
// so we cannot assume this is a for loop candidate.
if (ret)
{
for (auto &phi : block.phi_variables)
if (phi.parent == block.self || phi.parent == child.self)
return false;
for (auto &phi : child.phi_variables)
if (phi.parent == block.self)
return false;
auto *merge = maybe_get<SPIRBlock>(block.merge_block);
if (merge)
for (auto &phi : merge->phi_variables)
if (phi.parent == block.self || phi.parent == child.false_block)
return false;
}
return ret;
}
else
return false;
}
bool Compiler::block_is_outside_flow_control_from_block(const SPIRBlock &from, const SPIRBlock &to)
{
auto *start = &from;
if (start->self == to.self)
return true;
// Break cycles.
if (is_continue(start->self))
return false;
// If our select block doesn't merge, we must break or continue in these blocks,
// so if continues occur branchless within these blocks, consider them branchless as well.
// This is typically used for loop control.
if (start->terminator == SPIRBlock::Select && start->merge == SPIRBlock::MergeNone &&
(block_is_outside_flow_control_from_block(get<SPIRBlock>(start->true_block), to) ||
block_is_outside_flow_control_from_block(get<SPIRBlock>(start->false_block), to)))
{
return true;
}
else if (start->merge_block && block_is_outside_flow_control_from_block(get<SPIRBlock>(start->merge_block), to))
{
return true;
}
else if (start->next_block && block_is_outside_flow_control_from_block(get<SPIRBlock>(start->next_block), to))
{
return true;
}
else
return false;
}
bool Compiler::execution_is_noop(const SPIRBlock &from, const SPIRBlock &to) const
{
if (!execution_is_branchless(from, to))
return false;
auto *start = &from;
for (;;)
{
if (start->self == to.self)
return true;
if (!start->ops.empty())
return false;
start = &get<SPIRBlock>(start->next_block);
}
}
bool Compiler::execution_is_branchless(const SPIRBlock &from, const SPIRBlock &to) const
{
auto *start = &from;
for (;;)
{
if (start->self == to.self)
return true;
if (start->terminator == SPIRBlock::Direct && start->merge == SPIRBlock::MergeNone)
start = &get<SPIRBlock>(start->next_block);
else
return false;
}
}
SPIRBlock::ContinueBlockType Compiler::continue_block_type(const SPIRBlock &block) const
{
// The block was deemed too complex during code emit, pick conservative fallback paths.
if (block.complex_continue)
return SPIRBlock::ComplexLoop;
// In older glslang output continue block can be equal to the loop header.
// In this case, execution is clearly branchless, so just assume a while loop header here.
if (block.merge == SPIRBlock::MergeLoop)
return SPIRBlock::WhileLoop;
auto &dominator = get<SPIRBlock>(block.loop_dominator);
if (execution_is_noop(block, dominator))
return SPIRBlock::WhileLoop;
else if (execution_is_branchless(block, dominator))
return SPIRBlock::ForLoop;
else
{
if (block.merge == SPIRBlock::MergeNone && block.terminator == SPIRBlock::Select &&
block.true_block == dominator.self && block.false_block == dominator.merge_block)
{
return SPIRBlock::DoWhileLoop;
}
else
return SPIRBlock::ComplexLoop;
}
}
bool Compiler::traverse_all_reachable_opcodes(const SPIRBlock &block, OpcodeHandler &handler) const
{
handler.set_current_block(block);
// Ideally, perhaps traverse the CFG instead of all blocks in order to eliminate dead blocks,
// but this shouldn't be a problem in practice unless the SPIR-V is doing insane things like recursing
// inside dead blocks ...
for (auto &i : block.ops)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
if (!handler.handle(op, ops, i.length))
return false;
if (op == OpFunctionCall)
{
auto &func = get<SPIRFunction>(ops[2]);
if (handler.follow_function_call(func))
{
if (!handler.begin_function_scope(ops, i.length))
return false;
if (!traverse_all_reachable_opcodes(get<SPIRFunction>(ops[2]), handler))
return false;
if (!handler.end_function_scope(ops, i.length))
return false;
}
}
}
return true;
}
bool Compiler::traverse_all_reachable_opcodes(const SPIRFunction &func, OpcodeHandler &handler) const
{
for (auto block : func.blocks)
if (!traverse_all_reachable_opcodes(get<SPIRBlock>(block), handler))
return false;
return true;
}
uint32_t Compiler::type_struct_member_offset(const SPIRType &type, uint32_t index) const
{
// Decoration must be set in valid SPIR-V, otherwise throw.
auto &dec = meta[type.self].members.at(index);
if (dec.decoration_flags & (1ull << DecorationOffset))
return dec.offset;
else
SPIRV_CROSS_THROW("Struct member does not have Offset set.");
}
uint32_t Compiler::type_struct_member_array_stride(const SPIRType &type, uint32_t index) const
{
// Decoration must be set in valid SPIR-V, otherwise throw.
// ArrayStride is part of the array type not OpMemberDecorate.
auto &dec = meta[type.member_types[index]].decoration;
if (dec.decoration_flags & (1ull << DecorationArrayStride))
return dec.array_stride;
else
SPIRV_CROSS_THROW("Struct member does not have ArrayStride set.");
}
uint32_t Compiler::type_struct_member_matrix_stride(const SPIRType &type, uint32_t index) const
{
// Decoration must be set in valid SPIR-V, otherwise throw.
// MatrixStride is part of OpMemberDecorate.
auto &dec = meta[type.self].members[index];
if (dec.decoration_flags & (1ull << DecorationMatrixStride))
return dec.matrix_stride;
else
SPIRV_CROSS_THROW("Struct member does not have MatrixStride set.");
}
size_t Compiler::get_declared_struct_size(const SPIRType &type) const
{
uint32_t last = uint32_t(type.member_types.size() - 1);
size_t offset = type_struct_member_offset(type, last);
size_t size = get_declared_struct_member_size(type, last);
return offset + size;
}
size_t Compiler::get_declared_struct_member_size(const SPIRType &struct_type, uint32_t index) const
{
auto flags = get_member_decoration_mask(struct_type.self, index);
auto &type = get<SPIRType>(struct_type.member_types[index]);
switch (type.basetype)
{
case SPIRType::Unknown:
case SPIRType::Void:
case SPIRType::Boolean: // Bools are purely logical, and cannot be used for externally visible types.
case SPIRType::AtomicCounter:
case SPIRType::Image:
case SPIRType::SampledImage:
case SPIRType::Sampler:
SPIRV_CROSS_THROW("Querying size for object with opaque size.");
default:
break;
}
if (!type.array.empty())
{
// For arrays, we can use ArrayStride to get an easy check.
return type_struct_member_array_stride(struct_type, index) * type.array.back();
}
else if (type.basetype == SPIRType::Struct)
{
return get_declared_struct_size(type);
}
else
{
unsigned vecsize = type.vecsize;
unsigned columns = type.columns;
// Vectors.
if (columns == 1)
{
size_t component_size = type.width / 8;
return vecsize * component_size;
}
else
{
uint32_t matrix_stride = type_struct_member_matrix_stride(struct_type, index);
// Per SPIR-V spec, matrices must be tightly packed and aligned up for vec3 accesses.
if (flags & (1ull << DecorationRowMajor))
return matrix_stride * vecsize;
else if (flags & (1ull << DecorationColMajor))
return matrix_stride * columns;
else
SPIRV_CROSS_THROW("Either row-major or column-major must be declared for matrices.");
}
}
}
bool Compiler::BufferAccessHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
{
if (opcode != OpAccessChain && opcode != OpInBoundsAccessChain)
return true;
// Invalid SPIR-V.
if (length < 4)
return false;
if (args[2] != id)
return true;
// Don't bother traversing the entire access chain tree yet.
// If we access a struct member, assume we access the entire member.
uint32_t index = compiler.get<SPIRConstant>(args[3]).scalar();
// Seen this index already.
if (seen.find(index) != end(seen))
return true;
seen.insert(index);
auto &type = compiler.expression_type(id);
uint32_t offset = compiler.type_struct_member_offset(type, index);
size_t range;
// If we have another member in the struct, deduce the range by looking at the next member.
// This is okay since structs in SPIR-V can have padding, but Offset decoration must be
// monotonically increasing.
// Of course, this doesn't take into account if the SPIR-V for some reason decided to add
// very large amounts of padding, but that's not really a big deal.
if (index + 1 < type.member_types.size())
{
range = compiler.type_struct_member_offset(type, index + 1) - offset;
}
else
{
// No padding, so just deduce it from the size of the member directly.
range = compiler.get_declared_struct_member_size(type, index);
}
ranges.push_back({ index, offset, range });
return true;
}
std::vector<BufferRange> Compiler::get_active_buffer_ranges(uint32_t id) const
{
std::vector<BufferRange> ranges;
BufferAccessHandler handler(*this, ranges, id);
traverse_all_reachable_opcodes(get<SPIRFunction>(entry_point), handler);
return ranges;
}
// Increase the number of IDs by the specified incremental amount.
// Returns the value of the first ID available for use in the expanded bound.
uint32_t Compiler::increase_bound_by(uint32_t incr_amount)
{
auto curr_bound = ids.size();
auto new_bound = curr_bound + incr_amount;
ids.resize(new_bound);
meta.resize(new_bound);
return uint32_t(curr_bound);
}
bool Compiler::types_are_logically_equivalent(const SPIRType &a, const SPIRType &b) const
{
if (a.basetype != b.basetype)
return false;
if (a.width != b.width)
return false;
if (a.vecsize != b.vecsize)
return false;
if (a.columns != b.columns)
return false;
if (a.array.size() != b.array.size())
return false;
size_t array_count = a.array.size();
if (array_count && memcmp(a.array.data(), b.array.data(), array_count * sizeof(uint32_t)) != 0)
return false;
if (a.basetype == SPIRType::Image || a.basetype == SPIRType::SampledImage)
{
if (memcmp(&a.image, &b.image, sizeof(SPIRType::Image)) != 0)
return false;
}
if (a.member_types.size() != b.member_types.size())
return false;
size_t member_types = a.member_types.size();
for (size_t i = 0; i < member_types; i++)
{
if (!types_are_logically_equivalent(get<SPIRType>(a.member_types[i]), get<SPIRType>(b.member_types[i])))
return false;
}
return true;
}
uint64_t Compiler::get_execution_mode_mask() const
{
return get_entry_point().flags;
}
void Compiler::set_execution_mode(ExecutionMode mode, uint32_t arg0, uint32_t arg1, uint32_t arg2)
{
auto &execution = get_entry_point();
execution.flags |= 1ull << mode;
switch (mode)
{
case ExecutionModeLocalSize:
execution.workgroup_size.x = arg0;
execution.workgroup_size.y = arg1;
execution.workgroup_size.z = arg2;
break;
case ExecutionModeInvocations:
execution.invocations = arg0;
break;
case ExecutionModeOutputVertices:
execution.output_vertices = arg0;
break;
default:
break;
}
}
void Compiler::unset_execution_mode(ExecutionMode mode)
{
auto &execution = get_entry_point();
execution.flags &= ~(1ull << mode);
}
uint32_t Compiler::get_work_group_size_specialization_constants(SpecializationConstant &x, SpecializationConstant &y,
SpecializationConstant &z) const
{
auto &execution = get_entry_point();
x = { 0, 0 };
y = { 0, 0 };
z = { 0, 0 };
if (execution.workgroup_size.constant != 0)
{
auto &c = get<SPIRConstant>(execution.workgroup_size.constant);
if (c.m.c[0].id[0] != 0)
{
x.id = c.m.c[0].id[0];
x.constant_id = get_decoration(c.m.c[0].id[0], DecorationSpecId);
}
if (c.m.c[0].id[1] != 0)
{
y.id = c.m.c[0].id[1];
y.constant_id = get_decoration(c.m.c[0].id[1], DecorationSpecId);
}
if (c.m.c[0].id[2] != 0)
{
z.id = c.m.c[0].id[2];
z.constant_id = get_decoration(c.m.c[0].id[2], DecorationSpecId);
}
}
return execution.workgroup_size.constant;
}
uint32_t Compiler::get_execution_mode_argument(spv::ExecutionMode mode, uint32_t index) const
{
auto &execution = get_entry_point();
switch (mode)
{
case ExecutionModeLocalSize:
switch (index)
{
case 0:
return execution.workgroup_size.x;
case 1:
return execution.workgroup_size.y;
case 2:
return execution.workgroup_size.z;
default:
return 0;
}
case ExecutionModeInvocations:
return execution.invocations;
case ExecutionModeOutputVertices:
return execution.output_vertices;
default:
return 0;
}
}
ExecutionModel Compiler::get_execution_model() const
{
auto &execution = get_entry_point();
return execution.model;
}
void Compiler::set_remapped_variable_state(uint32_t id, bool remap_enable)
{
get<SPIRVariable>(id).remapped_variable = remap_enable;
}
bool Compiler::get_remapped_variable_state(uint32_t id) const
{
return get<SPIRVariable>(id).remapped_variable;
}
void Compiler::set_subpass_input_remapped_components(uint32_t id, uint32_t components)
{
get<SPIRVariable>(id).remapped_components = components;
}
uint32_t Compiler::get_subpass_input_remapped_components(uint32_t id) const
{
return get<SPIRVariable>(id).remapped_components;
}
void Compiler::inherit_expression_dependencies(uint32_t dst, uint32_t source_expression)
{
// Don't inherit any expression dependencies if the expression in dst
// is not a forwarded temporary.
if (forwarded_temporaries.find(dst) == end(forwarded_temporaries) ||
forced_temporaries.find(dst) != end(forced_temporaries))
{
return;
}
auto &e = get<SPIRExpression>(dst);
auto *s = maybe_get<SPIRExpression>(source_expression);
if (!s)
return;
auto &e_deps = e.expression_dependencies;
auto &s_deps = s->expression_dependencies;
// If we depend on a expression, we also depend on all sub-dependencies from source.
e_deps.push_back(source_expression);
e_deps.insert(end(e_deps), begin(s_deps), end(s_deps));
// Eliminate duplicated dependencies.
e_deps.erase(unique(begin(e_deps), end(e_deps)), end(e_deps));
}
vector<string> Compiler::get_entry_points() const
{
vector<string> entries;
for (auto &entry : entry_points)
entries.push_back(entry.second.orig_name);
return entries;
}
void Compiler::rename_entry_point(const std::string &old_name, const std::string &new_name)
{
auto &entry = get_entry_point(old_name);
entry.orig_name = new_name;
entry.name = new_name;
}
void Compiler::set_entry_point(const std::string &name)
{
auto &entry = get_entry_point(name);
entry_point = entry.self;
}
SPIREntryPoint &Compiler::get_entry_point(const std::string &name)
{
auto itr =
find_if(begin(entry_points), end(entry_points), [&](const std::pair<uint32_t, SPIREntryPoint> &entry) -> bool {
return entry.second.orig_name == name;
});
if (itr == end(entry_points))
SPIRV_CROSS_THROW("Entry point does not exist.");
return itr->second;
}
const SPIREntryPoint &Compiler::get_entry_point(const std::string &name) const
{
auto itr =
find_if(begin(entry_points), end(entry_points), [&](const std::pair<uint32_t, SPIREntryPoint> &entry) -> bool {
return entry.second.orig_name == name;
});
if (itr == end(entry_points))
SPIRV_CROSS_THROW("Entry point does not exist.");
return itr->second;
}
const string &Compiler::get_cleansed_entry_point_name(const std::string &name) const
{
return get_entry_point(name).name;
}
const SPIREntryPoint &Compiler::get_entry_point() const
{
return entry_points.find(entry_point)->second;
}
SPIREntryPoint &Compiler::get_entry_point()
{
return entry_points.find(entry_point)->second;
}
bool Compiler::interface_variable_exists_in_entry_point(uint32_t id) const
{
auto &var = get<SPIRVariable>(id);
if (var.storage != StorageClassInput && var.storage != StorageClassOutput &&
var.storage != StorageClassUniformConstant)
SPIRV_CROSS_THROW("Only Input, Output variables and Uniform constants are part of a shader linking interface.");
// This is to avoid potential problems with very old glslang versions which did
// not emit input/output interfaces properly.
// We can assume they only had a single entry point, and single entry point
// shaders could easily be assumed to use every interface variable anyways.
if (entry_points.size() <= 1)
return true;
auto &execution = get_entry_point();
return find(begin(execution.interface_variables), end(execution.interface_variables), id) !=
end(execution.interface_variables);
}
void Compiler::CombinedImageSamplerHandler::push_remap_parameters(const SPIRFunction &func, const uint32_t *args,
uint32_t length)
{
// If possible, pipe through a remapping table so that parameters know
// which variables they actually bind to in this scope.
unordered_map<uint32_t, uint32_t> remapping;
for (uint32_t i = 0; i < length; i++)
remapping[func.arguments[i].id] = remap_parameter(args[i]);
parameter_remapping.push(move(remapping));
}
void Compiler::CombinedImageSamplerHandler::pop_remap_parameters()
{
parameter_remapping.pop();
}
uint32_t Compiler::CombinedImageSamplerHandler::remap_parameter(uint32_t id)
{
auto *var = compiler.maybe_get_backing_variable(id);
if (var)
id = var->self;
if (parameter_remapping.empty())
return id;
auto &remapping = parameter_remapping.top();
auto itr = remapping.find(id);
if (itr != end(remapping))
return itr->second;
else
return id;
}
bool Compiler::CombinedImageSamplerHandler::begin_function_scope(const uint32_t *args, uint32_t length)
{
if (length < 3)
return false;
auto &callee = compiler.get<SPIRFunction>(args[2]);
args += 3;
length -= 3;
push_remap_parameters(callee, args, length);
functions.push(&callee);
return true;
}
bool Compiler::CombinedImageSamplerHandler::end_function_scope(const uint32_t *args, uint32_t length)
{
if (length < 3)
return false;
auto &callee = compiler.get<SPIRFunction>(args[2]);
args += 3;
// There are two types of cases we have to handle,
// a callee might call sampler2D(texture2D, sampler) directly where
// one or more parameters originate from parameters.
// Alternatively, we need to provide combined image samplers to our callees,
// and in this case we need to add those as well.
pop_remap_parameters();
// Our callee has now been processed at least once.
// No point in doing it again.
callee.do_combined_parameters = false;
auto &params = functions.top()->combined_parameters;
functions.pop();
if (functions.empty())
return true;
auto &caller = *functions.top();
if (caller.do_combined_parameters)
{
for (auto &param : params)
{
uint32_t image_id = param.global_image ? param.image_id : args[param.image_id];
uint32_t sampler_id = param.global_sampler ? param.sampler_id : args[param.sampler_id];
auto *i = compiler.maybe_get_backing_variable(image_id);
auto *s = compiler.maybe_get_backing_variable(sampler_id);
if (i)
image_id = i->self;
if (s)
sampler_id = s->self;
register_combined_image_sampler(caller, image_id, sampler_id, param.depth);
}
}
return true;
}
void Compiler::CombinedImageSamplerHandler::register_combined_image_sampler(SPIRFunction &caller, uint32_t image_id,
uint32_t sampler_id, bool depth)
{
// We now have a texture ID and a sampler ID which will either be found as a global
// or a parameter in our own function. If both are global, they will not need a parameter,
// otherwise, add it to our list.
SPIRFunction::CombinedImageSamplerParameter param = {
0u, image_id, sampler_id, true, true, depth,
};
auto texture_itr = find_if(begin(caller.arguments), end(caller.arguments),
[image_id](const SPIRFunction::Parameter &p) { return p.id == image_id; });
auto sampler_itr = find_if(begin(caller.arguments), end(caller.arguments),
[sampler_id](const SPIRFunction::Parameter &p) { return p.id == sampler_id; });
if (texture_itr != end(caller.arguments))
{
param.global_image = false;
param.image_id = uint32_t(texture_itr - begin(caller.arguments));
}
if (sampler_itr != end(caller.arguments))
{
param.global_sampler = false;
param.sampler_id = uint32_t(sampler_itr - begin(caller.arguments));
}
if (param.global_image && param.global_sampler)
return;
auto itr = find_if(begin(caller.combined_parameters), end(caller.combined_parameters),
[&param](const SPIRFunction::CombinedImageSamplerParameter &p) {
return param.image_id == p.image_id && param.sampler_id == p.sampler_id &&
param.global_image == p.global_image && param.global_sampler == p.global_sampler;
});
if (itr == end(caller.combined_parameters))
{
uint32_t id = compiler.increase_bound_by(3);
auto type_id = id + 0;
auto ptr_type_id = id + 1;
auto combined_id = id + 2;
auto &base = compiler.expression_type(image_id);
auto &type = compiler.set<SPIRType>(type_id);
auto &ptr_type = compiler.set<SPIRType>(ptr_type_id);
type = base;
type.self = type_id;
type.basetype = SPIRType::SampledImage;
type.pointer = false;
type.storage = StorageClassGeneric;
type.image.depth = depth;
ptr_type = type;
ptr_type.pointer = true;
ptr_type.storage = StorageClassUniformConstant;
// Build new variable.
compiler.set<SPIRVariable>(combined_id, ptr_type_id, StorageClassFunction, 0);
// Inherit RelaxedPrecision (and potentially other useful flags if deemed relevant).
auto &new_flags = compiler.meta[combined_id].decoration.decoration_flags;
auto old_flags = compiler.meta[sampler_id].decoration.decoration_flags;
new_flags = old_flags & (1ull << DecorationRelaxedPrecision);
param.id = combined_id;
compiler.set_name(combined_id,
join("SPIRV_Cross_Combined", compiler.to_name(image_id), compiler.to_name(sampler_id)));
caller.combined_parameters.push_back(param);
caller.shadow_arguments.push_back({ ptr_type_id, combined_id, 0u, 0u, true });
}
}
bool Compiler::CombinedImageSamplerHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
{
// We need to figure out where samplers and images are loaded from, so do only the bare bones compilation we need.
switch (opcode)
{
case OpLoad:
{
if (length < 3)
return false;
uint32_t result_type = args[0];
auto &type = compiler.get<SPIRType>(result_type);
bool separate_image = type.basetype == SPIRType::Image && type.image.sampled == 1;
bool separate_sampler = type.basetype == SPIRType::Sampler;
// If not separate image or sampler, don't bother.
if (!separate_image && !separate_sampler)
return true;
uint32_t id = args[1];
uint32_t ptr = args[2];
compiler.set<SPIRExpression>(id, "", result_type, true);
compiler.register_read(id, ptr, true);
return true;
}
case OpInBoundsAccessChain:
case OpAccessChain:
{
if (length < 3)
return false;
// Technically, it is possible to have arrays of textures and arrays of samplers and combine them, but this becomes essentially
// impossible to implement, since we don't know which concrete sampler we are accessing.
// One potential way is to create a combinatorial explosion where N textures and M samplers are combined into N * M sampler2Ds,
// but this seems ridiculously complicated for a problem which is easy to work around.
// Checking access chains like this assumes we don't have samplers or textures inside uniform structs, but this makes no sense.
auto &type = compiler.get<SPIRType>(args[0]);
bool separate_image = type.basetype == SPIRType::Image && type.image.sampled == 1;
bool separate_sampler = type.basetype == SPIRType::Sampler;
if (separate_image)
SPIRV_CROSS_THROW("Attempting to use arrays or structs of separate images. This is not possible to "
"statically remap to plain GLSL.");
if (separate_sampler)
SPIRV_CROSS_THROW(
"Attempting to use arrays or structs of separate samplers. This is not possible to statically "
"remap to plain GLSL.");
return true;
}
case OpSampledImage:
// Do it outside.
break;
default:
return true;
}
if (length < 4)
return false;
// Registers sampler2D calls used in case they are parameters so
// that their callees know which combined image samplers to propagate down the call stack.
if (!functions.empty())
{
auto &callee = *functions.top();
if (callee.do_combined_parameters)
{
uint32_t image_id = args[2];
auto *image = compiler.maybe_get_backing_variable(image_id);
if (image)
image_id = image->self;
uint32_t sampler_id = args[3];
auto *sampler = compiler.maybe_get_backing_variable(sampler_id);
if (sampler)
sampler_id = sampler->self;
auto &combined_type = compiler.get<SPIRType>(args[0]);
register_combined_image_sampler(callee, image_id, sampler_id, combined_type.image.depth);
}
}
// For function calls, we need to remap IDs which are function parameters into global variables.
// This information is statically known from the current place in the call stack.
// Function parameters are not necessarily pointers, so if we don't have a backing variable, remapping will know
// which backing variable the image/sample came from.
uint32_t image_id = remap_parameter(args[2]);
uint32_t sampler_id = remap_parameter(args[3]);
auto itr = find_if(begin(compiler.combined_image_samplers), end(compiler.combined_image_samplers),
[image_id, sampler_id](const CombinedImageSampler &combined) {
return combined.image_id == image_id && combined.sampler_id == sampler_id;
});
if (itr == end(compiler.combined_image_samplers))
{
auto id = compiler.increase_bound_by(2);
auto type_id = id + 0;
auto combined_id = id + 1;
auto sampled_type = args[0];
// Make a new type, pointer to OpTypeSampledImage, so we can make a variable of this type.
// We will probably have this type lying around, but it doesn't hurt to make duplicates for internal purposes.
auto &type = compiler.set<SPIRType>(type_id);
auto &base = compiler.get<SPIRType>(sampled_type);
type = base;
type.pointer = true;
type.storage = StorageClassUniformConstant;
// Build new variable.
compiler.set<SPIRVariable>(combined_id, type_id, StorageClassUniformConstant, 0);
// Inherit RelaxedPrecision (and potentially other useful flags if deemed relevant).
auto &new_flags = compiler.meta[combined_id].decoration.decoration_flags;
auto old_flags = compiler.meta[sampler_id].decoration.decoration_flags;
new_flags = old_flags & (1ull << DecorationRelaxedPrecision);
compiler.combined_image_samplers.push_back({ combined_id, image_id, sampler_id });
}
return true;
}
void Compiler::build_combined_image_samplers()
{
for (auto &id : ids)
{
if (id.get_type() == TypeFunction)
{
auto &func = id.get<SPIRFunction>();
func.combined_parameters.clear();
func.shadow_arguments.clear();
func.do_combined_parameters = true;
}
}
combined_image_samplers.clear();
CombinedImageSamplerHandler handler(*this);
traverse_all_reachable_opcodes(get<SPIRFunction>(entry_point), handler);
}
vector<SpecializationConstant> Compiler::get_specialization_constants() const
{
vector<SpecializationConstant> spec_consts;
for (auto &id : ids)
{
if (id.get_type() == TypeConstant)
{
auto &c = id.get<SPIRConstant>();
if (c.specialization)
{
spec_consts.push_back({ c.self, get_decoration(c.self, DecorationSpecId) });
}
}
}
return spec_consts;
}
SPIRConstant &Compiler::get_constant(uint32_t id)
{
return get<SPIRConstant>(id);
}
const SPIRConstant &Compiler::get_constant(uint32_t id) const
{
return get<SPIRConstant>(id);
}
// Recursively marks any constants referenced by the specified constant instruction as being used
// as an array length. The id must be a constant instruction (SPIRConstant or SPIRConstantOp).
void Compiler::mark_used_as_array_length(uint32_t id)
{
switch (ids[id].get_type())
{
case TypeConstant:
get<SPIRConstant>(id).is_used_as_array_length = true;
break;
case TypeConstantOp:
{
auto &cop = get<SPIRConstantOp>(id);
for (uint32_t arg_id : cop.arguments)
mark_used_as_array_length(arg_id);
}
case TypeUndef:
return;
default:
SPIRV_CROSS_THROW("Array lengths must be a constant instruction (OpConstant.. or OpSpecConstant...).");
}
}
static bool exists_unaccessed_path_to_return(const CFG &cfg, uint32_t block, const unordered_set<uint32_t> &blocks)
{
// This block accesses the variable.
if (blocks.find(block) != end(blocks))
return false;
// We are at the end of the CFG.
if (cfg.get_succeeding_edges(block).empty())
return true;
// If any of our successors have a path to the end, there exists a path from block.
for (auto &succ : cfg.get_succeeding_edges(block))
if (exists_unaccessed_path_to_return(cfg, succ, blocks))
return true;
return false;
}
void Compiler::analyze_parameter_preservation(
SPIRFunction &entry, const CFG &cfg, const unordered_map<uint32_t, unordered_set<uint32_t>> &variable_to_blocks,
const unordered_map<uint32_t, unordered_set<uint32_t>> &complete_write_blocks)
{
for (auto &arg : entry.arguments)
{
// Non-pointers are always inputs.
auto &type = get<SPIRType>(arg.type);
if (!type.pointer)
continue;
// Opaque argument types are always in
bool potential_preserve;
switch (type.basetype)
{
case SPIRType::Sampler:
case SPIRType::Image:
case SPIRType::SampledImage:
case SPIRType::AtomicCounter:
potential_preserve = false;
break;
default:
potential_preserve = true;
break;
}
if (!potential_preserve)
continue;
auto itr = variable_to_blocks.find(arg.id);
if (itr == end(variable_to_blocks))
{
// Variable is never accessed.
continue;
}
// We have accessed a variable, but there was no complete writes to that variable.
// We deduce that we must preserve the argument.
itr = complete_write_blocks.find(arg.id);
if (itr == end(complete_write_blocks))
{
arg.read_count++;
continue;
}
// If there is a path through the CFG where no block completely writes to the variable, the variable will be in an undefined state
// when the function returns. We therefore need to implicitly preserve the variable in case there are writers in the function.
// Major case here is if a function is
// void foo(int &var) { if (cond) var = 10; }
// Using read/write counts, we will think it's just an out variable, but it really needs to be inout,
// because if we don't write anything whatever we put into the function must return back to the caller.
if (exists_unaccessed_path_to_return(cfg, entry.entry_block, itr->second))
arg.read_count++;
}
}
void Compiler::analyze_variable_scope(SPIRFunction &entry)
{
struct AccessHandler : OpcodeHandler
{
public:
AccessHandler(Compiler &compiler_, SPIRFunction &entry_)
: compiler(compiler_)
, entry(entry_)
{
}
bool follow_function_call(const SPIRFunction &)
{
// Only analyze within this function.
return false;
}
void set_current_block(const SPIRBlock &block)
{
current_block = &block;
// If we're branching to a block which uses OpPhi, in GLSL
// this will be a variable write when we branch,
// so we need to track access to these variables as well to
// have a complete picture.
const auto test_phi = [this, &block](uint32_t to) {
auto &next = compiler.get<SPIRBlock>(to);
for (auto &phi : next.phi_variables)
{
if (phi.parent == block.self)
{
accessed_variables_to_block[phi.function_variable].insert(block.self);
// Phi variables are also accessed in our target branch block.
accessed_variables_to_block[phi.function_variable].insert(next.self);
}
}
};
// A Phi node might be reading other phi variables as input, so check for this as well.
for (auto &phi : block.phi_variables)
{
if (id_is_phi_variable(phi.local_variable))
accessed_variables_to_block[phi.local_variable].insert(block.self);
else
{
// Temporary variable, due to potential issues with scoping,
// always declare these variables up-front in the entry block.
if (!compiler.hoisted_temporaries.count(phi.local_variable))
{
auto *undef = compiler.maybe_get<SPIRUndef>(phi.local_variable);
// Undef variables are declared as global variables without initializer.
// Never declare these variables.
if (!undef)
{
auto &var = compiler.get<SPIRVariable>(phi.function_variable);
auto &entry_block = compiler.get<SPIRBlock>(entry.entry_block);
entry_block.declare_temporary.emplace_back(var.basetype, phi.local_variable);
compiler.hoisted_temporaries.insert(phi.local_variable);
compiler.forced_temporaries.insert(phi.local_variable);
}
}
}
}
switch (block.terminator)
{
case SPIRBlock::Direct:
notify_variable_access(block.condition, block.self);
test_phi(block.next_block);
break;
case SPIRBlock::Select:
notify_variable_access(block.condition, block.self);
test_phi(block.true_block);
test_phi(block.false_block);
break;
case SPIRBlock::MultiSelect:
notify_variable_access(block.condition, block.self);
for (auto &target : block.cases)
test_phi(target.block);
if (block.default_block)
test_phi(block.default_block);
break;
default:
break;
}
}
void notify_variable_access(uint32_t id, uint32_t block)
{
if (id_is_phi_variable(id))
accessed_variables_to_block[id].insert(block);
else if (id_is_potential_temporary(id))
accessed_temporaries_to_block[id].insert(block);
}
bool id_is_phi_variable(uint32_t id)
{
if (id >= compiler.get_current_id_bound())
return false;
auto *var = compiler.maybe_get<SPIRVariable>(id);
return var && var->phi_variable;
}
bool id_is_potential_temporary(uint32_t id)
{
if (id >= compiler.get_current_id_bound())
return false;
// Temporaries are not created before we start emitting code.
return compiler.ids[id].empty() || (compiler.ids[id].get_type() == TypeExpression);
}
bool handle(spv::Op op, const uint32_t *args, uint32_t length)
{
switch (op)
{
case OpStore:
{
if (length < 2)
return false;
uint32_t ptr = args[0];
auto *var = compiler.maybe_get_backing_variable(ptr);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
// If we store through an access chain, we have a partial write.
if (var && var->self == ptr && var->storage == StorageClassFunction)
complete_write_variables_to_block[var->self].insert(current_block->self);
// Might try to store a Phi variable here.
notify_variable_access(args[1], current_block->self);
break;
}
case OpAccessChain:
case OpInBoundsAccessChain:
{
if (length < 3)
return false;
uint32_t ptr = args[2];
auto *var = compiler.maybe_get<SPIRVariable>(ptr);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
for (uint32_t i = 3; i < length; i++)
notify_variable_access(args[i], current_block->self);
// The result of an access chain is a fixed expression and is not really considered a temporary.
break;
}
case OpCopyMemory:
{
if (length < 2)
return false;
uint32_t lhs = args[0];
uint32_t rhs = args[1];
auto *var = compiler.maybe_get_backing_variable(lhs);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
// If we store through an access chain, we have a partial write.
if (var->self == lhs)
complete_write_variables_to_block[var->self].insert(current_block->self);
var = compiler.maybe_get_backing_variable(rhs);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
break;
}
case OpCopyObject:
{
if (length < 3)
return false;
auto *var = compiler.maybe_get_backing_variable(args[2]);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
// Might try to copy a Phi variable here.
notify_variable_access(args[2], current_block->self);
break;
}
case OpLoad:
{
if (length < 3)
return false;
uint32_t ptr = args[2];
auto *var = compiler.maybe_get_backing_variable(ptr);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
// Loaded value is a temporary.
notify_variable_access(args[1], current_block->self);
break;
}
case OpFunctionCall:
{
if (length < 3)
return false;
length -= 3;
args += 3;
for (uint32_t i = 0; i < length; i++)
{
auto *var = compiler.maybe_get_backing_variable(args[i]);
if (var && var->storage == StorageClassFunction)
accessed_variables_to_block[var->self].insert(current_block->self);
// Cannot easily prove if argument we pass to a function is completely written.
// Usually, functions write to a dummy variable,
// which is then copied to in full to the real argument.
// Might try to copy a Phi variable here.
notify_variable_access(args[i], current_block->self);
}
// Return value may be a temporary.
notify_variable_access(args[1], current_block->self);
break;
}
case OpExtInst:
{
for (uint32_t i = 4; i < length; i++)
notify_variable_access(args[i], current_block->self);
notify_variable_access(args[1], current_block->self);
break;
}
case OpArrayLength:
// Uses literals, but cannot be a phi variable, so ignore.
break;
// Atomics shouldn't be able to access function-local variables.
// Some GLSL builtins access a pointer.
default:
{
// Rather dirty way of figuring out where Phi variables are used.
// As long as only IDs are used, we can scan through instructions and try to find any evidence that
// the ID of a variable has been used.
// There are potential false positives here where a literal is used in-place of an ID,
// but worst case, it does not affect the correctness of the compile.
// Exhaustive analysis would be better here, but it's not worth it for now.
for (uint32_t i = 0; i < length; i++)
notify_variable_access(args[i], current_block->self);
break;
}
}
return true;
}
Compiler &compiler;
SPIRFunction &entry;
std::unordered_map<uint32_t, std::unordered_set<uint32_t>> accessed_variables_to_block;
std::unordered_map<uint32_t, std::unordered_set<uint32_t>> accessed_temporaries_to_block;
std::unordered_map<uint32_t, std::unordered_set<uint32_t>> complete_write_variables_to_block;
const SPIRBlock *current_block = nullptr;
} handler(*this, entry);
// First, we map out all variable access within a function.
// Essentially a map of block -> { variables accessed in the basic block }
this->traverse_all_reachable_opcodes(entry, handler);
// Compute the control flow graph for this function.
CFG cfg(*this, entry);
// Analyze if there are parameters which need to be implicitly preserved with an "in" qualifier.
analyze_parameter_preservation(entry, cfg, handler.accessed_variables_to_block,
handler.complete_write_variables_to_block);
unordered_map<uint32_t, uint32_t> potential_loop_variables;
// For each variable which is statically accessed.
for (auto &var : handler.accessed_variables_to_block)
{
DominatorBuilder builder(cfg);
auto &blocks = var.second;
auto &type = this->expression_type(var.first);
// Figure out which block is dominating all accesses of those variables.
for (auto &block : blocks)
{
// If we're accessing a variable inside a continue block, this variable might be a loop variable.
// We can only use loop variables with scalars, as we cannot track static expressions for vectors.
if (this->is_continue(block))
{
// Potentially awkward case to check for.
// We might have a variable inside a loop, which is touched by the continue block,
// but is not actually a loop variable.
// The continue block is dominated by the inner part of the loop, which does not make sense in high-level
// language output because it will be declared before the body,
// so we will have to lift the dominator up to the relevant loop header instead.
builder.add_block(continue_block_to_loop_header[block]);
if (type.vecsize == 1 && type.columns == 1)
{
// The variable is used in multiple continue blocks, this is not a loop
// candidate, signal that by setting block to -1u.
auto &potential = potential_loop_variables[var.first];
if (potential == 0)
potential = block;
else
potential = ~(0u);
}
}
builder.add_block(block);
}
builder.lift_continue_block_dominator();
// Add it to a per-block list of variables.
uint32_t dominating_block = builder.get_dominator();
// If all blocks here are dead code, this will be 0, so the variable in question
// will be completely eliminated.
if (dominating_block)
{
auto &block = this->get<SPIRBlock>(dominating_block);
block.dominated_variables.push_back(var.first);
this->get<SPIRVariable>(var.first).dominator = dominating_block;
}
}
for (auto &var : handler.accessed_temporaries_to_block)
{
DominatorBuilder builder(cfg);
// Figure out which block is dominating all accesses of those temporaries.
auto &blocks = var.second;
for (auto &block : blocks)
builder.add_block(block);
builder.lift_continue_block_dominator();
uint32_t dominating_block = builder.get_dominator();
if (dominating_block)
expected_dominator_for_temporary[var.first] = dominating_block;
}
unordered_set<uint32_t> seen_blocks;
// Now, try to analyze whether or not these variables are actually loop variables.
for (auto &loop_variable : potential_loop_variables)
{
auto &var = this->get<SPIRVariable>(loop_variable.first);
auto dominator = var.dominator;
auto block = loop_variable.second;
// The variable was accessed in multiple continue blocks, ignore.
if (block == ~(0u) || block == 0)
continue;
// Dead code.
if (dominator == 0)
continue;
uint32_t header = 0;
// Find the loop header for this block.
for (auto b : this->loop_blocks)
{
auto &potential_header = this->get<SPIRBlock>(b);
if (potential_header.continue_block == block)
{
header = b;
break;
}
}
assert(header);
auto &header_block = this->get<SPIRBlock>(header);
// Now, there are two conditions we need to meet for the variable to be a loop variable.
// 1. The dominating block must have a branch-free path to the loop header,
// this way we statically know which expression should be part of the loop variable initializer.
// Walk from the dominator, if there is one straight edge connecting
// dominator and loop header, we statically know the loop initializer.
bool static_loop_init = true;
while (dominator != header)
{
auto &succ = cfg.get_succeeding_edges(dominator);
if (succ.size() != 1)
{
static_loop_init = false;
break;
}
auto &pred = cfg.get_preceding_edges(succ.front());
if (pred.size() != 1 || pred.front() != dominator)
{
static_loop_init = false;
break;
}
dominator = succ.front();
}
if (!static_loop_init)
continue;
// The second condition we need to meet is that no access after the loop
// merge can occur. Walk the CFG to see if we find anything.
auto &blocks = handler.accessed_variables_to_block[loop_variable.first];
seen_blocks.clear();
cfg.walk_from(seen_blocks, header_block.merge_block, [&](uint32_t walk_block) {
// We found a block which accesses the variable outside the loop.
if (blocks.find(walk_block) != end(blocks))
static_loop_init = false;
});
if (!static_loop_init)
continue;
// We have a loop variable.
header_block.loop_variables.push_back(loop_variable.first);
// Need to sort here as variables come from an unordered container, and pushing stuff in wrong order
// will break reproducability in regression runs.
sort(begin(header_block.loop_variables), end(header_block.loop_variables));
this->get<SPIRVariable>(loop_variable.first).loop_variable = true;
}
}
uint64_t Compiler::get_buffer_block_flags(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
assert(type.basetype == SPIRType::Struct);
// Some flags like non-writable, non-readable are actually found
// as member decorations. If all members have a decoration set, propagate
// the decoration up as a regular variable decoration.
uint64_t base_flags = meta[var.self].decoration.decoration_flags;
if (type.member_types.empty())
return base_flags;
uint64_t all_members_flag_mask = ~(0ull);
for (uint32_t i = 0; i < uint32_t(type.member_types.size()); i++)
all_members_flag_mask &= get_member_decoration_mask(type.self, i);
return base_flags | all_members_flag_mask;
}
bool Compiler::get_common_basic_type(const SPIRType &type, SPIRType::BaseType &base_type)
{
if (type.basetype == SPIRType::Struct)
{
base_type = SPIRType::Unknown;
for (auto &member_type : type.member_types)
{
SPIRType::BaseType member_base;
if (!get_common_basic_type(get<SPIRType>(member_type), member_base))
return false;
if (base_type == SPIRType::Unknown)
base_type = member_base;
else if (base_type != member_base)
return false;
}
return true;
}
else
{
base_type = type.basetype;
return true;
}
}
bool Compiler::ActiveBuiltinHandler::handle(spv::Op opcode, const uint32_t *args, uint32_t length)
{
const auto add_if_builtin = [&](uint32_t id) {
// Only handles variables here.
// Builtins which are part of a block are handled in AccessChain.
auto *var = compiler.maybe_get<SPIRVariable>(id);
if (var && compiler.meta[id].decoration.builtin)
{
auto &type = compiler.get<SPIRType>(var->basetype);
auto &flags =
type.storage == StorageClassInput ? compiler.active_input_builtins : compiler.active_output_builtins;
flags |= 1ull << compiler.meta[id].decoration.builtin_type;
}
};
switch (opcode)
{
case OpStore:
if (length < 1)
return false;
add_if_builtin(args[0]);
break;
case OpCopyMemory:
if (length < 2)
return false;
add_if_builtin(args[0]);
add_if_builtin(args[1]);
break;
case OpCopyObject:
case OpLoad:
if (length < 3)
return false;
add_if_builtin(args[2]);
break;
case OpFunctionCall:
{
if (length < 3)
return false;
uint32_t count = length - 3;
args += 3;
for (uint32_t i = 0; i < count; i++)
add_if_builtin(args[i]);
break;
}
case OpAccessChain:
case OpInBoundsAccessChain:
{
if (length < 4)
return false;
// Only consider global variables, cannot consider variables in functions yet, or other
// access chains as they have not been created yet.
auto *var = compiler.maybe_get<SPIRVariable>(args[2]);
if (!var)
break;
// Required if we access chain into builtins like gl_GlobalInvocationID.
add_if_builtin(args[2]);
auto *type = &compiler.get<SPIRType>(var->basetype);
// Start traversing type hierarchy at the proper non-pointer types.
while (type->pointer)
{
assert(type->parent_type);
type = &compiler.get<SPIRType>(type->parent_type);
}
auto &flags =
type->storage == StorageClassInput ? compiler.active_input_builtins : compiler.active_output_builtins;
uint32_t count = length - 3;
args += 3;
for (uint32_t i = 0; i < count; i++)
{
// Arrays
if (!type->array.empty())
{
type = &compiler.get<SPIRType>(type->parent_type);
}
// Structs
else if (type->basetype == SPIRType::Struct)
{
uint32_t index = compiler.get<SPIRConstant>(args[i]).scalar();
if (index < uint32_t(compiler.meta[type->self].members.size()))
{
auto &decorations = compiler.meta[type->self].members[index];
if (decorations.builtin)
flags |= 1ull << decorations.builtin_type;
}
type = &compiler.get<SPIRType>(type->member_types[index]);
}
else
{
// No point in traversing further. We won't find any extra builtins.
break;
}
}
break;
}
default:
break;
}
return true;
}
void Compiler::update_active_builtins()
{
active_input_builtins = 0;
active_output_builtins = 0;
ActiveBuiltinHandler handler(*this);
traverse_all_reachable_opcodes(get<SPIRFunction>(entry_point), handler);
}
// Returns whether this shader uses a builtin of the storage class
bool Compiler::has_active_builtin(BuiltIn builtin, StorageClass storage)
{
uint64_t flags;
switch (storage)
{
case StorageClassInput:
flags = active_input_builtins;
break;
case StorageClassOutput:
flags = active_output_builtins;
break;
default:
return false;
}
return flags & (1ull << builtin);
}
void Compiler::analyze_sampler_comparison_states()
{
CombinedImageSamplerUsageHandler handler(*this);
traverse_all_reachable_opcodes(get<SPIRFunction>(entry_point), handler);
comparison_samplers = move(handler.comparison_samplers);
}
bool Compiler::CombinedImageSamplerUsageHandler::begin_function_scope(const uint32_t *args, uint32_t length)
{
if (length < 3)
return false;
auto &func = compiler.get<SPIRFunction>(args[2]);
const auto *arg = &args[3];
length -= 3;
for (uint32_t i = 0; i < length; i++)
{
auto &argument = func.arguments[i];
dependency_hierarchy[argument.id].insert(arg[i]);
}
return true;
}
void Compiler::CombinedImageSamplerUsageHandler::add_hierarchy_to_comparison_samplers(uint32_t sampler)
{
// Traverse the variable dependency hierarchy and tag everything in its path with comparison samplers.
comparison_samplers.insert(sampler);
for (auto &samp : dependency_hierarchy[sampler])
add_hierarchy_to_comparison_samplers(samp);
}
bool Compiler::CombinedImageSamplerUsageHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
{
switch (opcode)
{
case OpAccessChain:
case OpInBoundsAccessChain:
case OpLoad:
{
if (length < 3)
return false;
dependency_hierarchy[args[1]].insert(args[2]);
break;
}
case OpSampledImage:
{
if (length < 4)
return false;
uint32_t result_type = args[0];
auto &type = compiler.get<SPIRType>(result_type);
if (type.image.depth)
{
// This sampler must be a SamplerComparisionState, and not a regular SamplerState.
uint32_t sampler = args[3];
add_hierarchy_to_comparison_samplers(sampler);
}
return true;
}
default:
break;
}
return true;
}
bool Compiler::buffer_is_hlsl_counter_buffer(uint32_t id) const
{
if (meta.at(id).hlsl_magic_counter_buffer_candidate)
{
auto *var = maybe_get<SPIRVariable>(id);
// Ensure that this is actually a buffer object.
return var && (var->storage == StorageClassStorageBuffer ||
has_decoration(get<SPIRType>(var->basetype).self, DecorationBufferBlock));
}
else
return false;
}
bool Compiler::buffer_get_hlsl_counter_buffer(uint32_t id, uint32_t &counter_id) const
{
auto &name = get_name(id);
uint32_t id_bound = get_current_id_bound();
for (uint32_t i = 0; i < id_bound; i++)
{
if (meta[i].hlsl_magic_counter_buffer_candidate && meta[i].hlsl_magic_counter_buffer_name == name)
{
auto *var = maybe_get<SPIRVariable>(i);
// Ensure that this is actually a buffer object.
if (var && (var->storage == StorageClassStorageBuffer ||
has_decoration(get<SPIRType>(var->basetype).self, DecorationBufferBlock)))
{
counter_id = i;
return true;
}
}
}
return false;
}
void Compiler::make_constant_null(uint32_t id, uint32_t type)
{
auto &constant_type = get<SPIRType>(type);
if (!constant_type.array.empty())
{
assert(constant_type.parent_type);
uint32_t parent_id = increase_bound_by(1);
make_constant_null(parent_id, constant_type.parent_type);
if (!constant_type.array_size_literal.back())
SPIRV_CROSS_THROW("Array size of OpConstantNull must be a literal.");
vector<uint32_t> elements(constant_type.array.back());
for (uint32_t i = 0; i < constant_type.array.back(); i++)
elements[i] = parent_id;
set<SPIRConstant>(id, type, elements.data(), uint32_t(elements.size()), false);
}
else if (!constant_type.member_types.empty())
{
uint32_t member_ids = increase_bound_by(uint32_t(constant_type.member_types.size()));
vector<uint32_t> elements(constant_type.member_types.size());
for (uint32_t i = 0; i < constant_type.member_types.size(); i++)
{
make_constant_null(member_ids + i, constant_type.member_types[i]);
elements[i] = member_ids + i;
}
set<SPIRConstant>(id, type, elements.data(), uint32_t(elements.size()), false);
}
else
{
auto &constant = set<SPIRConstant>(id, type);
constant.make_null(constant_type);
}
}
const std::vector<spv::Capability> &Compiler::get_declared_capabilities() const
{
return declared_capabilities;
}
const std::vector<std::string> &Compiler::get_declared_extensions() const
{
return declared_extensions;
}
std::string Compiler::get_remapped_declared_block_name(uint32_t id) const
{
auto itr = declared_block_names.find(id);
if (itr != end(declared_block_names))
return itr->second;
else
{
auto &var = get<SPIRVariable>(id);
auto &type = get<SPIRType>(var.basetype);
auto &block_name = meta[type.self].decoration.alias;
return block_name.empty() ? get_block_fallback_name(id) : block_name;
}
}