SPIRV-Tools/source/opt/local_access_chain_convert_pass.cpp
2020-09-08 14:13:01 -04:00

415 lines
14 KiB
C++

// Copyright (c) 2017 The Khronos Group Inc.
// Copyright (c) 2017 Valve Corporation
// Copyright (c) 2017 LunarG Inc.
//
// 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 "source/opt/local_access_chain_convert_pass.h"
#include "ir_builder.h"
#include "ir_context.h"
#include "iterator.h"
namespace spvtools {
namespace opt {
namespace {
const uint32_t kStoreValIdInIdx = 1;
const uint32_t kAccessChainPtrIdInIdx = 0;
const uint32_t kConstantValueInIdx = 0;
const uint32_t kTypeIntWidthInIdx = 0;
} // anonymous namespace
void LocalAccessChainConvertPass::BuildAndAppendInst(
SpvOp opcode, uint32_t typeId, uint32_t resultId,
const std::vector<Operand>& in_opnds,
std::vector<std::unique_ptr<Instruction>>* newInsts) {
std::unique_ptr<Instruction> newInst(
new Instruction(context(), opcode, typeId, resultId, in_opnds));
get_def_use_mgr()->AnalyzeInstDefUse(&*newInst);
newInsts->emplace_back(std::move(newInst));
}
uint32_t LocalAccessChainConvertPass::BuildAndAppendVarLoad(
const Instruction* ptrInst, uint32_t* varId, uint32_t* varPteTypeId,
std::vector<std::unique_ptr<Instruction>>* newInsts) {
const uint32_t ldResultId = TakeNextId();
if (ldResultId == 0) {
return 0;
}
*varId = ptrInst->GetSingleWordInOperand(kAccessChainPtrIdInIdx);
const Instruction* varInst = get_def_use_mgr()->GetDef(*varId);
assert(varInst->opcode() == SpvOpVariable);
*varPteTypeId = GetPointeeTypeId(varInst);
BuildAndAppendInst(SpvOpLoad, *varPteTypeId, ldResultId,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {*varId}}},
newInsts);
return ldResultId;
}
void LocalAccessChainConvertPass::AppendConstantOperands(
const Instruction* ptrInst, std::vector<Operand>* in_opnds) {
uint32_t iidIdx = 0;
ptrInst->ForEachInId([&iidIdx, &in_opnds, this](const uint32_t* iid) {
if (iidIdx > 0) {
const Instruction* cInst = get_def_use_mgr()->GetDef(*iid);
uint32_t val = cInst->GetSingleWordInOperand(kConstantValueInIdx);
in_opnds->push_back(
{spv_operand_type_t::SPV_OPERAND_TYPE_LITERAL_INTEGER, {val}});
}
++iidIdx;
});
}
bool LocalAccessChainConvertPass::ReplaceAccessChainLoad(
const Instruction* address_inst, Instruction* original_load) {
// Build and append load of variable in ptrInst
if (address_inst->NumInOperands() == 1) {
// An access chain with no indices is essentially a copy. All that is
// needed is to propagate the address.
context()->ReplaceAllUsesWith(
address_inst->result_id(),
address_inst->GetSingleWordInOperand(kAccessChainPtrIdInIdx));
return true;
}
std::vector<std::unique_ptr<Instruction>> new_inst;
uint32_t varId;
uint32_t varPteTypeId;
const uint32_t ldResultId =
BuildAndAppendVarLoad(address_inst, &varId, &varPteTypeId, &new_inst);
if (ldResultId == 0) {
return false;
}
context()->get_decoration_mgr()->CloneDecorations(
original_load->result_id(), ldResultId, {SpvDecorationRelaxedPrecision});
original_load->InsertBefore(std::move(new_inst));
// Rewrite |original_load| into an extract.
Instruction::OperandList new_operands;
// copy the result id and the type id to the new operand list.
new_operands.emplace_back(original_load->GetOperand(0));
new_operands.emplace_back(original_load->GetOperand(1));
new_operands.emplace_back(
Operand({spv_operand_type_t::SPV_OPERAND_TYPE_ID, {ldResultId}}));
AppendConstantOperands(address_inst, &new_operands);
original_load->SetOpcode(SpvOpCompositeExtract);
original_load->ReplaceOperands(new_operands);
context()->UpdateDefUse(original_load);
return true;
}
bool LocalAccessChainConvertPass::GenAccessChainStoreReplacement(
const Instruction* ptrInst, uint32_t valId,
std::vector<std::unique_ptr<Instruction>>* newInsts) {
if (ptrInst->NumInOperands() == 1) {
// An access chain with no indices is essentially a copy. However, we still
// have to create a new store because the old ones will be deleted.
BuildAndAppendInst(
SpvOpStore, 0, 0,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID,
{ptrInst->GetSingleWordInOperand(kAccessChainPtrIdInIdx)}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {valId}}},
newInsts);
return true;
}
// Build and append load of variable in ptrInst
uint32_t varId;
uint32_t varPteTypeId;
const uint32_t ldResultId =
BuildAndAppendVarLoad(ptrInst, &varId, &varPteTypeId, newInsts);
if (ldResultId == 0) {
return false;
}
context()->get_decoration_mgr()->CloneDecorations(
varId, ldResultId, {SpvDecorationRelaxedPrecision});
// Build and append Insert
const uint32_t insResultId = TakeNextId();
if (insResultId == 0) {
return false;
}
std::vector<Operand> ins_in_opnds = {
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {valId}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {ldResultId}}};
AppendConstantOperands(ptrInst, &ins_in_opnds);
BuildAndAppendInst(SpvOpCompositeInsert, varPteTypeId, insResultId,
ins_in_opnds, newInsts);
context()->get_decoration_mgr()->CloneDecorations(
varId, insResultId, {SpvDecorationRelaxedPrecision});
// Build and append Store
BuildAndAppendInst(SpvOpStore, 0, 0,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {varId}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {insResultId}}},
newInsts);
return true;
}
bool LocalAccessChainConvertPass::IsConstantIndexAccessChain(
const Instruction* acp) const {
uint32_t inIdx = 0;
return acp->WhileEachInId([&inIdx, this](const uint32_t* tid) {
if (inIdx > 0) {
Instruction* opInst = get_def_use_mgr()->GetDef(*tid);
if (opInst->opcode() != SpvOpConstant) return false;
}
++inIdx;
return true;
});
}
bool LocalAccessChainConvertPass::HasOnlySupportedRefs(uint32_t ptrId) {
if (supported_ref_ptrs_.find(ptrId) != supported_ref_ptrs_.end()) return true;
if (get_def_use_mgr()->WhileEachUser(ptrId, [this](Instruction* user) {
SpvOp op = user->opcode();
if (IsNonPtrAccessChain(op) || op == SpvOpCopyObject) {
if (!HasOnlySupportedRefs(user->result_id())) {
return false;
}
} else if (op != SpvOpStore && op != SpvOpLoad && op != SpvOpName &&
!IsNonTypeDecorate(op)) {
return false;
}
return true;
})) {
supported_ref_ptrs_.insert(ptrId);
return true;
}
return false;
}
void LocalAccessChainConvertPass::FindTargetVars(Function* func) {
for (auto bi = func->begin(); bi != func->end(); ++bi) {
for (auto ii = bi->begin(); ii != bi->end(); ++ii) {
switch (ii->opcode()) {
case SpvOpStore:
case SpvOpLoad: {
uint32_t varId;
Instruction* ptrInst = GetPtr(&*ii, &varId);
if (!IsTargetVar(varId)) break;
const SpvOp op = ptrInst->opcode();
// Rule out variables with non-supported refs eg function calls
if (!HasOnlySupportedRefs(varId)) {
seen_non_target_vars_.insert(varId);
seen_target_vars_.erase(varId);
break;
}
// Rule out variables with nested access chains
// TODO(): Convert nested access chains
if (IsNonPtrAccessChain(op) && ptrInst->GetSingleWordInOperand(
kAccessChainPtrIdInIdx) != varId) {
seen_non_target_vars_.insert(varId);
seen_target_vars_.erase(varId);
break;
}
// Rule out variables accessed with non-constant indices
if (!IsConstantIndexAccessChain(ptrInst)) {
seen_non_target_vars_.insert(varId);
seen_target_vars_.erase(varId);
break;
}
} break;
default:
break;
}
}
}
}
Pass::Status LocalAccessChainConvertPass::ConvertLocalAccessChains(
Function* func) {
FindTargetVars(func);
// Replace access chains of all targeted variables with equivalent
// extract and insert sequences
bool modified = false;
for (auto bi = func->begin(); bi != func->end(); ++bi) {
std::vector<Instruction*> dead_instructions;
for (auto ii = bi->begin(); ii != bi->end(); ++ii) {
switch (ii->opcode()) {
case SpvOpLoad: {
uint32_t varId;
Instruction* ptrInst = GetPtr(&*ii, &varId);
if (!IsNonPtrAccessChain(ptrInst->opcode())) break;
if (!IsTargetVar(varId)) break;
std::vector<std::unique_ptr<Instruction>> newInsts;
if (!ReplaceAccessChainLoad(ptrInst, &*ii)) {
return Status::Failure;
}
modified = true;
} break;
case SpvOpStore: {
uint32_t varId;
Instruction* ptrInst = GetPtr(&*ii, &varId);
if (!IsNonPtrAccessChain(ptrInst->opcode())) break;
if (!IsTargetVar(varId)) break;
std::vector<std::unique_ptr<Instruction>> newInsts;
uint32_t valId = ii->GetSingleWordInOperand(kStoreValIdInIdx);
if (!GenAccessChainStoreReplacement(ptrInst, valId, &newInsts)) {
return Status::Failure;
}
size_t num_of_instructions_to_skip = newInsts.size() - 1;
dead_instructions.push_back(&*ii);
++ii;
ii = ii.InsertBefore(std::move(newInsts));
for (size_t i = 0; i < num_of_instructions_to_skip; ++i) {
++ii;
}
modified = true;
} break;
default:
break;
}
}
while (!dead_instructions.empty()) {
Instruction* inst = dead_instructions.back();
dead_instructions.pop_back();
DCEInst(inst, [&dead_instructions](Instruction* other_inst) {
auto i = std::find(dead_instructions.begin(), dead_instructions.end(),
other_inst);
if (i != dead_instructions.end()) {
dead_instructions.erase(i);
}
});
}
}
return (modified ? Status::SuccessWithChange : Status::SuccessWithoutChange);
}
void LocalAccessChainConvertPass::Initialize() {
// Initialize Target Variable Caches
seen_target_vars_.clear();
seen_non_target_vars_.clear();
// Initialize collections
supported_ref_ptrs_.clear();
// Initialize extension allowlist
InitExtensions();
}
bool LocalAccessChainConvertPass::AllExtensionsSupported() const {
// This capability can now exist without the extension, so we have to check
// for the capability. This pass is only looking at function scope symbols,
// so we do not care if there are variable pointers on storage buffers.
if (context()->get_feature_mgr()->HasCapability(
SpvCapabilityVariablePointers))
return false;
// If any extension not in allowlist, return false
for (auto& ei : get_module()->extensions()) {
const char* extName =
reinterpret_cast<const char*>(&ei.GetInOperand(0).words[0]);
if (extensions_allowlist_.find(extName) == extensions_allowlist_.end())
return false;
}
return true;
}
Pass::Status LocalAccessChainConvertPass::ProcessImpl() {
// If non-32-bit integer type in module, terminate processing
// TODO(): Handle non-32-bit integer constants in access chains
for (const Instruction& inst : get_module()->types_values())
if (inst.opcode() == SpvOpTypeInt &&
inst.GetSingleWordInOperand(kTypeIntWidthInIdx) != 32)
return Status::SuccessWithoutChange;
// Do not process if module contains OpGroupDecorate. Additional
// support required in KillNamesAndDecorates().
// TODO(greg-lunarg): Add support for OpGroupDecorate
for (auto& ai : get_module()->annotations())
if (ai.opcode() == SpvOpGroupDecorate) return Status::SuccessWithoutChange;
// Do not process if any disallowed extensions are enabled
if (!AllExtensionsSupported()) return Status::SuccessWithoutChange;
// Process all functions in the module.
Status status = Status::SuccessWithoutChange;
for (Function& func : *get_module()) {
status = CombineStatus(status, ConvertLocalAccessChains(&func));
if (status == Status::Failure) {
break;
}
}
return status;
}
LocalAccessChainConvertPass::LocalAccessChainConvertPass() {}
Pass::Status LocalAccessChainConvertPass::Process() {
Initialize();
return ProcessImpl();
}
void LocalAccessChainConvertPass::InitExtensions() {
extensions_allowlist_.clear();
extensions_allowlist_.insert({
"SPV_AMD_shader_explicit_vertex_parameter",
"SPV_AMD_shader_trinary_minmax",
"SPV_AMD_gcn_shader",
"SPV_KHR_shader_ballot",
"SPV_AMD_shader_ballot",
"SPV_AMD_gpu_shader_half_float",
"SPV_KHR_shader_draw_parameters",
"SPV_KHR_subgroup_vote",
"SPV_KHR_8bit_storage",
"SPV_KHR_16bit_storage",
"SPV_KHR_device_group",
"SPV_KHR_multiview",
"SPV_NVX_multiview_per_view_attributes",
"SPV_NV_viewport_array2",
"SPV_NV_stereo_view_rendering",
"SPV_NV_sample_mask_override_coverage",
"SPV_NV_geometry_shader_passthrough",
"SPV_AMD_texture_gather_bias_lod",
"SPV_KHR_storage_buffer_storage_class",
// SPV_KHR_variable_pointers
// Currently do not support extended pointer expressions
"SPV_AMD_gpu_shader_int16",
"SPV_KHR_post_depth_coverage",
"SPV_KHR_shader_atomic_counter_ops",
"SPV_EXT_shader_stencil_export",
"SPV_EXT_shader_viewport_index_layer",
"SPV_AMD_shader_image_load_store_lod",
"SPV_AMD_shader_fragment_mask",
"SPV_EXT_fragment_fully_covered",
"SPV_AMD_gpu_shader_half_float_fetch",
"SPV_GOOGLE_decorate_string",
"SPV_GOOGLE_hlsl_functionality1",
"SPV_GOOGLE_user_type",
"SPV_NV_shader_subgroup_partitioned",
"SPV_EXT_demote_to_helper_invocation",
"SPV_EXT_descriptor_indexing",
"SPV_NV_fragment_shader_barycentric",
"SPV_NV_compute_shader_derivatives",
"SPV_NV_shader_image_footprint",
"SPV_NV_shading_rate",
"SPV_NV_mesh_shader",
"SPV_NV_ray_tracing",
"SPV_KHR_ray_tracing",
"SPV_KHR_ray_query",
"SPV_EXT_fragment_invocation_density",
"SPV_KHR_terminate_invocation",
});
}
} // namespace opt
} // namespace spvtools