SPIRV-Tools/source/opt/aggressive_dead_code_elim_pass.cpp
GregF 1a9061a2be ADCE: Treat privates like locals in entry point with no calls
This is needed for ongoing legalization of HLSL. It allows removal
of accesses to textures/buffers that are not used.
2017-10-13 15:39:14 -04:00

561 lines
16 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 "aggressive_dead_code_elim_pass.h"
#include "iterator.h"
#include "spirv/1.0/GLSL.std.450.h"
namespace spvtools {
namespace opt {
namespace {
const uint32_t kTypePointerStorageClassInIdx = 0;
const uint32_t kExtInstSetIdInIndx = 0;
const uint32_t kExtInstInstructionInIndx = 1;
const uint32_t kEntryPointFunctionIdInIdx = 1;
} // namespace anonymous
bool AggressiveDCEPass::IsVarOfStorage(uint32_t varId,
uint32_t storageClass) {
const ir::Instruction* varInst = def_use_mgr_->GetDef(varId);
const SpvOp op = varInst->opcode();
if (op != SpvOpVariable)
return false;
const uint32_t varTypeId = varInst->type_id();
const ir::Instruction* varTypeInst = def_use_mgr_->GetDef(varTypeId);
if (varTypeInst->opcode() != SpvOpTypePointer)
return false;
return varTypeInst->GetSingleWordInOperand(kTypePointerStorageClassInIdx) ==
storageClass;
}
bool AggressiveDCEPass::IsLocalVar(uint32_t varId) {
return IsVarOfStorage(varId, SpvStorageClassFunction) ||
(IsVarOfStorage(varId, SpvStorageClassPrivate) && private_like_local_);
}
void AggressiveDCEPass::AddStores(uint32_t ptrId) {
const analysis::UseList* uses = def_use_mgr_->GetUses(ptrId);
if (uses == nullptr)
return;
for (const auto u : *uses) {
const SpvOp op = u.inst->opcode();
switch (op) {
case SpvOpAccessChain:
case SpvOpInBoundsAccessChain:
case SpvOpCopyObject: {
AddStores(u.inst->result_id());
} break;
case SpvOpLoad:
break;
// If default, assume it stores eg frexp, modf, function call
case SpvOpStore:
default: {
if (live_insts_.find(u.inst) == live_insts_.end())
worklist_.push(u.inst);
} break;
}
}
}
bool AggressiveDCEPass::IsCombinator(uint32_t op) const {
return combinator_ops_shader_.find(op) != combinator_ops_shader_.end();
}
bool AggressiveDCEPass::IsCombinatorExt(ir::Instruction* inst) const {
assert(inst->opcode() == SpvOpExtInst);
if (inst->GetSingleWordInOperand(kExtInstSetIdInIndx) == glsl_std_450_id_) {
uint32_t op = inst->GetSingleWordInOperand(kExtInstInstructionInIndx);
return combinator_ops_glsl_std_450_.find(op) !=
combinator_ops_glsl_std_450_.end();
}
else
return false;
}
bool AggressiveDCEPass::AllExtensionsSupported() const {
// If any extension not in whitelist, return false
for (auto& ei : module_->extensions()) {
const char* extName = reinterpret_cast<const char*>(
&ei.GetInOperand(0).words[0]);
if (extensions_whitelist_.find(extName) == extensions_whitelist_.end())
return false;
}
return true;
}
bool AggressiveDCEPass::KillInstIfTargetDead(ir::Instruction* inst) {
const uint32_t tId = inst->GetSingleWordInOperand(0);
const ir::Instruction* tInst = def_use_mgr_->GetDef(tId);
if (dead_insts_.find(tInst) != dead_insts_.end()) {
def_use_mgr_->KillInst(inst);
return true;
}
return false;
}
void AggressiveDCEPass::ProcessLoad(uint32_t varId) {
// Only process locals
if (!IsLocalVar(varId))
return;
// Return if already processed
if (live_local_vars_.find(varId) != live_local_vars_.end())
return;
// Mark all stores to varId as live
AddStores(varId);
// Cache varId as processed
live_local_vars_.insert(varId);
}
bool AggressiveDCEPass::AggressiveDCE(ir::Function* func) {
bool modified = false;
// Add all control flow and instructions with external side effects
// to worklist
// TODO(greg-lunarg): Handle Frexp, Modf more optimally
call_in_func_ = false;
func_is_entry_point_ = false;
private_stores_.clear();
for (auto& blk : *func) {
for (auto& inst : blk) {
uint32_t op = inst.opcode();
switch (op) {
case SpvOpStore: {
uint32_t varId;
(void) GetPtr(&inst, &varId);
// Mark stores as live if their variable is not function scope
// and is not private scope. Remember private stores for possible
// later inclusion
if (IsVarOfStorage(varId, SpvStorageClassPrivate))
private_stores_.push_back(&inst);
else if (!IsVarOfStorage(varId, SpvStorageClassFunction))
worklist_.push(&inst);
} break;
case SpvOpExtInst: {
// eg. GLSL frexp, modf
if (!IsCombinatorExt(&inst))
worklist_.push(&inst);
} break;
default: {
// eg. control flow, function call, atomics, function param,
// function return
// TODO(greg-lunarg): function calls live only if write to non-local
if (!IsCombinator(op))
worklist_.push(&inst);
// Remember function calls
if (op == SpvOpFunctionCall)
call_in_func_ = true;
} break;
}
}
}
// See if current function is an entry point
for (auto& ei : module_->entry_points()) {
if (ei.GetSingleWordInOperand(kEntryPointFunctionIdInIdx) ==
func->result_id()) {
func_is_entry_point_ = true;
break;
}
}
// If the current function is an entry point and has no function calls,
// we can optimize private variables as locals
private_like_local_ = func_is_entry_point_ && !call_in_func_;
// If privates are not like local, add their stores to worklist
if (!private_like_local_)
for (auto& ps : private_stores_)
worklist_.push(ps);
// Add OpGroupDecorates to worklist because they are a pain to remove
// ids from.
// TODO(greg-lunarg): Handle dead ids in OpGroupDecorate
for (auto& ai : module_->annotations()) {
if (ai.opcode() == SpvOpGroupDecorate)
worklist_.push(&ai);
}
// Perform closure on live instruction set.
while (!worklist_.empty()) {
ir::Instruction* liveInst = worklist_.front();
live_insts_.insert(liveInst);
// Add all operand instructions if not already live
liveInst->ForEachInId([this](const uint32_t* iid) {
ir::Instruction* inInst = def_use_mgr_->GetDef(*iid);
if (live_insts_.find(inInst) == live_insts_.end())
worklist_.push(inInst);
});
// If local load, add all variable's stores if variable not already live
if (liveInst->opcode() == SpvOpLoad) {
uint32_t varId;
(void) GetPtr(liveInst, &varId);
ProcessLoad(varId);
}
// If function call, treat as if it loads from all pointer arguments
else if (liveInst->opcode() == SpvOpFunctionCall) {
liveInst->ForEachInId([this](const uint32_t* iid) {
// Skip non-ptr args
if (!IsPtr(*iid)) return;
uint32_t varId;
(void) GetPtr(*iid, &varId);
ProcessLoad(varId);
});
}
// If function parameter, treat as if it's result id is loaded from
else if (liveInst->opcode() == SpvOpFunctionParameter) {
ProcessLoad(liveInst->result_id());
}
worklist_.pop();
}
// Mark all non-live instructions dead
for (auto& blk : *func) {
for (auto& inst : blk) {
if (live_insts_.find(&inst) != live_insts_.end())
continue;
dead_insts_.insert(&inst);
}
}
// Remove debug and annotation statements referencing dead instructions.
// This must be done before killing the instructions, otherwise there are
// dead objects in the def/use database.
for (auto& di : module_->debugs2()) {
if (di.opcode() != SpvOpName)
continue;
if (KillInstIfTargetDead(&di))
modified = true;
}
for (auto& ai : module_->annotations()) {
if (ai.opcode() != SpvOpDecorate && ai.opcode() != SpvOpDecorateId)
continue;
if (KillInstIfTargetDead(&ai))
modified = true;
}
// Kill dead instructions
for (auto& blk : *func) {
for (auto& inst : blk) {
if (dead_insts_.find(&inst) == dead_insts_.end())
continue;
def_use_mgr_->KillInst(&inst);
modified = true;
}
}
return modified;
}
void AggressiveDCEPass::Initialize(ir::Module* module) {
module_ = module;
// Clear collections
worklist_ = std::queue<ir::Instruction*>{};
live_insts_.clear();
live_local_vars_.clear();
dead_insts_.clear();
combinator_ops_shader_.clear();
combinator_ops_glsl_std_450_.clear();
// TODO(greg-lunarg): Reuse def/use from previous passes
def_use_mgr_.reset(new analysis::DefUseManager(consumer(), module_));
// Initialize extensions whitelist
InitExtensions();
}
Pass::Status AggressiveDCEPass::ProcessImpl() {
// Current functionality assumes shader capability
// TODO(greg-lunarg): Handle additional capabilities
if (!module_->HasCapability(SpvCapabilityShader))
return Status::SuccessWithoutChange;
// Current functionality assumes logical addressing only
// TODO(greg-lunarg): Handle non-logical addressing
if (module_->HasCapability(SpvCapabilityAddresses))
return Status::SuccessWithoutChange;
// If any extensions in the module are not explicitly supported,
// return unmodified.
if (!AllExtensionsSupported())
return Status::SuccessWithoutChange;
// Initialize combinator whitelists
InitCombinatorSets();
// Process all entry point functions
ProcessFunction pfn = [this](ir::Function* fp) {
return AggressiveDCE(fp);
};
bool modified = ProcessEntryPointCallTree(pfn, module_);
return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}
AggressiveDCEPass::AggressiveDCEPass() {}
Pass::Status AggressiveDCEPass::Process(ir::Module* module) {
Initialize(module);
return ProcessImpl();
}
void AggressiveDCEPass::InitCombinatorSets() {
combinator_ops_shader_ = {
SpvOpNop,
SpvOpUndef,
SpvOpVariable,
SpvOpImageTexelPointer,
SpvOpLoad,
SpvOpAccessChain,
SpvOpInBoundsAccessChain,
SpvOpArrayLength,
SpvOpVectorExtractDynamic,
SpvOpVectorInsertDynamic,
SpvOpVectorShuffle,
SpvOpCompositeConstruct,
SpvOpCompositeExtract,
SpvOpCompositeInsert,
SpvOpCopyObject,
SpvOpTranspose,
SpvOpSampledImage,
SpvOpImageSampleImplicitLod,
SpvOpImageSampleExplicitLod,
SpvOpImageSampleDrefImplicitLod,
SpvOpImageSampleDrefExplicitLod,
SpvOpImageSampleProjImplicitLod,
SpvOpImageSampleProjExplicitLod,
SpvOpImageSampleProjDrefImplicitLod,
SpvOpImageSampleProjDrefExplicitLod,
SpvOpImageFetch,
SpvOpImageGather,
SpvOpImageDrefGather,
SpvOpImageRead,
SpvOpImage,
SpvOpConvertFToU,
SpvOpConvertFToS,
SpvOpConvertSToF,
SpvOpConvertUToF,
SpvOpUConvert,
SpvOpSConvert,
SpvOpFConvert,
SpvOpQuantizeToF16,
SpvOpBitcast,
SpvOpSNegate,
SpvOpFNegate,
SpvOpIAdd,
SpvOpFAdd,
SpvOpISub,
SpvOpFSub,
SpvOpIMul,
SpvOpFMul,
SpvOpUDiv,
SpvOpSDiv,
SpvOpFDiv,
SpvOpUMod,
SpvOpSRem,
SpvOpSMod,
SpvOpFRem,
SpvOpFMod,
SpvOpVectorTimesScalar,
SpvOpMatrixTimesScalar,
SpvOpVectorTimesMatrix,
SpvOpMatrixTimesVector,
SpvOpMatrixTimesMatrix,
SpvOpOuterProduct,
SpvOpDot,
SpvOpIAddCarry,
SpvOpISubBorrow,
SpvOpUMulExtended,
SpvOpSMulExtended,
SpvOpAny,
SpvOpAll,
SpvOpIsNan,
SpvOpIsInf,
SpvOpLogicalEqual,
SpvOpLogicalNotEqual,
SpvOpLogicalOr,
SpvOpLogicalAnd,
SpvOpLogicalNot,
SpvOpSelect,
SpvOpIEqual,
SpvOpINotEqual,
SpvOpUGreaterThan,
SpvOpSGreaterThan,
SpvOpUGreaterThanEqual,
SpvOpSGreaterThanEqual,
SpvOpULessThan,
SpvOpSLessThan,
SpvOpULessThanEqual,
SpvOpSLessThanEqual,
SpvOpFOrdEqual,
SpvOpFUnordEqual,
SpvOpFOrdNotEqual,
SpvOpFUnordNotEqual,
SpvOpFOrdLessThan,
SpvOpFUnordLessThan,
SpvOpFOrdGreaterThan,
SpvOpFUnordGreaterThan,
SpvOpFOrdLessThanEqual,
SpvOpFUnordLessThanEqual,
SpvOpFOrdGreaterThanEqual,
SpvOpFUnordGreaterThanEqual,
SpvOpShiftRightLogical,
SpvOpShiftRightArithmetic,
SpvOpShiftLeftLogical,
SpvOpBitwiseOr,
SpvOpBitwiseXor,
SpvOpBitwiseAnd,
SpvOpNot,
SpvOpBitFieldInsert,
SpvOpBitFieldSExtract,
SpvOpBitFieldUExtract,
SpvOpBitReverse,
SpvOpBitCount,
SpvOpDPdx,
SpvOpDPdy,
SpvOpFwidth,
SpvOpDPdxFine,
SpvOpDPdyFine,
SpvOpFwidthFine,
SpvOpDPdxCoarse,
SpvOpDPdyCoarse,
SpvOpFwidthCoarse,
SpvOpPhi,
SpvOpImageSparseSampleImplicitLod,
SpvOpImageSparseSampleExplicitLod,
SpvOpImageSparseSampleDrefImplicitLod,
SpvOpImageSparseSampleDrefExplicitLod,
SpvOpImageSparseSampleProjImplicitLod,
SpvOpImageSparseSampleProjExplicitLod,
SpvOpImageSparseSampleProjDrefImplicitLod,
SpvOpImageSparseSampleProjDrefExplicitLod,
SpvOpImageSparseFetch,
SpvOpImageSparseGather,
SpvOpImageSparseDrefGather,
SpvOpImageSparseTexelsResident,
SpvOpImageSparseRead,
SpvOpSizeOf
// TODO(dneto): Add instructions enabled by ImageQuery
};
// Find supported extension instruction set ids
glsl_std_450_id_ = module_->GetExtInstImportId("GLSL.std.450");
combinator_ops_glsl_std_450_ = {
GLSLstd450Round,
GLSLstd450RoundEven,
GLSLstd450Trunc,
GLSLstd450FAbs,
GLSLstd450SAbs,
GLSLstd450FSign,
GLSLstd450SSign,
GLSLstd450Floor,
GLSLstd450Ceil,
GLSLstd450Fract,
GLSLstd450Radians,
GLSLstd450Degrees,
GLSLstd450Sin,
GLSLstd450Cos,
GLSLstd450Tan,
GLSLstd450Asin,
GLSLstd450Acos,
GLSLstd450Atan,
GLSLstd450Sinh,
GLSLstd450Cosh,
GLSLstd450Tanh,
GLSLstd450Asinh,
GLSLstd450Acosh,
GLSLstd450Atanh,
GLSLstd450Atan2,
GLSLstd450Pow,
GLSLstd450Exp,
GLSLstd450Log,
GLSLstd450Exp2,
GLSLstd450Log2,
GLSLstd450Sqrt,
GLSLstd450InverseSqrt,
GLSLstd450Determinant,
GLSLstd450MatrixInverse,
GLSLstd450ModfStruct,
GLSLstd450FMin,
GLSLstd450UMin,
GLSLstd450SMin,
GLSLstd450FMax,
GLSLstd450UMax,
GLSLstd450SMax,
GLSLstd450FClamp,
GLSLstd450UClamp,
GLSLstd450SClamp,
GLSLstd450FMix,
GLSLstd450IMix,
GLSLstd450Step,
GLSLstd450SmoothStep,
GLSLstd450Fma,
GLSLstd450FrexpStruct,
GLSLstd450Ldexp,
GLSLstd450PackSnorm4x8,
GLSLstd450PackUnorm4x8,
GLSLstd450PackSnorm2x16,
GLSLstd450PackUnorm2x16,
GLSLstd450PackHalf2x16,
GLSLstd450PackDouble2x32,
GLSLstd450UnpackSnorm2x16,
GLSLstd450UnpackUnorm2x16,
GLSLstd450UnpackHalf2x16,
GLSLstd450UnpackSnorm4x8,
GLSLstd450UnpackUnorm4x8,
GLSLstd450UnpackDouble2x32,
GLSLstd450Length,
GLSLstd450Distance,
GLSLstd450Cross,
GLSLstd450Normalize,
GLSLstd450FaceForward,
GLSLstd450Reflect,
GLSLstd450Refract,
GLSLstd450FindILsb,
GLSLstd450FindSMsb,
GLSLstd450FindUMsb,
GLSLstd450InterpolateAtCentroid,
GLSLstd450InterpolateAtSample,
GLSLstd450InterpolateAtOffset,
GLSLstd450NMin,
GLSLstd450NMax,
GLSLstd450NClamp
};
}
void AggressiveDCEPass::InitExtensions() {
extensions_whitelist_.clear();
extensions_whitelist_.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_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",
});
}
} // namespace opt
} // namespace spvtools