SPIRV-Tools/source/opt/common_uniform_elim_pass.cpp
Alan Baker 5ffe862f28 Fixes missing increment in common uniform elim
* Addresses #1203
* Increments inIdx in IsConstantIndexAccessChain
 * added test to catch the bug
2018-01-16 14:47:35 -05:00

571 lines
22 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 "common_uniform_elim_pass.h"
#include "cfa.h"
#include "ir_context.h"
namespace spvtools {
namespace opt {
namespace {
const uint32_t kAccessChainPtrIdInIdx = 0;
const uint32_t kTypePointerStorageClassInIdx = 0;
const uint32_t kTypePointerTypeIdInIdx = 1;
const uint32_t kConstantValueInIdx = 0;
const uint32_t kExtractCompositeIdInIdx = 0;
const uint32_t kExtractIdx0InIdx = 1;
const uint32_t kStorePtrIdInIdx = 0;
const uint32_t kLoadPtrIdInIdx = 0;
const uint32_t kCopyObjectOperandInIdx = 0;
const uint32_t kTypeIntWidthInIdx = 0;
} // anonymous namespace
bool CommonUniformElimPass::IsNonPtrAccessChain(const SpvOp opcode) const {
return opcode == SpvOpAccessChain || opcode == SpvOpInBoundsAccessChain;
}
bool CommonUniformElimPass::IsSamplerOrImageType(
const ir::Instruction* typeInst) const {
switch (typeInst->opcode()) {
case SpvOpTypeSampler:
case SpvOpTypeImage:
case SpvOpTypeSampledImage:
return true;
default:
break;
}
if (typeInst->opcode() != SpvOpTypeStruct) return false;
// Return true if any member is a sampler or image
return !typeInst->WhileEachInId([this](const uint32_t* tid) {
const ir::Instruction* compTypeInst = get_def_use_mgr()->GetDef(*tid);
if (IsSamplerOrImageType(compTypeInst)) {
return false;
}
return true;
});
}
bool CommonUniformElimPass::IsSamplerOrImageVar(uint32_t varId) const {
const ir::Instruction* varInst = get_def_use_mgr()->GetDef(varId);
assert(varInst->opcode() == SpvOpVariable);
const uint32_t varTypeId = varInst->type_id();
const ir::Instruction* varTypeInst = get_def_use_mgr()->GetDef(varTypeId);
const uint32_t varPteTypeId =
varTypeInst->GetSingleWordInOperand(kTypePointerTypeIdInIdx);
ir::Instruction* varPteTypeInst = get_def_use_mgr()->GetDef(varPteTypeId);
return IsSamplerOrImageType(varPteTypeInst);
}
ir::Instruction* CommonUniformElimPass::GetPtr(ir::Instruction* ip,
uint32_t* objId) {
const SpvOp op = ip->opcode();
assert(op == SpvOpStore || op == SpvOpLoad);
*objId = ip->GetSingleWordInOperand(op == SpvOpStore ? kStorePtrIdInIdx
: kLoadPtrIdInIdx);
ir::Instruction* ptrInst = get_def_use_mgr()->GetDef(*objId);
while (ptrInst->opcode() == SpvOpCopyObject) {
*objId = ptrInst->GetSingleWordInOperand(kCopyObjectOperandInIdx);
ptrInst = get_def_use_mgr()->GetDef(*objId);
}
ir::Instruction* objInst = ptrInst;
while (objInst->opcode() != SpvOpVariable &&
objInst->opcode() != SpvOpFunctionParameter) {
if (IsNonPtrAccessChain(objInst->opcode())) {
*objId = objInst->GetSingleWordInOperand(kAccessChainPtrIdInIdx);
} else {
assert(objInst->opcode() == SpvOpCopyObject);
*objId = objInst->GetSingleWordInOperand(kCopyObjectOperandInIdx);
}
objInst = get_def_use_mgr()->GetDef(*objId);
}
return ptrInst;
}
bool CommonUniformElimPass::IsVolatileStruct(uint32_t type_id) {
assert(get_def_use_mgr()->GetDef(type_id)->opcode() == SpvOpTypeStruct);
return !get_decoration_mgr()->WhileEachDecoration(
type_id, SpvDecorationVolatile,
[](const ir::Instruction&) { return false; });
}
bool CommonUniformElimPass::IsAccessChainToVolatileStructType(
const ir::Instruction& AccessChainInst) {
assert(AccessChainInst.opcode() == SpvOpAccessChain);
uint32_t ptr_id = AccessChainInst.GetSingleWordInOperand(0);
const ir::Instruction* ptr_inst = get_def_use_mgr()->GetDef(ptr_id);
uint32_t pointee_type_id = GetPointeeTypeId(ptr_inst);
const uint32_t num_operands = AccessChainInst.NumOperands();
// walk the type tree:
for (uint32_t idx = 3; idx < num_operands; ++idx) {
ir::Instruction* pointee_type = get_def_use_mgr()->GetDef(pointee_type_id);
switch (pointee_type->opcode()) {
case SpvOpTypeMatrix:
case SpvOpTypeVector:
case SpvOpTypeArray:
case SpvOpTypeRuntimeArray:
pointee_type_id = pointee_type->GetSingleWordOperand(1);
break;
case SpvOpTypeStruct:
// check for volatile decorations:
if (IsVolatileStruct(pointee_type_id)) return true;
if (idx < num_operands - 1) {
const uint32_t index_id = AccessChainInst.GetSingleWordOperand(idx);
const ir::Instruction* index_inst =
get_def_use_mgr()->GetDef(index_id);
uint32_t index_value = index_inst->GetSingleWordOperand(
2); // TODO: replace with GetUintValueFromConstant()
pointee_type_id = pointee_type->GetSingleWordInOperand(index_value);
}
break;
default:
assert(false && "Unhandled pointee type.");
}
}
return false;
}
bool CommonUniformElimPass::IsVolatileLoad(const ir::Instruction& loadInst) {
assert(loadInst.opcode() == SpvOpLoad);
// Check if this Load instruction has Volatile Memory Access flag
if (loadInst.NumOperands() == 4) {
uint32_t memory_access_mask = loadInst.GetSingleWordOperand(3);
if (memory_access_mask & SpvMemoryAccessVolatileMask) return true;
}
// If we load a struct directly (result type is struct),
// check if the struct is decorated volatile
uint32_t type_id = loadInst.type_id();
if (get_def_use_mgr()->GetDef(type_id)->opcode() == SpvOpTypeStruct)
return IsVolatileStruct(type_id);
else
return false;
}
bool CommonUniformElimPass::IsUniformVar(uint32_t varId) {
const ir::Instruction* varInst =
get_def_use_mgr()->id_to_defs().find(varId)->second;
if (varInst->opcode() != SpvOpVariable) return false;
const uint32_t varTypeId = varInst->type_id();
const ir::Instruction* varTypeInst =
get_def_use_mgr()->id_to_defs().find(varTypeId)->second;
return varTypeInst->GetSingleWordInOperand(kTypePointerStorageClassInIdx) ==
SpvStorageClassUniform ||
varTypeInst->GetSingleWordInOperand(kTypePointerStorageClassInIdx) ==
SpvStorageClassUniformConstant;
}
bool CommonUniformElimPass::HasUnsupportedDecorates(uint32_t id) const {
return !get_def_use_mgr()->WhileEachUser(id, [this](ir::Instruction* user) {
if (IsNonTypeDecorate(user->opcode())) return false;
return true;
});
}
bool CommonUniformElimPass::HasOnlyNamesAndDecorates(uint32_t id) const {
return get_def_use_mgr()->WhileEachUser(id, [this](ir::Instruction* user) {
SpvOp op = user->opcode();
if (op != SpvOpName && !IsNonTypeDecorate(op)) return false;
return true;
});
}
void CommonUniformElimPass::DeleteIfUseless(ir::Instruction* inst) {
const uint32_t resId = inst->result_id();
assert(resId != 0);
if (HasOnlyNamesAndDecorates(resId)) {
context()->KillInst(inst);
}
}
ir::Instruction* CommonUniformElimPass::ReplaceAndDeleteLoad(
ir::Instruction* loadInst, uint32_t replId, ir::Instruction* ptrInst) {
const uint32_t loadId = loadInst->result_id();
context()->KillNamesAndDecorates(loadId);
(void)context()->ReplaceAllUsesWith(loadId, replId);
// remove load instruction
ir::Instruction* next_instruction = context()->KillInst(loadInst);
// if access chain, see if it can be removed as well
if (IsNonPtrAccessChain(ptrInst->opcode())) DeleteIfUseless(ptrInst);
return next_instruction;
}
void CommonUniformElimPass::GenACLoadRepl(
const ir::Instruction* ptrInst,
std::vector<std::unique_ptr<ir::Instruction>>* newInsts,
uint32_t* resultId) {
// Build and append Load
const uint32_t ldResultId = TakeNextId();
const uint32_t varId =
ptrInst->GetSingleWordInOperand(kAccessChainPtrIdInIdx);
const ir::Instruction* varInst = get_def_use_mgr()->GetDef(varId);
assert(varInst->opcode() == SpvOpVariable);
const uint32_t varPteTypeId = GetPointeeTypeId(varInst);
std::vector<ir::Operand> load_in_operands;
load_in_operands.push_back(
ir::Operand(spv_operand_type_t::SPV_OPERAND_TYPE_ID,
std::initializer_list<uint32_t>{varId}));
std::unique_ptr<ir::Instruction> newLoad(new ir::Instruction(
context(), SpvOpLoad, varPteTypeId, ldResultId, load_in_operands));
get_def_use_mgr()->AnalyzeInstDefUse(&*newLoad);
newInsts->emplace_back(std::move(newLoad));
// Build and append Extract
const uint32_t extResultId = TakeNextId();
const uint32_t ptrPteTypeId = GetPointeeTypeId(ptrInst);
std::vector<ir::Operand> ext_in_opnds;
ext_in_opnds.push_back(
ir::Operand(spv_operand_type_t::SPV_OPERAND_TYPE_ID,
std::initializer_list<uint32_t>{ldResultId}));
uint32_t iidIdx = 0;
ptrInst->ForEachInId([&iidIdx, &ext_in_opnds, this](const uint32_t* iid) {
if (iidIdx > 0) {
const ir::Instruction* cInst = get_def_use_mgr()->GetDef(*iid);
uint32_t val = cInst->GetSingleWordInOperand(kConstantValueInIdx);
ext_in_opnds.push_back(
ir::Operand(spv_operand_type_t::SPV_OPERAND_TYPE_LITERAL_INTEGER,
std::initializer_list<uint32_t>{val}));
}
++iidIdx;
});
std::unique_ptr<ir::Instruction> newExt(
new ir::Instruction(context(), SpvOpCompositeExtract, ptrPteTypeId,
extResultId, ext_in_opnds));
get_def_use_mgr()->AnalyzeInstDefUse(&*newExt);
newInsts->emplace_back(std::move(newExt));
*resultId = extResultId;
}
bool CommonUniformElimPass::IsConstantIndexAccessChain(ir::Instruction* acp) {
uint32_t inIdx = 0;
return acp->WhileEachInId([&inIdx, this](uint32_t* tid) {
if (inIdx > 0) {
ir::Instruction* opInst = get_def_use_mgr()->GetDef(*tid);
if (opInst->opcode() != SpvOpConstant) return false;
}
++inIdx;
return true;
});
}
bool CommonUniformElimPass::UniformAccessChainConvert(ir::Function* func) {
bool modified = false;
for (auto bi = func->begin(); bi != func->end(); ++bi) {
for (ir::Instruction* inst = &*bi->begin(); inst; inst = inst->NextNode()) {
if (inst->opcode() != SpvOpLoad) continue;
uint32_t varId;
ir::Instruction* ptrInst = GetPtr(inst, &varId);
if (!IsNonPtrAccessChain(ptrInst->opcode())) continue;
// Do not convert nested access chains
if (ptrInst->GetSingleWordInOperand(kAccessChainPtrIdInIdx) != varId)
continue;
if (!IsUniformVar(varId)) continue;
if (!IsConstantIndexAccessChain(ptrInst)) continue;
if (HasUnsupportedDecorates(inst->result_id())) continue;
if (HasUnsupportedDecorates(ptrInst->result_id())) continue;
if (IsVolatileLoad(*inst)) continue;
if (IsAccessChainToVolatileStructType(*ptrInst)) continue;
std::vector<std::unique_ptr<ir::Instruction>> newInsts;
uint32_t replId;
GenACLoadRepl(ptrInst, &newInsts, &replId);
inst = ReplaceAndDeleteLoad(inst, replId, ptrInst);
inst = inst->InsertBefore(std::move(newInsts));
modified = true;
};
}
return modified;
}
void CommonUniformElimPass::ComputeStructuredSuccessors(ir::Function* func) {
block2structured_succs_.clear();
for (auto& blk : *func) {
// If header, make merge block first successor.
uint32_t mbid = blk.MergeBlockIdIfAny();
if (mbid != 0) {
block2structured_succs_[&blk].push_back(cfg()->block(mbid));
uint32_t cbid = blk.ContinueBlockIdIfAny();
if (cbid != 0) {
block2structured_succs_[&blk].push_back(cfg()->block(mbid));
}
}
// add true successors
blk.ForEachSuccessorLabel([&blk, this](uint32_t sbid) {
block2structured_succs_[&blk].push_back(cfg()->block(sbid));
});
}
}
void CommonUniformElimPass::ComputeStructuredOrder(
ir::Function* func, std::list<ir::BasicBlock*>* order) {
// Compute structured successors and do DFS
ComputeStructuredSuccessors(func);
auto ignore_block = [](cbb_ptr) {};
auto ignore_edge = [](cbb_ptr, cbb_ptr) {};
auto get_structured_successors = [this](const ir::BasicBlock* block) {
return &(block2structured_succs_[block]);
};
// TODO(greg-lunarg): Get rid of const_cast by making moving const
// out of the cfa.h prototypes and into the invoking code.
auto post_order = [&](cbb_ptr b) {
order->push_front(const_cast<ir::BasicBlock*>(b));
};
order->clear();
spvtools::CFA<ir::BasicBlock>::DepthFirstTraversal(
&*func->begin(), get_structured_successors, ignore_block, post_order,
ignore_edge);
}
bool CommonUniformElimPass::CommonUniformLoadElimination(ir::Function* func) {
// Process all blocks in structured order. This is just one way (the
// simplest?) to keep track of the most recent block outside of control
// flow, used to copy common instructions, guaranteed to dominate all
// following load sites.
std::list<ir::BasicBlock*> structuredOrder;
ComputeStructuredOrder(func, &structuredOrder);
uniform2load_id_.clear();
bool modified = false;
// Find insertion point in first block to copy non-dominating loads.
auto insertItr = func->begin()->begin();
while (insertItr->opcode() == SpvOpVariable ||
insertItr->opcode() == SpvOpNop)
++insertItr;
uint32_t mergeBlockId = 0;
for (auto bi = structuredOrder.begin(); bi != structuredOrder.end(); ++bi) {
ir::BasicBlock* bp = *bi;
// Check if we are exiting outermost control construct. If so, remember
// new load insertion point. Trying to keep register pressure down.
if (mergeBlockId == bp->id()) {
mergeBlockId = 0;
insertItr = bp->begin();
}
for (ir::Instruction* inst = &*bp->begin(); inst; inst = inst->NextNode()) {
if (inst->opcode() != SpvOpLoad) continue;
uint32_t varId;
ir::Instruction* ptrInst = GetPtr(inst, &varId);
if (ptrInst->opcode() != SpvOpVariable) continue;
if (!IsUniformVar(varId)) continue;
if (IsSamplerOrImageVar(varId)) continue;
if (HasUnsupportedDecorates(inst->result_id())) continue;
if (IsVolatileLoad(*inst)) continue;
uint32_t replId;
const auto uItr = uniform2load_id_.find(varId);
if (uItr != uniform2load_id_.end()) {
replId = uItr->second;
} else {
if (mergeBlockId == 0) {
// Load is in dominating block; just remember it
uniform2load_id_[varId] = inst->result_id();
continue;
} else {
// Copy load into most recent dominating block and remember it
replId = TakeNextId();
std::unique_ptr<ir::Instruction> newLoad(new ir::Instruction(
context(), SpvOpLoad, inst->type_id(), replId,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {varId}}}));
get_def_use_mgr()->AnalyzeInstDefUse(&*newLoad);
insertItr = insertItr.InsertBefore(std::move(newLoad));
++insertItr;
uniform2load_id_[varId] = replId;
}
}
inst = ReplaceAndDeleteLoad(inst, replId, ptrInst);
modified = true;
}
// If we are outside of any control construct and entering one, remember
// the id of the merge block
if (mergeBlockId == 0) {
mergeBlockId = bp->MergeBlockIdIfAny();
}
}
return modified;
}
bool CommonUniformElimPass::CommonUniformLoadElimBlock(ir::Function* func) {
bool modified = false;
for (auto& blk : *func) {
uniform2load_id_.clear();
for (ir::Instruction* inst = &*blk.begin(); inst; inst = inst->NextNode()) {
if (inst->opcode() != SpvOpLoad) continue;
uint32_t varId;
ir::Instruction* ptrInst = GetPtr(inst, &varId);
if (ptrInst->opcode() != SpvOpVariable) continue;
if (!IsUniformVar(varId)) continue;
if (!IsSamplerOrImageVar(varId)) continue;
if (HasUnsupportedDecorates(inst->result_id())) continue;
if (IsVolatileLoad(*inst)) continue;
uint32_t replId;
const auto uItr = uniform2load_id_.find(varId);
if (uItr != uniform2load_id_.end()) {
replId = uItr->second;
} else {
uniform2load_id_[varId] = inst->result_id();
continue;
}
inst = ReplaceAndDeleteLoad(inst, replId, ptrInst);
modified = true;
}
}
return modified;
}
bool CommonUniformElimPass::CommonExtractElimination(ir::Function* func) {
// Find all composite ids with duplicate extracts.
for (auto bi = func->begin(); bi != func->end(); ++bi) {
for (auto ii = bi->begin(); ii != bi->end(); ++ii) {
if (ii->opcode() != SpvOpCompositeExtract) continue;
// TODO(greg-lunarg): Support multiple indices
if (ii->NumInOperands() > 2) continue;
if (HasUnsupportedDecorates(ii->result_id())) continue;
uint32_t compId = ii->GetSingleWordInOperand(kExtractCompositeIdInIdx);
uint32_t idx = ii->GetSingleWordInOperand(kExtractIdx0InIdx);
comp2idx2inst_[compId][idx].push_back(&*ii);
}
}
// For all defs of ids with duplicate extracts, insert new extracts
// after def, and replace and delete old extracts
bool modified = false;
for (auto bi = func->begin(); bi != func->end(); ++bi) {
for (auto ii = bi->begin(); ii != bi->end(); ++ii) {
const auto cItr = comp2idx2inst_.find(ii->result_id());
if (cItr == comp2idx2inst_.end()) continue;
for (auto idxItr : cItr->second) {
if (idxItr.second.size() < 2) continue;
uint32_t replId = TakeNextId();
std::unique_ptr<ir::Instruction> newExtract(
idxItr.second.front()->Clone(context()));
newExtract->SetResultId(replId);
get_def_use_mgr()->AnalyzeInstDefUse(&*newExtract);
++ii;
ii = ii.InsertBefore(std::move(newExtract));
for (auto instItr : idxItr.second) {
uint32_t resId = instItr->result_id();
context()->KillNamesAndDecorates(resId);
(void)context()->ReplaceAllUsesWith(resId, replId);
context()->KillInst(instItr);
}
modified = true;
}
}
}
return modified;
}
bool CommonUniformElimPass::EliminateCommonUniform(ir::Function* func) {
bool modified = false;
modified |= UniformAccessChainConvert(func);
modified |= CommonUniformLoadElimination(func);
modified |= CommonExtractElimination(func);
modified |= CommonUniformLoadElimBlock(func);
return modified;
}
void CommonUniformElimPass::Initialize(ir::IRContext* c) {
InitializeProcessing(c);
// Clear collections.
comp2idx2inst_.clear();
// Initialize extension whitelist
InitExtensions();
};
bool CommonUniformElimPass::AllExtensionsSupported() const {
// If any extension not in whitelist, return false
for (auto& ei : get_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;
}
Pass::Status CommonUniformElimPass::ProcessImpl() {
// Assumes all control flow structured.
// TODO(greg-lunarg): Do SSA rewrite for non-structured control flow
if (!context()->get_feature_mgr()->HasCapability(SpvCapabilityShader))
return Status::SuccessWithoutChange;
// Assumes logical addressing only
// TODO(greg-lunarg): Add support for physical addressing
if (context()->get_feature_mgr()->HasCapability(SpvCapabilityAddresses))
return Status::SuccessWithoutChange;
// Do not process if any disallowed extensions are enabled
if (!AllExtensionsSupported()) 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;
// If non-32-bit integer type in module, terminate processing
// TODO(): Handle non-32-bit integer constants in access chains
for (const ir::Instruction& inst : get_module()->types_values())
if (inst.opcode() == SpvOpTypeInt &&
inst.GetSingleWordInOperand(kTypeIntWidthInIdx) != 32)
return Status::SuccessWithoutChange;
// Process entry point functions
ProcessFunction pfn = [this](ir::Function* fp) {
return EliminateCommonUniform(fp);
};
bool modified = ProcessEntryPointCallTree(pfn, get_module());
return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}
CommonUniformElimPass::CommonUniformElimPass() {}
Pass::Status CommonUniformElimPass::Process(ir::IRContext* c) {
Initialize(c);
return ProcessImpl();
}
void CommonUniformElimPass::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