New spirv-reduce reduction pass: operand to dominating id. (#2099)

* Added a reduction pass to replace ids with ids of the same type that dominate them.
* Introduce helper method for querying whether an operand type is an input id.
This commit is contained in:
Alastair Donaldson 2018-11-26 22:06:21 +00:00 коммит произвёл alan-baker
Родитель e799bfb923
Коммит 3b13040cf9
11 изменённых файлов: 402 добавлений и 24 удалений

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@ -411,6 +411,21 @@ bool spvIsIdType(spv_operand_type_t type) {
}
}
bool spvIsInIdType(spv_operand_type_t type) {
if (!spvIsIdType(type)) {
// If it is not an ID it cannot be an input ID.
return false;
}
switch (type) {
// Blacklist non-input IDs.
case SPV_OPERAND_TYPE_TYPE_ID:
case SPV_OPERAND_TYPE_RESULT_ID:
return false;
default:
return true;
}
}
std::function<bool(unsigned)> spvOperandCanBeForwardDeclaredFunction(
SpvOp opcode) {
std::function<bool(unsigned index)> out;

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@ -131,6 +131,9 @@ spv_operand_pattern_t spvAlternatePatternFollowingImmediate(
// Is the operand an ID?
bool spvIsIdType(spv_operand_type_t type);
// Is the operand an input ID?
bool spvIsInIdType(spv_operand_type_t type);
// Takes the opcode of an instruction and returns
// a function object that will return true if the index
// of the operand can be forward declared. This function will

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@ -618,15 +618,8 @@ inline void Instruction::ForEachId(
inline bool Instruction::WhileEachInId(
const std::function<bool(uint32_t*)>& f) {
for (auto& opnd : operands_) {
switch (opnd.type) {
case SPV_OPERAND_TYPE_RESULT_ID:
case SPV_OPERAND_TYPE_TYPE_ID:
break;
default:
if (spvIsIdType(opnd.type)) {
if (!f(&opnd.words[0])) return false;
}
break;
if (spvIsInIdType(opnd.type)) {
if (!f(&opnd.words[0])) return false;
}
}
return true;
@ -635,15 +628,8 @@ inline bool Instruction::WhileEachInId(
inline bool Instruction::WhileEachInId(
const std::function<bool(const uint32_t*)>& f) const {
for (const auto& opnd : operands_) {
switch (opnd.type) {
case SPV_OPERAND_TYPE_RESULT_ID:
case SPV_OPERAND_TYPE_TYPE_ID:
break;
default:
if (spvIsIdType(opnd.type)) {
if (!f(&opnd.words[0])) return false;
}
break;
if (spvIsInIdType(opnd.type)) {
if (!f(&opnd.words[0])) return false;
}
}
return true;

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@ -14,6 +14,7 @@
set(SPIRV_TOOLS_REDUCE_SOURCES
change_operand_reduction_opportunity.h
operand_to_const_reduction_pass.h
operand_to_dominating_id_reduction_pass.h
reducer.h
reduction_opportunity.h
reduction_pass.h
@ -22,6 +23,7 @@ set(SPIRV_TOOLS_REDUCE_SOURCES
change_operand_reduction_opportunity.cpp
operand_to_const_reduction_pass.cpp
operand_to_dominating_id_reduction_pass.cpp
reducer.cpp
reduction_opportunity.cpp
reduction_pass.cpp

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@ -34,7 +34,7 @@ class ChangeOperandReductionOpportunity : public ReductionOpportunity {
uint32_t new_id)
: inst_(inst),
operand_index_(operand_index),
original_id_(inst_->GetOperand(operand_index_).words[0]),
original_id_(inst->GetOperand(operand_index).words[0]),
original_type_(inst->GetOperand(operand_index).type),
new_id_(new_id) {}

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@ -44,11 +44,7 @@ OperandToConstReductionPass::GetAvailableOpportunities(
// of a ChangeOperandReductionOpportunity
for (uint32_t index = 0; index < inst.NumOperands(); index++) {
const auto& operand = inst.GetOperand(index);
if (spvIsIdType(operand.type)) {
if (operand.type == SPV_OPERAND_TYPE_RESULT_ID ||
operand.type == SPV_OPERAND_TYPE_TYPE_ID) {
continue;
}
if (spvIsInIdType(operand.type)) {
const auto id = operand.words[0];
auto def = context->get_def_use_mgr()->GetDef(id);
if (spvOpcodeIsConstant(def->opcode())) {

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@ -0,0 +1,114 @@
// Copyright (c) 2018 Google 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 "operand_to_dominating_id_reduction_pass.h"
#include "change_operand_reduction_opportunity.h"
#include "source/opt/instruction.h"
namespace spvtools {
namespace reduce {
using namespace opt;
std::vector<std::unique_ptr<ReductionOpportunity>>
OperandToDominatingIdReductionPass::GetAvailableOpportunities(
opt::IRContext* context) const {
std::vector<std::unique_ptr<ReductionOpportunity>> result;
// Go through every instruction in every block, considering it as a potential
// dominator of other instructions. We choose this order for two reasons:
//
// (1) it is profitable for multiple opportunities to replace the same id x by
// different dominating ids y and z to be discontiguous, as they are
// incompatible.
//
// (2) We want to prioritise opportunities to replace an id with a more
// distant dominator. Intuitively, in a human-readable programming language
// if we have a complex expression e with many sub-expressions, we would like
// to prioritise replacing e with its smallest sub-expressions; generalising
// this idea to dominating ids this roughly corresponds to more distant
// dominators.
for (auto& function : *context->module()) {
for (auto dominating_block = function.begin();
dominating_block != function.end(); ++dominating_block) {
for (auto& dominating_inst : *dominating_block) {
if (dominating_inst.HasResultId() && dominating_inst.type_id()) {
// Consider replacing any operand with matching type in a dominated
// instruction with the id generated by this instruction.
GetOpportunitiesForDominatingInst(
&result, &dominating_inst, dominating_block, &function, context);
}
}
}
}
return result;
}
void OperandToDominatingIdReductionPass::GetOpportunitiesForDominatingInst(
std::vector<std::unique_ptr<ReductionOpportunity>>* opportunities,
opt::Instruction* candidate_dominator,
opt::Function::iterator candidate_dominator_block, opt::Function* function,
opt::IRContext* context) const {
assert(candidate_dominator->HasResultId());
assert(candidate_dominator->type_id());
auto dominator_analysis = context->GetDominatorAnalysis(function);
// SPIR-V requires a block to precede all blocks it dominates, so it suffices
// to search from the candidate dominator block onwards.
for (auto block = candidate_dominator_block; block != function->end();
++block) {
if (!dominator_analysis->Dominates(&*candidate_dominator_block, &*block)) {
// If the candidate dominator block doesn't dominate this block then there
// cannot be any of the desired reduction opportunities in this block.
continue;
}
for (auto& inst : *block) {
// We iterate through the operands using an explicit index (rather
// than using a lambda) so that we use said index in the construction
// of a ChangeOperandReductionOpportunity
for (uint32_t index = 0; index < inst.NumOperands(); index++) {
const auto& operand = inst.GetOperand(index);
if (spvIsInIdType(operand.type)) {
const auto id = operand.words[0];
auto def = context->get_def_use_mgr()->GetDef(id);
assert(def);
if (!context->get_instr_block(def)) {
// The definition does not come from a block; e.g. it might be a
// constant. It is thus not relevant to this pass.
continue;
}
// Sanity check that we don't get here if the argument is a constant.
assert(!context->get_constant_mgr()->GetConstantFromInst(def));
if (def->type_id() != candidate_dominator->type_id()) {
// The types need to match.
continue;
}
if (candidate_dominator != def &&
dominator_analysis->Dominates(candidate_dominator, def)) {
// A hit: the candidate dominator strictly dominates the definition.
opportunities->push_back(
MakeUnique<ChangeOperandReductionOpportunity>(
&inst, index, candidate_dominator->result_id()));
}
}
}
}
}
}
std::string OperandToDominatingIdReductionPass::GetName() const {
return "OperandToDominatingIdReductionPass";
}
} // namespace reduce
} // namespace spvtools

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@ -0,0 +1,62 @@
// Copyright (c) 2018 Google 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.
#ifndef SOURCE_REDUCE_OPERAND_TO_DOMINATING_ID_REDUCTION_PASS_H_
#define SOURCE_REDUCE_OPERAND_TO_DOMINATING_ID_REDUCTION_PASS_H_
#include "reduction_pass.h"
namespace spvtools {
namespace reduce {
// A reduction pass that aims to bring to SPIR-V (and generalize) the idea from
// human-readable languages of e.g. replacing an expression with one of its
// arguments, (x + y) -> x, or with a reference to an identifier that was
// assigned to higher up in the program. The generalization of this is to
// replace an id with a different id of the same type defined in some
// dominating instruction.
//
// If id x is defined and then used several times, changing each use of x to
// some dominating definition may eventually allow the statement defining x
// to be eliminated by another pass.
class OperandToDominatingIdReductionPass : public ReductionPass {
public:
// Creates the reduction pass in the context of the given target environment
// |target_env|
explicit OperandToDominatingIdReductionPass(const spv_target_env target_env)
: ReductionPass(target_env) {}
~OperandToDominatingIdReductionPass() override = default;
// The name of this pass.
std::string GetName() const final;
protected:
// Finds all opportunities for replacing an operand with a dominating
// instruction in a given module.
std::vector<std::unique_ptr<ReductionOpportunity>> GetAvailableOpportunities(
opt::IRContext* context) const final;
private:
void GetOpportunitiesForDominatingInst(
std::vector<std::unique_ptr<ReductionOpportunity>>* opportunities,
opt::Instruction* dominating_instruction,
opt::Function::iterator candidate_dominator_block,
opt::Function* function, opt::IRContext* context) const;
};
} // namespace reduce
} // namespace spvtools
#endif // SOURCE_REDUCE_OPERAND_TO_DOMINATING_ID_REDUCTION_PASS_H_

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@ -14,6 +14,7 @@
add_spvtools_unittest(TARGET reduce
SRCS operand_to_constant_reduction_pass_test.cpp
operand_to_dominating_id_reduction_pass_test.cpp
reduce_test_util.cpp
reduce_test_util.h
reducer_test.cpp

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@ -0,0 +1,196 @@
// Copyright (c) 2018 Google 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/reduce/operand_to_dominating_id_reduction_pass.h"
#include "reduce_test_util.h"
#include "source/opt/build_module.h"
namespace spvtools {
namespace reduce {
namespace {
TEST(OperandToDominatingIdReductionPassTest, BasicCheck) {
std::string original = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %4 "main"
OpExecutionMode %4 OriginUpperLeft
OpSource ESSL 310
%2 = OpTypeVoid
%3 = OpTypeFunction %2
%6 = OpTypeInt 32 1
%7 = OpTypePointer Function %6
%9 = OpConstant %6 2
%4 = OpFunction %2 None %3
%5 = OpLabel
%8 = OpVariable %7 Function
%10 = OpVariable %7 Function
%14 = OpVariable %7 Function
OpStore %8 %9
%11 = OpLoad %6 %8
%12 = OpLoad %6 %8
%13 = OpIAdd %6 %11 %12
OpStore %10 %13
%15 = OpLoad %6 %10
OpStore %14 %15
OpReturn
OpFunctionEnd
)";
const auto env = SPV_ENV_UNIVERSAL_1_3;
const auto consumer = nullptr;
const auto context =
BuildModule(env, consumer, original, kReduceAssembleOption);
const auto pass = TestSubclass<OperandToDominatingIdReductionPass>(env);
const auto ops = pass.WrapGetAvailableOpportunities(context.get());
ASSERT_EQ(10, ops.size());
ASSERT_TRUE(ops[0]->PreconditionHolds());
ops[0]->TryToApply();
std::string after_op_0 = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %4 "main"
OpExecutionMode %4 OriginUpperLeft
OpSource ESSL 310
%2 = OpTypeVoid
%3 = OpTypeFunction %2
%6 = OpTypeInt 32 1
%7 = OpTypePointer Function %6
%9 = OpConstant %6 2
%4 = OpFunction %2 None %3
%5 = OpLabel
%8 = OpVariable %7 Function
%10 = OpVariable %7 Function
%14 = OpVariable %7 Function
OpStore %8 %9
%11 = OpLoad %6 %8
%12 = OpLoad %6 %8
%13 = OpIAdd %6 %11 %12
OpStore %8 %13 ; %10 -> %8
%15 = OpLoad %6 %10
OpStore %14 %15
OpReturn
OpFunctionEnd
)";
CheckEqual(env, after_op_0, context.get());
ASSERT_TRUE(ops[1]->PreconditionHolds());
ops[1]->TryToApply();
std::string after_op_1 = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %4 "main"
OpExecutionMode %4 OriginUpperLeft
OpSource ESSL 310
%2 = OpTypeVoid
%3 = OpTypeFunction %2
%6 = OpTypeInt 32 1
%7 = OpTypePointer Function %6
%9 = OpConstant %6 2
%4 = OpFunction %2 None %3
%5 = OpLabel
%8 = OpVariable %7 Function
%10 = OpVariable %7 Function
%14 = OpVariable %7 Function
OpStore %8 %9
%11 = OpLoad %6 %8
%12 = OpLoad %6 %8
%13 = OpIAdd %6 %11 %12
OpStore %8 %13 ; %10 -> %8
%15 = OpLoad %6 %8 ; %10 -> %8
OpStore %14 %15
OpReturn
OpFunctionEnd
)";
CheckEqual(env, after_op_1, context.get());
ASSERT_TRUE(ops[2]->PreconditionHolds());
ops[2]->TryToApply();
std::string after_op_2 = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %4 "main"
OpExecutionMode %4 OriginUpperLeft
OpSource ESSL 310
%2 = OpTypeVoid
%3 = OpTypeFunction %2
%6 = OpTypeInt 32 1
%7 = OpTypePointer Function %6
%9 = OpConstant %6 2
%4 = OpFunction %2 None %3
%5 = OpLabel
%8 = OpVariable %7 Function
%10 = OpVariable %7 Function
%14 = OpVariable %7 Function
OpStore %8 %9
%11 = OpLoad %6 %8
%12 = OpLoad %6 %8
%13 = OpIAdd %6 %11 %12
OpStore %8 %13 ; %10 -> %8
%15 = OpLoad %6 %8 ; %10 -> %8
OpStore %8 %15 ; %14 -> %8
OpReturn
OpFunctionEnd
)";
CheckEqual(env, after_op_2, context.get());
// The precondition has been disabled by an earlier opportunity's application.
ASSERT_FALSE(ops[3]->PreconditionHolds());
ASSERT_TRUE(ops[4]->PreconditionHolds());
ops[4]->TryToApply();
std::string after_op_4 = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %4 "main"
OpExecutionMode %4 OriginUpperLeft
OpSource ESSL 310
%2 = OpTypeVoid
%3 = OpTypeFunction %2
%6 = OpTypeInt 32 1
%7 = OpTypePointer Function %6
%9 = OpConstant %6 2
%4 = OpFunction %2 None %3
%5 = OpLabel
%8 = OpVariable %7 Function
%10 = OpVariable %7 Function
%14 = OpVariable %7 Function
OpStore %8 %9
%11 = OpLoad %6 %8
%12 = OpLoad %6 %8
%13 = OpIAdd %6 %11 %11 ; %12 -> %11
OpStore %8 %13 ; %10 -> %8
%15 = OpLoad %6 %8 ; %10 -> %8
OpStore %8 %15 ; %14 -> %8
OpReturn
OpFunctionEnd
)";
CheckEqual(env, after_op_4, context.get());
}
} // namespace
} // namespace reduce
} // namespace spvtools

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@ -21,6 +21,7 @@
#include "source/opt/ir_context.h"
#include "source/opt/log.h"
#include "source/reduce/operand_to_const_reduction_pass.h"
#include "source/reduce/operand_to_dominating_id_reduction_pass.h"
#include "source/reduce/reducer.h"
#include "source/reduce/remove_unreferenced_instruction_reduction_pass.h"
#include "source/spirv_reducer_options.h"
@ -204,6 +205,8 @@ int main(int argc, const char** argv) {
reducer.AddReductionPass(
spvtools::MakeUnique<OperandToConstReductionPass>(target_env));
reducer.AddReductionPass(
spvtools::MakeUnique<OperandToDominatingIdReductionPass>(target_env));
reducer.AddReductionPass(
spvtools::MakeUnique<RemoveUnreferencedInstructionReductionPass>(
target_env));