SPIRV-Tools/source/opt/remove_duplicates_pass.cpp
Pierre Moreau 7183ad526e Linker code cleanups
Turn `Linker::Link()` into free functions

  As very little information was kept in the Linker class, we can get rid
  of the whole class and have the `Link()` as free functions instead; the
  environment target as well as the consumer are passed along through an
  `spv_context` object.
  The resulting linked_binary is passed as a pointer rather than a
  reference to follow the Google C++ Style guidelines.

  Addresses remaining comments from
  https://github.com/KhronosGroup/SPIRV-Tools/pull/693 about the SPIR-V
  linker.

Fix variable naming in the linker

  Some of the variables were using mixed case, which did not follow the
  Google C++ Style guidelines.

Linker: Use EXPECT_EQ when possible and update some test

* Replace occurrences of ASSERT_EQ by EXPECT_EQ when possible;
* Reformulated some of the error messages;
* Added the symbol name in the error message when there is a type or
  decoration mismatch between the imported and exported declarations.

Opt: List all duplicates removed by RemoveDuplicatePass in the header

Opt: Make the const version of GetLabelInst() return a pointer

  For consistency with the non-const version, as well as other similar
  functions.

Opt: Rename function_end to EndInst()

  As pointed out by dneto0 the previous name was quite confusing and could
  be mistaken with a function returning an end iterator.
  Also change the return type of the const version to a pointer rather
  than a reference, for consistency.

Opt: Add performance comment to RemoveDuplicateTypes and decorations

  This comment was requested during the review of
  https://github.com/KhronosGroup/SPIRV-Tools/pull/693.

Opt: Add comments and fix variable naming in RemoveDuplicatePass

* Add missing comments to private functions;
* Rename variables that were using mixed case;
* Add TODO for moving AreTypesEqual out.

Linker: Remove commented out code and add TODOs

Linker: Merged together strings that were too much splitted

Implement a C++ RAII wrapper around spv_context
2018-01-05 13:28:44 -05:00

206 lines
5.9 KiB
C++

// Copyright (c) 2017 Pierre Moreau
//
// 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 "remove_duplicates_pass.h"
#include <cstring>
#include <algorithm>
#include <limits>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "decoration_manager.h"
#include "ir_context.h"
#include "opcode.h"
#include "reflect.h"
namespace spvtools {
namespace opt {
using ir::Instruction;
using ir::Module;
using ir::Operand;
using opt::analysis::DecorationManager;
using opt::analysis::DefUseManager;
Pass::Status RemoveDuplicatesPass::Process(ir::IRContext* ir_context) {
bool modified = RemoveDuplicateCapabilities(ir_context);
modified |= RemoveDuplicatesExtInstImports(ir_context);
modified |= RemoveDuplicateTypes(ir_context);
modified |= RemoveDuplicateDecorations(ir_context);
return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}
bool RemoveDuplicatesPass::RemoveDuplicateCapabilities(
ir::IRContext* ir_context) const {
bool modified = false;
if (ir_context->capabilities().empty()) {
return modified;
}
std::unordered_set<uint32_t> capabilities;
for (auto* i = &*ir_context->capability_begin(); i;) {
auto res = capabilities.insert(i->GetSingleWordOperand(0u));
if (res.second) {
// Never seen before, keep it.
i = i->NextNode();
} else {
// It's a duplicate, remove it.
i = ir_context->KillInst(i);
modified = true;
}
}
return modified;
}
bool RemoveDuplicatesPass::RemoveDuplicatesExtInstImports(
ir::IRContext* ir_context) const {
bool modified = false;
if (ir_context->ext_inst_imports().empty()) {
return modified;
}
std::unordered_map<std::string, SpvId> ext_inst_imports;
for (auto* i = &*ir_context->ext_inst_import_begin(); i;) {
auto res = ext_inst_imports.emplace(
reinterpret_cast<const char*>(i->GetInOperand(0u).words.data()),
i->result_id());
if (res.second) {
// Never seen before, keep it.
i = i->NextNode();
} else {
// It's a duplicate, remove it.
ir_context->ReplaceAllUsesWith(i->result_id(), res.first->second);
i = ir_context->KillInst(i);
modified = true;
}
}
return modified;
}
bool RemoveDuplicatesPass::RemoveDuplicateTypes(
ir::IRContext* ir_context) const {
bool modified = false;
if (ir_context->types_values().empty()) {
return modified;
}
std::vector<Instruction*> visited_types;
std::vector<Instruction*> to_delete;
for (auto* i = &*ir_context->types_values_begin(); i; i = i->NextNode()) {
// We only care about types.
if (!spvOpcodeGeneratesType((i->opcode())) &&
i->opcode() != SpvOpTypeForwardPointer) {
continue;
}
// Is the current type equal to one of the types we have aready visited?
SpvId id_to_keep = 0u;
// TODO(dneto0): Use a trie to avoid quadratic behaviour? Extract the
// ResultIdTrie from unify_const_pass.cpp for this.
for (auto j : visited_types) {
if (AreTypesEqual(*i, *j, ir_context)) {
id_to_keep = j->result_id();
break;
}
}
if (id_to_keep == 0u) {
// This is a never seen before type, keep it around.
visited_types.emplace_back(i);
} else {
// The same type has already been seen before, remove this one.
ir_context->ReplaceAllUsesWith(i->result_id(), id_to_keep);
modified = true;
to_delete.emplace_back(i);
}
}
for (auto i : to_delete) {
ir_context->KillInst(i);
}
return modified;
}
// TODO(pierremoreau): Duplicate decoration groups should be removed. For
// example, in
// OpDecorate %1 Constant
// %1 = OpDecorationGroup
// OpDecorate %2 Constant
// %2 = OpDecorationGroup
// OpGroupDecorate %1 %3
// OpGroupDecorate %2 %4
// group %2 could be removed.
bool RemoveDuplicatesPass::RemoveDuplicateDecorations(
ir::IRContext* ir_context) const {
bool modified = false;
std::vector<const Instruction*> visited_decorations;
opt::analysis::DecorationManager decoration_manager(ir_context->module());
for (auto* i = &*ir_context->annotation_begin(); i;) {
// Is the current decoration equal to one of the decorations we have aready
// visited?
bool already_visited = false;
// TODO(dneto0): Use a trie to avoid quadratic behaviour? Extract the
// ResultIdTrie from unify_const_pass.cpp for this.
for (const Instruction* j : visited_decorations) {
if (decoration_manager.AreDecorationsTheSame(&*i, j, false)) {
already_visited = true;
break;
}
}
if (!already_visited) {
// This is a never seen before decoration, keep it around.
visited_decorations.emplace_back(&*i);
i = i->NextNode();
} else {
// The same decoration has already been seen before, remove this one.
modified = true;
i = ir_context->KillInst(i);
}
}
return modified;
}
bool RemoveDuplicatesPass::AreTypesEqual(const Instruction& inst1,
const Instruction& inst2,
ir::IRContext* context) {
if (inst1.opcode() != inst2.opcode()) return false;
if (!ir::IsTypeInst(inst1.opcode())) return false;
const analysis::Type* type1 =
context->get_type_mgr()->GetType(inst1.result_id());
const analysis::Type* type2 =
context->get_type_mgr()->GetType(inst2.result_id());
if (type1 && type2 && *type1 == *type2) return true;
return false;
}
} // namespace opt
} // namespace spvtools