SPIRV-Tools/source/opt/compact_ids_pass.cpp
Andrey Tuganov 1e309af80a Added --compact-ids to /tools/opt
The pass remaps ids to a compact set which starts with %1 and
has no gaps.
2017-04-20 10:54:39 -04:00

58 lines
1.8 KiB
C++

// Copyright (c) 2017 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 "compact_ids_pass.h"
#include <cassert>
#include <unordered_map>
namespace spvtools {
namespace opt {
using ir::Instruction;
using ir::Operand;
Pass::Status CompactIdsPass::Process(ir::Module* module) {
bool modified = false;
std::unordered_map<uint32_t, uint32_t> result_id_mapping;
module->ForEachInst([&result_id_mapping, &modified] (Instruction* inst) {
auto operand = inst->begin();
while (operand != inst->end()) {
if (spvIsIdType(operand->type)) {
assert(operand->words.size() == 1);
uint32_t& id = operand->words[0];
auto it = result_id_mapping.find(id);
if (it == result_id_mapping.end()) {
const uint32_t new_id =
static_cast<uint32_t>(result_id_mapping.size()) + 1;
const auto insertion_result = result_id_mapping.emplace(id, new_id);
it = insertion_result.first;
assert(insertion_result.second);
}
if (id != it->second) {
modified = true;
id = it->second;
}
}
++operand;
}
}, true);
return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}
} // namespace opt
} // namespace spvtools