SPIRV-Tools/source/opt/basic_block.cpp
Steven Perron bb7802b18c Change BasicBlock to use InstructionList to hold instructions.
This is the first step in replacing the std::vector of Instruction
pointers to using and intrusive linked list.

To this end, we created the InstructionList class.  It inherites from
the IntrusiveList class, but add the extra concept of ownership.  An
InstructionList owns the instruction that are in it.  This is to be
consistent with the current ownership rules where the vector owns the
instruction that are in it.

The other larger change is that the inst_ member of the BasicBlock class
was changed to using the InstructionList class.

Added test for the InsertBefore functions, and making sure that the
InstructionList destructor will delete the elements that it contains.

I've also add extra comments to explain ownership a little better.
2017-10-20 12:37:44 -04:00

114 lines
2.9 KiB
C++

// Copyright (c) 2016 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 "basic_block.h"
#include "make_unique.h"
namespace spvtools {
namespace ir {
BasicBlock::BasicBlock(const BasicBlock& bb)
: function_(nullptr),
label_(MakeUnique<Instruction>(bb.GetLabelInst())),
insts_() {
for (auto& inst : bb.insts_)
AddInstruction(std::unique_ptr<Instruction>(inst.Clone()));
}
const Instruction* BasicBlock::GetMergeInst() const {
const Instruction* result = nullptr;
// If it exists, the merge instruction immediately precedes the
// terminator.
auto iter = ctail();
if (iter != cbegin()) {
--iter;
const auto opcode = iter->opcode();
if (opcode == SpvOpLoopMerge || opcode == SpvOpSelectionMerge) {
result = &*iter;
}
}
return result;
}
Instruction* BasicBlock::GetMergeInst() {
Instruction* result = nullptr;
// If it exists, the merge instruction immediately precedes the
// terminator.
auto iter = tail();
if (iter != begin()) {
--iter;
const auto opcode = iter->opcode();
if (opcode == SpvOpLoopMerge || opcode == SpvOpSelectionMerge) {
result = &*iter;
}
}
return result;
}
const Instruction* BasicBlock::GetLoopMergeInst() const {
if (auto* merge = GetMergeInst()) {
if (merge->opcode() == SpvOpLoopMerge) {
return merge;
}
}
return nullptr;
}
Instruction* BasicBlock::GetLoopMergeInst() {
if (auto* merge = GetMergeInst()) {
if (merge->opcode() == SpvOpLoopMerge) {
return merge;
}
}
return nullptr;
}
void BasicBlock::ForEachSuccessorLabel(
const std::function<void(const uint32_t)>& f) {
const auto br = &insts_.back();
switch (br->opcode()) {
case SpvOpBranch: {
f(br->GetOperand(0).words[0]);
} break;
case SpvOpBranchConditional:
case SpvOpSwitch: {
bool is_first = true;
br->ForEachInId([&is_first, &f](const uint32_t* idp) {
if (!is_first) f(*idp);
is_first = false;
});
} break;
default:
break;
}
}
void BasicBlock::ForMergeAndContinueLabel(
const std::function<void(const uint32_t)>& f) {
auto ii = insts_.end();
--ii;
if (ii == insts_.begin()) return;
--ii;
if (ii->opcode() == SpvOpSelectionMerge ||
ii->opcode() == SpvOpLoopMerge)
ii->ForEachInId([&f](const uint32_t* idp) {
f(*idp);
});
}
} // namespace ir
} // namespace spvtools