SPIRV-Tools/source/opt/wrap_opkill.cpp
Steven Perron 60043edfa1
Replace OpKill With function call. (#2790)
We are no able to inline OpKill instructions into a continue construct.
See #2433.  However, we have to be able to inline to correctly do
legalization.  This commit creates a pass that will wrap OpKill
instructions into a function of its own.  That way we are able to inline
the rest of the code.

The follow up to this will be to not inline any function that contains
an OpKill.

Fixes #2726
2019-08-14 09:27:12 -04:00

126 lines
4.1 KiB
C++

// Copyright (c) 2019 Google LLC
//
// 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/opt/wrap_opkill.h"
#include "ir_builder.h"
namespace spvtools {
namespace opt {
Pass::Status WrapOpKill::Process() {
bool modified = false;
for (auto& func : *get_module()) {
func.ForEachInst([this, &modified](Instruction* inst) {
if (inst->opcode() == SpvOpKill) {
modified = true;
ReplaceWithFunctionCall(inst);
}
});
}
if (opkill_function_ != nullptr) {
assert(modified &&
"The function should only be generated if something was modified.");
context()->AddFunction(std::move(opkill_function_));
}
return (modified ? Status::SuccessWithChange : Status::SuccessWithoutChange);
}
void WrapOpKill::ReplaceWithFunctionCall(Instruction* inst) {
assert(inst->opcode() == SpvOpKill &&
"|inst| must be an OpKill instruction.");
InstructionBuilder ir_builder(
context(), inst,
IRContext::kAnalysisDefUse | IRContext::kAnalysisInstrToBlockMapping);
ir_builder.AddFunctionCall(GetVoidTypeId(), GetOpKillFuncId(), {});
ir_builder.AddUnreachable();
context()->KillInst(inst);
}
uint32_t WrapOpKill::GetVoidTypeId() {
if (void_type_id_ != 0) {
return void_type_id_;
}
analysis::TypeManager* type_mgr = context()->get_type_mgr();
analysis::Void void_type;
void_type_id_ = type_mgr->GetTypeInstruction(&void_type);
return void_type_id_;
}
uint32_t WrapOpKill::GetVoidFunctionTypeId() {
analysis::TypeManager* type_mgr = context()->get_type_mgr();
analysis::Void void_type;
const analysis::Type* registered_void_type =
type_mgr->GetRegisteredType(&void_type);
analysis::Function func_type(registered_void_type, {});
return type_mgr->GetTypeInstruction(&func_type);
}
uint32_t WrapOpKill::GetOpKillFuncId() {
if (opkill_function_ != nullptr) {
return opkill_function_->result_id();
}
uint32_t opkill_func_id = TakeNextId();
// Generate the function start instruction
std::unique_ptr<Instruction> func_start(new Instruction(
context(), SpvOpFunction, GetVoidTypeId(), opkill_func_id, {}));
func_start->AddOperand({SPV_OPERAND_TYPE_FUNCTION_CONTROL, {0}});
func_start->AddOperand({SPV_OPERAND_TYPE_ID, {GetVoidFunctionTypeId()}});
opkill_function_.reset(new Function(std::move(func_start)));
// Generate the function end instruction
std::unique_ptr<Instruction> func_end(
new Instruction(context(), SpvOpFunctionEnd, 0, 0, {}));
opkill_function_->SetFunctionEnd(std::move(func_end));
// Create the one basic block for the function.
std::unique_ptr<Instruction> label_inst(
new Instruction(context(), SpvOpLabel, 0, TakeNextId(), {}));
std::unique_ptr<BasicBlock> bb(new BasicBlock(std::move(label_inst)));
// Add the OpKill to the basic block
std::unique_ptr<Instruction> kill_inst(
new Instruction(context(), SpvOpKill, 0, 0, {}));
bb->AddInstruction(std::move(kill_inst));
// Add the bb to the function
opkill_function_->AddBasicBlock(std::move(bb));
// Add the function to the module.
if (context()->AreAnalysesValid(IRContext::kAnalysisDefUse)) {
opkill_function_->ForEachInst(
[this](Instruction* inst) { context()->AnalyzeDefUse(inst); });
}
if (context()->AreAnalysesValid(IRContext::kAnalysisInstrToBlockMapping)) {
for (BasicBlock& basic_block : *opkill_function_) {
context()->set_instr_block(basic_block.GetLabelInst(), &basic_block);
for (Instruction& inst : basic_block) {
context()->set_instr_block(&inst, &basic_block);
}
}
}
return opkill_function_->result_id();
}
} // namespace opt
} // namespace spvtools