lib/AddFunctionAttributesPass.cpp

// Copyright 2020 The Clspv Authors. All rights reserved.
//
// 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 "llvm/IR/Attributes.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"

#include "AddFunctionAttributesPass.h"
#include "Constants.h"

using namespace llvm;

PreservedAnalyses
clspv::AddFunctionAttributesPass::run(Module &M, ModuleAnalysisManager &) {
  PreservedAnalyses PA;

  // Clspv can't respect the optnone attribute.
  for (auto &F : M) {
    F.removeFnAttr(Attribute::AttrKind::OptimizeNone);
  }

  // Add ReadNone and Speculatable to literal sampler functions to avoid loop
  // optimizations producing phis with them.
  if (auto F = M.getFunction(clspv::TranslateSamplerInitializerFunction())) {
    F->setDoesNotAccessMemory();
    F->addFnAttr(Attribute::AttrKind::Speculatable);
  }

  return PA;
}