llvm/polly/lib/CodeGen/LoopGeneratorsGOMP.cpp

//===------ LoopGeneratorsGOMP.cpp - IR helper to create loops ------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains functions to create parallel loops as LLVM-IR.
//
//===----------------------------------------------------------------------===//

#include "polly/CodeGen/LoopGeneratorsGOMP.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Module.h"

usingnamespacellvm;
usingnamespacepolly;

void ParallelLoopGeneratorGOMP::createCallSpawnThreads(Value *SubFn,
                                                       Value *SubFnParam,
                                                       Value *LB, Value *UB,
                                                       Value *Stride) { … }

void ParallelLoopGeneratorGOMP::deployParallelExecution(Function *SubFn,
                                                        Value *SubFnParam,
                                                        Value *LB, Value *UB,
                                                        Value *Stride) { … }

Function *ParallelLoopGeneratorGOMP::prepareSubFnDefinition(Function *F) const { … }

// Create a subfunction of the following (preliminary) structure:
//
//    PrevBB
//       |
//       v
//    HeaderBB
//       |   _____
//       v  v    |
//   CheckNextBB  PreHeaderBB
//       |\       |
//       | \______/
//       |
//       v
//     ExitBB
//
// HeaderBB will hold allocations and loading of variables.
// CheckNextBB will check for more work.
// If there is more work to do: go to PreHeaderBB, otherwise go to ExitBB.
// PreHeaderBB loads the new boundaries (& will lead to the loop body later on).
// ExitBB marks the end of the parallel execution.
std::tuple<Value *, Function *>
ParallelLoopGeneratorGOMP::createSubFn(Value *Stride, AllocaInst *StructData,
                                       SetVector<Value *> Data,
                                       ValueMapT &Map) { … }

Value *ParallelLoopGeneratorGOMP::createCallGetWorkItem(Value *LBPtr,
                                                        Value *UBPtr) { … }

void ParallelLoopGeneratorGOMP::createCallJoinThreads() { … }

void ParallelLoopGeneratorGOMP::createCallCleanupThread() { … }