llvm/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp

//===- SIAnnotateControlFlow.cpp ------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
/// \file
/// Annotates the control flow with hardware specific intrinsics.
//
//===----------------------------------------------------------------------===//

#include "AMDGPU.h"
#include "AMDGPUTargetMachine.h"
#include "GCNSubtarget.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/UniformityAnalysis.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/IntrinsicsAMDGPU.h"
#include "llvm/InitializePasses.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"

usingnamespacellvm;

#define DEBUG_TYPE …

namespace {

// Complex types used in this pass
StackEntry;
StackVector;

class SIAnnotateControlFlow { … };

} // end anonymous namespace

/// Initialize all the types and constants used in the pass
void SIAnnotateControlFlow::initialize(Module &M, const GCNSubtarget &ST) { … }

/// Is the branch condition uniform or did the StructurizeCFG pass
/// consider it as such?
bool SIAnnotateControlFlow::isUniform(BranchInst *T) { … }

/// Is BB the last block saved on the stack ?
bool SIAnnotateControlFlow::isTopOfStack(BasicBlock *BB) { … }

/// Pop the last saved value from the control flow stack
Value *SIAnnotateControlFlow::popSaved() { … }

/// Push a BB and saved value to the control flow stack
void SIAnnotateControlFlow::push(BasicBlock *BB, Value *Saved) { … }

/// Can the condition represented by this PHI node treated like
/// an "Else" block?
bool SIAnnotateControlFlow::isElse(PHINode *Phi) { … }

bool SIAnnotateControlFlow::hasKill(const BasicBlock *BB) { … }

// Erase "Phi" if it is not used any more. Return true if any change was made.
bool SIAnnotateControlFlow::eraseIfUnused(PHINode *Phi) { … }

/// Open a new "If" block
bool SIAnnotateControlFlow::openIf(BranchInst *Term) { … }

/// Close the last "If" block and open a new "Else" block
bool SIAnnotateControlFlow::insertElse(BranchInst *Term) { … }

/// Recursively handle the condition leading to a loop
Value *SIAnnotateControlFlow::handleLoopCondition(
    Value *Cond, PHINode *Broken, llvm::Loop *L, BranchInst *Term) { … }

/// Handle a back edge (loop)
bool SIAnnotateControlFlow::handleLoop(BranchInst *Term) { … }

/// Close the last opened control flow
bool SIAnnotateControlFlow::closeControlFlow(BasicBlock *BB) { … }

/// Annotate the control flow with intrinsics so the backend can
/// recognize if/then/else and loops.
bool SIAnnotateControlFlow::run(Function &F) { … }

PreservedAnalyses SIAnnotateControlFlowPass::run(Function &F,
                                                 FunctionAnalysisManager &FAM) { … }

class SIAnnotateControlFlowLegacy : public FunctionPass { … };

INITIALIZE_PASS_BEGIN(SIAnnotateControlFlowLegacy, DEBUG_TYPE,
                      "Annotate SI Control Flow", false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(UniformityInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
INITIALIZE_PASS_END(SIAnnotateControlFlowLegacy, DEBUG_TYPE,
                    "Annotate SI Control Flow", false, false)

char SIAnnotateControlFlowLegacy::ID = …;

/// Create the annotation pass
FunctionPass *llvm::createSIAnnotateControlFlowLegacyPass() { … }