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-rw-r--r--contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp375
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diff --git a/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp b/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
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--- a/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
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@@ -1,375 +0,0 @@
-//===- 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 "AMDGPUSubtarget.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Analysis/LegacyDivergenceAnalysis.h"
-#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/CodeGen/TargetPassConfig.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CFG.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/ValueHandle.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include <cassert>
-#include <utility>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "si-annotate-control-flow"
-
-namespace {
-
-// Complex types used in this pass
-using StackEntry = std::pair<BasicBlock *, Value *>;
-using StackVector = SmallVector<StackEntry, 16>;
-
-class SIAnnotateControlFlow : public FunctionPass {
- LegacyDivergenceAnalysis *DA;
-
- Type *Boolean;
- Type *Void;
- Type *IntMask;
- Type *ReturnStruct;
-
- ConstantInt *BoolTrue;
- ConstantInt *BoolFalse;
- UndefValue *BoolUndef;
- Constant *IntMaskZero;
-
- Function *If;
- Function *Else;
- Function *IfBreak;
- Function *Loop;
- Function *EndCf;
-
- DominatorTree *DT;
- StackVector Stack;
-
- LoopInfo *LI;
-
- void initialize(Module &M, const GCNSubtarget &ST);
-
- bool isUniform(BranchInst *T);
-
- bool isTopOfStack(BasicBlock *BB);
-
- Value *popSaved();
-
- void push(BasicBlock *BB, Value *Saved);
-
- bool isElse(PHINode *Phi);
-
- void eraseIfUnused(PHINode *Phi);
-
- void openIf(BranchInst *Term);
-
- void insertElse(BranchInst *Term);
-
- Value *
- handleLoopCondition(Value *Cond, PHINode *Broken, llvm::Loop *L,
- BranchInst *Term);
-
- void handleLoop(BranchInst *Term);
-
- void closeControlFlow(BasicBlock *BB);
-
-public:
- static char ID;
-
- SIAnnotateControlFlow() : FunctionPass(ID) {}
-
- bool runOnFunction(Function &F) override;
-
- StringRef getPassName() const override { return "SI annotate control flow"; }
-
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<LoopInfoWrapperPass>();
- AU.addRequired<DominatorTreeWrapperPass>();
- AU.addRequired<LegacyDivergenceAnalysis>();
- AU.addPreserved<DominatorTreeWrapperPass>();
- AU.addRequired<TargetPassConfig>();
- FunctionPass::getAnalysisUsage(AU);
- }
-};
-
-} // end anonymous namespace
-
-INITIALIZE_PASS_BEGIN(SIAnnotateControlFlow, DEBUG_TYPE,
- "Annotate SI Control Flow", false, false)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(LegacyDivergenceAnalysis)
-INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
-INITIALIZE_PASS_END(SIAnnotateControlFlow, DEBUG_TYPE,
- "Annotate SI Control Flow", false, false)
-
-char SIAnnotateControlFlow::ID = 0;
-
-/// Initialize all the types and constants used in the pass
-void SIAnnotateControlFlow::initialize(Module &M, const GCNSubtarget &ST) {
- LLVMContext &Context = M.getContext();
-
- Void = Type::getVoidTy(Context);
- Boolean = Type::getInt1Ty(Context);
- IntMask = ST.isWave32() ? Type::getInt32Ty(Context)
- : Type::getInt64Ty(Context);
- ReturnStruct = StructType::get(Boolean, IntMask);
-
- BoolTrue = ConstantInt::getTrue(Context);
- BoolFalse = ConstantInt::getFalse(Context);
- BoolUndef = UndefValue::get(Boolean);
- IntMaskZero = ConstantInt::get(IntMask, 0);
-
- If = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if, { IntMask });
- Else = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_else,
- { IntMask, IntMask });
- IfBreak = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if_break,
- { IntMask, IntMask });
- Loop = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_loop, { IntMask });
- EndCf = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_end_cf, { IntMask });
-}
-
-/// Is the branch condition uniform or did the StructurizeCFG pass
-/// consider it as such?
-bool SIAnnotateControlFlow::isUniform(BranchInst *T) {
- return DA->isUniform(T) ||
- T->getMetadata("structurizecfg.uniform") != nullptr;
-}
-
-/// Is BB the last block saved on the stack ?
-bool SIAnnotateControlFlow::isTopOfStack(BasicBlock *BB) {
- return !Stack.empty() && Stack.back().first == BB;
-}
-
-/// Pop the last saved value from the control flow stack
-Value *SIAnnotateControlFlow::popSaved() {
- return Stack.pop_back_val().second;
-}
-
-/// Push a BB and saved value to the control flow stack
-void SIAnnotateControlFlow::push(BasicBlock *BB, Value *Saved) {
- Stack.push_back(std::make_pair(BB, Saved));
-}
-
-/// Can the condition represented by this PHI node treated like
-/// an "Else" block?
-bool SIAnnotateControlFlow::isElse(PHINode *Phi) {
- BasicBlock *IDom = DT->getNode(Phi->getParent())->getIDom()->getBlock();
- for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
- if (Phi->getIncomingBlock(i) == IDom) {
-
- if (Phi->getIncomingValue(i) != BoolTrue)
- return false;
-
- } else {
- if (Phi->getIncomingValue(i) != BoolFalse)
- return false;
-
- }
- }
- return true;
-}
-
-// Erase "Phi" if it is not used any more
-void SIAnnotateControlFlow::eraseIfUnused(PHINode *Phi) {
- if (RecursivelyDeleteDeadPHINode(Phi)) {
- LLVM_DEBUG(dbgs() << "Erased unused condition phi\n");
- }
-}
-
-/// Open a new "If" block
-void SIAnnotateControlFlow::openIf(BranchInst *Term) {
- if (isUniform(Term))
- return;
-
- Value *Ret = CallInst::Create(If, Term->getCondition(), "", Term);
- Term->setCondition(ExtractValueInst::Create(Ret, 0, "", Term));
- push(Term->getSuccessor(1), ExtractValueInst::Create(Ret, 1, "", Term));
-}
-
-/// Close the last "If" block and open a new "Else" block
-void SIAnnotateControlFlow::insertElse(BranchInst *Term) {
- if (isUniform(Term)) {
- return;
- }
- Value *Ret = CallInst::Create(Else, popSaved(), "", Term);
- Term->setCondition(ExtractValueInst::Create(Ret, 0, "", Term));
- push(Term->getSuccessor(1), ExtractValueInst::Create(Ret, 1, "", Term));
-}
-
-/// Recursively handle the condition leading to a loop
-Value *SIAnnotateControlFlow::handleLoopCondition(
- Value *Cond, PHINode *Broken, llvm::Loop *L, BranchInst *Term) {
- if (Instruction *Inst = dyn_cast<Instruction>(Cond)) {
- BasicBlock *Parent = Inst->getParent();
- Instruction *Insert;
- if (L->contains(Inst)) {
- Insert = Parent->getTerminator();
- } else {
- Insert = L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
- }
-
- Value *Args[] = { Cond, Broken };
- return CallInst::Create(IfBreak, Args, "", Insert);
- }
-
- // Insert IfBreak in the loop header TERM for constant COND other than true.
- if (isa<Constant>(Cond)) {
- Instruction *Insert = Cond == BoolTrue ?
- Term : L->getHeader()->getTerminator();
-
- Value *Args[] = { Cond, Broken };
- return CallInst::Create(IfBreak, Args, "", Insert);
- }
-
- llvm_unreachable("Unhandled loop condition!");
-}
-
-/// Handle a back edge (loop)
-void SIAnnotateControlFlow::handleLoop(BranchInst *Term) {
- if (isUniform(Term))
- return;
-
- BasicBlock *BB = Term->getParent();
- llvm::Loop *L = LI->getLoopFor(BB);
- if (!L)
- return;
-
- BasicBlock *Target = Term->getSuccessor(1);
- PHINode *Broken = PHINode::Create(IntMask, 0, "phi.broken", &Target->front());
-
- Value *Cond = Term->getCondition();
- Term->setCondition(BoolTrue);
- Value *Arg = handleLoopCondition(Cond, Broken, L, Term);
-
- for (BasicBlock *Pred : predecessors(Target)) {
- Value *PHIValue = IntMaskZero;
- if (Pred == BB) // Remember the value of the previous iteration.
- PHIValue = Arg;
- // If the backedge from Pred to Target could be executed before the exit
- // of the loop at BB, it should not reset or change "Broken", which keeps
- // track of the number of threads exited the loop at BB.
- else if (L->contains(Pred) && DT->dominates(Pred, BB))
- PHIValue = Broken;
- Broken->addIncoming(PHIValue, Pred);
- }
-
- Term->setCondition(CallInst::Create(Loop, Arg, "", Term));
-
- push(Term->getSuccessor(0), Arg);
-}
-
-/// Close the last opened control flow
-void SIAnnotateControlFlow::closeControlFlow(BasicBlock *BB) {
- llvm::Loop *L = LI->getLoopFor(BB);
-
- assert(Stack.back().first == BB);
-
- if (L && L->getHeader() == BB) {
- // We can't insert an EndCF call into a loop header, because it will
- // get executed on every iteration of the loop, when it should be
- // executed only once before the loop.
- SmallVector <BasicBlock *, 8> Latches;
- L->getLoopLatches(Latches);
-
- SmallVector<BasicBlock *, 2> Preds;
- for (BasicBlock *Pred : predecessors(BB)) {
- if (!is_contained(Latches, Pred))
- Preds.push_back(Pred);
- }
-
- BB = SplitBlockPredecessors(BB, Preds, "endcf.split", DT, LI, nullptr,
- false);
- }
-
- Value *Exec = popSaved();
- Instruction *FirstInsertionPt = &*BB->getFirstInsertionPt();
- if (!isa<UndefValue>(Exec) && !isa<UnreachableInst>(FirstInsertionPt))
- CallInst::Create(EndCf, Exec, "", FirstInsertionPt);
-}
-
-/// Annotate the control flow with intrinsics so the backend can
-/// recognize if/then/else and loops.
-bool SIAnnotateControlFlow::runOnFunction(Function &F) {
- DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
- LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
- DA = &getAnalysis<LegacyDivergenceAnalysis>();
- TargetPassConfig &TPC = getAnalysis<TargetPassConfig>();
- const TargetMachine &TM = TPC.getTM<TargetMachine>();
-
- initialize(*F.getParent(), TM.getSubtarget<GCNSubtarget>(F));
-
- for (df_iterator<BasicBlock *> I = df_begin(&F.getEntryBlock()),
- E = df_end(&F.getEntryBlock()); I != E; ++I) {
- BasicBlock *BB = *I;
- BranchInst *Term = dyn_cast<BranchInst>(BB->getTerminator());
-
- if (!Term || Term->isUnconditional()) {
- if (isTopOfStack(BB))
- closeControlFlow(BB);
-
- continue;
- }
-
- if (I.nodeVisited(Term->getSuccessor(1))) {
- if (isTopOfStack(BB))
- closeControlFlow(BB);
-
- handleLoop(Term);
- continue;
- }
-
- if (isTopOfStack(BB)) {
- PHINode *Phi = dyn_cast<PHINode>(Term->getCondition());
- if (Phi && Phi->getParent() == BB && isElse(Phi)) {
- insertElse(Term);
- eraseIfUnused(Phi);
- continue;
- }
-
- closeControlFlow(BB);
- }
-
- openIf(Term);
- }
-
- if (!Stack.empty()) {
- // CFG was probably not structured.
- report_fatal_error("failed to annotate CFG");
- }
-
- return true;
-}
-
-/// Create the annotation pass
-FunctionPass *llvm::createSIAnnotateControlFlowPass() {
- return new SIAnnotateControlFlow();
-}
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-04 19:50:15 +0000