diff options
Diffstat (limited to 'contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp | 169 |
1 files changed, 82 insertions, 87 deletions
diff --git a/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp b/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp index d70f52e..8cb35c5 100644 --- a/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp +++ b/contrib/llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp @@ -22,6 +22,7 @@ #include "llvm/IR/Module.h" #include "llvm/Pass.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "llvm/Transforms/Utils/Local.h" #include "llvm/Transforms/Utils/SSAUpdater.h" using namespace llvm; @@ -34,15 +35,6 @@ namespace { typedef std::pair<BasicBlock *, Value *> StackEntry; typedef SmallVector<StackEntry, 16> StackVector; -// Intrinsic names the control flow is annotated with -static const char *const IfIntrinsic = "llvm.amdgcn.if"; -static const char *const ElseIntrinsic = "llvm.amdgcn.else"; -static const char *const BreakIntrinsic = "llvm.amdgcn.break"; -static const char *const IfBreakIntrinsic = "llvm.amdgcn.if.break"; -static const char *const ElseBreakIntrinsic = "llvm.amdgcn.else.break"; -static const char *const LoopIntrinsic = "llvm.amdgcn.loop"; -static const char *const EndCfIntrinsic = "llvm.amdgcn.end.cf"; - class SIAnnotateControlFlow : public FunctionPass { DivergenceAnalysis *DA; @@ -56,13 +48,13 @@ class SIAnnotateControlFlow : public FunctionPass { UndefValue *BoolUndef; Constant *Int64Zero; - Constant *If; - Constant *Else; - Constant *Break; - Constant *IfBreak; - Constant *ElseBreak; - Constant *Loop; - Constant *EndCf; + Function *If; + Function *Else; + Function *Break; + Function *IfBreak; + Function *ElseBreak; + Function *Loop; + Function *EndCf; DominatorTree *DT; StackVector Stack; @@ -85,8 +77,10 @@ class SIAnnotateControlFlow : public FunctionPass { void insertElse(BranchInst *Term); - Value *handleLoopCondition(Value *Cond, PHINode *Broken, - llvm::Loop *L, BranchInst *Term); + Value * + handleLoopCondition(Value *Cond, PHINode *Broken, llvm::Loop *L, + BranchInst *Term, + SmallVectorImpl<WeakTrackingVH> &LoopPhiConditions); void handleLoop(BranchInst *Term); @@ -118,6 +112,7 @@ public: INITIALIZE_PASS_BEGIN(SIAnnotateControlFlow, DEBUG_TYPE, "Annotate SI Control Flow", false, false) +INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) INITIALIZE_PASS_DEPENDENCY(DivergenceAnalysis) INITIALIZE_PASS_END(SIAnnotateControlFlow, DEBUG_TYPE, "Annotate SI Control Flow", false, false) @@ -131,37 +126,20 @@ bool SIAnnotateControlFlow::doInitialization(Module &M) { Void = Type::getVoidTy(Context); Boolean = Type::getInt1Ty(Context); Int64 = Type::getInt64Ty(Context); - ReturnStruct = StructType::get(Boolean, Int64, (Type *)nullptr); + ReturnStruct = StructType::get(Boolean, Int64); BoolTrue = ConstantInt::getTrue(Context); BoolFalse = ConstantInt::getFalse(Context); BoolUndef = UndefValue::get(Boolean); Int64Zero = ConstantInt::get(Int64, 0); - If = M.getOrInsertFunction( - IfIntrinsic, ReturnStruct, Boolean, (Type *)nullptr); - - Else = M.getOrInsertFunction( - ElseIntrinsic, ReturnStruct, Int64, (Type *)nullptr); - - Break = M.getOrInsertFunction( - BreakIntrinsic, Int64, Int64, (Type *)nullptr); - cast<Function>(Break)->setDoesNotAccessMemory(); - - IfBreak = M.getOrInsertFunction( - IfBreakIntrinsic, Int64, Boolean, Int64, (Type *)nullptr); - cast<Function>(IfBreak)->setDoesNotAccessMemory();; - - ElseBreak = M.getOrInsertFunction( - ElseBreakIntrinsic, Int64, Int64, Int64, (Type *)nullptr); - cast<Function>(ElseBreak)->setDoesNotAccessMemory(); - - Loop = M.getOrInsertFunction( - LoopIntrinsic, Boolean, Int64, (Type *)nullptr); - - EndCf = M.getOrInsertFunction( - EndCfIntrinsic, Void, Int64, (Type *)nullptr); - + If = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if); + Else = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_else); + Break = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_break); + IfBreak = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if_break); + ElseBreak = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_else_break); + Loop = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_loop); + EndCf = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_end_cf); return false; } @@ -208,15 +186,16 @@ bool SIAnnotateControlFlow::isElse(PHINode *Phi) { // \brief Erase "Phi" if it is not used any more void SIAnnotateControlFlow::eraseIfUnused(PHINode *Phi) { - if (!Phi->hasNUsesOrMore(1)) - Phi->eraseFromParent(); + if (llvm::RecursivelyDeleteDeadPHINode(Phi)) { + DEBUG(dbgs() << "Erased unused condition phi\n"); + } } /// \brief Open a new "If" block void SIAnnotateControlFlow::openIf(BranchInst *Term) { - if (isUniform(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)); @@ -233,8 +212,9 @@ void SIAnnotateControlFlow::insertElse(BranchInst *Term) { } /// \brief Recursively handle the condition leading to a loop -Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, - llvm::Loop *L, BranchInst *Term) { +Value *SIAnnotateControlFlow::handleLoopCondition( + Value *Cond, PHINode *Broken, llvm::Loop *L, BranchInst *Term, + SmallVectorImpl<WeakTrackingVH> &LoopPhiConditions) { // Only search through PHI nodes which are inside the loop. If we try this // with PHI nodes that are outside of the loop, we end up inserting new PHI @@ -245,7 +225,7 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, if ((Phi = dyn_cast<PHINode>(Cond)) && L->contains(Phi)) { BasicBlock *Parent = Phi->getParent(); - PHINode *NewPhi = PHINode::Create(Int64, 0, "", &Parent->front()); + PHINode *NewPhi = PHINode::Create(Int64, 0, "loop.phi", &Parent->front()); Value *Ret = NewPhi; // Handle all non-constant incoming values first @@ -258,14 +238,14 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, } Phi->setIncomingValue(i, BoolFalse); - Value *PhiArg = handleLoopCondition(Incoming, Broken, L, Term); + Value *PhiArg = handleLoopCondition(Incoming, Broken, L, + Term, LoopPhiConditions); NewPhi->addIncoming(PhiArg, From); } BasicBlock *IDom = DT->getNode(Parent)->getIDom()->getBlock(); for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) { - Value *Incoming = Phi->getIncomingValue(i); if (Incoming != BoolTrue) continue; @@ -295,14 +275,17 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, continue; } } + TerminatorInst *Insert = From->getTerminator(); Value *PhiArg = CallInst::Create(Break, Broken, "", Insert); NewPhi->setIncomingValue(i, PhiArg); } - eraseIfUnused(Phi); + + LoopPhiConditions.push_back(WeakTrackingVH(Phi)); return Ret; + } - } else if (Instruction *Inst = dyn_cast<Instruction>(Cond)) { + if (Instruction *Inst = dyn_cast<Instruction>(Cond)) { BasicBlock *Parent = Inst->getParent(); Instruction *Insert; if (L->contains(Inst)) { @@ -310,46 +293,55 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, } else { Insert = L->getHeader()->getFirstNonPHIOrDbgOrLifetime(); } + Value *Args[] = { Cond, Broken }; return CallInst::Create(IfBreak, Args, "", Insert); + } - // Insert IfBreak before TERM for constant COND. - } else if (isa<ConstantInt>(Cond)) { - Value *Args[] = { Cond, Broken }; - return CallInst::Create(IfBreak, Args, "", Term); + // 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(); - } else { - llvm_unreachable("Unhandled loop condition!"); + Value *Args[] = { Cond, Broken }; + return CallInst::Create(IfBreak, Args, "", Insert); } - return nullptr; + + llvm_unreachable("Unhandled loop condition!"); } /// \brief Handle a back edge (loop) void SIAnnotateControlFlow::handleLoop(BranchInst *Term) { - if (isUniform(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(Int64, 0, "", &Target->front()); + PHINode *Broken = PHINode::Create(Int64, 0, "phi.broken", &Target->front()); + SmallVector<WeakTrackingVH, 8> LoopPhiConditions; Value *Cond = Term->getCondition(); Term->setCondition(BoolTrue); - Value *Arg = handleLoopCondition(Cond, Broken, L, Term); + Value *Arg = handleLoopCondition(Cond, Broken, L, Term, LoopPhiConditions); - for (pred_iterator PI = pred_begin(Target), PE = pred_end(Target); - PI != PE; ++PI) { + for (BasicBlock *Pred : predecessors(Target)) + Broken->addIncoming(Pred == BB ? Arg : Int64Zero, Pred); + + Term->setCondition(CallInst::Create(Loop, Arg, "", Term)); - Broken->addIncoming(*PI == BB ? Arg : Int64Zero, *PI); + for (WeakTrackingVH Val : reverse(LoopPhiConditions)) { + if (PHINode *Cond = cast_or_null<PHINode>(Val)) + eraseIfUnused(Cond); } - Term->setCondition(CallInst::Create(Loop, Arg, "", Term)); push(Term->getSuccessor(0), Arg); -}/// \brief Close the last opened control flow +} + +/// \brief Close the last opened control flow void SIAnnotateControlFlow::closeControlFlow(BasicBlock *BB) { llvm::Loop *L = LI->getLoopFor(BB); @@ -359,59 +351,62 @@ void SIAnnotateControlFlow::closeControlFlow(BasicBlock *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; + SmallVector <BasicBlock *, 8> Latches; L->getLoopLatches(Latches); - std::vector<BasicBlock*> Preds; - for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) { - if (!is_contained(Latches, *PI)) - Preds.push_back(*PI); + SmallVector<BasicBlock *, 2> Preds; + for (BasicBlock *Pred : predecessors(BB)) { + if (!is_contained(Latches, Pred)) + Preds.push_back(Pred); } + BB = llvm::SplitBlockPredecessors(BB, Preds, "endcf.split", DT, LI, false); } Value *Exec = popSaved(); - if (!isa<UndefValue>(Exec)) - CallInst::Create(EndCf, Exec, "", &*BB->getFirstInsertionPt()); + Instruction *FirstInsertionPt = &*BB->getFirstInsertionPt(); + if (!isa<UndefValue>(Exec) && !isa<UnreachableInst>(FirstInsertionPt)) + CallInst::Create(EndCf, Exec, "", FirstInsertionPt); } /// \brief 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<DivergenceAnalysis>(); for (df_iterator<BasicBlock *> I = df_begin(&F.getEntryBlock()), E = df_end(&F.getEntryBlock()); I != E; ++I) { - - BranchInst *Term = dyn_cast<BranchInst>((*I)->getTerminator()); + BasicBlock *BB = *I; + BranchInst *Term = dyn_cast<BranchInst>(BB->getTerminator()); if (!Term || Term->isUnconditional()) { - if (isTopOfStack(*I)) - closeControlFlow(*I); + if (isTopOfStack(BB)) + closeControlFlow(BB); continue; } if (I.nodeVisited(Term->getSuccessor(1))) { - if (isTopOfStack(*I)) - closeControlFlow(*I); + if (isTopOfStack(BB)) + closeControlFlow(BB); handleLoop(Term); continue; } - if (isTopOfStack(*I)) { + if (isTopOfStack(BB)) { PHINode *Phi = dyn_cast<PHINode>(Term->getCondition()); - if (Phi && Phi->getParent() == *I && isElse(Phi)) { + if (Phi && Phi->getParent() == BB && isElse(Phi)) { insertElse(Term); eraseIfUnused(Phi); continue; } - closeControlFlow(*I); + + closeControlFlow(BB); } + openIf(Term); } |
