From 97ecd91e2025f23c3ed38594454aeb7027ad82b7 Mon Sep 17 00:00:00 2001 From: Tyker Date: Fri, 24 Apr 2020 21:38:12 +0200 Subject: [PATCH] [NFC] Refactor SimplifyCFG to make propagating information easier. Reviewers: jdoerfert Reviewed By: jdoerfert Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D77742 --- llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 48 +++++++++++++++++++++---------- 1 file changed, 33 insertions(+), 15 deletions(-) diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 2bc5fe9..be5a375 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -202,10 +202,23 @@ class SimplifyCFGOpt { bool simplifyBranch(BranchInst *Branch, IRBuilder<> &Builder); bool simplifyUncondBranch(BranchInst *BI, IRBuilder<> &Builder); bool simplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder); + bool SimplifyCondBranchToTwoReturns(BranchInst *BI, IRBuilder<> &Builder); bool tryToSimplifyUncondBranchWithICmpInIt(ICmpInst *ICI, IRBuilder<> &Builder); + bool HoistThenElseCodeToIf(BranchInst *BI, const TargetTransformInfo &TTI); + bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB, + const TargetTransformInfo &TTI); + bool SimplifyTerminatorOnSelect(Instruction *OldTerm, Value *Cond, + BasicBlock *TrueBB, BasicBlock *FalseBB, + uint32_t TrueWeight, uint32_t FalseWeight); + bool SimplifyBranchOnICmpChain(BranchInst *BI, IRBuilder<> &Builder, + const DataLayout &DL); + bool SimplifySwitchOnSelect(SwitchInst *SI, SelectInst *Select); + bool SimplifyIndirectBrOnSelect(IndirectBrInst *IBI, SelectInst *SI); + bool TurnSwitchRangeIntoICmp(SwitchInst *SI, IRBuilder<> &Builder); + public: SimplifyCFGOpt(const TargetTransformInfo &TTI, const DataLayout &DL, SmallPtrSetImpl *LoopHeaders, @@ -1235,8 +1248,8 @@ static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I); /// Given a conditional branch that goes to BB1 and BB2, hoist any common code /// in the two blocks up into the branch block. The caller of this function /// guarantees that BI's block dominates BB1 and BB2. -static bool HoistThenElseCodeToIf(BranchInst *BI, - const TargetTransformInfo &TTI) { +bool SimplifyCFGOpt::HoistThenElseCodeToIf(BranchInst *BI, + const TargetTransformInfo &TTI) { // This does very trivial matching, with limited scanning, to find identical // instructions in the two blocks. In particular, we don't want to get into // O(M*N) situations here where M and N are the sizes of BB1 and BB2. As @@ -1969,8 +1982,8 @@ static Value *isSafeToSpeculateStore(Instruction *I, BasicBlock *BrBB, /// \endcode /// /// \returns true if the conditional block is removed. -static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB, - const TargetTransformInfo &TTI) { +bool SimplifyCFGOpt::SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB, + const TargetTransformInfo &TTI) { // Be conservative for now. FP select instruction can often be expensive. Value *BrCond = BI->getCondition(); if (isa(BrCond)) @@ -2462,8 +2475,8 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetTransformInfo &TTI, /// If we found a conditional branch that goes to two returning blocks, /// try to merge them together into one return, /// introducing a select if the return values disagree. -static bool SimplifyCondBranchToTwoReturns(BranchInst *BI, - IRBuilder<> &Builder) { +bool SimplifyCFGOpt::SimplifyCondBranchToTwoReturns(BranchInst *BI, + IRBuilder<> &Builder) { assert(BI->isConditional() && "Must be a conditional branch"); BasicBlock *TrueSucc = BI->getSuccessor(0); BasicBlock *FalseSucc = BI->getSuccessor(1); @@ -3522,10 +3535,11 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI, // Takes care of updating the successors and removing the old terminator. // Also makes sure not to introduce new successors by assuming that edges to // non-successor TrueBBs and FalseBBs aren't reachable. -static bool SimplifyTerminatorOnSelect(Instruction *OldTerm, Value *Cond, - BasicBlock *TrueBB, BasicBlock *FalseBB, - uint32_t TrueWeight, - uint32_t FalseWeight) { +bool SimplifyCFGOpt::SimplifyTerminatorOnSelect(Instruction *OldTerm, + Value *Cond, BasicBlock *TrueBB, + BasicBlock *FalseBB, + uint32_t TrueWeight, + uint32_t FalseWeight) { // Remove any superfluous successor edges from the CFG. // First, figure out which successors to preserve. // If TrueBB and FalseBB are equal, only try to preserve one copy of that @@ -3585,7 +3599,8 @@ static bool SimplifyTerminatorOnSelect(Instruction *OldTerm, Value *Cond, // (switch (select cond, X, Y)) on constant X, Y // with a branch - conditional if X and Y lead to distinct BBs, // unconditional otherwise. -static bool SimplifySwitchOnSelect(SwitchInst *SI, SelectInst *Select) { +bool SimplifyCFGOpt::SimplifySwitchOnSelect(SwitchInst *SI, + SelectInst *Select) { // Check for constant integer values in the select. ConstantInt *TrueVal = dyn_cast(Select->getTrueValue()); ConstantInt *FalseVal = dyn_cast(Select->getFalseValue()); @@ -3621,7 +3636,8 @@ static bool SimplifySwitchOnSelect(SwitchInst *SI, SelectInst *Select) { // blockaddress(@fn, BlockB))) // with // (br cond, BlockA, BlockB). -static bool SimplifyIndirectBrOnSelect(IndirectBrInst *IBI, SelectInst *SI) { +bool SimplifyCFGOpt::SimplifyIndirectBrOnSelect(IndirectBrInst *IBI, + SelectInst *SI) { // Check that both operands of the select are block addresses. BlockAddress *TBA = dyn_cast(SI->getTrueValue()); BlockAddress *FBA = dyn_cast(SI->getFalseValue()); @@ -3756,8 +3772,9 @@ bool SimplifyCFGOpt::tryToSimplifyUncondBranchWithICmpInIt( /// The specified branch is a conditional branch. /// Check to see if it is branching on an or/and chain of icmp instructions, and /// fold it into a switch instruction if so. -static bool SimplifyBranchOnICmpChain(BranchInst *BI, IRBuilder<> &Builder, - const DataLayout &DL) { +bool SimplifyCFGOpt::SimplifyBranchOnICmpChain(BranchInst *BI, + IRBuilder<> &Builder, + const DataLayout &DL) { Instruction *Cond = dyn_cast(BI->getCondition()); if (!Cond) return false; @@ -4407,7 +4424,8 @@ static void createUnreachableSwitchDefault(SwitchInst *Switch) { /// Turn a switch with two reachable destinations into an integer range /// comparison and branch. -static bool TurnSwitchRangeIntoICmp(SwitchInst *SI, IRBuilder<> &Builder) { +bool SimplifyCFGOpt::TurnSwitchRangeIntoICmp(SwitchInst *SI, + IRBuilder<> &Builder) { assert(SI->getNumCases() > 1 && "Degenerate switch?"); bool HasDefault = -- 2.7.4