diff options
Diffstat (limited to 'llvm/lib/Transforms/Utils/SimplifyCFG.cpp')
-rw-r--r-- | llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 91 |
1 files changed, 42 insertions, 49 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index 290f4151c0a..d3e7d70b1a9 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -167,11 +167,10 @@ struct ValueEqualityComparisonCase { class SimplifyCFGOpt { const TargetTransformInfo &TTI; const DataLayout &DL; - unsigned BonusInstThreshold; AssumptionCache *AC; SmallPtrSetImpl<BasicBlock *> *LoopHeaders; - // See comments in SimplifyCFGOpt::SimplifySwitch. - bool LateSimplifyCFG; + const SimplifyCFGOptions &Options; + Value *isValueEqualityComparison(TerminatorInst *TI); BasicBlock *GetValueEqualityComparisonCases( TerminatorInst *TI, std::vector<ValueEqualityComparisonCase> &Cases); @@ -194,11 +193,10 @@ class SimplifyCFGOpt { public: SimplifyCFGOpt(const TargetTransformInfo &TTI, const DataLayout &DL, - unsigned BonusInstThreshold, AssumptionCache *AC, + AssumptionCache *AC, SmallPtrSetImpl<BasicBlock *> *LoopHeaders, - bool LateSimplifyCFG) - : TTI(TTI), DL(DL), BonusInstThreshold(BonusInstThreshold), AC(AC), - LoopHeaders(LoopHeaders), LateSimplifyCFG(LateSimplifyCFG) {} + const SimplifyCFGOptions &Opts) + : TTI(TTI), DL(DL), AC(AC), LoopHeaders(LoopHeaders), Options(Opts) {} bool run(BasicBlock *BB); }; @@ -3491,8 +3489,8 @@ static bool SimplifyIndirectBrOnSelect(IndirectBrInst *IBI, SelectInst *SI) { /// the PHI, merging the third icmp into the switch. static bool TryToSimplifyUncondBranchWithICmpInIt( ICmpInst *ICI, IRBuilder<> &Builder, const DataLayout &DL, - const TargetTransformInfo &TTI, unsigned BonusInstThreshold, - AssumptionCache *AC) { + const TargetTransformInfo &TTI, AssumptionCache *AC, + const SimplifyCFGOptions &Options) { BasicBlock *BB = ICI->getParent(); // If the block has any PHIs in it or the icmp has multiple uses, it is too @@ -3527,7 +3525,7 @@ static bool TryToSimplifyUncondBranchWithICmpInIt( ICI->eraseFromParent(); } // BB is now empty, so it is likely to simplify away. - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } // Ok, the block is reachable from the default dest. If the constant we're @@ -3543,7 +3541,7 @@ static bool TryToSimplifyUncondBranchWithICmpInIt( ICI->replaceAllUsesWith(V); ICI->eraseFromParent(); // BB is now empty, so it is likely to simplify away. - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } // The use of the icmp has to be in the 'end' block, by the only PHI node in @@ -5522,12 +5520,12 @@ bool SimplifyCFGOpt::SimplifySwitch(SwitchInst *SI, IRBuilder<> &Builder) { // see if that predecessor totally determines the outcome of this switch. if (BasicBlock *OnlyPred = BB->getSinglePredecessor()) if (SimplifyEqualityComparisonWithOnlyPredecessor(SI, OnlyPred, Builder)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; Value *Cond = SI->getCondition(); if (SelectInst *Select = dyn_cast<SelectInst>(Cond)) if (SimplifySwitchOnSelect(SI, Select)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; // If the block only contains the switch, see if we can fold the block // away into any preds. @@ -5537,33 +5535,34 @@ bool SimplifyCFGOpt::SimplifySwitch(SwitchInst *SI, IRBuilder<> &Builder) { ++BBI; if (SI == &*BBI) if (FoldValueComparisonIntoPredecessors(SI, Builder)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } // Try to transform the switch into an icmp and a branch. if (TurnSwitchRangeIntoICmp(SI, Builder)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; // Remove unreachable cases. if (EliminateDeadSwitchCases(SI, AC, DL)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; if (SwitchToSelect(SI, Builder, AC, DL, TTI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; if (ForwardSwitchConditionToPHI(SI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; // The conversion from switch to lookup tables results in difficult-to-analyze // code and makes pruning branches much harder. This is a problem if the // switch expression itself can still be restricted as a result of inlining or // CVP. Therefore, only apply this transformation during late stages of the // optimisation pipeline. - if (LateSimplifyCFG && SwitchToLookupTable(SI, Builder, DL, TTI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + if (Options.ConvertSwitchToLookupTable && + SwitchToLookupTable(SI, Builder, DL, TTI)) + return SimplifyCFG(BB, TTI, AC, Options) | true; if (ReduceSwitchRange(SI, Builder, DL, TTI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; return false; } @@ -5601,7 +5600,7 @@ bool SimplifyCFGOpt::SimplifyIndirectBr(IndirectBrInst *IBI) { if (SelectInst *SI = dyn_cast<SelectInst>(IBI->getAddress())) { if (SimplifyIndirectBrOnSelect(IBI, SI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } return Changed; } @@ -5697,7 +5696,7 @@ bool SimplifyCFGOpt::SimplifyUncondBranch(BranchInst *BI, // vectorization to keep canonical loop forms for nested loops. These blocks // can be eliminated when the pass is invoked later in the back-end.) bool NeedCanonicalLoop = - !LateSimplifyCFG && + Options.NeedCanonicalLoop && (LoopHeaders && (LoopHeaders->count(BB) || LoopHeaders->count(Succ))); BasicBlock::iterator I = BB->getFirstNonPHIOrDbg()->getIterator(); if (I->isTerminator() && BB != &BB->getParent()->getEntryBlock() && @@ -5711,8 +5710,8 @@ bool SimplifyCFGOpt::SimplifyUncondBranch(BranchInst *BI, for (++I; isa<DbgInfoIntrinsic>(I); ++I) ; if (I->isTerminator() && - TryToSimplifyUncondBranchWithICmpInIt(ICI, Builder, DL, TTI, - BonusInstThreshold, AC)) + TryToSimplifyUncondBranchWithICmpInIt(ICI, Builder, DL, TTI, AC, + Options)) return true; } @@ -5729,8 +5728,8 @@ bool SimplifyCFGOpt::SimplifyUncondBranch(BranchInst *BI, // branches to us and our successor, fold the comparison into the // predecessor and use logical operations to update the incoming value // for PHI nodes in common successor. - if (FoldBranchToCommonDest(BI, BonusInstThreshold)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + if (FoldBranchToCommonDest(BI, Options.BonusInstThreshold)) + return SimplifyCFG(BB, TTI, AC, Options) | true; return false; } @@ -5755,7 +5754,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { // switch. if (BasicBlock *OnlyPred = BB->getSinglePredecessor()) if (SimplifyEqualityComparisonWithOnlyPredecessor(BI, OnlyPred, Builder)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; // This block must be empty, except for the setcond inst, if it exists. // Ignore dbg intrinsics. @@ -5765,14 +5764,14 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { ++I; if (&*I == BI) { if (FoldValueComparisonIntoPredecessors(BI, Builder)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } else if (&*I == cast<Instruction>(BI->getCondition())) { ++I; // Ignore dbg intrinsics. while (isa<DbgInfoIntrinsic>(I)) ++I; if (&*I == BI && FoldValueComparisonIntoPredecessors(BI, Builder)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } } @@ -5799,7 +5798,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { : ConstantInt::getFalse(BB->getContext()); BI->setCondition(CI); RecursivelyDeleteTriviallyDeadInstructions(OldCond); - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } } } @@ -5807,8 +5806,8 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { // If this basic block is ONLY a compare and a branch, and if a predecessor // branches to us and one of our successors, fold the comparison into the // predecessor and use logical operations to pick the right destination. - if (FoldBranchToCommonDest(BI, BonusInstThreshold)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + if (FoldBranchToCommonDest(BI, Options.BonusInstThreshold)) + return SimplifyCFG(BB, TTI, AC, Options) | true; // We have a conditional branch to two blocks that are only reachable // from BI. We know that the condbr dominates the two blocks, so see if @@ -5817,7 +5816,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { if (BI->getSuccessor(0)->getSinglePredecessor()) { if (BI->getSuccessor(1)->getSinglePredecessor()) { if (HoistThenElseCodeToIf(BI, TTI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } else { // If Successor #1 has multiple preds, we may be able to conditionally // execute Successor #0 if it branches to Successor #1. @@ -5825,7 +5824,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { if (Succ0TI->getNumSuccessors() == 1 && Succ0TI->getSuccessor(0) == BI->getSuccessor(1)) if (SpeculativelyExecuteBB(BI, BI->getSuccessor(0), TTI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } } else if (BI->getSuccessor(1)->getSinglePredecessor()) { // If Successor #0 has multiple preds, we may be able to conditionally @@ -5834,7 +5833,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { if (Succ1TI->getNumSuccessors() == 1 && Succ1TI->getSuccessor(0) == BI->getSuccessor(0)) if (SpeculativelyExecuteBB(BI, BI->getSuccessor(1), TTI)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; } // If this is a branch on a phi node in the current block, thread control @@ -5842,14 +5841,14 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { if (PHINode *PN = dyn_cast<PHINode>(BI->getCondition())) if (PN->getParent() == BI->getParent()) if (FoldCondBranchOnPHI(BI, DL, AC)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; // Scan predecessor blocks for conditional branches. for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) if (BranchInst *PBI = dyn_cast<BranchInst>((*PI)->getTerminator())) if (PBI != BI && PBI->isConditional()) if (SimplifyCondBranchToCondBranch(PBI, BI, DL)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; // Look for diamond patterns. if (MergeCondStores) @@ -5857,7 +5856,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { if (BranchInst *PBI = dyn_cast<BranchInst>(PrevBB->getTerminator())) if (PBI != BI && PBI->isConditional()) if (mergeConditionalStores(PBI, BI, DL)) - return SimplifyCFG(BB, TTI, BonusInstThreshold, AC) | true; + return SimplifyCFG(BB, TTI, AC, Options) | true; return false; } @@ -6013,16 +6012,10 @@ bool SimplifyCFGOpt::run(BasicBlock *BB) { return Changed; } -/// This function is used to do simplification of a CFG. -/// For example, it adjusts branches to branches to eliminate the extra hop, -/// eliminates unreachable basic blocks, and does other "peephole" optimization -/// of the CFG. It returns true if a modification was made. -/// bool llvm::SimplifyCFG(BasicBlock *BB, const TargetTransformInfo &TTI, - unsigned BonusInstThreshold, AssumptionCache *AC, - SmallPtrSetImpl<BasicBlock *> *LoopHeaders, - bool LateSimplifyCFG) { - return SimplifyCFGOpt(TTI, BB->getModule()->getDataLayout(), - BonusInstThreshold, AC, LoopHeaders, LateSimplifyCFG) + AssumptionCache *AC, const SimplifyCFGOptions &Options, + SmallPtrSetImpl<BasicBlock *> *LoopHeaders) { + return SimplifyCFGOpt(TTI, BB->getModule()->getDataLayout(), AC, LoopHeaders, + Options) .run(BB); } |