diff options
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
-rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 870e2b2ade..427ac4ed14 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -3583,32 +3583,30 @@ static bool SwitchToLookupTable(SwitchInst *SI, } bool SimplifyCFGOpt::SimplifySwitch(SwitchInst *SI, IRBuilder<> &Builder) { - // If this switch is too complex to want to look at, ignore it. - if (!isValueEqualityComparison(SI)) - return false; - BasicBlock *BB = SI->getParent(); - // If we only have one predecessor, and if it is a branch on this value, - // see if that predecessor totally determines the outcome of this switch. - if (BasicBlock *OnlyPred = BB->getSinglePredecessor()) - if (SimplifyEqualityComparisonWithOnlyPredecessor(SI, OnlyPred, Builder)) - return SimplifyCFG(BB) | true; + if (isValueEqualityComparison(SI)) { + // If we only have one predecessor, and if it is a branch on this value, + // see if that predecessor totally determines the outcome of this switch. + if (BasicBlock *OnlyPred = BB->getSinglePredecessor()) + if (SimplifyEqualityComparisonWithOnlyPredecessor(SI, OnlyPred, Builder)) + return SimplifyCFG(BB) | true; - Value *Cond = SI->getCondition(); - if (SelectInst *Select = dyn_cast<SelectInst>(Cond)) - if (SimplifySwitchOnSelect(SI, Select)) - return SimplifyCFG(BB) | true; + Value *Cond = SI->getCondition(); + if (SelectInst *Select = dyn_cast<SelectInst>(Cond)) + if (SimplifySwitchOnSelect(SI, Select)) + return SimplifyCFG(BB) | true; - // If the block only contains the switch, see if we can fold the block - // away into any preds. - BasicBlock::iterator BBI = BB->begin(); - // Ignore dbg intrinsics. - while (isa<DbgInfoIntrinsic>(BBI)) - ++BBI; - if (SI == &*BBI) - if (FoldValueComparisonIntoPredecessors(SI, Builder)) - return SimplifyCFG(BB) | true; + // If the block only contains the switch, see if we can fold the block + // away into any preds. + BasicBlock::iterator BBI = BB->begin(); + // Ignore dbg intrinsics. + while (isa<DbgInfoIntrinsic>(BBI)) + ++BBI; + if (SI == &*BBI) + if (FoldValueComparisonIntoPredecessors(SI, Builder)) + return SimplifyCFG(BB) | true; + } // Try to transform the switch into an icmp and a branch. if (TurnSwitchRangeIntoICmp(SI, Builder)) |