diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp index de62d9de7a8..141e99b92cd 100644 --- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp +++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp @@ -481,9 +481,14 @@ static Constant *getConstantAt(Value *V, Instruction *At, LazyValueInfo *LVI) { static bool runImpl(Function &F, LazyValueInfo *LVI) { bool FnChanged = false; - for (BasicBlock &BB : F) { + // Visiting in a pre-order depth-first traversal causes us to simplify early + // blocks before querying later blocks (which require us to analyze early + // blocks). Eagerly simplifying shallow blocks means there is strictly less + // work to do for deep blocks. This also means we don't visit unreachable + // blocks. + for (BasicBlock *BB : depth_first(&F.getEntryBlock())) { bool BBChanged = false; - for (BasicBlock::iterator BI = BB.begin(), BE = BB.end(); BI != BE;) { + for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) { Instruction *II = &*BI++; switch (II->getOpcode()) { case Instruction::Select: @@ -519,7 +524,7 @@ static bool runImpl(Function &F, LazyValueInfo *LVI) { } } - Instruction *Term = BB.getTerminator(); + Instruction *Term = BB->getTerminator(); switch (Term->getOpcode()) { case Instruction::Switch: BBChanged |= processSwitch(cast<SwitchInst>(Term), LVI); |
