Always skip ptr-to-ptr bitcasts when counting,
per Chris' suggestion. Slightly faster.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65999 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 5b50ab5..66ac481 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11484,12 +11484,12 @@
for (unsigned ScanInsts = 6; BBI != SI.getParent()->begin() && ScanInsts;
--ScanInsts) {
--BBI;
- // Don't count debug info directives, lest they affect codegen.
- // Likewise, we skip bitcasts that feed into a llvm.dbg.declare; these are
- // not present when debugging is off.
+ // Don't count debug info directives, lest they affect codegen,
+ // and we skip pointer-to-pointer bitcasts, which are NOPs.
+ // It is necessary for correctness to skip those that feed into a
+ // llvm.dbg.declare, as these are not present when debugging is off.
if (isa<DbgInfoIntrinsic>(BBI) ||
- (isa<BitCastInst>(BBI) && BBI->hasOneUse() &&
- isa<DbgDeclareInst>(BBI->use_begin()))) {
+ (isa<BitCastInst>(BBI) && isa<PointerType>(BBI->getType()))) {
ScanInsts++;
continue;
}