diff options
| -rw-r--r-- | lib/Analysis/ValueTracking.cpp | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp index 1782edee7b..9494a2f4c5 100644 --- a/lib/Analysis/ValueTracking.cpp +++ b/lib/Analysis/ValueTracking.cpp @@ -16,6 +16,7 @@ #include "llvm/Constants.h" #include "llvm/Instructions.h" #include "llvm/GlobalVariable.h" +#include "llvm/GlobalAlias.h" #include "llvm/IntrinsicInst.h" #include "llvm/LLVMContext.h" #include "llvm/Operator.h" @@ -105,6 +106,17 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask, KnownOne.clear(); return; } + // A weak GlobalAlias is totally unknown. A non-weak GlobalAlias has + // the bits of its aliasee. + if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) { + if (GA->mayBeOverridden()) { + KnownZero.clear(); KnownOne.clear(); + } else { + ComputeMaskedBits(GA->getAliasee(), Mask, KnownZero, KnownOne, + TD, Depth+1); + } + return; + } KnownZero.clear(); KnownOne.clear(); // Start out not knowing anything. |