Fix GetMinTrailingZeros for SCEVSignExtend and SCEVZeroExtendExpr to

return the correct value when the cast operand is all zeros. This ought
to be pretty rare, because it would mean that the regular SCEV folding
routines missed a case, though there are cases they might legitimately
miss. Also, it's unlikely anything currently using GetMinTrailingZeros
cares about this case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71532 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 107a7c4d818ca055eec9035c5f67cf5e6c64109b..5cd9739e223f085cb1260c50919b01c4de88f006 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1984,13 +1984,13 @@ static uint32_t GetMinTrailingZeros(SCEVHandle S, const ScalarEvolution &SE) {
   if (const SCEVZeroExtendExpr *E = dyn_cast<SCEVZeroExtendExpr>(S)) {
     uint32_t OpRes = GetMinTrailingZeros(E->getOperand(), SE);
     return OpRes == SE.getTypeSizeInBits(E->getOperand()->getType()) ?
-             SE.getTypeSizeInBits(E->getOperand()->getType()) : OpRes;
+             SE.getTypeSizeInBits(E->getType()) : OpRes;
   }
 
   if (const SCEVSignExtendExpr *E = dyn_cast<SCEVSignExtendExpr>(S)) {
     uint32_t OpRes = GetMinTrailingZeros(E->getOperand(), SE);
     return OpRes == SE.getTypeSizeInBits(E->getOperand()->getType()) ?
-             SE.getTypeSizeInBits(E->getOperand()->getType()) : OpRes;
+             SE.getTypeSizeInBits(E->getType()) : OpRes;
   }
 
   if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(S)) {