[ConstantFolding] Fix constant folding for vector cttz and ctlz intrinsics to understand that the second argument is still a scalar.

llvm-svn: 304668

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index a906770dbb3..d33fe4a0094 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -2034,6 +2034,13 @@ Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID,
   for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) {
     // Gather a column of constants.
     for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
+      // These intrinsics use a scalar type for their second argument.
+      if (J == 1 &&
+          (IntrinsicID == Intrinsic::cttz || IntrinsicID == Intrinsic::ctlz)) {
+        Lane[J] = Operands[J];
+        continue;
+      }
+
       Constant *Agg = Operands[J]->getAggregateElement(I);
       if (!Agg)
         return nullptr;