[InstCombine] use m_APInt to allow icmp (shl 1, Y), C folds for splat constant vectors

llvm-svn: 279266

1 files changed, 5 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 41106cd..262c86c 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -1988,15 +1988,16 @@ static Instruction *foldICmpShlOne(ICmpInst &Cmp, Instruction *Shl,
 
 Instruction *InstCombiner::foldICmpShlConstant(ICmpInst &ICI, Instruction *LHSI,
                                                const APInt *RHSV) {
+  // FIXME: This should use m_APInt to allow splat vectors.
+  ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1));
+  if (!ShAmt)
+    return foldICmpShlOne(ICI, LHSI, RHSV);
+
   // FIXME: This check restricts all folds under here to scalar types.
   ConstantInt *RHS = dyn_cast<ConstantInt>(ICI.getOperand(1));
   if (!RHS)
     return nullptr;
 
-  ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1));
-  if (!ShAmt)
-    return foldICmpShlOne(ICI, LHSI, RHSV);
-
   // Check that the shift amount is in range.  If not, don't perform
   // undefined shifts.  When the shift is visited it will be
   // simplified.