[InterleaveAccess] Check that binop shuffles have an undef second operand

It is expected that shuffles that we hoist through binops only have a single
vector operand, the other being undef/poison. The checks for
isDeInterleaveMaskOfFactor check that all the elements come from inside the
first vector, but with non-canonical shuffles the second operand could still
have a value. Add a quick check to make sure it is UndefValue as expected, to
make sure we don't run into problems with BinOpShuffles not using BinOps.

Fixes #61749

Differential Revision: https://reviews.llvm.org/D147306

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/InterleavedAccessPass.cpp b/llvm/lib/CodeGen/InterleavedAccessPass.cpp
index 95c4faf..a65fafc4 100644
--- a/llvm/lib/CodeGen/InterleavedAccessPass.cpp
+++ b/llvm/lib/CodeGen/InterleavedAccessPass.cpp
@@ -240,8 +240,10 @@ bool InterleavedAccess::lowerInterleavedLoad(
       continue;
     }
     if (auto *BI = dyn_cast<BinaryOperator>(User)) {
-      if (all_of(BI->users(),
-                 [](auto *U) { return isa<ShuffleVectorInst>(U); })) {
+      if (all_of(BI->users(), [](auto *U) {
+            auto *SVI = dyn_cast<ShuffleVectorInst>(U);
+            return SVI && isa<UndefValue>(SVI->getOperand(1));
+          })) {
         for (auto *SVI : BI->users())
           BinOpShuffles.insert(cast<ShuffleVectorInst>(SVI));
         continue;