[clang] [mlir] [mlir][llvm] Fix metadata and alignment on masked memory intrinsics (PR #221879)

[Christian Ulmann via cfe-commits]

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@@ -514,36 +514,48 @@ define <7 x i1> @get_active_lane_mask(i64 %0, i64 %1) {
 ; CHECK-SAME:  %[[VEC:[a-zA-Z0-9]+]]
 ; CHECK-SAME:  %[[MASK:[a-zA-Z0-9]+]]
 define void @masked_load_store_intrinsics(ptr %vec, <7 x i1> %mask) {
-  ; CHECK:  %[[UNDEF:.+]] = llvm.mlir.undef
-  ; CHECK:  %[[VAL1:.+]] = llvm.intr.masked.load %[[VEC]], %[[MASK]], %[[UNDEF]] {alignment = 1 : i32}
+  ; CHECK:  %[[POISON:.+]] = llvm.mlir.poison
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Dinistro wrote:

Is there a particular reason to change `undef` to `poison` here?

https://github.com/llvm/llvm-project/pull/221879