[Mlir-commits] [mlir] [mlir][spirv] Support poison index when converting vector.insert/extract (PR #125560)

[Andrea Faulds]

================
@@ -154,14 +174,26 @@ struct VectorExtractOpConvert final
     }
 
     if (std::optional<int64_t> id =
-            getConstantIntValue(extractOp.getMixedPosition()[0]))
-      rewriter.replaceOpWithNewOp<spirv::CompositeExtractOp>(
-          extractOp, dstType, adaptor.getVector(),
-          rewriter.getI32ArrayAttr(id.value()));
-    else
+            getConstantIntValue(extractOp.getMixedPosition()[0])) {
+      // TODO: It would be better to apply the ub.poison folding for this case
+      //       unconditionally, and have a specific SPIR-V lowering for it,
+      //       rather than having to handle it here.
----------------
andfau-amd wrote:

Oh, I didn't know about that PR! I ended up implementing basically the same thing, but it turns out that's not enough by itself to fix things for `-convert-vector-to-spirv`. Presumably the SPIR-V dialect is rejecting the `ub.poison` after it's created or something along these lines, I need to keep digging.

https://github.com/llvm/llvm-project/pull/125560