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

[Andrea Faulds]

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@@ -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.
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andfau-amd wrote:

It seems like if I make this conversion pattern reject the poison index, the operation just never gets legalized (looking at the unit test output). I guess this means the folder isn't aware of or for some other reason doesn't apply the poison folding pattern; I'm not yet sure why.

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