[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:

I was assuming this thing didn't try to fold first because otherwise the test would be failing, but looking at that code snippet, it seems I hadn't considered the possibility it actually folds _second_ (if legalization fails). I should see what happens if I make it reject the poison index instead.

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