[llvm] [DAG] Scalarise trivial splat operations (PR #226257)

[David Green via llvm-commits]

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@@ -57,6 +57,9 @@ void DAGTypeLegalizer::ScalarizeVectorResult(SDNode *N, unsigned ResNo) {
     report_fatal_error("Do not know how to scalarize the result of this "
                        "operator!\n");
 
+  case ISD::SPLAT_VECTOR:
+    R = N->getOperand(0);
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davemgreen wrote:

Not in the example we have so far, it was a f16. But we can reuse the buildvector code if we think that truncated splats will appear in the future.

https://github.com/llvm/llvm-project/pull/226257