[llvm] [DAGCombiner] Require same type of splat & element for build_vector (PR #88284)

[Feng Zou via llvm-commits]

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@@ -0,0 +1,24 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: llc < %s -mtriple=x86_64 -mattr=avx512bw | FileCheck %s
+
+; Verify that the DAGCombiner doesn't change build_vector to concat_vectors if
+; the vector element type is different than splat type. The example here:
+;   v8i1 = build_vector (i8 (bitcast (v8i1 X))), ..., (i8 (bitcast (v8i1 X))))
+
+define void @foo(<8 x i1> %mask.i1) {
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fzou1 wrote:

Updated.

https://github.com/llvm/llvm-project/pull/88284