[llvm] [X86][GISel] Fix crash on bitcasting i16 <-> half with gisel enabled. (PR #168456)

[Evgenii Kudriashov via llvm-commits]

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@@ -0,0 +1,44 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -global-isel | FileCheck %s --check-prefixes=SSE2
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -global-isel -mattr=+avx | FileCheck %s --check-prefixes=AVX
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -global-isel -mattr=+avx512f | FileCheck %s --check-prefixes=AVX512
+
+define dso_local noundef half @test_i16_to_half(i16 %0) {
+; SSE2-LABEL: test_i16_to_half:
+; SSE2:       # %bb.0: # %entry
+; SSE2-NEXT:    pinsrw $0, %di, %xmm0
+; SSE2-NEXT:    retq
+;
+; AVX-LABEL: test_i16_to_half:
+; AVX:       # %bb.0: # %entry
+; AVX-NEXT:    vpinsrw $0, %di, %xmm0, %xmm0
+; AVX-NEXT:    retq
+;
+; AVX512-LABEL: test_i16_to_half:
+; AVX512:       # %bb.0: # %entry
+; AVX512-NEXT:    vpinsrw $0, %di, %xmm0, %xmm0
+; AVX512-NEXT:    retq
+entry:
+  %2 = bitcast i16 %0 to half
+  ret half %2
+}
+
+define dso_local noundef i16 @test_half_to_i16(half %0) {
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e-kud wrote:

```suggestion
define i16 @test_half_to_i16(half %0) {
```

https://github.com/llvm/llvm-project/pull/168456