[llvm] [DAGCombiner] Fix subvector extraction index for big-endian STLF (PR #180795)

[Phoebe Wang via llvm-commits]

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@@ -37,8 +37,11 @@ define <2 x bfloat> @shuffle_chained_v16bf16(<16 x bfloat> %a) {
 ; CHECK-NEXT:    .cfi_def_cfa_register %rbp
 ; CHECK-NEXT:    andq $-32, %rsp
 ; CHECK-NEXT:    subq $96, %rsp
-; CHECK-NEXT:    vmovdqa %ymm0, (%rsp)
+; CHECK-NEXT:    vmovaps %ymm0, (%rsp)
+; CHECK-NEXT:    vmovdqa (%rsp), %xmm0
 ; CHECK-NEXT:    vpunpcklwd {{.*#+}} xmm0 = xmm0[0],mem[0],xmm0[1],mem[1],xmm0[2],mem[2],xmm0[3],mem[3]
+; CHECK-NEXT:    vmovdqa %ymm0, {{[0-9]+}}(%rsp)
+; CHECK-NEXT:    vmovaps {{[0-9]+}}(%rsp), %xmm0
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phoebewang wrote:

Yeah, I think so. We only set INSERT_SUBVECTOR legal.

https://github.com/llvm/llvm-project/pull/180795