[llvm] [X86] Fix arithmetic error in extractVector (PR #128052)

[Phoebe Wang via llvm-commits]

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@@ -0,0 +1,30 @@
+; Ensure assertion is not hit when folding concat of two contiguous extract_subvector operations
+; from a source with a non-power-of-two vector length.
+; RUN: llc -mattr=+avx2 < %s
+
+source_filename = "foo.c"
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
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phoebewang wrote:

These are not needed. And add the triple to RUN line, e.g,
`; RUN: llc -mtriple=x86_64 -mattr=+avx2 < %s`

https://github.com/llvm/llvm-project/pull/128052