[llvm] [PowerPC][NFC] Pre-commit test case for checking whether `mtvsrbmi` power10 instruction not used (PR #143956)

[Lei Huang via llvm-commits]

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@@ -0,0 +1,38 @@
+; Verify whether the generated assembly for the following function includes the mtvsrbmi instruction.
+; vector unsigned char v00FF()
+; {
+; vector unsigned char x = { 0xFF, 0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0 };
+; return x;
+; }
+
+; RUN: llc < %s -ppc-asm-full-reg-names  -mtriple=powerpc-ibm-aix -mcpu=pwr10  -verify-machineinstrs \
+; RUN:   | FileCheck %s --check-prefix=CHECK
+
+define dso_local noundef range(i8 -1, 1) <16 x i8> @_Z5v00FFv() local_unnamed_addr {
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lei137 wrote:

is `dso_local` and `local_unnamed_addr` needed?

In general we prefer to use the update_llc_* utils to generate the checks.  If this can't be used, can you please add doc about why?

https://github.com/llvm/llvm-project/pull/143956