[clang] [PowerPC][NFC] Define new alias for mma accumulate builtins (PR #147382)

[Lei Huang via cfe-commits]

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@@ -1148,14 +1078,33 @@ UNALIASED_CUSTOM_BUILTIN(mma_dmxvi8gerx4pp, "vW1024*W256V", true,
                          "mma,paired-vector-memops")
 UNALIASED_CUSTOM_BUILTIN(mma_pmdmxvi8gerx4pp, "vW1024*W256Vi255i15i15", true,
                          "mma,paired-vector-memops")
-UNALIASED_CUSTOM_BUILTIN(mma_dmxvi8gerx4spp,  "vW1024*W256V", true,
+UNALIASED_CUSTOM_BUILTIN(mma_dmxvi8gerx4spp, "vW1024*W256V", true,
                          "mma,paired-vector-memops")
 UNALIASED_CUSTOM_BUILTIN(mma_pmdmxvi8gerx4spp, "vW1024*W256Vi255i15i15", true,
                          "mma,paired-vector-memops")
 
+// MMA builtins with positive/negative multiply/accumulate.
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lei137 wrote:

I feel that would be a bit of an overkill.  I have added an example at the top to further document the new macro usage.

https://github.com/llvm/llvm-project/pull/147382