[llvm] [AMDGPU] Add initial version of gfx950 MFMA co-exec rules (PR #214682)

[Matt Arsenault via llvm-commits]

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@@ -346,12 +346,183 @@ inline CoExecInfo CoExecInfo::build(unsigned TotalWindow, const char *Pattern) {
   return Info;
 }
 
+/// Apply \p ExtraBits to every slot in \p Info starting with \p StartIndex
+/// Used by MFMA co-exec rules, because MFMA co-exec slots are incremental, i.e.
+/// for every slot N it supports all instructions which were supported by the
+/// previous slot N-1 and may support something extra.
+inline void AllowCoExec(CoExecInfo &Info, CoExecMaskT ExtraBits,
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arsenm wrote:

Start with lowercase 

https://github.com/llvm/llvm-project/pull/214682