[llvm-branch-commits] [llvm] [AMDGPU] Make AMDGPURewriteAGPRCopyMFMA aware of subreg reload (PR #174998)

[Matt Arsenault via llvm-branch-commits]

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@@ -546,6 +546,16 @@ TargetRegisterInfo::getRegSizeInBits(Register Reg,
   return getRegSizeInBits(*RC);
 }
 
+unsigned
+TargetRegisterInfo::getSubRegIdxFromLaneMask(LaneBitmask LaneMask) const {
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arsenm wrote:

This is just getCoveringSubRegIndexes, except it silently doesn't work sometimes? 

https://github.com/llvm/llvm-project/pull/174998