[llvm] [AMDGPU] Use correct VGPR threshold for flagging ExcessRP regions in unified register file case (PR #85860)

[Stanislav Mekhanoshin via llvm-commits]

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@@ -1155,12 +1155,16 @@ unsigned getMinNumVGPRs(const MCSubtargetInfo *STI, unsigned WavesPerEU) {
   return std::min(MinNumVGPRs, AddrsableNumVGPRs);
 }
 
-unsigned getMaxNumVGPRs(const MCSubtargetInfo *STI, unsigned WavesPerEU) {
+unsigned getMaxNumVGPRs(const MCSubtargetInfo *STI, unsigned WavesPerEU,
+                        bool WholeRegisterFile) {
   assert(WavesPerEU != 0);
 
-  unsigned MaxNumVGPRs = alignDown(getTotalNumVGPRs(STI) / WavesPerEU,
-                                   getVGPRAllocGranule(STI));
-  unsigned AddressableNumVGPRs = getAddressableNumVGPRs(STI);
+  unsigned MaxNumVGPRs =
+      alignDown(getTotalNumVGPRs(STI, WholeRegisterFile) / WavesPerEU,
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rampitec wrote:

This assumes equal allocation. I.e. assume you want occupancy 2 and you have no agprs at all. You will end up with the limit of 128 vgprs, but you can use 256.

https://github.com/llvm/llvm-project/pull/85860