[llvm] [AMDGPU] Compiler should synthesize private buffer resource descriptor from flat_scratch_init (PR #79586)

[Scott Linder via llvm-commits]

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@@ -378,7 +378,7 @@ class PrologEpilogSGPRSpillBuilder {
 } // namespace llvm
 
 // Emit flat scratch setup code, assuming `MFI->hasFlatScratchInit()`
-void SIFrameLowering::emitEntryFunctionFlatScratchInit(
+Register SIFrameLowering::emitEntryFunctionFlatScratchInit(
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slinder1 wrote:

Nit: can you update the comment to include "... and return the FlatScratchInit Register used" (or something more precise if I'm not making sense)

https://github.com/llvm/llvm-project/pull/79586