[PATCH] D124193: [AMDGPU] Add WWM reserved VGPRs to WWMSpills

[Christudasan Devadasan via Phabricator via llvm-commits]

cdevadas added a comment.

@sebastian-ne Is there a case when `SIPreAllocateWWMRegs` pass allocates a CSR VGPR to operands in WWM instructions?
If it is true, we may have a bug in the current handling that we failed to reset the `WWMReservedRegs` from the `SavedVGPRs` during `determineCalleeSaves` that allow us later to custom insert these spills in the emitPrologue/emitEpilogue functions.

Here is what we do for VGPRs used for SGPR spills.
https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/AMDGPU/SIFrameLowering.cpp#L1278

It doesn't come under the scope of this patch. But if this case can arise, we must fix it.


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https://reviews.llvm.org/D124193