[PATCH] D138044: AMDGPU/GlobalISel: Fix crash after mad/fma_mix fails selection

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp:3412-3414
+Register AMDGPUInstructionSelector::copyToVGPR(Register Src, unsigned Mods,
+                                               MachineOperand Root,
+                                               bool ForceVGPR) const {
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The name isn't accurate since this isn't just blindly inserting a copy. How about copyToVGPRIfSrcFolded


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp:3415
+                                               bool ForceVGPR) const {
   if ((Mods != 0 || ForceVGPR) &&
       RBI.getRegBank(Src, *MRI, TRI)->getID() != AMDGPU::VGPRRegBankID) {
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Unrelated, but I don't understand why this modifier check is here. It doesn't factor into the constant bus restriction 


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Comment at: llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp:3647
+                                           /* OpSel */ true);
+  Src = copyToVGPR(Src, Mods, Root, /* ForceVGPR */ true);
 
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Could you put this down in the callback with the addReg (same with the rest)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D138044/new/

https://reviews.llvm.org/D138044