[PATCH] D154083: [AMDGPU] Rematerialize scalar loads

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/SIInstrInfo.cpp:2354
+    MI->getOperand(0).setIsUndef(false);
+    MRI.setRegClass(DestReg, &AMDGPU::SGPR_256RegClass);
+
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piotr wrote:
> arsenm wrote:
> > arsenm wrote:
> > > Can you go through getSubRegisterClass (possibly with getMatchingSuperRegClass and getSubClassWithSubReg) to avoid hardcoding this 
> > Easier yet would be just use the result class from the instruction desc 
> > 
> > Also, is this safe from other users with a different class?
> Thanks - will rewrite this, but what exactly do you mean here by "safe from other users"?
I mean other instructions using the same virtual register that aren't expecting the class to change. You're mutating the existing register and not creating a new one with the new class


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  https://reviews.llvm.org/D154083/new/

https://reviews.llvm.org/D154083