[PATCH] D117725: [AVR] Fix atomicrmw result value

[Ayke via Phabricator via llvm-commits]

aykevl added inline comments.


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Comment at: llvm/lib/Target/AVR/AVRISelLowering.cpp:1705
+  MachineBasicBlock::iterator I(MI);
+  const Register SCRATCH_REGISTER = AVR::R0;
+  const unsigned SREG_ADDR = 0x3f;
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benshi001 wrote:
> Also, do we need to make a helper function `int getRegScratch(void)` in `AVRSubtarget.h`, just like I have done as `getIORegRAMPZ(void)` ? The new helper function will return r16 for avr-tiny devices.
> 
> Also, do we need a helper function `int getIORegSREG(void)` instead of hard coded `0x3f` ?
See my comment in D117426.


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Comment at: llvm/lib/Target/AVR/AVRISelLowering.cpp:1733
+  Register Result = MRI.createVirtualRegister(RC);
+  BuildMI(*BB, I, dl, TII.get(Opcode), Result)
+      .addReg(MI.getOperand(0).getReg())
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benshi001 wrote:
> Do we need a flag `RegState::Define` for `Result` ?
No, because `BuildMI` will always set `RegState::Define` for the last parameter (`Result` in this case).


Repository:
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  https://reviews.llvm.org/D117725/new/

https://reviews.llvm.org/D117725