[PATCH] D140570: [AVR] Optimize 32-bit shift: move bytes around

[Ben Shi via Phabricator via llvm-commits]

benshi001 added inline comments.


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Comment at: llvm/lib/Target/AVR/AVRISelLowering.cpp:1863
+    Register Out = MRI.createVirtualRegister(&AVR::GPR8RegClass);
+    BuildMI(*BB, MI, dl, TII.get(AVR::COPY), Out).addReg(STI.getZeroRegister());
+    Regs[Regs.size() - 1] = std::pair(Out, 0);
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Do we need to do `AVR::COPY` for each iteration ? Can it be a unique `Register Out` shared by all iterations, and even shared with  `lshr` ?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140570/new/

https://reviews.llvm.org/D140570