[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:1853
+  // zero the bottom registers.
+  auto MSBReg = Regs[0];
+  Register ShrExtendReg = 0;
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These two variables are only used inside `while (ShiftAmt >= 8)`, so how about moving them down to the head of the loop ?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D140570/new/

https://reviews.llvm.org/D140570