[PATCH] D138529: [AVR] Optimize constant 32-bit shifts

[Ben Shi via Phabricator via llvm-commits]

benshi001 added inline comments.


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Comment at: llvm/lib/Target/AVR/AVRISelLowering.cpp:1843
+// https://aykevl.nl/2021/02/avr-bitshift
+static void insertMultibyteShift(MachineInstr &MI, MachineBasicBlock *BB,
+                                 MutableArrayRef<std::pair<Register, int>> Regs,
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I think using negative ShiftAmt for left shift is so counter-intuitive, it would be better to use one more argument `bool leftShift`, or direct expose the Opcode `{shl, lshr, ashr}`.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D138529/new/

https://reviews.llvm.org/D138529