[all-commits] [llvm/llvm-project] b80e1a: [M68k] Improve codegen of overflow arithmetics

[Min-Yih Hsu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b80e1acc8cfb82158255de24fb2887acd72a4049
      https://github.com/llvm/llvm-project/commit/b80e1acc8cfb82158255de24fb2887acd72a4049
  Author: Min-Yih Hsu <min at myhsu.dev>
  Date:   2023-12-26 (Tue, 26 Dec 2023)

  Changed paths:
    M llvm/lib/Target/M68k/M68kISelLowering.cpp
    M llvm/lib/Target/M68k/M68kInstrArithmetic.td
    M llvm/lib/Target/M68k/M68kInstrInfo.td
    M llvm/test/CodeGen/M68k/Arith/smul-with-overflow.ll
    M llvm/test/CodeGen/M68k/Arith/umul-with-overflow.ll

  Log Message:
  -----------
  [M68k] Improve codegen of overflow arithmetics

The codegen logic for overflow arithmetics (e.g. llvm.uadd.overflow)
was a mess; overflow multiplications were not even supported.
This patch clean up the legalization of overflow arithmetics and add
supports for common variants of overflow multiplications.