[PATCH] D98233: [RISCV] Improve legalization of i32 UADDO/USUBO on RV64.

[Craig Topper via Phabricator via llvm-commits]

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The default legalization uses zero extends that require pair of shifts
on RISCV. Instead we can take advantage of the fact that unsigned
compares work equally well on sign extended inputs. This allows
us to use addw/subw and sext.w.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D98233

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp
  llvm/test/CodeGen/RISCV/xaluo.ll

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