[PATCH] D130508: [RISCV] Teach translateSetCCForBranch to help improve constant materialization.

[Craig Topper via Phabricator via llvm-commits]

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InstCombine and DAGCombine both canonicalize setge X, C to
setgt X, C-1. C might be easier to materialize than C.

This patch teaches translateSetCCForBranch to reverse the canonicalize
if it will give us a single 'addi' or 'lui' to materialize the constant.

This was inspired by https://github.com/llvm/llvm-project/issues/56666
and wondering if we should do something like getAArch64Cmp.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D130508

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp
  llvm/test/CodeGen/RISCV/rv32zbt.ll
  llvm/test/CodeGen/RISCV/rv64zbt.ll
  llvm/test/CodeGen/RISCV/select-cc.ll

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