[all-commits] [llvm/llvm-project] 6227b7: [RISCV] Move xori creation for scalar setccs to lo...

Craig Topper via All-commits all-commits at lists.llvm.org
Fri Aug 19 13:52:14 PDT 2022

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6227b7ae313d8bb45cd271208b5e6da389795690
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2022-08-19 (Fri, 19 Aug 2022)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/lib/Target/RISCV/RISCVInstrInfo.td
    M llvm/lib/Target/RISCV/RISCVInstrInfoZb.td
    M llvm/test/CodeGen/RISCV/forced-atomics.ll
    M llvm/test/CodeGen/RISCV/fpclamptosat.ll
    M llvm/test/CodeGen/RISCV/fpclamptosat_vec.ll
    M llvm/test/CodeGen/RISCV/rv32zbt.ll
    M llvm/test/CodeGen/RISCV/select-cc.ll
    M llvm/test/CodeGen/RISCV/urem-seteq-illegal-types.ll
    M llvm/test/CodeGen/RISCV/xaluo.ll

  Log Message:
  [RISCV] Move xori creation for scalar setccs to lowering.

This patch enables expansion or custom lowering for some integer
condition codes so that any xori that is needed is created before
the last DAG combine to enable optimization.

I've seen cases where we end up with
(or (xori (setcc), 1), (xori (setcc), 1)) which we would ideally
convert to (xori (and (setcc), (setcc)), 1). This patch doesn't
accomplish that yet, but it should allow us to add DAG
combines as follow ups. Example https://godbolt.org/z/Y4qnvsq1b

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D131729

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