[all-commits] [llvm/llvm-project] 544a24: [RISCV] Use v(f)slide1up for shuffle+insert idiom

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 544a240ff7ff5bbacd3d50692335a93665ded8d5
      https://github.com/llvm/llvm-project/commit/544a240ff7ff5bbacd3d50692335a93665ded8d5
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2023-05-30 (Tue, 30 May 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/test/CodeGen/RISCV/rvv/fixed-vector-shuffle-transpose.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vector-shuffle-vslide1up.ll

  Log Message:
  -----------
  [RISCV] Use v(f)slide1up for shuffle+insert idiom

This is pretty straight forward in the basic form. I did need to move the slideup matching earlier, but that looks generally profitable on it's own.

As follow ups, I plan to explore the v(f)slide1down variants, and see what I can do to canonicalize the shuffle then insert pattern (see _inverse tests at the end of the vslide1up.ll test).

Differential Revision: https://reviews.llvm.org/D151468