[all-commits] [llvm/llvm-project] 229eeb: [RISCV] Look through copies when trying to find an...

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 229eeb187d42fab9ef73be7ce82a50ed63914819
      https://github.com/llvm/llvm-project/commit/229eeb187d42fab9ef73be7ce82a50ed63914819
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2021-03-16 (Tue, 16 Mar 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/test/CodeGen/RISCV/rvv/masked-load-fp.ll
    M llvm/test/CodeGen/RISCV/rvv/masked-load-int.ll
    A llvm/test/CodeGen/RISCV/rvv/tail-agnostic-impdef-copy.mir

  Log Message:
  -----------
  [RISCV] Look through copies when trying to find an implicit def in addVSetVL.

The InstrEmitter can sometimes insert a copy after an IMPLICIT_DEF
before connecting it to the vector instruction. This occurs when
constrainRegClass reduces to a class with less than 4 registers.
I believe LMUL8 on masked instructions triggers this since the
result can only use the v8, v16, or v24 register group as the mask
is using v0.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D98567