[all-commits] [llvm/llvm-project] 148470: [RISCV] Delete unexercised VL=0 vsetvli compatibil...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 14847098f90b291e847d283fe985d5f15b49ffe3
      https://github.com/llvm/llvm-project/commit/14847098f90b291e847d283fe985d5f15b49ffe3
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2022-06-20 (Mon, 20 Jun 2022)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp

  Log Message:
  -----------
  [RISCV] Delete unexercised VL=0 vsetvli compatibility logic

The code being removed is technically correct; if we end up with two VL=0 instructions next to each other, we can avoid a state transition if the second is a scalar move.  However, since both ops are also nops, we should simply delete them instead.  As such, this compatibility rule simply complicates the code for no purpose.