[all-commits] [llvm/llvm-project] 46dee4: [RISCV][InsertVSETVLI] Split out demanded property...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 46dee4a3a3dfb372a0eaa0b4490c80be2f421f29
      https://github.com/llvm/llvm-project/commit/46dee4a3a3dfb372a0eaa0b4490c80be2f421f29
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2023-01-03 (Tue, 03 Jan 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-buildvec.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-shuffles.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-mask-buildvec.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-fp.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-reduction-int.ll
    M llvm/test/CodeGen/RISCV/rvv/fold-binary-reduce.ll
    M llvm/test/CodeGen/RISCV/rvv/vreductions-fp-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/vreductions-int.ll

  Log Message:
  -----------
  [RISCV][InsertVSETVLI] Split out demanded property for zero/non-zero of VL

The scalar move instructions (vmv.s.x, and fvmv.s.f) depend solely on whether the VL is 0 or non-zero. By tracking the fact we only demand the zeroness and not the whole VL value, we can allow changing VL over a scalar move. This helps to eliminate vsetvli toggles.

Differential Revision: https://reviews.llvm.org/D140157