[all-commits] [llvm/llvm-project] 4dc9a2: [RISCV] Use scalar stores for splats of zero to me...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4dc9a2c5b93682c12d7a80bbe790b14ddb301877
      https://github.com/llvm/llvm-project/commit/4dc9a2c5b93682c12d7a80bbe790b14ddb301877
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2023-05-17 (Wed, 17 May 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-splat.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-mask-splat.ll

  Log Message:
  -----------
  [RISCV] Use scalar stores for splats of zero to memory up to XLen

The direct motivation here is to undo an unprofitable vectorization performed by SLP, but the transform seems generally useful as well. If we are storing a zero to memory, we can use a single scalar store (from X0) for all power of two sizes up to XLen.

Differential Revision: https://reviews.llvm.org/D150717