[all-commits] [llvm/llvm-project] d70e91: [RISCV] Optimize getVLENFactoredAmount function.

[luxufan via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d70e9195a3339a6d56ed46ad4b8b467a0053322a
      https://github.com/llvm/llvm-project/commit/d70e9195a3339a6d56ed46ad4b8b467a0053322a
  Author: luxufan <932494295 at qq.com>
  Date:   2021-05-24 (Mon, 24 May 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
    M llvm/test/CodeGen/RISCV/rvv/allocate-lmul-2-4-8.ll
    M llvm/test/CodeGen/RISCV/rvv/rvv-framelayout.ll

  Log Message:
  -----------
  [RISCV] Optimize getVLENFactoredAmount function.

If the local variable `NumOfVReg` isPowerOf2_32(NumOfVReg - 1) or isPowerOf2_32(NumOfVReg + 1), the ADDI and MUL instructions can be replaced with SLLI and ADD(or SUB) instructions.

Based on original patch by StephenFan.

Reviewed By: frasercrmck, StephenFan

Differential Revision: https://reviews.llvm.org/D100577