[all-commits] [llvm/llvm-project] d934b7: [RISCV] Optimize add-mul in the zba extension with...

[Ben Shi via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d934b72809cb3cbc9f646a2b505e781e0b8b3d7b
      https://github.com/llvm/llvm-project/commit/d934b72809cb3cbc9f646a2b505e781e0b8b3d7b
  Author: Ben Shi <powerman1st at 163.com>
  Date:   2021-06-19 (Sat, 19 Jun 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInstrInfo.td
    M llvm/lib/Target/RISCV/RISCVInstrInfoB.td
    M llvm/test/CodeGen/RISCV/rv32zba.ll
    M llvm/test/CodeGen/RISCV/rv64zba.ll

  Log Message:
  -----------
  [RISCV] Optimize add-mul in the zba extension with SH*ADD

This patch does the following optimization.

Rx + Ry * 18 => (SH1ADD (SH3ADD Rx, Rx), Ry)
Rx + Ry * 20 => (SH2ADD (SH2ADD Rx, Rx), Ry)
Rx + Ry * 24 => (SH3ADD (SH1ADD Rx, Rx), Ry)
Rx + Ry * 36 => (SH2ADD (SH3ADD Rx, Rx), Ry)
Rx + Ry * 40 => (SH3ADD (SH2ADD Rx, Rx), Ry)
Rx + Ry * 72 => (SH3ADD (SH3ADD Rx, Rx), Ry)

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D104588