[all-commits] [llvm/llvm-project] c705b7: [RISCV] Optimize bitwise and with constant for the...

[Ben Shi via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c705b7b04dba467a67871a1bbb77907d0ed7fc19
      https://github.com/llvm/llvm-project/commit/c705b7b04dba467a67871a1bbb77907d0ed7fc19
  Author: Ben Shi <powerman1st at 163.com>
  Date:   2021-06-08 (Tue, 08 Jun 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInstrInfoB.td
    M llvm/test/CodeGen/RISCV/rv32zbs.ll
    M llvm/test/CodeGen/RISCV/rv64zbs.ll

  Log Message:
  -----------
  [RISCV] Optimize bitwise and with constant for the Zbs extension

This patch optimizes (and r i) to
(BCLRI (BCLRI r, i0), i1) in which i = ~((1<<i0) | (1<<i1)).
or
(BCLRI (ANDI r, i0), i1) in which i = i0 & ~(1<<i1).

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D103743