[all-commits] [llvm/llvm-project] 41454a: [RISCV] Use constant pool for large integers

[Wang Pengcheng via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 41454ab25645f28d53fe6db08ae41b9898142655
      https://github.com/llvm/llvm-project/commit/41454ab25645f28d53fe6db08ae41b9898142655
  Author: wangpc <pc.wang at linux.alibaba.com>
  Date:   2021-12-31 (Fri, 31 Dec 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
    M llvm/lib/Target/RISCV/RISCVISelLowering.h
    M llvm/lib/Target/RISCV/RISCVSubtarget.cpp
    M llvm/lib/Target/RISCV/RISCVSubtarget.h
    M llvm/test/CodeGen/RISCV/bswap-ctlz-cttz-ctpop.ll
    M llvm/test/CodeGen/RISCV/div-by-constant.ll
    M llvm/test/CodeGen/RISCV/div.ll
    M llvm/test/CodeGen/RISCV/double-imm.ll
    M llvm/test/CodeGen/RISCV/imm.ll
    M llvm/test/CodeGen/RISCV/rv64zbb.ll
    M llvm/test/CodeGen/RISCV/rv64zbp.ll
    M llvm/test/CodeGen/RISCV/rvv/bitreverse-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/ctlz-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/ctpop-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/cttz-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-bitreverse.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-ctlz.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-ctpop.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-cttz.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-buildvec.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-mask-buildvec.ll
    M llvm/test/CodeGen/RISCV/rvv/interleave-crash.ll
    M llvm/test/CodeGen/RISCV/rvv/vdiv-sdnode.ll
    M llvm/test/CodeGen/RISCV/rvv/vrem-sdnode.ll
    M llvm/test/CodeGen/RISCV/srem-lkk.ll
    M llvm/test/CodeGen/RISCV/srem-seteq-illegal-types.ll
    M llvm/test/CodeGen/RISCV/srem-vector-lkk.ll
    M llvm/test/CodeGen/RISCV/urem-lkk.ll
    M llvm/test/CodeGen/RISCV/urem-vector-lkk.ll
    M llvm/test/CodeGen/RISCV/vararg.ll

  Log Message:
  -----------
  [RISCV] Use constant pool for large integers

For large integers (for example, magic numbers generated by
TargetLowering::BuildSDIV when dividing by constant), we may
need about 4~8 instructions to build them.
In the same time, it just takes two instructions to load
constants (with extra cycles to access memory), so it may be
profitable to put these integers into constant pool.

Reviewed By: asb, craig.topper

Differential Revision: https://reviews.llvm.org/D114950