[all-commits] [llvm/llvm-project] 1806ce: [RISCV] Teach RISCVMatInt to prefer li+slli over l...

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1806ce9097a635aa7a5530b5bf52547c78c87479
      https://github.com/llvm/llvm-project/commit/1806ce9097a635aa7a5530b5bf52547c78c87479
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2022-12-06 (Tue, 06 Dec 2022)

  Changed paths:
    M llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp
    M llvm/test/CodeGen/RISCV/calling-conv-half.ll
    M llvm/test/CodeGen/RISCV/i32-icmp.ll
    M llvm/test/CodeGen/RISCV/i64-icmp.ll
    M llvm/test/CodeGen/RISCV/macro-fusion-lui-addi.ll
    M llvm/test/CodeGen/RISCV/mul.ll
    M llvm/test/CodeGen/RISCV/pr58511.ll
    M llvm/test/CodeGen/RISCV/rv32zbs.ll
    M llvm/test/CodeGen/RISCV/rv64zbs.ll
    M llvm/test/CodeGen/RISCV/rvv/active_lane_mask.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-buildvec.ll
    M llvm/test/CodeGen/RISCV/rvv/large-rvv-stack-size.mir
    M llvm/test/CodeGen/RISCV/rvv/vscale-power-of-two.ll
    M llvm/test/MC/RISCV/rv32c-aliases-valid.s
    M llvm/test/MC/RISCV/rv32i-aliases-valid.s
    M llvm/test/MC/RISCV/rv64c-aliases-valid.s
    M llvm/test/MC/RISCV/rv64i-aliases-valid.s

  Log Message:
  -----------
  [RISCV] Teach RISCVMatInt to prefer li+slli over lui+addi(w) for compressibility.

With C extension, li with a 6 bit immediate followed by slli is 4 bytes.
The lui+addi(w) sequence is at least 6 bytes.

The two sequences probably have similar execution latency. The exception
being if the target supports lui+addi(w) macrofusion.

Since the execution latency is probably the same I didn't restrict
this to C extension.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D139135