[all-commits] [llvm/llvm-project] 9c3c0e: [RISCV] Separate addend from FMA operands to suppo...

[Yingwei Zheng via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9c3c0e324f5152c699cc14b79a630589be5eced3
      https://github.com/llvm/llvm-project/commit/9c3c0e324f5152c699cc14b79a630589be5eced3
  Author: Yingwei Zheng <dtcxzyw2333 at gmail.com>
  Date:   2023-10-26 (Thu, 26 Oct 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInstrInfoD.td
    M llvm/lib/Target/RISCV/RISCVInstrInfoF.td
    M llvm/lib/Target/RISCV/RISCVInstrInfoZfh.td
    M llvm/lib/Target/RISCV/RISCVSchedRocket.td
    M llvm/lib/Target/RISCV/RISCVSchedSiFive7.td
    M llvm/lib/Target/RISCV/RISCVSchedSyntacoreSCR1.td
    M llvm/lib/Target/RISCV/RISCVSchedule.td

  Log Message:
  -----------
  [RISCV] Separate addend from FMA operands to support cascade FMA. NFC. (#70241)

This PR separate addend from FMA operands to support cascade FMA. In
some microarchitectures (e.g., ARM cortex-a72 and XiangShan-NanHu), FP
multiply-accumulate pipelines support late-forwarding of accumulate
operands, which reduces the latency of a sequence of multiply-accumulate
instructions.
See also #70232.