[all-commits] [llvm/llvm-project] cfa709: [RISCV] Add -mtune support

[Kito Cheng via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: cfa7094e49cfb7e37a84c0aa57c85c64c0581d17
      https://github.com/llvm/llvm-project/commit/cfa7094e49cfb7e37a84c0aa57c85c64c0581d17
  Author: Kito Cheng <kito.cheng at sifive.com>
  Date:   2020-10-16 (Fri, 16 Oct 2020)

  Changed paths:
    M clang/include/clang/Driver/Options.td
    M clang/lib/Basic/Targets/RISCV.cpp
    M clang/lib/Basic/Targets/RISCV.h
    M clang/lib/Driver/ToolChains/Clang.cpp
    M clang/test/Driver/riscv-cpus.c
    M clang/test/Misc/target-invalid-cpu-note.c
    M llvm/include/llvm/Support/RISCVTargetParser.def
    M llvm/include/llvm/Support/TargetParser.h
    M llvm/lib/Support/TargetParser.cpp
    M llvm/lib/Target/RISCV/RISCVAsmPrinter.cpp
    M llvm/lib/Target/RISCV/RISCVSubtarget.cpp
    M llvm/lib/Target/RISCV/RISCVSubtarget.h
    M llvm/lib/Target/RISCV/RISCVTargetMachine.cpp

  Log Message:
  -----------
  [RISCV] Add -mtune support

 - The goal of this patch is improve option compatible with RISCV-V GCC,
   -mcpu support on GCC side will sent patch in next few days.

 - -mtune only affect the pipeline model and non-arch/extension related
   target feature, e.g. instruction fusion; in td file it called
   TuneFeatures, which is introduced by X86 back-end[1].

 - -mtune accept all valid option for -mcpu and extra alias processor
   option, e.g. `generic`, `rocket` and `sifive-7-series`, the purpose is
   option compatible with RISCV-V GCC.

 - Processor alias for -mtune will resolve according the current target arch,
   rv32 or rv64, e.g. `rocket` will resolve to `rocket-rv32` or `rocket-rv64`.

 - Interaction between -mcpu and -mtune:
   * -mtune has higher priority than -mcpu for pipeline model and
     TuneFeatures.

[1] https://reviews.llvm.org/D85165

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D89025