commit 294d1eae75bf8867821a4491f0d67445227f8470
author Zakk Chen <zakk.chen@sifive.com> Thu Jul 16 10:32:01 2020 -0700
committer Zakk Chen <zakk.chen@sifive.com> Thu Jul 16 11:46:22 2020 -0700
tree 40906f95b1c53922ad1adcc3eb285457a2398e80
parent a394aa1b974bd320242569e5bed53284010cfa63

[RISCV] Add support for -mcpu option.

Summary:
1. gcc uses `-march` and `-mtune` flag to chose arch and
pipeline model, but clang does not have `-mtune` flag,
we uses `-mcpu` to chose both infos.
2. Add SiFive e31 and u54 cpu which have default march
and pipeline model.
3. Specific `-mcpu` with rocket-rv[32|64] would select
pipeline model only, and use the driver's arch choosing
logic to get default arch.

Reviewers: lenary, asb, evandro, HsiangKai

Reviewed By: lenary, asb, evandro

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D71124

clang/lib/Basic/Targets/RISCV.h

diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 73652b4..6db526d 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -24,7 +24,7 @@
 // RISC-V Target
 class RISCVTargetInfo : public TargetInfo {
 protected:
-  std::string ABI;
+  std::string ABI, CPU;
   bool HasM;
   bool HasA;
   bool HasF;
@@ -44,6 +44,13 @@
     WIntType = UnsignedInt;
   }
 
+  bool setCPU(const std::string &Name) override {
+    if (!isValidCPUName(Name))
+      return false;
+    CPU = Name;
+    return true;
+  }
+
   StringRef getABI() const override { return ABI; }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
@@ -97,6 +104,9 @@
     return false;
   }
 
+  bool isValidCPUName(StringRef Name) const override;
+  void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;
+
   void setMaxAtomicWidth() override {
     MaxAtomicPromoteWidth = 128;
 
@@ -121,6 +131,9 @@
     return false;
   }
 
+  bool isValidCPUName(StringRef Name) const override;
+  void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;
+
   void setMaxAtomicWidth() override {
     MaxAtomicPromoteWidth = 128;