[mips][mips64r6] Define _MIPS_FPSET, __mips_fpr, and __mips_nan2008 correctly on MIPS32r6/MIPS64r6

[dsanders]

Summary

This removes the need to pass -mnan=2008 explicitly to be able to compile
the test-suite for MIPS32r6/MIPS64r6.

[atanasyan]

LGTM

lib/Basic/Targets.cpp

 
 public:
   MipsTargetInfoBase(const llvm::Triple &Triple, const std::string &ABIStr,
                      const std::string &CPUStr)
       : TargetInfo(Triple), CPU(CPUStr), IsMips16(false), IsMicromips(false),
         IsNan2008(false), IsSingleFloat(false), FloatABI(HardFloat),
         DspRev(NoDSP), HasMSA(false), HasFP64(false), ABI(ABIStr) {}
 
+  bool isNaN2008Default() const {
+    return CPU == "mips32r6" || CPU == "mips64r6";
+  }
+
+  bool isFP64Default() const {
+    return CPU == "mips32r6" || ABI == "n32" || ABI == "n64" || ABI == "64";
+  }
+
   StringRef getABI() const override { return ABI; }
   bool setCPU(const std::string &Name) override {
     bool IsMips32 = getTriple().getArch() == llvm::Triple::mips ||
                     getTriple().getArch() == llvm::Triple::mipsel;
     CPU = Name;
     return llvm::StringSwitch<bool>(Name)
         .Case("mips1", IsMips32)
         .Case("mips2", IsMips32)
const char *getClobbers() const override {
     // FIXME: Implement!
     return "";
   }
 
   bool handleTargetFeatures(std::vector<std::string> &Features,
                             DiagnosticsEngine &Diags) override {
     IsMips16 = false;
     IsMicromips = false;
-    IsNan2008 = false;
+    IsNan2008 = isNaN2008Default();
     IsSingleFloat = false;
     FloatABI = HardFloat;
     DspRev = NoDSP;
-    HasFP64 = ABI == "n32" || ABI == "n64" || ABI == "64";
+    HasFP64 = isFP64Default();
 
     for (std::vector<std::string>::iterator it = Features.begin(),
          ie = Features.end(); it != ie; ++it) {
       if (*it == "+single-float")
         IsSingleFloat = true;
       else if (*it == "+soft-float")
         FloatABI = SoftFloat;
       else if (*it == "+mips16")
         IsMips16 = true;
       else if (*it == "+micromips")
         IsMicromips = true;
       else if (*it == "+dsp")
         DspRev = std::max(DspRev, DSP1);
       else if (*it == "+dspr2")
         DspRev = std::max(DspRev, DSP2);
       else if (*it == "+msa")
         HasMSA = true;
       else if (*it == "+fp64")
         HasFP64 = true;
       else if (*it == "-fp64")
         HasFP64 = false;
       else if (*it == "+nan2008")
         IsNan2008 = true;
+      else if (*it == "-nan2008")
+        IsNan2008 = false;
     }
 
     // Remove front-end specific options.
     std::vector<std::string>::iterator it =
       std::find(Features.begin(), Features.end(), "+soft-float");
     if (it != Features.end())
       Features.erase(it);
 

test/Preprocessor/init.c

 // MIPS64-MFP64:#define __mips_fpr 64
 //
 // RUN: %clang_cc1 -target-feature -fp64 -target-feature +single-float \
 // RUN:   -E -dM -triple=mips64-none-none < /dev/null \
 // RUN:   | FileCheck -check-prefix MIPS64-NOMFP64 %s
 // MIPS64-NOMFP64:#define _MIPS_FPSET 32
 // MIPS64-NOMFP64:#define __mips_fpr 32
 //
+// RUN: %clang_cc1 -target-cpu mips32r6 \
+// RUN:   -E -dM -triple=mips-none-none < /dev/null \
+// RUN:   | FileCheck -check-prefix MIPS-XXR6 %s
+// RUN: %clang_cc1 -target-cpu mips64r6 \
+// RUN:   -E -dM -triple=mips64-none-none < /dev/null \
+// RUN:   | FileCheck -check-prefix MIPS-XXR6 %s
+// MIPS-XXR6:#define _MIPS_FPSET 32
+// MIPS-XXR6:#define __mips_fpr 64
+// MIPS-XXR6:#define __mips_nan2008 1
+//
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=msp430-none-none < /dev/null | FileCheck -check-prefix MSP430 %s
 //
 // MSP430:#define MSP430 1
 // MSP430-NOT:#define _LP64
 // MSP430:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
 // MSP430:#define __CHAR16_TYPE__ unsigned short
 // MSP430:#define __CHAR32_TYPE__ unsigned int
 // MSP430:#define __CHAR_BIT__ 8