[Mips] Finetuning MIPS32 Android default variants

[petarj]

Summary

MIPS32 Android defaults to FPXX ("-fpxx").
MIPS32R6 Android defaults to FP64A ("-mfp64 -mno-odd-spreg").

[atanasyan]

LGTM

lib/Driver/Tools.h

 void getMipsCPUAndABI(const llvm::opt::ArgList &Args,
                       const llvm::Triple &Triple, StringRef &CPUName,
                       StringRef &ABIName);
 std::string getMipsABILibSuffix(const llvm::opt::ArgList &Args,
                                 const llvm::Triple &Triple);
 bool hasMipsAbiArg(const llvm::opt::ArgList &Args, const char *Value);
 bool isUCLibc(const llvm::opt::ArgList &Args);
 bool isNaN2008(const llvm::opt::ArgList &Args, const llvm::Triple &Triple);
+bool isFP64ADefault(const llvm::Triple &Triple, StringRef CPUName);
 bool isFPXXDefault(const llvm::Triple &Triple, StringRef CPUName,
                    StringRef ABIName, mips::FloatABI FloatABI);
 bool shouldUseFPXX(const llvm::opt::ArgList &Args, const llvm::Triple &Triple,
                    StringRef CPUName, StringRef ABIName,
                    mips::FloatABI FloatABI);
 } // end namespace mips
 
 namespace ppc {

lib/Driver/Tools.cpp

AddTargetFeature(Args, Features, options::OPT_mmicromips,
                    options::OPT_mno_micromips, "micromips");
   AddTargetFeature(Args, Features, options::OPT_mdsp, options::OPT_mno_dsp,
                    "dsp");
   AddTargetFeature(Args, Features, options::OPT_mdspr2, options::OPT_mno_dspr2,
                    "dspr2");
   AddTargetFeature(Args, Features, options::OPT_mmsa, options::OPT_mno_msa,
                    "msa");
 
-  // Add the last -mfp32/-mfpxx/-mfp64 or if none are given and the ABI is O32
-  // pass -mfpxx
+  // Add the last -mfp32/-mfpxx/-mfp64, if none are given and the ABI is O32
+  // pass -mfpxx, or if none are given and fp64a is default, pass fp64 and
+  // nooddspreg.
   if (Arg *A = Args.getLastArg(options::OPT_mfp32, options::OPT_mfpxx,
                                options::OPT_mfp64)) {
     if (A->getOption().matches(options::OPT_mfp32))
       Features.push_back(Args.MakeArgString("-fp64"));
     else if (A->getOption().matches(options::OPT_mfpxx)) {
       Features.push_back(Args.MakeArgString("+fpxx"));
       Features.push_back(Args.MakeArgString("+nooddspreg"));
     } else
       Features.push_back(Args.MakeArgString("+fp64"));
   } else if (mips::shouldUseFPXX(Args, Triple, CPUName, ABIName, FloatABI)) {
     Features.push_back(Args.MakeArgString("+fpxx"));
     Features.push_back(Args.MakeArgString("+nooddspreg"));
+  } else if (mips::isFP64ADefault(Triple, CPUName)) {
+    Features.push_back(Args.MakeArgString("+fp64"));
+    Features.push_back(Args.MakeArgString("+nooddspreg"));
   }
 
   AddTargetFeature(Args, Features, options::OPT_mno_odd_spreg,
                    options::OPT_modd_spreg, "nooddspreg");
 }
 
 void Clang::AddMIPSTargetArgs(const ArgList &Args,
                               ArgStringList &CmdArgs) const {
bool mips::isNaN2008(const ArgList &Args, const llvm::Triple &Triple) {
   // NaN2008 is the default for MIPS32r6/MIPS64r6.
   return llvm::StringSwitch<bool>(getCPUName(Args, Triple))
       .Cases("mips32r6", "mips64r6", true)
       .Default(false);
 
   return false;
 }
 
+bool mips::isFP64ADefault(const llvm::Triple &Triple, StringRef CPUName) {
+  if (!Triple.isAndroid())
+    return false;
+
+  // Android MIPS32R6 defaults to FP64A.
+  return llvm::StringSwitch<bool>(CPUName)
+      .Case("mips32r6", true)
+      .Default(false);
+}
+
 bool mips::isFPXXDefault(const llvm::Triple &Triple, StringRef CPUName,
                          StringRef ABIName, mips::FloatABI FloatABI) {
   if (Triple.getVendor() != llvm::Triple::ImaginationTechnologies &&
-      Triple.getVendor() != llvm::Triple::MipsTechnologies)
+      Triple.getVendor() != llvm::Triple::MipsTechnologies &&
+      !Triple.isAndroid())
     return false;
 
   if (ABIName != "32")
     return false;
 
   // FPXX shouldn't be used if either -msoft-float or -mfloat-abi=soft is
   // present.
   if (FloatABI == mips::FloatABI::Soft)

test/Driver/clang-translation.c

 // MIPSEL: "-target-cpu" "mips32r2"
 // MIPSEL: "-mfloat-abi" "hard"
 
 // RUN: %clang -target mipsel-linux-android -### -S %s 2>&1 | \
 // RUN: FileCheck -check-prefix=MIPSEL-ANDROID %s
 // MIPSEL-ANDROID: clang
 // MIPSEL-ANDROID: "-cc1"
 // MIPSEL-ANDROID: "-target-cpu" "mips32"
+// MIPSEL-ANDROID: "-target-feature" "+fpxx"
+// MIPSEL-ANDROID: "-target-feature" "+nooddspreg"
 // MIPSEL-ANDROID: "-mfloat-abi" "hard"
 
+// RUN: %clang -target mipsel-linux-android -### -S %s -mcpu=mips32r6 2>&1 | \
+// RUN: FileCheck -check-prefix=MIPSEL-ANDROID-R6 %s
+// MIPSEL-ANDROID-R6: clang
+// MIPSEL-ANDROID-R6: "-cc1"
+// MIPSEL-ANDROID-R6: "-target-cpu" "mips32r6"
+// MIPSEL-ANDROID-R6: "-target-feature" "+fp64"
+// MIPSEL-ANDROID-R6: "-target-feature" "+nooddspreg"
+// MIPSEL-ANDROID-R6: "-mfloat-abi" "hard"
+
 // RUN: %clang -target mips64-linux-gnu -### -S %s 2>&1 | \
 // RUN: FileCheck -check-prefix=MIPS64 %s
 // MIPS64: clang
 // MIPS64: "-cc1"
 // MIPS64: "-target-cpu" "mips64r2"
 // MIPS64: "-mfloat-abi" "hard"
 
 // RUN: %clang -target mips64el-linux-gnu -### -S %s 2>&1 | \