[clang][mips] Set __mips_fpr correctly for -mfpxx

Set __mips_fpr to 0 if o32 ABI is used with either -mfpxx
or none of -mfp32, -mfpxx, -mfp64 being specified.

Introduce additional checks:
-mfpxx is only to be used in conjunction with the o32 ABI.
report an error when incompatible options are provided.

Formerly no errors were raised when combining n32/n64 ABIs
with -mfp32 and -mfpxx.

There are other cases when __mips_fpr should be set to 0
that are not covered, ex. using o32 on a mips64 cpu
which is valid but not supported in the backend as of yet.

Differential Revision: https://reviews.llvm.org/D50557

llvm-svn: 340391

1 files changed, 9 insertions, 5 deletions

diff --git a/clang/lib/Basic/Targets/Mips.h b/clang/lib/Basic/Targets/Mips.h
index 11e9ac91443..fd1db5aa23d 100644
--- a/clang/lib/Basic/Targets/Mips.h
+++ b/clang/lib/Basic/Targets/Mips.h
@@ -57,7 +57,7 @@ class LLVM_LIBRARY_VISIBILITY MipsTargetInfo : public TargetInfo {
   bool UseIndirectJumpHazard;
 
 protected:
-  bool HasFP64;
+  enum FPModeEnum { FPXX, FP32, FP64 } FPMode;
   std::string ABI;
 
 public:
@@ -66,7 +66,7 @@ public:
         IsNan2008(false), IsAbs2008(false), IsSingleFloat(false),
         IsNoABICalls(false), CanUseBSDABICalls(false), FloatABI(HardFloat),
         DspRev(NoDSP), HasMSA(false), DisableMadd4(false),
-        UseIndirectJumpHazard(false), HasFP64(false) {
+        UseIndirectJumpHazard(false), FPMode(FPXX) {
     TheCXXABI.set(TargetCXXABI::GenericMIPS);
 
     setABI(getTriple().isMIPS32() ? "o32" : "n64");
@@ -181,6 +181,8 @@ public:
     return TargetInfo::initFeatureMap(Features, Diags, CPU, FeaturesVec);
   }
 
+  unsigned getISARev() const;
+
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
 
@@ -305,7 +307,7 @@ public:
     IsSingleFloat = false;
     FloatABI = HardFloat;
     DspRev = NoDSP;
-    HasFP64 = isFP64Default();
+    FPMode = isFP64Default() ? FP64 : FPXX;
 
     for (const auto &Feature : Features) {
       if (Feature == "+single-float")
@@ -325,9 +327,11 @@ public:
       else if (Feature == "+nomadd4")
         DisableMadd4 = true;
       else if (Feature == "+fp64")
-        HasFP64 = true;
+        FPMode = FP64;
       else if (Feature == "-fp64")
-        HasFP64 = false;
+        FPMode = FP32;
+      else if (Feature == "+fpxx")
+        FPMode = FPXX;
       else if (Feature == "+nan2008")
         IsNan2008 = true;
       else if (Feature == "-nan2008")