[mips] Added -mfp64 and -mfp32 options.

These options specify 64-bit FP registers and 32-bit FP registers respectively.

When using -mfp32, the FPU has 16x double-precision registers overlapping with
the 32x single-precision registers (each double-precision register overlaps
two single-precision registers).

When using -mfp64, the FPU has 32x double-precision registers overlapping with
the 32x single-precision registers (each double-precision register overlaps
with one single-precision register and has an additional 32-bits).

MSA requires -mfp64.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192899 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 5404ede..b2f7517 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -1104,6 +1104,10 @@
   HelpText<"Enable MSA ASE (MIPS only)">;
 def mno_msa : Flag<["-"], "mno-msa">, Group<m_Group>,
   HelpText<"Disable MSA ASE (MIPS only)">;
+def mfp64 : Flag<["-"], "mfp64">, Group<m_Group>,
+  HelpText<"Use 64-bit floating point registers (MIPS only)">;
+def mfp32 : Flag<["-"], "mfp32">, Group<m_Group>,
+  HelpText<"Use 32-bit floating point registers (MIPS only)">;
 def mnan_EQ : Joined<["-"], "mnan=">, Group<m_Group>;
 def mips32 : Flag<["-"], "mips32">,
   Alias<march_EQ>, AliasArgs<["mips32"]>,
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 68a5fe8..d6ddd02 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -982,6 +982,8 @@
                    "dspr2");
   AddTargetFeature(Args, Features, options::OPT_mmsa, options::OPT_mno_msa,
                    "msa");
+  AddTargetFeature(Args, Features, options::OPT_mfp64, options::OPT_mfp32,
+                   "fp64");
 }
 
 void Clang::AddMIPSTargetArgs(const ArgList &Args,
diff --git a/test/Driver/mips-features.c b/test/Driver/mips-features.c
index 8de26d4..d663e66 100644
--- a/test/Driver/mips-features.c
+++ b/test/Driver/mips-features.c
@@ -60,6 +60,18 @@
 // RUN:   | FileCheck --check-prefix=CHECK-NOMMSA %s
 // CHECK-NOMMSA: "-target-feature" "-msa"
 //
+// -mfp64
+// RUN: %clang -target mips-linux-gnu -### -c %s \
+// RUN:     -mfp32 -mfp64 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MFP64 %s
+// CHECK-MFP64: "-target-feature" "+fp64"
+//
+// -mfp32
+// RUN: %clang -target mips-linux-gnu -### -c %s \
+// RUN:     -mfp64 -mfp32 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOMFP64 %s
+// CHECK-NOMFP64: "-target-feature" "-fp64"
+//
 // -mxgot
 // RUN: %clang -target mips-linux-gnu -### -c %s \
 // RUN:     -mno-xgot -mxgot 2>&1 \