[Mips] Adjust float ABI settings in case of MIPS16 mode.

Hard float for mips16 means essentially to compile as soft float but to
use a runtime library for soft float that is written with native mips32
floating point instructions (those runtime routines run in mips32 hard
float mode).

The patch reviewed by Reed Kotler.

llvm-svn: 195123

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 0a81072b085..9688f0e264b 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -81,6 +81,16 @@ MipsSubtarget::MipsSubtarget(const std::string &TT, const std::string &CPU,
   // Parse features string.
   ParseSubtargetFeatures(CPUName, FS);
 
+  if (InMips16Mode && !TM->Options.UseSoftFloat) {
+    // Hard float for mips16 means essentially to compile as soft float
+    // but to use a runtime library for soft float that is written with
+    // native mips32 floating point instructions (those runtime routines
+    // run in mips32 hard float mode).
+    TM->Options.UseSoftFloat = true;
+    TM->Options.FloatABIType = FloatABI::Soft;
+    InMips16HardFloat = true;
+  }
+
   PreviousInMips16Mode = InMips16Mode;
 
   // Initialize scheduling itinerary for the specified CPU.