ARM: __gnu_h2f_ieee and __gnu_f2h_ieee always use the soft-float calling convention

By default, LLVM uses the "C" calling convention for all runtime
library functions. The half-precision FP conversion functions use the
soft-float calling convention, and are needed for some targets which
use the hard-float convention by default, so must have their calling
convention explicitly set.

llvm-svn: 215348

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 3a4f788c848..a47d05ebe81 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -388,6 +388,19 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
     setLibcallName(RTLIB::UDIVREM_I32, "__udivmodsi4");
   }
 
+  // The half <-> float conversion functions are always soft-float, but are
+  // needed for some targets which use a hard-float calling convention by
+  // default.
+  if (Subtarget->isAAPCS_ABI()) {
+    setLibcallCallingConv(RTLIB::FPROUND_F32_F16, CallingConv::ARM_AAPCS);
+    setLibcallCallingConv(RTLIB::FPROUND_F64_F16, CallingConv::ARM_AAPCS);
+    setLibcallCallingConv(RTLIB::FPEXT_F16_F32, CallingConv::ARM_AAPCS);
+  } else {
+    setLibcallCallingConv(RTLIB::FPROUND_F32_F16, CallingConv::ARM_APCS);
+    setLibcallCallingConv(RTLIB::FPROUND_F64_F16, CallingConv::ARM_APCS);
+    setLibcallCallingConv(RTLIB::FPEXT_F16_F32, CallingConv::ARM_APCS);
+  }
+
   if (Subtarget->isThumb1Only())
     addRegisterClass(MVT::i32, &ARM::tGPRRegClass);
   else