Teach SDISel to combine fsin / fcos into a fsincos node if the following
conditions are met:
1. They share the same operand and are in the same BB.
2. Both outputs are used.
3. The target has a native instruction that maps to ISD::FSINCOS node or
   the target provides a sincos library call.

Implemented the generic optimization in sdisel and enabled it for
Mac OSX. Also added an additional optimization for x86_64 Mac OSX by
using an alternative entry point __sincos_stret which returns the two
results in xmm0 / xmm1.

rdar://13087969
PR13204


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173755 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index bdbf45c..3d283a5 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -781,6 +781,8 @@
   setOperationAction(ISD::FSIN,      MVT::f32, Expand);
   setOperationAction(ISD::FCOS,      MVT::f32, Expand);
   setOperationAction(ISD::FCOS,      MVT::f64, Expand);
+  setOperationAction(ISD::FSINCOS,   MVT::f64, Expand);
+  setOperationAction(ISD::FSINCOS,   MVT::f32, Expand);
   setOperationAction(ISD::FREM,      MVT::f64, Expand);
   setOperationAction(ISD::FREM,      MVT::f32, Expand);
   if (!TM.Options.UseSoftFloat && Subtarget->hasVFP2() &&