Don't dag combine floating point select to max and min intrinsics. Those

take v4f32 / v2f64 operands and may end up causing larger spills / restores.
Added X86 specific nodes X86ISD::FMAX, X86ISD::FMIN instead.

This fixes PR996.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31645 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ISelLowering.h

@@ -160,7 +160,11 @@ namespace llvm {
 
       /// PINSRW - Insert the lower 16-bits of a 32-bit value to a vector,
       /// corresponds to X86::PINSRW.
-      PINSRW
+      PINSRW,
+
+      /// FMAX, FMIN - Floating point max and min.
+      ///
+      FMAX, FMIN
     };
   }