add comparison functions for ARM

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@81597 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/arm/ltdf2vfp.S b/lib/arm/ltdf2vfp.S
new file mode 100644
index 0000000..315bb6f
--- /dev/null
+++ b/lib/arm/ltdf2vfp.S
@@ -0,0 +1,26 @@
+//===-- ltdf2vfp.S - Implement ltdf2vfp -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+
+//
+// extern double __ltdf2vfp(double a, double b);
+//
+// Returns one iff a < b and neither is NaN.
+// Uses Darwin calling convention where double precision arguments are passsed 
+// like in GPR pairs.
+//
+	.globl ___ltdf2vfp
+___ltdf2vfp:
+	fmdrr	d6, r0, r1	// load r0/r1 pair in double register
+	fmdrr	d7, r2, r3	// load r2/r3 pair in double register
+	fcmpd	d6, d7		
+	fmstat
+	movmi	r0, #1		// set result register to 1 if equal
+	movpl	r0, #0
+	bx	lr