ptx: Use __clc_nextafter to implement nextafter

using clang builtin results in external library call

Reviewer: Jeroen Ketema
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
llvm-svn: 315191

libclc/ptx/lib/SOURCES

@@ -0,0 +1 @@
+math/nextafter.cl

libclc/ptx/lib/math/nextafter.cl

@@ -0,0 +1,10 @@
+#include <clc/clc.h>
+#include "../lib/clcmacro.h"
+#include <math/clc_nextafter.h>
+
+_CLC_DEFINE_BINARY_BUILTIN(float, nextafter, __clc_nextafter, float, float)
+
+#ifdef cl_khr_fp64
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+_CLC_DEFINE_BINARY_BUILTIN(double, nextafter, __clc_nextafter, double, double)
+#endif