backend: add double version of remainder

cp from fdlibm and pass the cft after refined

Signed-off-by: rander <rander.wang@intel.com>
Tested-by: Yang Rong <rong.r.yang@intel.com>

2 files changed, 43 insertions, 0 deletions

diff --git a/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl b/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl
index 52253fbb..31cb1bad 100644
--- a/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl
+++ b/backend/src/libocl/tmpl/ocl_math_common.tmpl.cl
@@ -2089,6 +2089,48 @@ OVERLOADABLE double fmod (double x, double y)
 
 }
 
+OVERLOADABLE double remainder(double x, double p)
+{
+	int hx,hp;
+	unsigned sx,lx,lp;
+	double p_half, zero = 0.0;
+
+	hx = __HI(x);		/* high word of x */
+	lx = __LO(x);		/* low  word of x */
+	hp = __HI(p);		/* high word of p */
+	lp = __LO(p);		/* low  word of p */
+	sx = hx&0x80000000;
+	hp &= 0x7fffffff;
+	hx &= 0x7fffffff;
+
+	/* purge off exception values */
+	if((hp|lp)==0) return (x*p)/(x*p); 	/* p = 0 */
+	if((hx>=0x7ff00000)||			/* x not finite */
+	  ((hp>=0x7ff00000)&&			/* p is NaN */
+	  (((hp-0x7ff00000)|lp)!=0)))
+		return (x*p)/(x*p);
+
+
+	if (hp<=0x7fdfffff) x = fmod(x,p+p);	/* now x < 2p */
+	if (((hx-hp)|(lx-lp))==0) return zero*x;
+	x  = fabs(x);
+	p  = fabs(p);
+	if (hp<0x00200000) {
+		if(x+x>p) {
+		x-=p;
+		if(x+x>=p) x -= p;
+		}
+	} else {
+		p_half = 0.5*p;
+		if(x>p_half) {
+		x-=p;
+		if(x>=p_half) x -= p;
+		}
+	}
+	__setHigh(&x,  __HI(x) ^sx);
+	return x;
+}
+
 OVERLOADABLE double rint(double x)
 {
 	long ret;
diff --git a/backend/src/libocl/tmpl/ocl_math_common.tmpl.h b/backend/src/libocl/tmpl/ocl_math_common.tmpl.h
index de459465..6b6a741b 100644
--- a/backend/src/libocl/tmpl/ocl_math_common.tmpl.h
+++ b/backend/src/libocl/tmpl/ocl_math_common.tmpl.h
@@ -57,6 +57,7 @@ OVERLOADABLE double lgamma(double x);
 OVERLOADABLE double mad(double a, double b, double c);
 OVERLOADABLE double nan(ulong code);
 OVERLOADABLE double nextafter(double x, double y);
+OVERLOADABLE double remainder(double x, double p);
 OVERLOADABLE double rint(double x);
 OVERLOADABLE double round(double x);
 OVERLOADABLE double sin(double x);