2.5-18.1

math/s_nexttowardf.c

@@ -0,0 +1,85 @@
+/* Single precision version of nexttoward.c.
+   Conversion to IEEE single float by Jakub Jelinek, jj@ultra.linux.cz. */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/* IEEE functions
+ *	nexttowardf(x,y)
+ *	return the next machine floating-point number of x in the
+ *	direction toward y.
+ * This is for machines which use the same binary type for double and
+ * long double.
+ *   Special cases:
+ */
+
+#include <math.h>
+#include <math_private.h>
+#include <float.h>
+
+#ifdef __STDC__
+	float __nexttowardf(float x, long double y)
+#else
+	float __nexttowardf(x,y)
+	float x;
+	long double y;
+#endif
+{
+	int32_t hx,hy,ix,iy;
+	u_int32_t ly;
+
+	GET_FLOAT_WORD(hx,x);
+	EXTRACT_WORDS(hy,ly,y);
+	ix = hx&0x7fffffff;		/* |x| */
+	iy = hy&0x7fffffff;		/* |y| */
+
+	if((ix>0x7f800000) ||				   /* x is nan */
+	   ((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0))    /* y is nan */
+	   return x+y;
+	if((long double) x==y) return y;	/* x=y, return y */
+	if(ix==0) {				/* x == 0 */
+	    float u;
+	    SET_FLOAT_WORD(x,(u_int32_t)(hy&0x80000000)|1);/* return +-minsub*/
+	    u = math_opt_barrier (x);
+	    u = u * u;
+	    math_force_eval (u);		 /* raise underflow flag */
+	    return x;
+	}
+	if(hx>=0) {				/* x > 0 */
+	    if(hy<0||(ix>>23)>(iy>>20)-0x380
+	       || ((ix>>23)==(iy>>20)-0x380
+		   && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff)))	/* x > y, x -= ulp */
+		hx -= 1;
+	    else				/* x < y, x += ulp */
+		hx += 1;
+	} else {				/* x < 0 */
+	    if(hy>=0||(ix>>23)>(iy>>20)-0x380
+	       || ((ix>>23)==(iy>>20)-0x380
+		   && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff)))	/* x < y, x -= ulp */
+		hx -= 1;
+	    else				/* x > y, x += ulp */
+		hx += 1;
+	}
+	hy = hx&0x7f800000;
+	if(hy>=0x7f800000) {
+	  x = x+x;	/* overflow  */
+	  if (FLT_EVAL_METHOD != 0)
+	    /* Force conversion to float.  */
+	    asm ("" : "+m"(x));
+	  return x;
+	}
+	if(hy<0x00800000) {
+	    float u = x*x;			/* underflow */
+	    math_force_eval (u);		/* raise underflow flag */
+	}
+	SET_FLOAT_WORD(x,hx);
+	return x;
+}
+weak_alias (__nexttowardf, nexttowardf)