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authorUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
committerUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
commitabfbdde177c3a7155070dda1b2cdc8292054cc26 (patch)
treee021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/i386/fpu/s_nextafterl.c
parent86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff)
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Update.
Diffstat (limited to 'sysdeps/i386/fpu/s_nextafterl.c')
-rw-r--r--sysdeps/i386/fpu/s_nextafterl.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/s_nextafterl.c b/sysdeps/i386/fpu/s_nextafterl.c
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@@ -0,0 +1,102 @@
+/* s_nextafterl.c -- long double version of s_nextafter.c.
+ * Special version for i387.
+ * Conversion to long double by Ulrich Drepper,
+ * Cygnus Support, drepper@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: $";
+#endif
+
+/* IEEE functions
+ *	nextafterl(x,y)
+ *	return the next machine floating-point number of x in the
+ *	direction toward y.
+ *   Special cases:
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+	long double __nextafterl(long double x, long double y)
+#else
+	long double __nextafterl(x,y)
+	long double x,y;
+#endif
+{
+	int32_t hx,hy,ix,iy;
+	u_int32_t lx,ly,esx,esy;
+
+	GET_LDOUBLE_WORDS(esx,hx,lx,x);
+	GET_LDOUBLE_WORDS(esy,hy,ly,y);
+	ix = esx&0x7fff;		/* |x| */
+	iy = esy&0x7fff;		/* |y| */
+
+	/* The additional &hx/&hy is required because Intel's extended format
+           has the normally implicit 1 explicit present.  Sigh!  */
+	if(((ix==0x7fff)&&(((hx|lx)|-(hx|lx))&hx)>>31!=0) ||   /* x is nan */
+	   ((iy==0x7fff)&&(((hy|ly)|-(hy|ly))&hy)>>31!=0))     /* y is nan */
+	   return x+y;
+	if(x==y) return y;		/* x=y, return y */
+	if((ix|hx|lx)==0) {			/* x == 0 */
+	    SET_LDOUBLE_WORDS(x,esx&0x8000,0,1);/* return +-minsubnormal */
+	    y = x*x;
+	    if(y==x) return y; else return x;	/* raise underflow flag */
+	}
+	if(esx<0x8000) {			/* x > 0 */
+	    if(ix>iy||((ix==iy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
+	      /* x > y, x -= ulp */
+		if(lx==0) {
+		    if (hx==0) esx -= 1;
+		    hx -= 1;
+		}
+		lx -= 1;
+	    } else {				/* x < y, x += ulp */
+		lx += 1;
+		if(lx==0) {
+		    hx += 1;
+		    if (hx==0)
+			esx += 1;
+		}
+	    }
+	} else {				/* x < 0 */
+	    if(esy>=0||(ix>iy||((ix==iy)&&(hx>hy||((hx==hy)&&(lx>ly)))))){
+	      /* x < y, x -= ulp */
+		if(lx==0) {
+		    if (hx==0) esx -= 1;
+		    hx -= 1;
+		}
+		lx -= 1;
+	    } else {				/* x > y, x += ulp */
+		lx += 1;
+		if(lx==0) {
+		    hx += 1;
+		    if (hx==0) esx += 1;
+		}
+	    }
+	}
+	esy = esx&0x7fff;
+	if(esy==0x7fff) return x+x;	/* overflow  */
+	if(esy==0) {			/* underflow */
+	    y = x*x;
+	    if(y!=x) {		/* raise underflow flag */
+	        SET_LDOUBLE_WORDS(y,esx,hx,lx);
+		return y;
+	    }
+	}
+	SET_LDOUBLE_WORDS(x,esx,hx,lx);
+	return x;
+}
+weak_alias (__nextafterl, nextafterl)