From 0ecb606cb6cf65de1d9fc8a919bceb4be476c602 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 12 Jul 2007 18:26:36 +0000
Subject: 2.5-18.1

---
 sysdeps/ieee754/ldbl-128ibm/e_fmodl.c | 145 ++++++++++++++++++++++++++++++++++
 1 file changed, 145 insertions(+)
 create mode 100644 sysdeps/ieee754/ldbl-128ibm/e_fmodl.c

(limited to 'sysdeps/ieee754/ldbl-128ibm/e_fmodl.c')

diff --git a/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c b/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c
new file mode 100644
index 0000000..e99b0ba
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/e_fmodl.c
@@ -0,0 +1,145 @@
+/* e_fmodl.c -- long double version of e_fmod.c.
+ * Conversion to IEEE quad long double 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.
+ * ====================================================
+ */
+
+/*
+ * __ieee754_fmodl(x,y)
+ * Return x mod y in exact arithmetic
+ * Method: shift and subtract
+ */
+
+#include "math.h"
+#include "math_private.h"
+#include <ieee754.h>
+
+#ifdef __STDC__
+static const long double one = 1.0, Zero[] = {0.0, -0.0,};
+#else
+static long double one = 1.0, Zero[] = {0.0, -0.0,};
+#endif
+
+#ifdef __STDC__
+	long double __ieee754_fmodl(long double x, long double y)
+#else
+	long double __ieee754_fmodl(x,y)
+	long double x,y;
+#endif
+{
+	int64_t n,hx,hy,hz,ix,iy,sx,i;
+	u_int64_t lx,ly,lz;
+	int temp;
+
+	GET_LDOUBLE_WORDS64(hx,lx,x);
+	GET_LDOUBLE_WORDS64(hy,ly,y);
+	sx = hx&0x8000000000000000ULL;		/* sign of x */
+	hx ^=sx;				/* |x| */
+	hy &= 0x7fffffffffffffffLL;		/* |y| */
+
+    /* purge off exception values */
+	if((hy|(ly&0x7fffffffffffffff))==0||(hx>=0x7ff0000000000000LL)|| /* y=0,or x not finite */
+	  (hy>0x7ff0000000000000LL))	/* or y is NaN */
+	    return (x*y)/(x*y);
+	if(hx<=hy) {
+	    if((hx<hy)||(lx<ly)) return x;	/* |x|<|y| return x */
+	    if(lx==ly)
+		return Zero[(u_int64_t)sx>>63];	/* |x|=|y| return x*0*/
+	}
+
+    /* determine ix = ilogb(x) */
+	if(hx<0x0010000000000000LL) {	/* subnormal x */
+	    if(hx==0) {
+		for (ix = -1043, i=lx; i>0; i<<=1) ix -=1;
+	    } else {
+		for (ix = -1022, i=hx<<19; i>0; i<<=1) ix -=1;
+	    }
+	} else ix = (hx>>52)-0x3ff;
+
+    /* determine iy = ilogb(y) */
+	if(hy<0x0010000000000000LL) {	/* subnormal y */
+	    if(hy==0) {
+		for (iy = -1043, i=ly; i>0; i<<=1) iy -=1;
+	    } else {
+		for (iy = -1022, i=hy<<19; i>0; i<<=1) iy -=1;
+	    }
+	} else iy = (hy>>52)-0x3ff;
+
+    /* Make the IBM extended format 105 bit mantissa look like the ieee854 112
+       bit mantissa so the following operatations will give the correct
+       result.  */
+        ldbl_extract_mantissa(&hx, &lx, &temp, x);
+        ldbl_extract_mantissa(&hy, &ly, &temp, y);
+
+    /* set up {hx,lx}, {hy,ly} and align y to x */
+	if(ix >= -1022)
+	    hx = 0x0001000000000000LL|(0x0000ffffffffffffLL&hx);
+	else {		/* subnormal x, shift x to normal */
+	    n = -1022-ix;
+	    if(n<=63) {
+	        hx = (hx<<n)|(lx>>(64-n));
+	        lx <<= n;
+	    } else {
+		hx = lx<<(n-64);
+		lx = 0;
+	    }
+	}
+	if(iy >= -1022)
+	    hy = 0x0001000000000000LL|(0x0000ffffffffffffLL&hy);
+	else {		/* subnormal y, shift y to normal */
+	    n = -1022-iy;
+	    if(n<=63) {
+	        hy = (hy<<n)|(ly>>(64-n));
+	        ly <<= n;
+	    } else {
+		hy = ly<<(n-64);
+		ly = 0;
+	    }
+	}
+
+    /* fix point fmod */
+	n = ix - iy;
+	while(n--) {
+	    hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
+	    if(hz<0){hx = hx+hx+(lx>>63); lx = lx+lx;}
+	    else {
+	    	if((hz|(lz&0x7fffffffffffffff))==0) 		/* return sign(x)*0 */
+		    return Zero[(u_int64_t)sx>>63];
+	    	hx = hz+hz+(lz>>63); lx = lz+lz;
+	    }
+	}
+	hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
+	if(hz>=0) {hx=hz;lx=lz;}
+
+    /* convert back to floating value and restore the sign */
+	if((hx|(lx&0x7fffffffffffffff))==0) 			/* return sign(x)*0 */
+	    return Zero[(u_int64_t)sx>>63];
+	while(hx<0x0001000000000000LL) {	/* normalize x */
+	    hx = hx+hx+(lx>>63); lx = lx+lx;
+	    iy -= 1;
+	}
+	if(iy>= -1022) {	/* normalize output */
+	    x = ldbl_insert_mantissa((sx>>63), iy, hx, lx);
+	} else {		/* subnormal output */
+	    n = -1022 - iy;
+	    if(n<=48) {
+		lx = (lx>>n)|((u_int64_t)hx<<(64-n));
+		hx >>= n;
+	    } else if (n<=63) {
+		lx = (hx<<(64-n))|(lx>>n); hx = sx;
+	    } else {
+		lx = hx>>(n-64); hx = sx;
+	    }
+	    x = ldbl_insert_mantissa((sx>>63), iy, hx, lx);
+	    x *= one;		/* create necessary signal */
+	}
+	return x;		/* exact output */
+}
-- 
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