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Diffstat (limited to 'usr/src/lib/libm/common/m9x/remquo.c')
-rw-r--r--usr/src/lib/libm/common/m9x/remquo.c267
1 files changed, 267 insertions, 0 deletions
diff --git a/usr/src/lib/libm/common/m9x/remquo.c b/usr/src/lib/libm/common/m9x/remquo.c
new file mode 100644
index 0000000000..2d05ec6de6
--- /dev/null
+++ b/usr/src/lib/libm/common/m9x/remquo.c
@@ -0,0 +1,267 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma weak remquo = __remquo
+
+/* INDENT OFF */
+/*
+ * double remquo(double x, double y, int *quo) return remainder(x,y) and an
+ * integer pointer quo such that *quo = N mod {2**31}, where N is the
+ * exact integral part of x/y rounded to nearest even.
+ *
+ * remquo call internal fmodquo
+ */
+/* INDENT ON */
+
+#include "libm.h"
+#include "libm_synonyms.h"
+#include "libm_protos.h"
+#include <math.h> /* fabs() */
+#include <sys/isa_defs.h>
+
+#if defined(_BIG_ENDIAN)
+#define HIWORD 0
+#define LOWORD 1
+#else
+#define HIWORD 1
+#define LOWORD 0
+#endif
+#define __HI(x) ((int *) &x)[HIWORD]
+#define __LO(x) ((int *) &x)[LOWORD]
+
+static const double one = 1.0, Zero[] = {0.0, -0.0};
+
+static double
+fmodquo(double x, double y, int *quo) {
+ int n, hx, hy, hz, ix, iy, sx, sq, i, m;
+ unsigned lx, ly, lz;
+
+ hx = __HI(x); /* high word of x */
+ lx = __LO(x); /* low word of x */
+ hy = __HI(y); /* high word of y */
+ ly = __LO(y); /* low word of y */
+ sx = hx & 0x80000000; /* sign of x */
+ sq = (hx ^ hy) & 0x80000000; /* sign of x/y */
+ hx ^= sx; /* |x| */
+ hy &= 0x7fffffff; /* |y| */
+
+ /* purge off exception values */
+ *quo = 0;
+ if ((hy | ly) == 0 || hx >= 0x7ff00000 || /* y=0, or x !finite */
+ (hy | ((ly | -ly) >> 31)) > 0x7ff00000) /* 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) {
+ *quo = 1 + (sq >> 30);
+ /* |x|=|y| return x*0 */
+ return (Zero[(unsigned) sx >> 31]);
+ }
+ }
+
+ /* determine ix = ilogb(x) */
+ if (hx < 0x00100000) { /* subnormal x */
+ if (hx == 0) {
+ for (ix = -1043, i = lx; i > 0; i <<= 1)
+ ix -= 1;
+ } else {
+ for (ix = -1022, i = (hx << 11); i > 0; i <<= 1)
+ ix -= 1;
+ }
+ } else
+ ix = (hx >> 20) - 1023;
+
+ /* determine iy = ilogb(y) */
+ if (hy < 0x00100000) { /* subnormal y */
+ if (hy == 0) {
+ for (iy = -1043, i = ly; i > 0; i <<= 1)
+ iy -= 1;
+ } else {
+ for (iy = -1022, i = (hy << 11); i > 0; i <<= 1)
+ iy -= 1;
+ }
+ } else
+ iy = (hy >> 20) - 1023;
+
+ /* set up {hx,lx}, {hy,ly} and align y to x */
+ if (ix >= -1022)
+ hx = 0x00100000 | (0x000fffff & hx);
+ else { /* subnormal x, shift x to normal */
+ n = -1022 - ix;
+ if (n <= 31) {
+ hx = (hx << n) | (lx >> (32 - n));
+ lx <<= n;
+ } else {
+ hx = lx << (n - 32);
+ lx = 0;
+ }
+ }
+ if (iy >= -1022)
+ hy = 0x00100000 | (0x000fffff & hy);
+ else { /* subnormal y, shift y to normal */
+ n = -1022 - iy;
+ if (n <= 31) {
+ hy = (hy << n) | (ly >> (32 - n));
+ ly <<= n;
+ } else {
+ hy = ly << (n - 32);
+ ly = 0;
+ }
+ }
+
+ /* fix point fmod */
+ n = ix - iy;
+ m = 0;
+ while (n--) {
+ hz = hx - hy;
+ lz = lx - ly;
+ if (lx < ly)
+ hz -= 1;
+ if (hz < 0) {
+ hx = hx + hx + (lx >> 31);
+ lx = lx + lx;
+ } else {
+ m += 1;
+ if ((hz | lz) == 0) { /* return sign(x)*0 */
+ if (n < 31)
+ m <<= 1 + n;
+ else
+ m = 0;
+ m &= 0x7fffffff;
+ *quo = sq >= 0 ? m : -m;
+ return (Zero[(unsigned) sx >> 31]);
+ }
+ hx = hz + hz + (lz >> 31);
+ lx = lz + lz;
+ }
+ m += m;
+ }
+ hz = hx - hy;
+ lz = lx - ly;
+ if (lx < ly)
+ hz -= 1;
+ if (hz >= 0) {
+ hx = hz;
+ lx = lz;
+ m += 1;
+ }
+ m &= 0x7fffffff;
+ *quo = sq >= 0 ? m : -m;
+
+ /* convert back to floating value and restore the sign */
+ if ((hx | lx) == 0) { /* return sign(x)*0 */
+ return (Zero[(unsigned) sx >> 31]);
+ }
+ while (hx < 0x00100000) { /* normalize x */
+ hx = hx + hx + (lx >> 31);
+ lx = lx + lx;
+ iy -= 1;
+ }
+ if (iy >= -1022) { /* normalize output */
+ hx = (hx - 0x00100000) | ((iy + 1023) << 20);
+ __HI(x) = hx | sx;
+ __LO(x) = lx;
+ } else { /* subnormal output */
+ n = -1022 - iy;
+ if (n <= 20) {
+ lx = (lx >> n) | ((unsigned) hx << (32 - n));
+ hx >>= n;
+ } else if (n <= 31) {
+ lx = (hx << (32 - n)) | (lx >> n);
+ hx = sx;
+ } else {
+ lx = hx >> (n - 32);
+ hx = sx;
+ }
+ __HI(x) = hx | sx;
+ __LO(x) = lx;
+ x *= one; /* create necessary signal */
+ }
+ return (x); /* exact output */
+}
+
+#define zero Zero[0]
+
+double
+remquo(double x, double y, int *quo) {
+ int hx, hy, sx, sq;
+ double v;
+ unsigned ly;
+
+ hx = __HI(x); /* high word of x */
+ hy = __HI(y); /* high word of y */
+ ly = __LO(y); /* low word of y */
+ sx = hx & 0x80000000; /* sign of x */
+ sq = (hx ^ hy) & 0x80000000; /* sign of x/y */
+ hx ^= sx; /* |x| */
+ hy &= 0x7fffffff; /* |y| */
+
+ /* purge off exception values */
+ *quo = 0;
+ if ((hy | ly) == 0 || hx >= 0x7ff00000 || /* y=0, or x !finite */
+ (hy | ((ly | -ly) >> 31)) > 0x7ff00000) /* or y is NaN */
+ return ((x * y) / (x * y));
+
+ y = fabs(y);
+ x = fabs(x);
+ if (hy <= 0x7fdfffff) {
+ x = fmodquo(x, y + y, quo);
+ *quo = ((*quo) & 0x3fffffff) << 1;
+ }
+ if (hy < 0x00200000) {
+ if (x + x > y) {
+ *quo += 1;
+ if (x == y)
+ x = zero;
+ else
+ x -= y;
+ if (x + x >= y) {
+ x -= y;
+ *quo += 1;
+ }
+ }
+ } else {
+ v = 0.5 * y;
+ if (x > v) {
+ *quo += 1;
+ if (x == y)
+ x = zero;
+ else
+ x -= y;
+ if (x >= v) {
+ x -= y;
+ *quo += 1;
+ }
+ }
+ }
+ if (sq != 0)
+ *quo = -(*quo);
+ return (sx == 0 ? x : -x);
+}
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