1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 */
25 /*
26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
27 * Use is subject to license terms.
28 */
29
30 #pragma weak fmodl = __fmodl
31
32 #include "libm.h"
33
34 static const int
35 is = -0x7fffffff - 1,
36 im = 0x0000ffff,
37 iu = 0x00010000;
38
39 static const long double
40 zero = 0.0L,
41 one = 1.0L;
42
43 #ifdef __LITTLE_ENDIAN
44 #define __H0(x) *(3 + (int *) &x)
45 #define __H1(x) *(2 + (int *) &x)
46 #define __H2(x) *(1 + (int *) &x)
47 #define __H3(x) *(0 + (int *) &x)
48 #else
49 #define __H0(x) *(0 + (int *) &x)
50 #define __H1(x) *(1 + (int *) &x)
51 #define __H2(x) *(2 + (int *) &x)
52 #define __H3(x) *(3 + (int *) &x)
53 #endif
54
55 long double
56 fmodl(long double x, long double y) {
57 long double a, b;
58 int n, ix, iy, k, sx;
59 int hx;
60 int x0, y0, z0, carry;
61 unsigned x1, x2, x3, y1, y2, y3, z1, z2, z3;
62
63 hx = __H0(x);
64 x1 = __H1(x);
65 x2 = __H2(x);
66 x3 = __H3(x);
67 y0 = __H0(y);
68 y1 = __H1(y);
69 y2 = __H2(y);
70 y3 = __H3(y);
71
72 sx = hx & 0x80000000;
73 x0 = hx ^ sx;
74 y0 &= 0x7fffffff;
75
76 /* purge off exception values */
77 if (x0 >= 0x7fff0000 || /* !finitel(x) */
78 (y0 > 0x7fff0000) || (y0 == 0x7fff0000 && ((y1 | y2 | y3) != 0)) ||
79 (y0 | y1 | y2 | y3) == 0) /* isnanl(y) || y = 0 */
80 return ((x * y) / (x * y));
81 a = fabsl(x);
82 b = fabsl(y);
83 if (a <= b) {
84 if (a < b)
85 return (x);
86 else
87 return (zero * x);
88 }
89 /* determine ix = ilogbl(x) */
90 if (x0 < iu) { /* subnormal x */
91 ix = -16382;
92 while (x0 == 0) {
93 ix -= 16;
94 x0 = x1 >> 16;
95 x1 = (x1 << 16) | (x2 >> 16);
96 x2 = (x2 << 16) | (x3 >> 16);
97 x3 = (x3 << 16);
98 }
99 while (x0 < iu) {
100 ix -= 1;
101 x0 = (x0 << 1) | (x1 >> 31);
102 x1 = (x1 << 1) | (x2 >> 31);
103 x2 = (x2 << 1) | (x3 >> 31);
104 x3 <<= 1;
105 }
106 } else {
107 ix = (x0 >> 16) - 16383;
108 x0 = iu | (x0 & im);
109 }
110
111 /* determine iy = ilogbl(y) */
112 if (y0 < iu) { /* subnormal y */
113 iy = -16382;
114 while (y0 == 0) {
115 iy -= 16;
116 y0 = y1 >> 16;
117 y1 = (y1 << 16) | (y2 >> 16);
118 y2 = (y2 << 16) | (y3 >> 16);
119 y3 = (y3 << 16);
120 }
121 while (y0 < iu) {
122 iy -= 1;
123 y0 = (y0 << 1) | (y1 >> 31);
124 y1 = (y1 << 1) | (y2 >> 31);
125 y2 = (y2 << 1) | (y3 >> 31);
126 y3 <<= 1;
127 }
128 } else {
129 iy = (y0 >> 16) - 16383;
130 y0 = iu | (y0 & im);
131 }
132
133 /* fix point fmod */
134 n = ix - iy;
135 while (n--) {
136 while (x0 == 0 && n >= 16) {
137 n -= 16;
138 x0 = x1 >> 16;
139 x1 = (x1 << 16) | (x2 >> 16);
140 x2 = (x2 << 16) | (x3 >> 16);
141 x3 = (x3 << 16);
142 }
143 while (x0 < iu && n >= 1) {
144 n -= 1;
145 x0 = (x0 << 1) | (x1 >> 31);
146 x1 = (x1 << 1) | (x2 >> 31);
147 x2 = (x2 << 1) | (x3 >> 31);
148 x3 = (x3 << 1);
149 }
150 carry = 0;
151 z3 = x3 - y3;
152 carry = (z3 > x3);
153 if (carry == 0) {
154 z2 = x2 - y2;
155 carry = (z2 > x2);
156 } else {
157 z2 = x2 - y2 - 1;
158 carry = (z2 >= x2);
159 }
160 if (carry == 0) {
161 z1 = x1 - y1;
162 carry = (z1 > x1);
163 } else {
164 z1 = x1 - y1 - 1;
165 carry = (z1 >= x1);
166 }
167 z0 = x0 - y0 - carry;
168 if (z0 < 0) { /* double x */
169 x0 = x0 + x0 + ((x1 & is) != 0);
170 x1 = x1 + x1 + ((x2 & is) != 0);
171 x2 = x2 + x2 + ((x3 & is) != 0);
172 x3 = x3 + x3;
173 } else {
174 if (z0 == 0) {
175 if ((z1 | z2 | z3) == 0) { /* 0: done */
176 __H0(a) = hx & is;
177 __H1(a) = __H2(a) = __H3(a) = 0;
178 return (a);
179 }
180 }
181 /* x = z << 1 */
182 z0 = z0 + z0 + ((z1 & is) != 0);
183 z1 = z1 + z1 + ((z2 & is) != 0);
184 z2 = z2 + z2 + ((z3 & is) != 0);
185 z3 = z3 + z3;
186 x0 = z0;
187 x1 = z1;
188 x2 = z2;
189 x3 = z3;
190 }
191 }
192
193 carry = 0;
194 z3 = x3 - y3;
195 carry = (z3 > x3);
196 if (carry == 0) {
197 z2 = x2 - y2;
198 carry = (z2 > x2);
199 } else {
200 z2 = x2 - y2 - 1;
201 carry = (z2 >= x2);
202 }
203 if (carry == 0) {
204 z1 = x1 - y1;
205 carry = (z1 > x1);
206 } else {
207 z1 = x1 - y1 - 1;
208 carry = (z1 >= x1);
209 }
210 z0 = x0 - y0 - carry;
211 if (z0 >= 0) {
212 x0 = z0;
213 x1 = z1;
214 x2 = z2;
215 x3 = z3;
216 }
217 /* convert back to floating value and restore the sign */
218 if ((x0 | x1 | x2 | x3) == 0) {
219 __H0(a) = hx & is;
220 __H1(a) = __H2(a) = __H3(a) = 0;
221 return (a);
222 }
223 while (x0 < iu) {
224 if (x0 == 0) {
225 iy -= 16;
226 x0 = x1 >> 16;
227 x1 = (x1 << 16) | (x2 >> 16);
228 x2 = (x2 << 16) | (x3 >> 16);
229 x3 = (x3 << 16);
230 } else {
231 x0 = x0 + x0 + ((x1 & is) != 0);
232 x1 = x1 + x1 + ((x2 & is) != 0);
233 x2 = x2 + x2 + ((x3 & is) != 0);
234 x3 = x3 + x3;
235 iy -= 1;
236 }
237 }
238
239 /* normalize output */
240 if (iy >= -16382) {
241 __H0(a) = sx | (x0 - iu) | ((iy + 16383) << 16);
242 __H1(a) = x1;
243 __H2(a) = x2;
244 __H3(a) = x3;
245 } else { /* subnormal output */
246 n = -16382 - iy;
247 k = n & 31;
248 if (k != 0) {
249 if (k <= 16) {
250 x3 = (x2 << (32 - k)) | (x3 >> k);
251 x2 = (x1 << (32 - k)) | (x2 >> k);
252 x1 = (x0 << (32 - k)) | (x1 >> k);
253 x0 >>= k;
254 } else {
255 x3 = (x2 << (32 - k)) | (x3 >> k);
256 x2 = (x1 << (32 - k)) | (x2 >> k);
257 x1 = (x0 << (32 - k)) | (x1 >> k);
258 x0 = 0;
259 }
260 }
261 while (n >= 32) {
262 n -= 32;
263 x3 = x2;
264 x2 = x1;
265 x1 = x0;
266 x0 = 0;
267 }
268 __H0(a) = x0 | sx;
269 __H1(a) = x1;
270 __H2(a) = x2;
271 __H3(a) = x3;
272 a *= one;
273 }
274 return (a);
275 }