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11210 libm should be cstyle(1ONBLD) clean
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--- old/usr/src/lib/libm/common/C/log.c
+++ new/usr/src/lib/libm/common/C/log.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
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11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 +
21 22 /*
22 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 24 */
25 +
24 26 /*
25 27 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
26 28 * Use is subject to license terms.
27 29 */
28 30
29 31 #pragma weak __log = log
30 32
31 -/* INDENT OFF */
33 +
32 34 /*
33 35 * log(x)
34 36 * Table look-up algorithm with product polynomial approximation.
35 37 * By K.C. Ng, Oct 23, 2004. Updated Oct 18, 2005.
36 38 *
37 39 * (a). For x in [1-0.125, 1+0.1328125], using a special approximation:
38 40 * Let f = x - 1 and z = f*f.
39 41 * return f + ((a1*z) *
40 42 * ((a2 + (a3*f)*(a4+f)) + (f*z)*(a5+f))) *
41 43 * (((a6 + f*(a7+f)) + (f*z)*(a8+f)) *
42 44 * ((a9 + (a10*f)*(a11+f)) + (f*z)*(a12+f)))
43 45 * a1 -6.88821452420390473170286327331268694251775741577e-0002,
44 46 * a2 1.97493380704769294631262255279580131173133850098e+0000,
45 47 * a3 2.24963218866067560242072431719861924648284912109e+0000,
46 48 * a4 -9.02975906958474405783476868236903101205825805664e-0001,
47 49 * a5 -1.47391630715542865104339398385491222143173217773e+0000,
48 50 * a6 1.86846544648220058704168877738993614912033081055e+0000,
49 51 * a7 1.82277370459347465292410106485476717352867126465e+0000,
50 52 * a8 1.25295479915214102994980294170090928673744201660e+0000,
51 53 * a9 1.96709676945198275177517643896862864494323730469e+0000,
52 54 * a10 -4.00127989749189894030934055990655906498432159424e-0001,
53 55 * a11 3.01675528558798333733648178167641162872314453125e+0000,
54 56 * a12 -9.52325445049240770778453679668018594384193420410e-0001,
55 57 *
56 58 * with remez error |(log(1+f) - P(f))/f| <= 2**-56.81 and
57 59 *
58 60 * (b). For 0.09375 <= x < 24
59 61 * Use an 8-bit table look-up (3-bit for exponent and 5 bit for
60 62 * significand):
61 63 * Let ix stands for the high part of x in IEEE double format.
62 64 * Since 0.09375 <= x < 24, we have
63 65 * 0x3fb80000 <= ix < 0x40380000.
64 66 * Let j = (ix - 0x3fb80000) >> 15. Then 0 <= j < 256. Choose
65 67 * a Y[j] such that HIWORD(Y[j]) ~ 0x3fb8400 + (j<<15) (the middle
66 68 * number between 0x3fb80000 + (j<<15) and 3fb80000 + ((j+1)<<15)),
67 69 * and at the same time 1/Y[j] as well as log(Y[j]) are very close
68 70 * to 53-bits floating point numbers.
69 71 * A table of Y[j], 1/Y[j], and log(Y[j]) are pre-computed and thus
70 72 * log(x) = log(Y[j]) + log(1 + (x-Y[j])*(1/Y[j]))
71 73 * = log(Y[j]) + log(1 + s)
72 74 * where
73 75 * s = (x-Y[j])*(1/Y[j])
74 76 * We compute max (x-Y[j])*(1/Y[j]) for the chosen Y[j] and obtain
75 77 * |s| < 0.0154. By applying remez algorithm with Product Polynomial
76 78 * Approximiation, we find the following approximated of log(1+s)
77 79 * (b1*s)*(b2+s*(b3+s))*((b4+s*b5)+(s*s)*(b6+s))*(b7+s*(b8+s))
78 80 * with remez error |log(1+s) - P(s)| <= 2**-63.5
79 81 *
80 82 * (c). Otherwise, get "n", the exponent of x, and then normalize x to
81 83 * z in [1,2). Then similar to (b) find a Y[i] that matches z to 5.5
82 84 * significant bits. Then
83 85 * log(x) = n*ln2 + log(Y[i]) + log(z/Y[i]).
84 86 *
85 87 * Special cases:
86 88 * log(x) is NaN with signal if x < 0 (including -INF) ;
87 89 * log(+INF) is +INF; log(0) is -INF with signal;
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88 90 * log(NaN) is that NaN with no signal.
89 91 *
90 92 * Maximum error observed: less than 0.90 ulp
91 93 *
92 94 * Constants:
93 95 * The hexadecimal values are the intended ones for the following constants.
94 96 * The decimal values may be used, provided that the compiler will convert
95 97 * from decimal to binary accurately enough to produce the hexadecimal values
96 98 * shown.
97 99 */
98 -/* INDENT ON */
99 100
100 101 #include "libm.h"
101 102
102 103 extern const double _TBL_log[];
103 104
104 105 static const double P[] = {
105 -/* ONE */ 1.0,
106 -/* TWO52 */ 4503599627370496.0,
107 -/* LN2HI */ 6.93147180369123816490e-01, /* 3fe62e42, fee00000 */
108 -/* LN2LO */ 1.90821492927058770002e-10, /* 3dea39ef, 35793c76 */
106 +/* ONE */
107 + 1.0,
108 +/* TWO52 */ 4503599627370496.0,
109 +/* LN2HI */ 6.93147180369123816490e-01, /* 3fe62e42, fee00000 */
110 +/* LN2LO */ 1.90821492927058770002e-10, /* 3dea39ef, 35793c76 */
109 111 /* A1 */ -6.88821452420390473170286327331268694251775741577e-0002,
110 -/* A2 */ 1.97493380704769294631262255279580131173133850098e+0000,
111 -/* A3 */ 2.24963218866067560242072431719861924648284912109e+0000,
112 +/* A2 */ 1.97493380704769294631262255279580131173133850098e+0000,
113 +/* A3 */ 2.24963218866067560242072431719861924648284912109e+0000,
112 114 /* A4 */ -9.02975906958474405783476868236903101205825805664e-0001,
113 115 /* A5 */ -1.47391630715542865104339398385491222143173217773e+0000,
114 -/* A6 */ 1.86846544648220058704168877738993614912033081055e+0000,
115 -/* A7 */ 1.82277370459347465292410106485476717352867126465e+0000,
116 -/* A8 */ 1.25295479915214102994980294170090928673744201660e+0000,
117 -/* A9 */ 1.96709676945198275177517643896862864494323730469e+0000,
116 +/* A6 */ 1.86846544648220058704168877738993614912033081055e+0000,
117 +/* A7 */ 1.82277370459347465292410106485476717352867126465e+0000,
118 +/* A8 */ 1.25295479915214102994980294170090928673744201660e+0000,
119 +/* A9 */ 1.96709676945198275177517643896862864494323730469e+0000,
118 120 /* A10 */ -4.00127989749189894030934055990655906498432159424e-0001,
119 -/* A11 */ 3.01675528558798333733648178167641162872314453125e+0000,
121 +/* A11 */ 3.01675528558798333733648178167641162872314453125e+0000,
120 122 /* A12 */ -9.52325445049240770778453679668018594384193420410e-0001,
121 123 /* B1 */ -1.25041641589283658575482149899471551179885864258e-0001,
122 -/* B2 */ 1.87161713283355151891381127914642725337613123482e+0000,
124 +/* B2 */ 1.87161713283355151891381127914642725337613123482e+0000,
123 125 /* B3 */ -1.89082956295731507978530316904652863740921020508e+0000,
124 126 /* B4 */ -2.50562891673640253387134180229622870683670043945e+0000,
125 -/* B5 */ 1.64822828085258366037635369139024987816810607910e+0000,
127 +/* B5 */ 1.64822828085258366037635369139024987816810607910e+0000,
126 128 /* B6 */ -1.24409107065868340669112512841820716857910156250e+0000,
127 -/* B7 */ 1.70534231658220414296067701798165217041969299316e+0000,
128 -/* B8 */ 1.99196833784655646937267192697618156671524047852e+0000,
129 +/* B7 */ 1.70534231658220414296067701798165217041969299316e+0000,
130 +/* B8 */ 1.99196833784655646937267192697618156671524047852e+0000,
129 131 };
130 132
131 -#define ONE P[0]
132 -#define TWO52 P[1]
133 -#define LN2HI P[2]
134 -#define LN2LO P[3]
135 -#define A1 P[4]
136 -#define A2 P[5]
137 -#define A3 P[6]
138 -#define A4 P[7]
139 -#define A5 P[8]
140 -#define A6 P[9]
141 -#define A7 P[10]
142 -#define A8 P[11]
143 -#define A9 P[12]
144 -#define A10 P[13]
145 -#define A11 P[14]
146 -#define A12 P[15]
147 -#define B1 P[16]
148 -#define B2 P[17]
149 -#define B3 P[18]
150 -#define B4 P[19]
151 -#define B5 P[20]
152 -#define B6 P[21]
153 -#define B7 P[22]
154 -#define B8 P[23]
133 +#define ONE P[0]
134 +#define TWO52 P[1]
135 +#define LN2HI P[2]
136 +#define LN2LO P[3]
137 +#define A1 P[4]
138 +#define A2 P[5]
139 +#define A3 P[6]
140 +#define A4 P[7]
141 +#define A5 P[8]
142 +#define A6 P[9]
143 +#define A7 P[10]
144 +#define A8 P[11]
145 +#define A9 P[12]
146 +#define A10 P[13]
147 +#define A11 P[14]
148 +#define A12 P[15]
149 +#define B1 P[16]
150 +#define B2 P[17]
151 +#define B3 P[18]
152 +#define B4 P[19]
153 +#define B5 P[20]
154 +#define B6 P[21]
155 +#define B7 P[22]
156 +#define B8 P[23]
155 157
156 158 double
157 -log(double x) {
158 - double *tb, dn, dn1, s, z, r, w;
159 - int i, hx, ix, n, lx;
159 +log(double x)
160 +{
161 + double *tb, dn, dn1, s, z, r, w;
162 + int i, hx, ix, n, lx;
160 163
161 164 n = 0;
162 165 hx = ((int *)&x)[HIWORD];
163 166 ix = hx & 0x7fffffff;
164 167 lx = ((int *)&x)[LOWORD];
165 168
166 169 /* subnormal,0,negative,inf,nan */
167 170 if ((hx + 0x100000) < 0x200000) {
168 171 if (ix > 0x7ff00000 || (ix == 0x7ff00000 && lx != 0)) /* nan */
169 172 return (x * x);
170 - if (((hx << 1) | lx) == 0) /* zero */
173 +
174 + if (((hx << 1) | lx) == 0) /* zero */
171 175 return (_SVID_libm_err(x, x, 16));
172 - if (hx < 0) /* negative */
176 +
177 + if (hx < 0) /* negative */
173 178 return (_SVID_libm_err(x, x, 17));
174 - if (((hx - 0x7ff00000) | lx) == 0) /* +inf */
179 +
180 + if (((hx - 0x7ff00000) | lx) == 0) /* +inf */
175 181 return (x);
176 182
177 183 /* x must be positive and subnormal */
178 184 x *= TWO52;
179 185 n = -52;
180 186 ix = ((int *)&x)[HIWORD];
181 187 lx = ((int *)&x)[LOWORD];
182 188 }
183 189
184 190 i = ix >> 19;
191 +
185 192 if (i >= 0x7f7 && i <= 0x806) {
186 193 /* 0.09375 (0x3fb80000) <= x < 24 (0x40380000) */
187 194 if (ix >= 0x3fec0000 && ix < 0x3ff22000) {
188 195 /* 0.875 <= x < 1.125 */
189 196 s = x - ONE;
190 197 z = s * s;
191 - if (((ix - 0x3ff00000) | lx) == 0) /* x = 1 */
198 +
199 + if (((ix - 0x3ff00000) | lx) == 0) /* x = 1 */
192 200 return (z);
201 +
193 202 r = (A10 * s) * (A11 + s);
194 203 w = z * s;
195 - return (s + ((A1 * z) *
196 - (A2 + ((A3 * s) * (A4 + s) + w * (A5 + s)))) *
197 - ((A6 + (s * (A7 + s) + w * (A8 + s))) *
198 - (A9 + (r + w * (A12 + s)))));
204 + return (s + ((A1 * z) * (A2 + ((A3 * s) * (A4 + s) + w *
205 + (A5 + s)))) * ((A6 + (s * (A7 + s) + w *
206 + (A8 + s))) * (A9 + (r + w * (A12 + s)))));
199 207 } else {
200 208 i = (ix - 0x3fb80000) >> 15;
201 209 tb = (double *)_TBL_log + (i + i + i);
202 210 s = (x - tb[0]) * tb[1];
203 - return (tb[2] + ((B1 * s) * (B2 + s * (B3 + s))) *
204 - (((B4 + s * B5) + (s * s) * (B6 + s)) *
205 - (B7 + s * (B8 + s))));
211 + return (tb[2] + ((B1 * s) * (B2 + s * (B3 + s))) *
212 + (((B4 + s * B5) + (s * s) * (B6 + s)) *
213 + (B7 + s * (B8 + s))));
206 214 }
207 215 } else {
208 216 dn = (double)(n + ((ix >> 20) - 0x3ff));
209 217 dn1 = dn * LN2HI;
210 218 i = (ix & 0x000fffff) | 0x3ff00000; /* scale x to [1,2] */
211 219 ((int *)&x)[HIWORD] = i;
212 220 i = (i - 0x3fb80000) >> 15;
213 221 tb = (double *)_TBL_log + (i + i + i);
214 222 s = (x - tb[0]) * tb[1];
215 223 dn = dn * LN2LO + tb[2];
216 224 return (dn1 + (dn + ((B1 * s) * (B2 + s * (B3 + s))) *
217 - (((B4 + s * B5) + (s * s) * (B6 + s)) *
218 - (B7 + s * (B8 + s)))));
225 + (((B4 + s * B5) + (s * s) * (B6 + s)) *
226 + (B7 + s * (B8 + s)))));
219 227 }
220 228 }
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