Commit | Line | Data |
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b70021f4 | 1 | /* Primitive operations on floating point for GNU Emacs Lisp interpreter. |
95df8112 | 2 | |
ab422c4d PE |
3 | Copyright (C) 1988, 1993-1994, 1999, 2001-2013 Free Software Foundation, |
4 | Inc. | |
b70021f4 | 5 | |
0a9dd3a7 GM |
6 | Author: Wolfgang Rupprecht |
7 | (according to ack.texi) | |
8 | ||
b70021f4 MR |
9 | This file is part of GNU Emacs. |
10 | ||
9ec0b715 | 11 | GNU Emacs is free software: you can redistribute it and/or modify |
b70021f4 | 12 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
13 | the Free Software Foundation, either version 3 of the License, or |
14 | (at your option) any later version. | |
b70021f4 MR |
15 | |
16 | GNU Emacs is distributed in the hope that it will be useful, | |
17 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | GNU General Public License for more details. | |
20 | ||
21 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 22 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
b70021f4 MR |
23 | |
24 | ||
c990426a PE |
25 | /* C89 requires only the following math.h functions, and Emacs omits |
26 | the starred functions since we haven't found a use for them: | |
27 | acos, asin, atan, atan2, ceil, cos, *cosh, exp, fabs, floor, fmod, | |
89561f72 PE |
28 | frexp, ldexp, log, log10 [via (log X 10)], *modf, pow, sin, *sinh, |
29 | sqrt, tan, *tanh. | |
33cbd259 PE |
30 | |
31 | C99 and C11 require the following math.h functions in addition to | |
32 | the C89 functions. Of these, Emacs currently exports only the | |
33 | starred ones to Lisp, since we haven't found a use for the others: | |
34 | acosh, atanh, cbrt, *copysign, erf, erfc, exp2, expm1, fdim, fma, | |
35 | fmax, fmin, fpclassify, hypot, ilogb, isfinite, isgreater, | |
36 | isgreaterequal, isinf, isless, islessequal, islessgreater, *isnan, | |
89561f72 PE |
37 | isnormal, isunordered, lgamma, log1p, *log2 [via (log X 2)], *logb |
38 | (approximately), lrint/llrint, lround/llround, nan, nearbyint, | |
39 | nextafter, nexttoward, remainder, remquo, *rint, round, scalbln, | |
40 | scalbn, signbit, tgamma, trunc. | |
4b6baf5f RS |
41 | */ |
42 | ||
18160b98 | 43 | #include <config.h> |
0328b6de | 44 | |
523e9291 | 45 | #include "lisp.h" |
d137ae2f | 46 | |
b70021f4 | 47 | #include <math.h> |
4b6baf5f | 48 | |
e4ea223d PE |
49 | /* 'isfinite' and 'isnan' cause build failures on Solaris 10 with the |
50 | bundled GCC in c99 mode. Work around the bugs with simple | |
51 | implementations that are good enough. */ | |
52 | #undef isfinite | |
53 | #define isfinite(x) ((x) - (x) == 0) | |
54 | #undef isnan | |
55 | #define isnan(x) ((x) != (x)) | |
c26406fe | 56 | |
84575e67 PE |
57 | /* Check that X is a floating point number. */ |
58 | ||
59 | static void | |
60 | CHECK_FLOAT (Lisp_Object x) | |
61 | { | |
62 | CHECK_TYPE (FLOATP (x), Qfloatp, x); | |
63 | } | |
64 | ||
b70021f4 MR |
65 | /* Extract a Lisp number as a `double', or signal an error. */ |
66 | ||
67 | double | |
d5a3eaaf | 68 | extract_float (Lisp_Object num) |
b70021f4 | 69 | { |
b7826503 | 70 | CHECK_NUMBER_OR_FLOAT (num); |
b70021f4 | 71 | |
207a45c1 | 72 | if (FLOATP (num)) |
70949dac | 73 | return XFLOAT_DATA (num); |
b70021f4 MR |
74 | return (double) XINT (num); |
75 | } | |
c2d4ea74 RS |
76 | \f |
77 | /* Trig functions. */ | |
b70021f4 MR |
78 | |
79 | DEFUN ("acos", Facos, Sacos, 1, 1, 0, | |
335c5470 | 80 | doc: /* Return the inverse cosine of ARG. */) |
f6196b87 | 81 | (Lisp_Object arg) |
b70021f4 | 82 | { |
4b6baf5f | 83 | double d = extract_float (arg); |
f6196b87 | 84 | d = acos (d); |
b70021f4 MR |
85 | return make_float (d); |
86 | } | |
87 | ||
c2d4ea74 | 88 | DEFUN ("asin", Fasin, Sasin, 1, 1, 0, |
335c5470 | 89 | doc: /* Return the inverse sine of ARG. */) |
f6196b87 | 90 | (Lisp_Object arg) |
b70021f4 | 91 | { |
4b6baf5f | 92 | double d = extract_float (arg); |
f6196b87 | 93 | d = asin (d); |
b70021f4 MR |
94 | return make_float (d); |
95 | } | |
96 | ||
250ffca6 EZ |
97 | DEFUN ("atan", Fatan, Satan, 1, 2, 0, |
98 | doc: /* Return the inverse tangent of the arguments. | |
99 | If only one argument Y is given, return the inverse tangent of Y. | |
100 | If two arguments Y and X are given, return the inverse tangent of Y | |
101 | divided by X, i.e. the angle in radians between the vector (X, Y) | |
102 | and the x-axis. */) | |
f6196b87 | 103 | (Lisp_Object y, Lisp_Object x) |
b70021f4 | 104 | { |
250ffca6 EZ |
105 | double d = extract_float (y); |
106 | ||
107 | if (NILP (x)) | |
f6196b87 | 108 | d = atan (d); |
250ffca6 EZ |
109 | else |
110 | { | |
111 | double d2 = extract_float (x); | |
f6196b87 | 112 | d = atan2 (d, d2); |
250ffca6 | 113 | } |
b70021f4 MR |
114 | return make_float (d); |
115 | } | |
116 | ||
c2d4ea74 | 117 | DEFUN ("cos", Fcos, Scos, 1, 1, 0, |
335c5470 | 118 | doc: /* Return the cosine of ARG. */) |
f6196b87 | 119 | (Lisp_Object arg) |
b70021f4 | 120 | { |
4b6baf5f | 121 | double d = extract_float (arg); |
f6196b87 | 122 | d = cos (d); |
b70021f4 MR |
123 | return make_float (d); |
124 | } | |
125 | ||
c2d4ea74 | 126 | DEFUN ("sin", Fsin, Ssin, 1, 1, 0, |
335c5470 | 127 | doc: /* Return the sine of ARG. */) |
f6196b87 | 128 | (Lisp_Object arg) |
b70021f4 | 129 | { |
4b6baf5f | 130 | double d = extract_float (arg); |
f6196b87 | 131 | d = sin (d); |
b70021f4 MR |
132 | return make_float (d); |
133 | } | |
134 | ||
c2d4ea74 | 135 | DEFUN ("tan", Ftan, Stan, 1, 1, 0, |
335c5470 | 136 | doc: /* Return the tangent of ARG. */) |
f6196b87 | 137 | (Lisp_Object arg) |
4b6baf5f RS |
138 | { |
139 | double d = extract_float (arg); | |
f6196b87 | 140 | d = tan (d); |
b70021f4 MR |
141 | return make_float (d); |
142 | } | |
15e12598 | 143 | |
15e12598 VB |
144 | DEFUN ("isnan", Fisnan, Sisnan, 1, 1, 0, |
145 | doc: /* Return non nil iff argument X is a NaN. */) | |
5842a27b | 146 | (Lisp_Object x) |
15e12598 VB |
147 | { |
148 | CHECK_FLOAT (x); | |
149 | return isnan (XFLOAT_DATA (x)) ? Qt : Qnil; | |
150 | } | |
151 | ||
c8199d0f | 152 | #ifdef HAVE_COPYSIGN |
3c2907f7 | 153 | DEFUN ("copysign", Fcopysign, Scopysign, 2, 2, 0, |
15e12598 VB |
154 | doc: /* Copy sign of X2 to value of X1, and return the result. |
155 | Cause an error if X1 or X2 is not a float. */) | |
5842a27b | 156 | (Lisp_Object x1, Lisp_Object x2) |
15e12598 VB |
157 | { |
158 | double f1, f2; | |
159 | ||
160 | CHECK_FLOAT (x1); | |
161 | CHECK_FLOAT (x2); | |
162 | ||
163 | f1 = XFLOAT_DATA (x1); | |
164 | f2 = XFLOAT_DATA (x2); | |
165 | ||
166 | return make_float (copysign (f1, f2)); | |
167 | } | |
c990426a | 168 | #endif |
15e12598 VB |
169 | |
170 | DEFUN ("frexp", Ffrexp, Sfrexp, 1, 1, 0, | |
171 | doc: /* Get significand and exponent of a floating point number. | |
172 | Breaks the floating point number X into its binary significand SGNFCAND | |
173 | \(a floating point value between 0.5 (included) and 1.0 (excluded)) | |
174 | and an integral exponent EXP for 2, such that: | |
175 | ||
176 | X = SGNFCAND * 2^EXP | |
177 | ||
178 | The function returns the cons cell (SGNFCAND . EXP). | |
179 | If X is zero, both parts (SGNFCAND and EXP) are zero. */) | |
5842a27b | 180 | (Lisp_Object x) |
15e12598 VB |
181 | { |
182 | double f = XFLOATINT (x); | |
c990426a PE |
183 | int exponent; |
184 | double sgnfcand = frexp (f, &exponent); | |
185 | return Fcons (make_float (sgnfcand), make_number (exponent)); | |
15e12598 VB |
186 | } |
187 | ||
188 | DEFUN ("ldexp", Fldexp, Sldexp, 1, 2, 0, | |
189 | doc: /* Construct number X from significand SGNFCAND and exponent EXP. | |
190 | Returns the floating point value resulting from multiplying SGNFCAND | |
191 | (the significand) by 2 raised to the power of EXP (the exponent). */) | |
a885e2ed | 192 | (Lisp_Object sgnfcand, Lisp_Object exponent) |
15e12598 | 193 | { |
a885e2ed PE |
194 | CHECK_NUMBER (exponent); |
195 | return make_float (ldexp (XFLOATINT (sgnfcand), XINT (exponent))); | |
15e12598 | 196 | } |
706ac90d | 197 | \f |
c2d4ea74 | 198 | DEFUN ("exp", Fexp, Sexp, 1, 1, 0, |
335c5470 | 199 | doc: /* Return the exponential base e of ARG. */) |
f6196b87 | 200 | (Lisp_Object arg) |
4b6baf5f RS |
201 | { |
202 | double d = extract_float (arg); | |
f6196b87 | 203 | d = exp (d); |
b70021f4 MR |
204 | return make_float (d); |
205 | } | |
206 | ||
b70021f4 | 207 | DEFUN ("expt", Fexpt, Sexpt, 2, 2, 0, |
335c5470 | 208 | doc: /* Return the exponential ARG1 ** ARG2. */) |
f6196b87 | 209 | (Lisp_Object arg1, Lisp_Object arg2) |
b70021f4 | 210 | { |
2742fe30 | 211 | double f1, f2, f3; |
b70021f4 | 212 | |
b7826503 PJ |
213 | CHECK_NUMBER_OR_FLOAT (arg1); |
214 | CHECK_NUMBER_OR_FLOAT (arg2); | |
207a45c1 | 215 | if (INTEGERP (arg1) /* common lisp spec */ |
5a9807a8 | 216 | && INTEGERP (arg2) /* don't promote, if both are ints, and */ |
908589fd | 217 | && XINT (arg2) >= 0) /* we are sure the result is not fractional */ |
b70021f4 | 218 | { /* this can be improved by pre-calculating */ |
125b3835 PE |
219 | EMACS_INT y; /* some binary powers of x then accumulating */ |
220 | EMACS_UINT acc, x; /* Unsigned so that overflow is well defined. */ | |
4be1d460 RS |
221 | Lisp_Object val; |
222 | ||
4b6baf5f RS |
223 | x = XINT (arg1); |
224 | y = XINT (arg2); | |
8d1da888 | 225 | acc = (y & 1 ? x : 1); |
177c0ea7 | 226 | |
8d1da888 | 227 | while ((y >>= 1) != 0) |
b70021f4 | 228 | { |
8d1da888 PE |
229 | x *= x; |
230 | if (y & 1) | |
231 | acc *= x; | |
b70021f4 | 232 | } |
e0cb2a68 | 233 | XSETINT (val, acc); |
4be1d460 | 234 | return val; |
b70021f4 | 235 | } |
70949dac KR |
236 | f1 = FLOATP (arg1) ? XFLOAT_DATA (arg1) : XINT (arg1); |
237 | f2 = FLOATP (arg2) ? XFLOAT_DATA (arg2) : XINT (arg2); | |
f6196b87 | 238 | f3 = pow (f1, f2); |
2742fe30 | 239 | return make_float (f3); |
b70021f4 | 240 | } |
c2d4ea74 | 241 | |
56abb480 | 242 | DEFUN ("log", Flog, Slog, 1, 2, 0, |
335c5470 | 243 | doc: /* Return the natural logarithm of ARG. |
356e6d8d | 244 | If the optional argument BASE is given, return log ARG using that base. */) |
f6196b87 | 245 | (Lisp_Object arg, Lisp_Object base) |
b70021f4 | 246 | { |
4b6baf5f | 247 | double d = extract_float (arg); |
56abb480 JB |
248 | |
249 | if (NILP (base)) | |
f6196b87 | 250 | d = log (d); |
56abb480 JB |
251 | else |
252 | { | |
253 | double b = extract_float (base); | |
254 | ||
4b6baf5f | 255 | if (b == 10.0) |
f6196b87 | 256 | d = log10 (d); |
89561f72 PE |
257 | #if HAVE_LOG2 |
258 | else if (b == 2.0) | |
259 | d = log2 (d); | |
260 | #endif | |
4b6baf5f | 261 | else |
f6196b87 | 262 | d = log (d) / log (b); |
56abb480 | 263 | } |
b70021f4 MR |
264 | return make_float (d); |
265 | } | |
266 | ||
b70021f4 | 267 | DEFUN ("sqrt", Fsqrt, Ssqrt, 1, 1, 0, |
335c5470 | 268 | doc: /* Return the square root of ARG. */) |
f6196b87 | 269 | (Lisp_Object arg) |
b70021f4 | 270 | { |
4b6baf5f | 271 | double d = extract_float (arg); |
f6196b87 | 272 | d = sqrt (d); |
b70021f4 MR |
273 | return make_float (d); |
274 | } | |
c2d4ea74 | 275 | \f |
b70021f4 | 276 | DEFUN ("abs", Fabs, Sabs, 1, 1, 0, |
335c5470 | 277 | doc: /* Return the absolute value of ARG. */) |
5842a27b | 278 | (register Lisp_Object arg) |
b70021f4 | 279 | { |
b7826503 | 280 | CHECK_NUMBER_OR_FLOAT (arg); |
b70021f4 | 281 | |
207a45c1 | 282 | if (FLOATP (arg)) |
7c26cf3c | 283 | arg = make_float (fabs (XFLOAT_DATA (arg))); |
4b6baf5f | 284 | else if (XINT (arg) < 0) |
db37cb37 | 285 | XSETINT (arg, - XINT (arg)); |
b70021f4 | 286 | |
4b6baf5f | 287 | return arg; |
b70021f4 MR |
288 | } |
289 | ||
a7ca3326 | 290 | DEFUN ("float", Ffloat, Sfloat, 1, 1, 0, |
335c5470 | 291 | doc: /* Return the floating point number equal to ARG. */) |
5842a27b | 292 | (register Lisp_Object arg) |
b70021f4 | 293 | { |
b7826503 | 294 | CHECK_NUMBER_OR_FLOAT (arg); |
b70021f4 | 295 | |
207a45c1 | 296 | if (INTEGERP (arg)) |
4b6baf5f | 297 | return make_float ((double) XINT (arg)); |
b70021f4 | 298 | else /* give 'em the same float back */ |
4b6baf5f | 299 | return arg; |
b70021f4 MR |
300 | } |
301 | ||
302 | DEFUN ("logb", Flogb, Slogb, 1, 1, 0, | |
335c5470 PJ |
303 | doc: /* Returns largest integer <= the base 2 log of the magnitude of ARG. |
304 | This is the same as the exponent of a float. */) | |
5842a27b | 305 | (Lisp_Object arg) |
b70021f4 | 306 | { |
340176df | 307 | Lisp_Object val; |
a7bf3c54 | 308 | EMACS_INT value; |
5bf54166 | 309 | double f = extract_float (arg); |
340176df | 310 | |
6694b327 | 311 | if (f == 0.0) |
b916d672 | 312 | value = MOST_NEGATIVE_FIXNUM; |
c990426a | 313 | else if (isfinite (f)) |
6694b327 | 314 | { |
c8bf6cf3 | 315 | int ivalue; |
f6196b87 | 316 | frexp (f, &ivalue); |
c8bf6cf3 | 317 | value = ivalue - 1; |
6694b327 | 318 | } |
c990426a PE |
319 | else |
320 | value = MOST_POSITIVE_FIXNUM; | |
321 | ||
e0cb2a68 | 322 | XSETINT (val, value); |
c26406fe | 323 | return val; |
b70021f4 MR |
324 | } |
325 | ||
fc2157cb | 326 | |
acbbacbe PE |
327 | /* the rounding functions */ |
328 | ||
329 | static Lisp_Object | |
d2aa42f8 DN |
330 | rounding_driver (Lisp_Object arg, Lisp_Object divisor, |
331 | double (*double_round) (double), | |
332 | EMACS_INT (*int_round2) (EMACS_INT, EMACS_INT), | |
8ea90aa3 | 333 | const char *name) |
b70021f4 | 334 | { |
b7826503 | 335 | CHECK_NUMBER_OR_FLOAT (arg); |
b70021f4 | 336 | |
fc2157cb PE |
337 | if (! NILP (divisor)) |
338 | { | |
9a51b24a | 339 | EMACS_INT i1, i2; |
fc2157cb | 340 | |
b7826503 | 341 | CHECK_NUMBER_OR_FLOAT (divisor); |
fc2157cb | 342 | |
207a45c1 | 343 | if (FLOATP (arg) || FLOATP (divisor)) |
fc2157cb PE |
344 | { |
345 | double f1, f2; | |
346 | ||
70949dac KR |
347 | f1 = FLOATP (arg) ? XFLOAT_DATA (arg) : XINT (arg); |
348 | f2 = (FLOATP (divisor) ? XFLOAT_DATA (divisor) : XINT (divisor)); | |
d137ae2f | 349 | if (! IEEE_FLOATING_POINT && f2 == 0) |
edef1631 | 350 | xsignal0 (Qarith_error); |
fc2157cb | 351 | |
f6196b87 PE |
352 | f1 = (*double_round) (f1 / f2); |
353 | if (FIXNUM_OVERFLOW_P (f1)) | |
354 | xsignal3 (Qrange_error, build_string (name), arg, divisor); | |
355 | arg = make_number (f1); | |
fc2157cb PE |
356 | return arg; |
357 | } | |
fc2157cb PE |
358 | |
359 | i1 = XINT (arg); | |
360 | i2 = XINT (divisor); | |
361 | ||
362 | if (i2 == 0) | |
edef1631 | 363 | xsignal0 (Qarith_error); |
fc2157cb | 364 | |
acbbacbe | 365 | XSETINT (arg, (*int_round2) (i1, i2)); |
fc2157cb PE |
366 | return arg; |
367 | } | |
368 | ||
207a45c1 | 369 | if (FLOATP (arg)) |
81a63ccc | 370 | { |
f6196b87 PE |
371 | double d = (*double_round) (XFLOAT_DATA (arg)); |
372 | if (FIXNUM_OVERFLOW_P (d)) | |
373 | xsignal2 (Qrange_error, build_string (name), arg); | |
374 | arg = make_number (d); | |
81a63ccc | 375 | } |
b70021f4 | 376 | |
4b6baf5f | 377 | return arg; |
b70021f4 MR |
378 | } |
379 | ||
acbbacbe PE |
380 | /* With C's /, the result is implementation-defined if either operand |
381 | is negative, so take care with negative operands in the following | |
382 | integer functions. */ | |
383 | ||
384 | static EMACS_INT | |
d2aa42f8 | 385 | ceiling2 (EMACS_INT i1, EMACS_INT i2) |
acbbacbe PE |
386 | { |
387 | return (i2 < 0 | |
388 | ? (i1 < 0 ? ((-1 - i1) / -i2) + 1 : - (i1 / -i2)) | |
389 | : (i1 <= 0 ? - (-i1 / i2) : ((i1 - 1) / i2) + 1)); | |
390 | } | |
391 | ||
392 | static EMACS_INT | |
d2aa42f8 | 393 | floor2 (EMACS_INT i1, EMACS_INT i2) |
acbbacbe PE |
394 | { |
395 | return (i2 < 0 | |
396 | ? (i1 <= 0 ? -i1 / -i2 : -1 - ((i1 - 1) / -i2)) | |
397 | : (i1 < 0 ? -1 - ((-1 - i1) / i2) : i1 / i2)); | |
398 | } | |
399 | ||
400 | static EMACS_INT | |
d2aa42f8 | 401 | truncate2 (EMACS_INT i1, EMACS_INT i2) |
acbbacbe PE |
402 | { |
403 | return (i2 < 0 | |
404 | ? (i1 < 0 ? -i1 / -i2 : - (i1 / -i2)) | |
405 | : (i1 < 0 ? - (-i1 / i2) : i1 / i2)); | |
406 | } | |
407 | ||
408 | static EMACS_INT | |
d2aa42f8 | 409 | round2 (EMACS_INT i1, EMACS_INT i2) |
acbbacbe PE |
410 | { |
411 | /* The C language's division operator gives us one remainder R, but | |
412 | we want the remainder R1 on the other side of 0 if R1 is closer | |
413 | to 0 than R is; because we want to round to even, we also want R1 | |
414 | if R and R1 are the same distance from 0 and if C's quotient is | |
415 | odd. */ | |
416 | EMACS_INT q = i1 / i2; | |
417 | EMACS_INT r = i1 % i2; | |
71376d4b PE |
418 | EMACS_INT abs_r = eabs (r); |
419 | EMACS_INT abs_r1 = eabs (i2) - abs_r; | |
acbbacbe PE |
420 | return q + (abs_r + (q & 1) <= abs_r1 ? 0 : (i2 ^ r) < 0 ? -1 : 1); |
421 | } | |
422 | ||
dca6c914 RS |
423 | /* The code uses emacs_rint, so that it works to undefine HAVE_RINT |
424 | if `rint' exists but does not work right. */ | |
425 | #ifdef HAVE_RINT | |
426 | #define emacs_rint rint | |
427 | #else | |
4b5878a8 | 428 | static double |
d2aa42f8 | 429 | emacs_rint (double d) |
4b5878a8 | 430 | { |
1b65c684 | 431 | return floor (d + 0.5); |
4b5878a8 KH |
432 | } |
433 | #endif | |
434 | ||
acbbacbe | 435 | static double |
d2aa42f8 | 436 | double_identity (double d) |
acbbacbe PE |
437 | { |
438 | return d; | |
439 | } | |
440 | ||
441 | DEFUN ("ceiling", Fceiling, Sceiling, 1, 2, 0, | |
1d6ea92f RS |
442 | doc: /* Return the smallest integer no less than ARG. |
443 | This rounds the value towards +inf. | |
335c5470 | 444 | With optional DIVISOR, return the smallest integer no less than ARG/DIVISOR. */) |
5842a27b | 445 | (Lisp_Object arg, Lisp_Object divisor) |
acbbacbe PE |
446 | { |
447 | return rounding_driver (arg, divisor, ceil, ceiling2, "ceiling"); | |
448 | } | |
449 | ||
450 | DEFUN ("floor", Ffloor, Sfloor, 1, 2, 0, | |
1d6ea92f | 451 | doc: /* Return the largest integer no greater than ARG. |
568b6e41 | 452 | This rounds the value towards -inf. |
335c5470 | 453 | With optional DIVISOR, return the largest integer no greater than ARG/DIVISOR. */) |
5842a27b | 454 | (Lisp_Object arg, Lisp_Object divisor) |
acbbacbe PE |
455 | { |
456 | return rounding_driver (arg, divisor, floor, floor2, "floor"); | |
457 | } | |
458 | ||
459 | DEFUN ("round", Fround, Sround, 1, 2, 0, | |
335c5470 | 460 | doc: /* Return the nearest integer to ARG. |
6ded2c89 EZ |
461 | With optional DIVISOR, return the nearest integer to ARG/DIVISOR. |
462 | ||
a32a4857 EZ |
463 | Rounding a value equidistant between two integers may choose the |
464 | integer closer to zero, or it may prefer an even integer, depending on | |
465 | your machine. For example, \(round 2.5\) can return 3 on some | |
59fe0cee | 466 | systems, but 2 on others. */) |
5842a27b | 467 | (Lisp_Object arg, Lisp_Object divisor) |
acbbacbe | 468 | { |
dca6c914 | 469 | return rounding_driver (arg, divisor, emacs_rint, round2, "round"); |
acbbacbe PE |
470 | } |
471 | ||
a7ca3326 | 472 | DEFUN ("truncate", Ftruncate, Struncate, 1, 2, 0, |
335c5470 PJ |
473 | doc: /* Truncate a floating point number to an int. |
474 | Rounds ARG toward zero. | |
475 | With optional DIVISOR, truncate ARG/DIVISOR. */) | |
5842a27b | 476 | (Lisp_Object arg, Lisp_Object divisor) |
acbbacbe PE |
477 | { |
478 | return rounding_driver (arg, divisor, double_identity, truncate2, | |
479 | "truncate"); | |
480 | } | |
481 | ||
fc2157cb | 482 | |
d137ae2f | 483 | Lisp_Object |
dd4c5104 | 484 | fmod_float (Lisp_Object x, Lisp_Object y) |
d137ae2f PE |
485 | { |
486 | double f1, f2; | |
487 | ||
70949dac KR |
488 | f1 = FLOATP (x) ? XFLOAT_DATA (x) : XINT (x); |
489 | f2 = FLOATP (y) ? XFLOAT_DATA (y) : XINT (y); | |
d137ae2f | 490 | |
f6196b87 | 491 | f1 = fmod (f1, f2); |
d137ae2f PE |
492 | |
493 | /* If the "remainder" comes out with the wrong sign, fix it. */ | |
908589fd | 494 | if (f2 < 0 ? f1 > 0 : f1 < 0) |
f6196b87 PE |
495 | f1 += f2; |
496 | ||
d137ae2f PE |
497 | return make_float (f1); |
498 | } | |
4b6baf5f | 499 | \f |
4b6baf5f | 500 | DEFUN ("fceiling", Ffceiling, Sfceiling, 1, 1, 0, |
335c5470 PJ |
501 | doc: /* Return the smallest integer no less than ARG, as a float. |
502 | \(Round toward +inf.\) */) | |
f6196b87 | 503 | (Lisp_Object arg) |
4b6baf5f RS |
504 | { |
505 | double d = extract_float (arg); | |
f6196b87 | 506 | d = ceil (d); |
4b6baf5f RS |
507 | return make_float (d); |
508 | } | |
509 | ||
510 | DEFUN ("ffloor", Fffloor, Sffloor, 1, 1, 0, | |
335c5470 PJ |
511 | doc: /* Return the largest integer no greater than ARG, as a float. |
512 | \(Round towards -inf.\) */) | |
f6196b87 | 513 | (Lisp_Object arg) |
4b6baf5f RS |
514 | { |
515 | double d = extract_float (arg); | |
f6196b87 | 516 | d = floor (d); |
4b6baf5f RS |
517 | return make_float (d); |
518 | } | |
b70021f4 | 519 | |
4b6baf5f | 520 | DEFUN ("fround", Ffround, Sfround, 1, 1, 0, |
335c5470 | 521 | doc: /* Return the nearest integer to ARG, as a float. */) |
f6196b87 | 522 | (Lisp_Object arg) |
4b6baf5f RS |
523 | { |
524 | double d = extract_float (arg); | |
f6196b87 | 525 | d = emacs_rint (d); |
4b6baf5f RS |
526 | return make_float (d); |
527 | } | |
528 | ||
529 | DEFUN ("ftruncate", Fftruncate, Sftruncate, 1, 1, 0, | |
335c5470 PJ |
530 | doc: /* Truncate a floating point number to an integral float value. |
531 | Rounds the value toward zero. */) | |
f6196b87 | 532 | (Lisp_Object arg) |
4b6baf5f RS |
533 | { |
534 | double d = extract_float (arg); | |
535 | if (d >= 0.0) | |
f6196b87 | 536 | d = floor (d); |
4b6baf5f | 537 | else |
f6196b87 | 538 | d = ceil (d); |
4b6baf5f | 539 | return make_float (d); |
b70021f4 MR |
540 | } |
541 | \f | |
dfcf069d | 542 | void |
d5a3eaaf | 543 | syms_of_floatfns (void) |
b70021f4 MR |
544 | { |
545 | defsubr (&Sacos); | |
b70021f4 | 546 | defsubr (&Sasin); |
b70021f4 | 547 | defsubr (&Satan); |
c2d4ea74 RS |
548 | defsubr (&Scos); |
549 | defsubr (&Ssin); | |
550 | defsubr (&Stan); | |
15e12598 | 551 | defsubr (&Sisnan); |
c8199d0f | 552 | #ifdef HAVE_COPYSIGN |
15e12598 | 553 | defsubr (&Scopysign); |
c990426a | 554 | #endif |
15e12598 VB |
555 | defsubr (&Sfrexp); |
556 | defsubr (&Sldexp); | |
4b6baf5f RS |
557 | defsubr (&Sfceiling); |
558 | defsubr (&Sffloor); | |
559 | defsubr (&Sfround); | |
560 | defsubr (&Sftruncate); | |
b70021f4 | 561 | defsubr (&Sexp); |
c2d4ea74 | 562 | defsubr (&Sexpt); |
b70021f4 | 563 | defsubr (&Slog); |
b70021f4 | 564 | defsubr (&Ssqrt); |
b70021f4 MR |
565 | |
566 | defsubr (&Sabs); | |
567 | defsubr (&Sfloat); | |
568 | defsubr (&Slogb); | |
569 | defsubr (&Sceiling); | |
acbbacbe | 570 | defsubr (&Sfloor); |
b70021f4 MR |
571 | defsubr (&Sround); |
572 | defsubr (&Struncate); | |
573 | } |