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1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 *
3 * ***** BEGIN LICENSE BLOCK *****
4 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5 *
6 * The contents of this file are subject to the Mozilla Public License Version
7 * 1.1 (the "License"); you may not use this file except in compliance with
8 * the License. You may obtain a copy of the License at
9 * http://www.mozilla.org/MPL/
10 *
11 * Software distributed under the License is distributed on an "AS IS" basis,
12 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13 * for the specific language governing rights and limitations under the
14 * License.
15 *
16 * The Original Code is Mozilla Communicator client code, released
17 * March 31, 1998.
18 *
19 * The Initial Developer of the Original Code is
20 * Netscape Communications Corporation.
21 * Portions created by the Initial Developer are Copyright (C) 1998
22 * the Initial Developer. All Rights Reserved.
23 *
24 * Contributor(s):
25 *
26 * Alternatively, the contents of this file may be used under the terms of
27 * either of the GNU General Public License Version 2 or later (the "GPL"),
28 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29 * in which case the provisions of the GPL or the LGPL are applicable instead
30 * of those above. If you wish to allow use of your version of this file only
31 * under the terms of either the GPL or the LGPL, and not to allow others to
32 * use your version of this file under the terms of the MPL, indicate your
33 * decision by deleting the provisions above and replace them with the notice
34 * and other provisions required by the GPL or the LGPL. If you do not delete
35 * the provisions above, a recipient may use your version of this file under
36 * the terms of any one of the MPL, the GPL or the LGPL.
37 *
38 * ***** END LICENSE BLOCK ***** */
39
40 #ifndef jsnum_h___
41 #define jsnum_h___
42
43 /*
44 * JS number (IEEE double) interface.
45 *
46 * JS numbers are optimistically stored in the top 31 bits of 32-bit integers,
47 * but floating point literals, results that overflow 31 bits, and division and
48 * modulus operands and results require a 64-bit IEEE double. These are GC'ed
49 * and pointed to by 32-bit jsvals on the stack and in object properties.
50 */
51
52 JS_BEGIN_EXTERN_C
53
54 /*
55 * The ARM architecture supports two floating point models: VFP and FPA. When
56 * targetting FPA, doubles are mixed-endian on little endian ARMs (meaning that
57 * the high and low words are in big endian order).
58 */
59 #if defined(__arm) || defined(__arm32__) || defined(__arm26__) || defined(__arm__)
60 #if !defined(__VFP_FP__)
61 #define FPU_IS_ARM_FPA
62 #endif
63 #endif
64
65 typedef union jsdpun {
66 struct {
67 #if defined(IS_LITTLE_ENDIAN) && !defined(FPU_IS_ARM_FPA)
68 uint32 lo, hi;
69 #else
70 uint32 hi, lo;
71 #endif
72 } s;
73 uint64 u64;
74 jsdouble d;
75 } jsdpun;
76
77 #if (__GNUC__ == 2 && __GNUC_MINOR__ > 95) || __GNUC__ > 2
78 /*
79 * This version of the macros is safe for the alias optimizations that gcc
80 * does, but uses gcc-specific extensions.
81 */
82
83 #define JSDOUBLE_HI32(x) (__extension__ ({ jsdpun u; u.d = (x); u.s.hi; }))
84 #define JSDOUBLE_LO32(x) (__extension__ ({ jsdpun u; u.d = (x); u.s.lo; }))
85 #define JSDOUBLE_SET_HI32(x, y) \
86 (__extension__ ({ jsdpun u; u.d = (x); u.s.hi = (y); (x) = u.d; }))
87 #define JSDOUBLE_SET_LO32(x, y) \
88 (__extension__ ({ jsdpun u; u.d = (x); u.s.lo = (y); (x) = u.d; }))
89
90 #else /* not or old GNUC */
91
92 /*
93 * We don't know of any non-gcc compilers that perform alias optimization,
94 * so this code should work.
95 */
96
97 #if defined(IS_LITTLE_ENDIAN) && !defined(FPU_IS_ARM_FPA)
98 #define JSDOUBLE_HI32(x) (((uint32 *)&(x))[1])
99 #define JSDOUBLE_LO32(x) (((uint32 *)&(x))[0])
100 #else
101 #define JSDOUBLE_HI32(x) (((uint32 *)&(x))[0])
102 #define JSDOUBLE_LO32(x) (((uint32 *)&(x))[1])
103 #endif
104
105 #define JSDOUBLE_SET_HI32(x, y) (JSDOUBLE_HI32(x)=(y))
106 #define JSDOUBLE_SET_LO32(x, y) (JSDOUBLE_LO32(x)=(y))
107
108 #endif /* not or old GNUC */
109
110 #define JSDOUBLE_HI32_SIGNBIT 0x80000000
111 #define JSDOUBLE_HI32_EXPMASK 0x7ff00000
112 #define JSDOUBLE_HI32_MANTMASK 0x000fffff
113
114 #define JSDOUBLE_IS_NaN(x) \
115 ((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) == JSDOUBLE_HI32_EXPMASK && \
116 (JSDOUBLE_LO32(x) || (JSDOUBLE_HI32(x) & JSDOUBLE_HI32_MANTMASK)))
117
118 #define JSDOUBLE_IS_INFINITE(x) \
119 ((JSDOUBLE_HI32(x) & ~JSDOUBLE_HI32_SIGNBIT) == JSDOUBLE_HI32_EXPMASK && \
120 !JSDOUBLE_LO32(x))
121
122 #define JSDOUBLE_IS_FINITE(x) \
123 ((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) != JSDOUBLE_HI32_EXPMASK)
124
125 #define JSDOUBLE_IS_NEGZERO(d) (JSDOUBLE_HI32(d) == JSDOUBLE_HI32_SIGNBIT && \
126 JSDOUBLE_LO32(d) == 0)
127
128 /*
129 * JSDOUBLE_IS_INT first checks that d is neither NaN nor infinite, to avoid
130 * raising SIGFPE on platforms such as Alpha Linux, then (only if the cast is
131 * safe) leaves i as (jsint)d. This also avoid anomalous NaN floating point
132 * comparisons under MSVC.
133 */
134 #define JSDOUBLE_IS_INT(d, i) (JSDOUBLE_IS_FINITE(d) \
135 && !JSDOUBLE_IS_NEGZERO(d) \
136 && ((d) == (i = (jsint)(d))))
137
138 #if defined(XP_WIN)
139 #define JSDOUBLE_COMPARE(LVAL, OP, RVAL, IFNAN) \
140 ((JSDOUBLE_IS_NaN(LVAL) || JSDOUBLE_IS_NaN(RVAL)) \
141 ? (IFNAN) \
142 : (LVAL) OP (RVAL))
143 #else
144 #define JSDOUBLE_COMPARE(LVAL, OP, RVAL, IFNAN) ((LVAL) OP (RVAL))
145 #endif
146
147 extern jsdouble js_NaN;
148
149 /* Initialize number constants and runtime state for the first context. */
150 extern JSBool
151 js_InitRuntimeNumberState(JSContext *cx);
152
153 extern void
154 js_TraceRuntimeNumberState(JSTracer *trc);
155
156 extern void
157 js_FinishRuntimeNumberState(JSContext *cx);
158
159 /* Initialize the Number class, returning its prototype object. */
160 extern JSClass js_NumberClass;
161
162 extern JSObject *
163 js_InitNumberClass(JSContext *cx, JSObject *obj);
164
165 /*
166 * String constants for global function names, used in jsapi.c and jsnum.c.
167 */
168 extern const char js_Infinity_str[];
169 extern const char js_NaN_str[];
170 extern const char js_isNaN_str[];
171 extern const char js_isFinite_str[];
172 extern const char js_parseFloat_str[];
173 extern const char js_parseInt_str[];
174
175 /*
176 * vp must be a root.
177 */
178 extern JSBool
179 js_NewNumberInRootedValue(JSContext *cx, jsdouble d, jsval *vp);
180
181 /* Convert a number to a GC'ed string. */
182 extern JSString * JS_FASTCALL
183 js_NumberToString(JSContext *cx, jsdouble d);
184
185 /*
186 * Convert int to C string. The buf must be big enough for MIN_INT to fit
187 * including '-' and '\0'.
188 */
189 char *
190 js_IntToCString(jsint i, jsint base, char *buf, size_t bufSize);
191
192 /*
193 * Convert a number to C string. The buf must be at least
194 * DTOSTR_STANDARD_BUFFER_SIZE.
195 */
196 char *
197 js_NumberToCString(JSContext *cx, jsdouble d, jsint base, char *buf, size_t bufSize);
198
199 /*
200 * Convert a value to a number. On exit JSVAL_IS_NULL(*vp) iff there was an
201 * error. If on exit JSVAL_IS_NUMBER(*vp), then *vp holds the jsval that
202 * matches the result. Otherwise *vp is JSVAL_TRUE indicating that the jsval
203 * for result has to be created explicitly using, for example, the
204 * js_NewNumberInRootedValue function.
205 */
206 extern jsdouble
207 js_ValueToNumber(JSContext *cx, jsval* vp);
208
209 /*
210 * Convert a value to an int32 or uint32, according to the ECMA rules for
211 * ToInt32 and ToUint32. On exit JSVAL_IS_NULL(*vp) iff there was an error. If
212 * on exit JSVAL_IS_INT(*vp), then *vp holds the jsval matching the result.
213 * Otherwise *vp is JSVAL_TRUE indicating that the jsval for result has to be
214 * created explicitly using, for example, the js_NewNumberInRootedValue
215 * function.
216 */
217 extern int32
218 js_ValueToECMAInt32(JSContext *cx, jsval *vp);
219
220 extern uint32
221 js_ValueToECMAUint32(JSContext *cx, jsval *vp);
222
223 /*
224 * Specialized ToInt32 and ToUint32 converters for doubles.
225 */
226 extern int32
227 js_DoubleToECMAInt32(jsdouble d);
228
229 extern uint32
230 js_DoubleToECMAUint32(jsdouble d);
231
232 /*
233 * Convert a value to a number, then to an int32 if it fits by rounding to
234 * nearest; but failing with an error report if the double is out of range
235 * or unordered. On exit JSVAL_IS_NULL(*vp) iff there was an error. If on exit
236 * JSVAL_IS_INT(*vp), then *vp holds the jsval matching the result. Otherwise
237 * *vp is JSVAL_TRUE indicating that the jsval for result has to be created
238 * explicitly using, for example, the js_NewNumberInRootedValue function.
239 */
240 extern int32
241 js_ValueToInt32(JSContext *cx, jsval *vp);
242
243 /*
244 * Convert a value to a number, then to a uint16 according to the ECMA rules
245 * for ToUint16. On exit JSVAL_IS_NULL(*vp) iff there was an error, otherwise
246 * vp is jsval matching the result.
247 */
248 extern uint16
249 js_ValueToUint16(JSContext *cx, jsval *vp);
250
251 /*
252 * Convert a jsdouble to an integral number, stored in a jsdouble.
253 * If d is NaN, return 0. If d is an infinity, return it without conversion.
254 */
255 extern jsdouble
256 js_DoubleToInteger(jsdouble d);
257
258 /*
259 * Similar to strtod except that it replaces overflows with infinities of the
260 * correct sign, and underflows with zeros of the correct sign. Guaranteed to
261 * return the closest double number to the given input in dp.
262 *
263 * Also allows inputs of the form [+|-]Infinity, which produce an infinity of
264 * the appropriate sign. The case of the "Infinity" string must match exactly.
265 * If the string does not contain a number, set *ep to s and return 0.0 in dp.
266 * Return false if out of memory.
267 */
268 extern JSBool
269 js_strtod(JSContext *cx, const jschar *s, const jschar *send,
270 const jschar **ep, jsdouble *dp);
271
272 /*
273 * Similar to strtol except that it handles integers of arbitrary size.
274 * Guaranteed to return the closest double number to the given input when radix
275 * is 10 or a power of 2. Callers may see round-off errors for very large
276 * numbers of a different radix than 10 or a power of 2.
277 *
278 * If the string does not contain a number, set *ep to s and return 0.0 in dp.
279 * Return false if out of memory.
280 */
281 extern JSBool
282 js_strtointeger(JSContext *cx, const jschar *s, const jschar *send,
283 const jschar **ep, jsint radix, jsdouble *dp);
284
285 JS_END_EXTERN_C
286
287 #endif /* jsnum_h___ */

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