1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
3 * ***** BEGIN LICENSE BLOCK *****
4 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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/
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
16 * The Original Code is Mozilla Communicator client code, released
19 * The Initial Developer of the Original Code is
20 * Netscape Communications Corporation.
21 * Portions created by the Initial Developer are Copyright (C) 1998-1999
22 * the Initial Developer. All Rights Reserved.
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.
38 * ***** END LICENSE BLOCK ***** */
45 typedef double (*UnaryFunType)(double);
49 static const unsigned SizeLog2 = 12;
50 static const unsigned Size = 1 << SizeLog2;
51 struct Entry { double in; UnaryFunType f; double out; };
57 uintN hash(double x) {
58 union { double d; struct { uint32 one, two; } s; } u = { x };
59 uint32 hash32 = u.s.one ^ u.s.two;
60 uint16 hash16 = (uint16)(hash32 ^ (hash32 >> 16));
61 return (hash16 & (Size - 1)) ^ (hash16 >> (16 - SizeLog2));
65 * N.B. lookup uses double-equality. This is only safe if hash() maps +0
66 * and -0 to different table entries, which is asserted in MathCache().
68 double lookup(UnaryFunType f, double x) {
69 uintN index = hash(x);
70 Entry &e = table[index];
71 if (e.in == x && e.f == f)
75 return (e.out = f(x));
85 extern js::Class js_MathClass;
88 js_InitMathClass(JSContext *cx, JSObject *obj);
91 js_IsMathFunction(JSNative native);
94 js_InitRandom(JSContext *cx);
97 js_math_abs(JSContext *cx, uintN argc, js::Value *vp);
100 js_math_ceil(JSContext *cx, uintN argc, js::Value *vp);
103 js_math_floor(JSContext *cx, uintN argc, js::Value *vp);
106 js_math_max(JSContext *cx, uintN argc, js::Value *vp);
109 js_math_min(JSContext *cx, uintN argc, js::Value *vp);
112 js_math_round(JSContext *cx, uintN argc, js::Value *vp);
115 js_math_ceil_impl(jsdouble x);
118 js_math_floor_impl(jsdouble x);
121 js_math_round_impl(jsdouble x);
123 #endif /* jsmath_h___ */