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https://gitlab.winehq.org/wine/wine-gecko.git
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91 lines
2.2 KiB
C++
91 lines
2.2 KiB
C++
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef jsmath_h___
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#define jsmath_h___
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namespace js {
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typedef double (*UnaryFunType)(double);
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class MathCache
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{
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static const unsigned SizeLog2 = 12;
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static const unsigned Size = 1 << SizeLog2;
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struct Entry { double in; UnaryFunType f; double out; };
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Entry table[Size];
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public:
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MathCache();
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unsigned hash(double x) {
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union { double d; struct { uint32_t one, two; } s; } u = { x };
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uint32_t hash32 = u.s.one ^ u.s.two;
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uint16_t hash16 = uint16_t(hash32 ^ (hash32 >> 16));
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return (hash16 & (Size - 1)) ^ (hash16 >> (16 - SizeLog2));
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}
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/*
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* N.B. lookup uses double-equality. This is only safe if hash() maps +0
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* and -0 to different table entries, which is asserted in MathCache().
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*/
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double lookup(UnaryFunType f, double x) {
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unsigned index = hash(x);
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Entry &e = table[index];
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if (e.in == x && e.f == f)
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return e.out;
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e.in = x;
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e.f = f;
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return (e.out = f(x));
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}
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size_t sizeOfIncludingThis(JSMallocSizeOfFun mallocSizeOf);
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};
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} /* namespace js */
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/*
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* JS math functions.
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*/
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extern JSObject *
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js_InitMathClass(JSContext *cx, JSObject *obj);
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extern void
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js_InitRandom(JSContext *cx);
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extern JSBool
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js_math_abs(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_ceil(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_floor(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_max(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_min(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_round(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_sqrt(JSContext *cx, unsigned argc, js::Value *vp);
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extern JSBool
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js_math_pow(JSContext *cx, unsigned argc, js::Value *vp);
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extern double
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js_math_ceil_impl(double x);
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extern double
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js_math_floor_impl(double x);
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#endif /* jsmath_h___ */
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