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118 lines
2.9 KiB
Plaintext
118 lines
2.9 KiB
Plaintext
module std::math::nolibc @if(env::NO_LIBC || $feature(C3_MATH));
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/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */
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/*
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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* Optimized by Bruce D. Evans.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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fn float _sinf(float x) @weak @cname("sinf") @nostrip
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{
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uint ix = x.word();
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int sign = ix >> 31;
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ix &= 0x7fffffff;
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switch
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{
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case ix <= 0x3f490fda:
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// |x| ~<= pi/4
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if (ix < 0x39800000)
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{
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/* |x| < 2**-12 */
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// raise inexact if x!=0 and underflow if subnormal
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if (ix < 0x00800000)
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{
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@volatile_load(x) / 0x1p120f;
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}
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else
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{
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@volatile_load(x) + 0x1p120f;
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}
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return x;
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}
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return __sindf(x);
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case ix <= 0x407b53d1:
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// |x| ~<= 5*pi/4
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if (ix <= 0x4016cbe3)
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{
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// |x| ~<= 3pi/4
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if (sign) return -__cosdf(x + S1PI2);
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return __cosdf(x - S1PI2);
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}
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return __sindf(sign ? -(x + S2PI2) : -(x - S2PI2));
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case ix <= 0x40e231d5:
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// |x| ~<= 9*pi/4
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if (ix <= 0x40afeddf)
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{
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// |x| ~<= 7*pi/4
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return sign ? __cosdf(x + S3PI2) : -__cosdf(x - S3PI2);
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}
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return __sindf(sign ? x + S4PI2 : x - S4PI2);
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case ix >= 0x7f800000:
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// sin(Inf or NaN) is NaN
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return x - x;
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}
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/* general argument reduction needed */
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double y @noinit;
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switch (__rem_pio2f(x, &y) & 3)
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{
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case 0: return __sindf(y);
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case 1: return __cosdf(y);
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case 2: return __sindf(-y);
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default: return -__cosdf(y);
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}
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}
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/* origin: FreeBSD /usr/src/lib/msun/src/s_sin.c */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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fn double sin(double x) @cname("sin") @weak @nostrip
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{
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// High word of x.
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uint ix = x.high_word() & 0x7fffffff;
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switch
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{
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// |x| ~< pi/4
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case ix <= 0x3fe921fb:
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// |x| < 2**-26
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if (ix < 0x3e500000)
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{
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// raise inexact if x != 0 and underflow if subnormal
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force_eval_add(x, ix < 0x00100000 ? -0x1p120f : 0x1p120f);
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return x;
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}
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return __sin(x, 0.0, 0);
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// sin(Inf or NaN) is NaN
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case ix >= 0x7ff00000:
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return x - x;
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default:
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// argument reduction needed
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double[2] y;
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switch (__rem_pio2(x, &y) & 3)
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{
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case 0: return __sin(y[0], y[1], 1);
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case 1: return __cos(y[0], y[1]);
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case 2: return -__sin(y[0], y[1], 1);
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default: return -__cos(y[0], y[1]);
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}
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}
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}
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