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  • Committer: Package Import Robot
  • Author(s): Kevin Bortis
  • Date: 2013-09-20 20:54:14 UTC
  • Revision ID: package-import@ubuntu.com-20130920205414-5b61trtmma18w58o
Tags: upstream-0.9.13
Import upstream version 0.9.13

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src/math/sinf.c
 
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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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#include "libm.h"
 
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/* Small multiples of pi/2 rounded to double precision. */
 
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static const double
 
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s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
 
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s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
 
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s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
 
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s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
 
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float sinf(float x)
 
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{
 
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        double y;
 
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        uint32_t ix;
 
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        int n, sign;
 
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        GET_FLOAT_WORD(ix, x);
 
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        sign = ix >> 31;
 
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        ix &= 0x7fffffff;
 
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        if (ix <= 0x3f490fda) {  /* |x| ~<= pi/4 */
 
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                if (ix < 0x39800000) {  /* |x| < 2**-12 */
 
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                        /* raise inexact if x!=0 and underflow if subnormal */
 
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                        FORCE_EVAL(ix < 0x00800000 ? x/0x1p120f : x+0x1p120f);
 
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                        return x;
 
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                }
 
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                return __sindf(x);
 
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        }
 
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        if (ix <= 0x407b53d1) {  /* |x| ~<= 5*pi/4 */
 
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                if (ix <= 0x4016cbe3) {  /* |x| ~<= 3pi/4 */
 
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                        if (sign)
 
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                                return -__cosdf(x + s1pio2);
 
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                        else
 
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                                return __cosdf(x - s1pio2);
 
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                }
 
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                return __sindf(sign ? -(x + s2pio2) : -(x - s2pio2));
 
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        }
 
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        if (ix <= 0x40e231d5) {  /* |x| ~<= 9*pi/4 */
 
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                if (ix <= 0x40afeddf) {  /* |x| ~<= 7*pi/4 */
 
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                        if (sign)
 
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                                return __cosdf(x + s3pio2);
 
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                        else
 
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                                return -__cosdf(x - s3pio2);
 
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                }
 
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                return __sindf(sign ? x + s4pio2 : x - s4pio2);
 
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        }
 
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        /* sin(Inf or NaN) is NaN */
 
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        if (ix >= 0x7f800000)
 
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                return x - x;
 
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        /* general argument reduction needed */
 
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        n = __rem_pio2f(x, &y);
 
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        switch (n&3) {
 
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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:
 
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                return -__cosdf(y);
 
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        }
 
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}