1 | /* sf_cos.c -- float version of s_cos.c. |
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2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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3 | */ |
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4 | |
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5 | /* |
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6 | * ==================================================== |
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7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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8 | * |
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9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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10 | * Permission to use, copy, modify, and distribute this |
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11 | * software is freely granted, provided that this notice |
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12 | * is preserved. |
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13 | * ==================================================== |
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14 | */ |
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15 | |
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16 | #include "fdlibm.h" |
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17 | |
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18 | #ifdef __STDC__ |
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19 | static const float one=1.0; |
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20 | #else |
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21 | static float one=1.0; |
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22 | #endif |
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23 | |
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24 | #ifdef __STDC__ |
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25 | float cosf(float x) |
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26 | #else |
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27 | float cosf(x) |
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28 | float x; |
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29 | #endif |
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30 | { |
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31 | float y[2],z=0.0; |
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32 | __int32_t n,ix; |
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33 | |
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34 | GET_FLOAT_WORD(ix,x); |
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35 | |
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36 | /* |x| ~< pi/4 */ |
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37 | ix &= 0x7fffffff; |
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38 | if(ix <= 0x3f490fd8) return __kernel_cosf(x,z); |
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39 | |
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40 | /* cos(Inf or NaN) is NaN */ |
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41 | else if (!FLT_UWORD_IS_FINITE(ix)) return x-x; |
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42 | |
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43 | /* argument reduction needed */ |
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44 | else { |
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45 | n = __ieee754_rem_pio2f(x,y); |
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46 | switch(n&3) { |
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47 | case 0: return __kernel_cosf(y[0],y[1]); |
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48 | case 1: return -__kernel_sinf(y[0],y[1],1); |
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49 | case 2: return -__kernel_cosf(y[0],y[1]); |
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50 | default: |
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51 | return __kernel_sinf(y[0],y[1],1); |
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52 | } |
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53 | } |
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54 | } |
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55 | |
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56 | #ifdef _DOUBLE_IS_32BITS |
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57 | |
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58 | #ifdef __STDC__ |
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59 | double cos(double x) |
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60 | #else |
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61 | double cos(x) |
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62 | double x; |
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63 | #endif |
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64 | { |
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65 | return (double) cosf((float) x); |
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66 | } |
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67 | |
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68 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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