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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | /* s_tanf.c -- float version of s_tan.c. |
| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 3 | */ |
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| 4 | |||
| 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 | |||
| 16 | #ifndef lint |
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| 17 | static char rcsid[] = "$\Id: s_tanf.c,v 1.2 1995/05/30 05:50:34 rgrimes Exp $"; |
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| 18 | #endif |
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| 19 | |||
| 20 | #include "math.h" |
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| 21 | #include "math_private.h" |
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| 22 | |||
| 23 | #ifdef __STDC__ |
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| 24 | float tanf(float x) |
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| 25 | #else |
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| 26 | float tanf(x) |
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| 27 | float x; |
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| 28 | #endif |
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| 29 | { |
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| 30 | float y[2],z=0.0; |
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| 31 | int32_t n, ix; |
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| 32 | |||
| 33 | GET_FLOAT_WORD(ix,x); |
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| 34 | |||
| 35 | /* |x| ~< pi/4 */ |
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| 36 | ix &= 0x7fffffff; |
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| 37 | if(ix <= 0x3f490fda) return __kernel_tanf(x,z,1); |
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| 38 | |||
| 39 | /* tan(Inf or NaN) is NaN */ |
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| 40 | else if (ix>=0x7f800000) return x-x; /* NaN */ |
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| 41 | |||
| 42 | /* argument reduction needed */ |
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| 43 | else { |
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| 44 | n = __ieee754_rem_pio2f(x,y); |
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| 45 | return __kernel_tanf(y[0],y[1],1-((n&1)<<1)); /* 1 -- n even |
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| 46 | -1 -- n odd */ |
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| 47 | } |
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| 48 | } |