The Android Open Source Project | b07e1d9 | 2009-03-03 19:29:30 -0800 | [diff] [blame] | 1 | |
| 2 | /* @(#)w_exp.c 1.4 04/04/22 */ |
| 3 | /* |
| 4 | * ==================================================== |
| 5 | * Copyright (C) 2004 by Sun Microsystems, Inc. All rights reserved. |
| 6 | * |
| 7 | * Permission to use, copy, modify, and distribute this |
| 8 | * software is freely granted, provided that this notice |
| 9 | * is preserved. |
| 10 | * ==================================================== |
| 11 | */ |
| 12 | |
| 13 | /* |
| 14 | * wrapper ieee_exp(x) |
| 15 | */ |
| 16 | |
| 17 | #include "fdlibm.h" |
| 18 | |
| 19 | #ifdef __STDC__ |
| 20 | static const double |
| 21 | #else |
| 22 | static double |
| 23 | #endif |
| 24 | o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */ |
| 25 | u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */ |
| 26 | |
| 27 | #ifdef __STDC__ |
| 28 | double ieee_exp(double x) /* wrapper exp */ |
| 29 | #else |
| 30 | double ieee_exp(x) /* wrapper exp */ |
| 31 | double x; |
| 32 | #endif |
| 33 | { |
| 34 | #ifdef _IEEE_LIBM |
| 35 | return __ieee754_exp(x); |
| 36 | #else |
| 37 | double z; |
| 38 | z = __ieee754_exp(x); |
| 39 | if(_LIB_VERSION == _IEEE_) return z; |
| 40 | if(ieee_finite(x)) { |
| 41 | if(x>o_threshold) |
| 42 | return __kernel_standard(x,x,6); /* exp overflow */ |
| 43 | else if(x<u_threshold) |
| 44 | return __kernel_standard(x,x,7); /* exp underflow */ |
| 45 | } |
| 46 | return z; |
| 47 | #endif |
| 48 | } |