| 1 | /* wf_exp.c -- float version of w_exp.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 | /* |
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| 17 | * wrapper expf(x) |
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| 18 | */ |
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| 19 | |
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| 20 | #include "fdlibm.h" |
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| 21 | #if __OBSOLETE_MATH |
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| 22 | #include <errno.h> |
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| 23 | |
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| 24 | #ifdef __STDC__ |
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| 25 | static const float |
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| 26 | #else |
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| 27 | static float |
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| 28 | #endif |
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| 29 | o_threshold= 8.8721679688e+01, /* 0x42b17180 */ |
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| 30 | u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ |
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| 31 | |
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| 32 | #ifdef __STDC__ |
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| 33 | float expf(float x) /* wrapper expf */ |
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| 34 | #else |
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| 35 | float expf(x) /* wrapper expf */ |
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| 36 | float x; |
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| 37 | #endif |
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| 38 | { |
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| 39 | #ifdef _IEEE_LIBM |
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| 40 | return __ieee754_expf(x); |
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| 41 | #else |
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| 42 | float z; |
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| 43 | struct exception exc; |
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| 44 | z = __ieee754_expf(x); |
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| 45 | if(_LIB_VERSION == _IEEE_) return z; |
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| 46 | if(finitef(x)) { |
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| 47 | if(x>o_threshold) { |
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| 48 | /* expf(finite) overflow */ |
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| 49 | #ifndef HUGE_VAL |
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| 50 | #define HUGE_VAL inf |
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| 51 | double inf = 0.0; |
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| 52 | |
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| 53 | SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */ |
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| 54 | #endif |
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| 55 | exc.type = OVERFLOW; |
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| 56 | exc.name = "expf"; |
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| 57 | exc.err = 0; |
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| 58 | exc.arg1 = exc.arg2 = (double)x; |
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| 59 | if (_LIB_VERSION == _SVID_) |
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| 60 | exc.retval = HUGE; |
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| 61 | else |
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| 62 | exc.retval = HUGE_VAL; |
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| 63 | if (_LIB_VERSION == _POSIX_) |
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| 64 | errno = ERANGE; |
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| 65 | else if (!matherr(&exc)) { |
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| 66 | errno = ERANGE; |
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| 67 | } |
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| 68 | if (exc.err != 0) |
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| 69 | errno = exc.err; |
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| 70 | return exc.retval; |
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| 71 | } else if(x<u_threshold) { |
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| 72 | /* expf(finite) underflow */ |
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| 73 | exc.type = UNDERFLOW; |
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| 74 | exc.name = "expf"; |
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| 75 | exc.err = 0; |
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| 76 | exc.arg1 = exc.arg2 = (double)x; |
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| 77 | exc.retval = 0.0; |
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| 78 | if (_LIB_VERSION == _POSIX_) |
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| 79 | errno = ERANGE; |
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| 80 | else if (!matherr(&exc)) { |
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| 81 | errno = ERANGE; |
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| 82 | } |
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| 83 | if (exc.err != 0) |
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| 84 | errno = exc.err; |
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| 85 | return exc.retval; |
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| 86 | } |
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| 87 | } |
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| 88 | return z; |
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| 89 | #endif |
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| 90 | } |
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| 91 | |
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| 92 | #ifdef _DOUBLE_IS_32BITS |
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| 93 | |
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| 94 | #ifdef __STDC__ |
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| 95 | double exp(double x) |
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| 96 | #else |
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| 97 | double exp(x) |
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| 98 | double x; |
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| 99 | #endif |
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| 100 | { |
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| 101 | return (double) expf((float) x); |
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| 102 | } |
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| 103 | |
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| 104 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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| 105 | #endif /* __OBSOLETE_MATH */ |
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