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author | Tom Tromey <tromey@gcc.gnu.org> | 2005-07-16 00:30:23 +0000 |
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committer | Tom Tromey <tromey@gcc.gnu.org> | 2005-07-16 00:30:23 +0000 |
commit | f911ba985aa7fe0096c386c5be385ac5825ea527 (patch) | |
tree | a0b991cf5866ae1d616639b906ac001811d74508 /libjava/classpath/native/fdlibm/w_exp.c | |
parent | 6f4434b39b261de5317dc81ddfdd94d2e1d62b11 (diff) | |
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Initial revision
From-SVN: r102074
Diffstat (limited to 'libjava/classpath/native/fdlibm/w_exp.c')
-rw-r--r-- | libjava/classpath/native/fdlibm/w_exp.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/libjava/classpath/native/fdlibm/w_exp.c b/libjava/classpath/native/fdlibm/w_exp.c new file mode 100644 index 0000000..45e087b --- /dev/null +++ b/libjava/classpath/native/fdlibm/w_exp.c @@ -0,0 +1,140 @@ + +/* @(#)w_exp.c 5.1 93/09/24 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +/* +FUNCTION + <<exp>>, <<expf>>---exponential +INDEX + exp +INDEX + expf + +ANSI_SYNOPSIS + #include <math.h> + double exp(double <[x]>); + float expf(float <[x]>); + +TRAD_SYNOPSIS + #include <math.h> + double exp(<[x]>); + double <[x]>; + + float expf(<[x]>); + float <[x]>; + +DESCRIPTION + <<exp>> and <<expf>> calculate the exponential of <[x]>, that is, + @ifinfo + e raised to the power <[x]> (where e + @end ifinfo + @tex + $e^x$ (where $e$ + @end tex + is the base of the natural system of logarithms, approximately 2.71828). + + You can use the (non-ANSI) function <<matherr>> to specify + error handling for these functions. + +RETURNS + On success, <<exp>> and <<expf>> return the calculated value. + If the result underflows, the returned value is <<0>>. If the + result overflows, the returned value is <<HUGE_VAL>>. In + either case, <<errno>> is set to <<ERANGE>>. + +PORTABILITY + <<exp>> is ANSI C. <<expf>> is an extension. + +*/ + +/* + * wrapper exp(x) + */ + +#include "fdlibm.h" +#include <errno.h> + +#ifndef _DOUBLE_IS_32BITS + +#ifndef _IEEE_LIBM + +#ifdef __STDC__ +static const double +#else +static double +#endif +o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */ +u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */ + +#endif + +#ifdef __STDC__ + double exp(double x) /* wrapper exp */ +#else + double exp(x) /* wrapper exp */ + double x; +#endif +{ +#ifdef _IEEE_LIBM + return __ieee754_exp(x); +#else + double z; + struct exception exc; + z = __ieee754_exp(x); + if(_LIB_VERSION == _IEEE_) return z; + if(finite(x)) { + if(x>o_threshold) { + /* exp(finite) overflow */ +#ifndef HUGE_VAL +#define HUGE_VAL inf + double inf = 0.0; + + SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */ +#endif + exc.type = OVERFLOW; + exc.name = "exp"; + exc.err = 0; + exc.arg1 = exc.arg2 = x; + if (_LIB_VERSION == _SVID_) + exc.retval = HUGE; + else + exc.retval = HUGE_VAL; + if (_LIB_VERSION == _POSIX_) + errno = ERANGE; + else if (!matherr(&exc)) { + errno = ERANGE; + } + if (exc.err != 0) + errno = exc.err; + return exc.retval; + } else if(x<u_threshold) { + /* exp(finite) underflow */ + exc.type = UNDERFLOW; + exc.name = "exp"; + exc.err = 0; + exc.arg1 = exc.arg2 = x; + exc.retval = 0.0; + if (_LIB_VERSION == _POSIX_) + errno = ERANGE; + else if (!matherr(&exc)) { + errno = ERANGE; + } + if (exc.err != 0) + errno = exc.err; + return exc.retval; + } + } + return z; +#endif +} + +#endif /* defined(_DOUBLE_IS_32BITS) */ |