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Diffstat (limited to 'newlib/libm/math/w_lgamma.c')
-rw-r--r-- | newlib/libm/math/w_lgamma.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/newlib/libm/math/w_lgamma.c b/newlib/libm/math/w_lgamma.c new file mode 100644 index 00000000000..1dc63994f54 --- /dev/null +++ b/newlib/libm/math/w_lgamma.c @@ -0,0 +1,89 @@ + +/* @(#)w_lgamma.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. + * ==================================================== + * + */ + +/* double lgamma(double x) + * Return the logarithm of the Gamma function of x. + * + * Method: call __ieee754_lgamma_r + */ + +#include "fdlibm.h" +#include <reent.h> +#include <errno.h> + +#ifndef _DOUBLE_IS_32BITS + +#ifdef __STDC__ + double lgamma(double x) +#else + double lgamma(x) + double x; +#endif +{ +#ifdef _IEEE_LIBM + return __ieee754_lgamma_r(x,&(_REENT->_new._reent._gamma_signgam)); +#else + double y; + struct exception exc; + y = __ieee754_lgamma_r(x,&(_REENT->_new._reent._gamma_signgam)); + if(_LIB_VERSION == _IEEE_) return y; + if(!finite(y)&&finite(x)) { +#ifndef HUGE_VAL +#define HUGE_VAL inf + double inf = 0.0; + + SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */ +#endif + exc.name = "lgamma"; + exc.err = 0; + exc.arg1 = x; + exc.arg2 = x; + if (_LIB_VERSION == _SVID_) + exc.retval = HUGE; + else + exc.retval = HUGE_VAL; + if(floor(x)==x&&x<=0.0) { + /* lgamma(-integer) */ + exc.type = SING; + if (_LIB_VERSION == _POSIX_) + errno = EDOM; + else if (!matherr(&exc)) { + errno = EDOM; + } + + } else { + /* lgamma(finite) overflow */ + exc.type = OVERFLOW; + if (_LIB_VERSION == _POSIX_) + errno = ERANGE; + else if (!matherr(&exc)) { + errno = ERANGE; + } + } + if (exc.err != 0) + errno = exc.err; + return exc.retval; + } else + return y; +#endif +} + +#endif /* defined(_DOUBLE_IS_32BITS) */ + + + + + + + |