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-rw-r--r--newlib/libm/math/w_lgamma.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/newlib/libm/math/w_lgamma.c b/newlib/libm/math/w_lgamma.c
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+
+/* @(#)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) */
+
+
+
+
+
+
+