import newlib-2000-02-17 snapshot

1 files changed, 115 insertions, 0 deletions

diff --git a/newlib/libm/math/w_log10.c b/newlib/libm/math/w_log10.c
new file mode 100644
index 000000000..f427b86cc
--- /dev/null
+++ b/newlib/libm/math/w_log10.c
@@ -0,0 +1,115 @@
+
+/* @(#)w_log10.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
+	<<log10>>, <<log10f>>---base 10 logarithms
+
+INDEX
+log10
+INDEX
+log10f
+
+ANSI_SYNOPSIS
+	#include <math.h>
+	double log10(double <[x]>);
+	float log10f(float <[x]>);
+
+TRAD_SYNOPSIS
+	#include <math.h>
+	double log10(<[x]>)
+	double <[x]>;
+
+	float log10f(<[x]>)
+	float <[x]>;
+
+DESCRIPTION
+<<log10>> returns the base 10 logarithm of <[x]>.
+It is implemented as <<log(<[x]>) / log(10)>>.
+
+<<log10f>> is identical, save that it takes and returns <<float>> values.
+
+RETURNS
+<<log10>> and <<log10f>> return the calculated value. 
+
+See the description of <<log>> for information on errors.
+
+PORTABILITY
+<<log10>> is ANSI C.  <<log10f>> is an extension.
+
+ */
+
+/* 
+ * wrapper log10(X)
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double log10(double x)		/* wrapper log10 */
+#else
+	double log10(x)			/* wrapper log10 */
+	double x;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return __ieee754_log10(x);
+#else
+	double z;
+	struct exception exc;
+	z = __ieee754_log10(x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
+	if(x<=0.0) {
+#ifndef HUGE_VAL 
+#define HUGE_VAL inf
+	    double inf = 0.0;
+
+	    SET_HIGH_WORD(inf,0x7ff00000);	/* set inf to infinite */
+#endif
+	    exc.name = "log10";
+	    exc.err = 0;
+	    exc.arg1 = x;
+	    exc.arg2 = x;
+	    if (_LIB_VERSION == _SVID_)
+               exc.retval = -HUGE;
+	    else
+	       exc.retval = -HUGE_VAL;
+	    if(x==0.0) {
+	        /* log10(0) */
+	        exc.type = SING;
+	        if (_LIB_VERSION == _POSIX_)
+	           errno = ERANGE;
+	        else if (!matherr(&exc)) {
+	           errno = EDOM;
+	        }
+	    } else { 
+	        /* log10(x<0) */
+	        exc.type = DOMAIN;
+	        if (_LIB_VERSION == _POSIX_)
+	           errno = EDOM;
+	        else if (!matherr(&exc)) {
+	           errno = EDOM;
+	        }
+            }
+	    if (exc.err != 0)
+               errno = exc.err;
+            return exc.retval; 
+	} else
+	    return z;
+#endif
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */