Replace the ldexp() implementation in libc with a renamed copy of the

scalbn() implementation from libm.  (The two functions are defined to
be identical, but ldexp() lives in libc for backwards compatibility.)
The old ldexp() implementation...
  - was more complicated than this one
  - set errno instead of raising FP exceptions
  - got some corner cases wrong
    (e.g. ldexp(1.0, 2000) in round-to-zero mode)

The new implementation lives in libc/gen instead of
libc/$MACHINE_ARCH/gen, since we don't need N copies of a
machine-independent file.  The amd64 and i386 platforms
retain their fast and correct MD implementations and
override this one.

1 files changed, 0 insertions, 137 deletions

diff --git a/lib/libc/alpha/gen/ldexp.c b/lib/libc/alpha/gen/ldexp.c
deleted file mode 100644
index 78decbb..0000000
--- a/lib/libc/alpha/gen/ldexp.c
+++ /dev/null
@@ -1,137 +0,0 @@
-/*
- * Copyright (c) 1994, 1995 Carnegie-Mellon University.
- * All rights reserved.
- *
- * Author: Chris G. Demetriou
- * 
- * Permission to use, copy, modify and distribute this software and
- * its documentation is hereby granted, provided that both the copyright
- * notice and this permission notice appear in all copies of the
- * software, derivative works or modified versions, and any portions
- * thereof, and that both notices appear in supporting documentation.
- * 
- * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
- * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
- * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
- * Carnegie Mellon requests users of this software to return to
- *
- *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
- *  School of Computer Science
- *  Carnegie Mellon University
- *  Pittsburgh PA 15213-3890
- *
- * any improvements or extensions that they make and grant Carnegie the
- * rights to redistribute these changes.
- *
- *	$NetBSD: ldexp.c,v 1.1 1995/02/10 17:50:24 cgd Exp $
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include <sys/types.h>
-#include <machine/ieee.h>
-#include <errno.h>
-#include <math.h>
-
-/*
- * double ldexp(double val, int exp)
- * returns: val * (2**exp)
- */
-double
-ldexp(val, exp)
-	double val;
-	int exp;
-{
-	int oldexp, newexp, mulexp;
-	union doub {
-		double v;
-		struct ieee_double s;
-	} u, mul;
-
-	/*
-	 * If input is zero, or no change, just return input.
-	 * Likewise, if input is Inf or NaN, just return it.
-	 */
-	u.v = val;
-	oldexp = u.s.dbl_exp;
-	if (val == 0 || exp == 0 || oldexp == DBL_EXP_INFNAN)
-		return (val);
-
-	/*
-	 * Compute new exponent and check for over/under flow.
-	 * Underflow, unfortunately, could mean switching to denormal.
-	 * If result out of range, set ERANGE and return 0 if too small
-	 * or Inf if too big, with the same sign as the input value.
-	 */
-	newexp = oldexp + exp;
-	if (newexp >= DBL_EXP_INFNAN) {
-		/* u.s.dbl_sign = val < 0; -- already set */
-		u.s.dbl_exp = DBL_EXP_INFNAN;
-		u.s.dbl_frach = u.s.dbl_fracl = 0;
-		errno = ERANGE;
-		return (u.v);		/* Inf */
-	}
-	if (newexp <= 0) {
-		/*
-		 * The output number is either a denormal or underflows
-		 * (see comments in machine/ieee.h).
-		 */
-		if (newexp <= -DBL_FRACBITS) {
-			/* u.s.dbl_sign = val < 0; -- already set */
-			u.s.dbl_exp = 0;
-			u.s.dbl_frach = u.s.dbl_fracl = 0;
-			errno = ERANGE;
-			return (u.v);		/* zero */
-		}
-		/*
-		 * We are going to produce a denorm.  Our `exp' argument
-		 * might be as small as -2097, and we cannot compute
-		 * 2^-2097, so we may have to do this as many as three
-		 * steps (not just two, as for positive `exp's below).
-		 */
-		mul.v = 0;
-		while (exp <= -DBL_EXP_BIAS) {
-			mul.s.dbl_exp = 1;
-			val *= mul.v;
-			exp += DBL_EXP_BIAS - 1;
-		}
-		mul.s.dbl_exp = exp + DBL_EXP_BIAS;
-		val *= mul.v;
-		return (val);
-	}
-
-	/*
-	 * Newexp is positive.
-	 *
-	 * If oldexp is zero, we are starting with a denorm, and simply
-	 * adjusting the exponent will produce bogus answers.  We need
-	 * to fix that first.
-	 */
-	if (oldexp == 0) {
-		/*
-		 * Multiply by 2^mulexp to make the number normalizable.
-		 * We cannot multiply by more than 2^1023, but `exp'
-		 * argument might be as large as 2046.  A single
-		 * adjustment, however, will normalize the number even
-		 * for huge `exp's, and then we can use exponent
-		 * arithmetic just as for normal `double's.
-		 */
-		mulexp = exp <= DBL_EXP_BIAS ? exp : DBL_EXP_BIAS;
-		mul.v = 0;
-		mul.s.dbl_exp = mulexp + DBL_EXP_BIAS;
-		val *= mul.v;
-		if (mulexp == exp)
-			return (val);
-		u.v = val;
-		newexp -= mulexp;
-	}
-
-	/*
-	 * Both oldexp and newexp are positive; just replace the
-	 * old exponent with the new one.
-	 */
-	u.s.dbl_exp = newexp;
-	return (u.v);
-}