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, 155 deletions

diff --git a/lib/libc/powerpc/gen/ldexp.c b/lib/libc/powerpc/gen/ldexp.c
deleted file mode 100644
index 3a85612..0000000
--- a/lib/libc/powerpc/gen/ldexp.c
+++ /dev/null
@@ -1,155 +0,0 @@
-/*-
- * Copyright (c) 1999 The NetBSD Foundation, Inc.
- * All rights reserved.
- *
- * This code is derived from software contributed to The NetBSD Foundation
- * by Charles M. Hannum.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *        This product includes software developed by the NetBSD
- *        Foundation, Inc. and its contributors.
- * 4. Neither the name of The NetBSD Foundation nor the names of its
- *    contributors may be used to endorse or promote products derived
- *    from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
- * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
- * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <sys/cdefs.h>
-#if 0
-#if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: ldexp.c,v 1.8 1999/08/30 18:28:26 mycroft Exp $");
-#endif /* LIBC_SCCS and not lint */
-#endif
-__FBSDID("$FreeBSD$");
-
-#include <sys/types.h>
-#include <machine/ieee.h>
-#include <errno.h>
-#include <math.h>
-
-/*
- * Multiply the given value by 2^exp.
- */
-double
-ldexp(val, exp)
-	double val;
-	int exp;
-{
-	int oldexp, newexp;
-	union {
-		double v;
-		struct ieee_double s;
-	} u, mul;
-
-	u.v = val;
-	oldexp = u.s.dbl_exp;
-
-	/*
-	 * If input is zero, Inf or NaN, just return it.
-	 */
-	if (u.v == 0.0 || oldexp == DBL_EXP_INFNAN)
-		return (val);
-
-	if (oldexp == 0) {
-		/*
-		 * u.v is denormal.  We must adjust it so that the exponent
-		 * arithmetic below will work.
-		 */
-		if (exp <= DBL_EXP_BIAS) {
-			/*
-			 * Optimization: if the scaling can be done in a single
-			 * multiply, or underflows, just do it now.
-			 */
-			if (exp <= -DBL_FRACBITS) {
-				errno = ERANGE;
-				return (0.0);
-			}
-			mul.v = 0.0;
-			mul.s.dbl_exp = exp + DBL_EXP_BIAS;
-			u.v *= mul.v;
-			if (u.v == 0.0) {
-				errno = ERANGE;
-				return (0.0);
-			}
-			return (u.v);
-		} else {
-			/*
-			 * We know that exp is very large, and therefore the
-			 * result cannot be denormal (though it may be Inf).
-			 * Shift u.v by just enough to make it normal.
-			 */
-			mul.v = 0.0;
-			mul.s.dbl_exp = DBL_FRACBITS + DBL_EXP_BIAS;
-			u.v *= mul.v;
-			exp -= DBL_FRACBITS;
-			oldexp = u.s.dbl_exp;
-		}
-	}
-
-	/*
-	 * u.v is now normalized and oldexp has been adjusted if necessary.
-	 * Calculate the new exponent and check for underflow and overflow.
-	 */
-	newexp = oldexp + exp;
-
-	if (newexp <= 0) {
-		/*
-		 * The output number is either denormal or underflows (see
-		 * comments in machine/ieee.h).
-		 */
-		if (newexp <= -DBL_FRACBITS) {
-			errno = ERANGE;
-			return (0.0);
-		}
-		/*
-		 * Denormalize the result.  We do this with a multiply.  If exp
-		 * is very large, it won't fit in a double, so we have to
-		 * adjust the exponent first.  This is safe because we know
-		 * that u.v is normal at this point.
-		 */
-		if (exp <= -DBL_EXP_BIAS) {
-			u.s.dbl_exp = 1;
-			exp += oldexp - 1;
-		}
-		mul.v = 0.0;
-		mul.s.dbl_exp = exp + DBL_EXP_BIAS;
-		u.v *= mul.v;
-		return (u.v);
-	} else if (newexp >= DBL_EXP_INFNAN) {
-		/*
-		 * The result overflowed; return +/-Inf.
-		 */
-		u.s.dbl_exp = DBL_EXP_INFNAN;
-		u.s.dbl_frach = 0;
-		u.s.dbl_fracl = 0;
-		errno = ERANGE;
-		return (u.v);
-	} else {
-		/*
-		 * The result is normal; just replace the old exponent with the
-		 * new one.
-		 */
-		u.s.dbl_exp = newexp;
-		return (u.v);
-	}
-}