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-rw-r--r--libc/misc/time/difftime.c64
1 files changed, 0 insertions, 64 deletions
diff --git a/libc/misc/time/difftime.c b/libc/misc/time/difftime.c
deleted file mode 100644
index 88a9244ba..000000000
--- a/libc/misc/time/difftime.c
+++ /dev/null
@@ -1,64 +0,0 @@
-/* Copyright (C) 1991, 1994, 1996 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Library General Public License as
- published by the Free Software Foundation; either version 2 of the
- License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Library General Public License for more details.
-
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
-
-#include <time.h>
-#include <limits.h>
-#include <sys/types.h>
-
-
-/* Return the difference between TIME1 and TIME0. */
-double difftime (time_t time1, time_t time0)
-{
- /* Algorithm courtesy Paul Eggert (eggert@twinsun.com). */
-
- time_t delta, hibit;
-
- if (sizeof (time_t) < sizeof (double))
- return (double) time1 - (double) time0;
- if (sizeof (time_t) < sizeof (long double))
- return (long double) time1 - (long double) time0;
-
- if (time1 < time0)
- return - difftime (time0, time1);
-
- /* As much as possible, avoid loss of precision by computing the
- difference before converting to double. */
- delta = time1 - time0;
- if (delta >= 0)
- return delta;
-
- /* Repair delta overflow. */
- hibit = (~ (time_t) 0) << ((sizeof (time_t) * CHAR_BIT) - 1);
-
- /* The following expression rounds twice, which means the result may not
- be the closest to the true answer. For example, suppose time_t is
- 64-bit signed int, long_double is IEEE 754 double with default
- rounding, time1 = 9223372036854775807 and time0 = -1536. Then the
- true difference is 9223372036854777343, which rounds to
- 9223372036854777856 with a total error of 513. But delta overflows to
- -9223372036854774273, which rounds to -9223372036854774784, and
- correcting this by subtracting 2 * (long_double) hibit (i.e. by adding
- 2**64 = 18446744073709551616) yields 9223372036854776832, which rounds
- to 9223372036854775808 with a total error of 1535 instead. This
- problem occurs only with very large differences. It's too painful to
- fix this portably. We are not alone in this problem; many C compilers
- round twice when converting large unsigned types to small floating
- types, so if time_t is unsigned the "return delta" above has the same
- double-rounding problem. */
- return delta - 2 * (long double) hibit;
-}