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authorJoseph Myers <joseph@codesourcery.com>2015-10-07 00:40:12 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-10-07 00:40:12 +0000
commitb75bc69cdfe5247b2156ce249518f1c1df4d797d (patch)
tree7cbc51c7f8a7954e5394fcd873f42f7abeaa22df /sysdeps/ieee754
parenta68dec3b03b9c163ad79192cbe837208b2f90de1 (diff)
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Don't use dbl-64/wordsize-64 lround based on llround for ILP32 (bug 19079).
The implementation of lround in dbl-64/wordsize-64 as an alias or wrapper for llround is always incorrect when long is not 64-bit, because it misses required exceptions in overflow cases, as shown by my recently added tests. This patch removes that alias / wrapper in the non-LP64 case, together with the REGISTER_CAST_INT32_TO_INT64 macro, restoring the previous version of lround for dbl-64/wordsize-64 (newly conditioned on !_LP64). Tested for x86_64, and for mips64 with use of dbl-64/wordsize-64 enabled. [BZ #19079] * sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c: Restore previous file, conditioned on [!_LP64]. * sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c [!_LP64] (__lround): Do not define as function or alias. [!_LP64] (lround): Likewise. [!_LP64] (__lroundl): Likewise. [!_LP64] (lroundl): Likewise. * sysdeps/tile/sysdep.h (REGISTER_CAST_INT32_TO_INT64): Remove macro. * sysdeps/x86_64/x32/sysdep.h (REGISTER_CAST_INT32_TO_INT64): Likewise.
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c17
-rw-r--r--sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c70
2 files changed, 71 insertions, 16 deletions
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c
index 8bb5252..483d4a0 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c
@@ -69,23 +69,10 @@ strong_alias (__llround, __llroundl)
weak_alias (__llround, llroundl)
#endif
-/* long has the same width as long long on LP64 machines, so use an alias.
- If building for ILP32 on a machine with 64-bit registers, however,
- use a cast if necessary. */
+/* long has the same width as long long on LP64 machines, so use an alias. */
#undef lround
#undef __lround
-#if !defined (_LP64) && REGISTER_CAST_INT32_TO_INT64
-long int
-__lround (double x)
-{
- return __llround (x);
-}
-weak_alias (__lround, lround)
-# ifdef NO_LONG_DOUBLE
-strong_alias (__lround, __lroundl)
-weak_alias (__lround, lroundl)
-# endif
-#else
+#ifdef _LP64
strong_alias (__llround, __lround)
weak_alias (__llround, lround)
# ifdef NO_LONG_DOUBLE
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c
index 1e06fcb..390e733 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c
@@ -1 +1,69 @@
-/* The code is the same as llround. Use an alias, see s_llround.c. */
+/* Round double value to long int.
+ Copyright (C) 1997-2015 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 Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <math.h>
+
+#include <math_private.h>
+
+/* For LP64, lround is an alias for llround. */
+#ifndef _LP64
+
+long int
+__lround (double x)
+{
+ int32_t j0;
+ int64_t i0;
+ long int result;
+ int sign;
+
+ EXTRACT_WORDS64 (i0, x);
+ j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
+ sign = i0 < 0 ? -1 : 1;
+ i0 &= UINT64_C(0xfffffffffffff);
+ i0 |= UINT64_C(0x10000000000000);
+
+ if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
+ {
+ if (j0 < 0)
+ return j0 < -1 ? 0 : sign;
+ else if (j0 >= 52)
+ result = i0 << (j0 - 52);
+ else
+ {
+ i0 += UINT64_C(0x8000000000000) >> j0;
+
+ result = i0 >> (52 - j0);
+ }
+ }
+ else
+ {
+ /* The number is too large. It is left implementation defined
+ what happens. */
+ return (long int) x;
+ }
+
+ return sign * result;
+}
+
+weak_alias (__lround, lround)
+# ifdef NO_LONG_DOUBLE
+strong_alias (__lround, __lroundl)
+weak_alias (__lround, lroundl)
+# endif
+
+#endif