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-rw-r--r--lib/count-trailing-zeros.h29
1 files changed, 18 insertions, 11 deletions
diff --git a/lib/count-trailing-zeros.h b/lib/count-trailing-zeros.h
index 9f9f07f5a0d..9a989a43245 100644
--- a/lib/count-trailing-zeros.h
+++ b/lib/count-trailing-zeros.h
@@ -1,17 +1,17 @@
/* count-trailing-zeros.h -- counts the number of trailing 0 bits in a word.
- Copyright 2013-2017 Free Software Foundation, Inc.
+ Copyright 2013-2022 Free Software Foundation, Inc.
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
+ This file 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.
- This program is distributed in the hope that it will be useful,
+ This file 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 General Public License for more details.
+ GNU Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Paul Eggert. */
@@ -30,11 +30,16 @@ _GL_INLINE_HEADER_BEGIN
# define COUNT_TRAILING_ZEROS_INLINE _GL_INLINE
#endif
+#ifdef __cplusplus
+extern "C" {
+#endif
+
/* Assuming the GCC builtin is BUILTIN and the MSC builtin is MSC_BUILTIN,
expand to code that computes the number of trailing zeros of the local
variable 'x' of type TYPE (an unsigned integer type) and return it
from the current function. */
-#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) \
+ || (__clang_major__ >= 4)
# define COUNT_TRAILING_ZEROS(BUILTIN, MSC_BUILTIN, TYPE) \
return x ? BUILTIN (x) : CHAR_BIT * sizeof x;
#elif _MSC_VER
@@ -69,7 +74,7 @@ COUNT_TRAILING_ZEROS_INLINE int
count_trailing_zeros_32 (unsigned int x)
{
/* <https://github.com/gibsjose/BitHacks>
- <http://www.fit.vutbr.cz/~ibarina/pub/bithacks.pdf> */
+ <https://www.fit.vutbr.cz/~ibarina/pub/bithacks.pdf> */
static const char de_Bruijn_lookup[32] = {
0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
@@ -92,7 +97,6 @@ count_trailing_zeros_l (unsigned long int x)
COUNT_TRAILING_ZEROS (__builtin_ctzl, _BitScanForward, unsigned long int);
}
-#if HAVE_UNSIGNED_LONG_LONG_INT
/* Compute and return the number of trailing zeros in X. */
COUNT_TRAILING_ZEROS_INLINE int
count_trailing_zeros_ll (unsigned long long int x)
@@ -100,6 +104,9 @@ count_trailing_zeros_ll (unsigned long long int x)
COUNT_TRAILING_ZEROS (__builtin_ctzll, _BitScanForward64,
unsigned long long int);
}
+
+#ifdef __cplusplus
+}
#endif
_GL_INLINE_HEADER_END