summaryrefslogtreecommitdiff
path: root/posix
diff options
context:
space:
mode:
authorPaul Eggert <eggert@cs.ucla.edu>2020-08-04 23:39:20 -0700
committerPaul Eggert <eggert@cs.ucla.edu>2020-08-04 23:39:20 -0700
commit70c609f30311a4bcd6289b616adaaad4b42ed4a8 (patch)
tree95fc20400e7abedf0829b7f9a4c54b91d5de3340 /posix
parent6aa1160d16b0886af125a7e7883aab2203ed156d (diff)
downloadglibc-70c609f30311a4bcd6289b616adaaad4b42ed4a8.tar.gz
Copy regex BITSET_WORD_BITS porting from Gnulib
* posix/regex.c (__STDC_WANT_IEC_60559_BFP_EXT__): Define, for ULONG_WIDTH. This syncs regex.c from Gnujlib. * posix/regex_internal.h (ULONG_WIDTH): Use a more-portable fallback, from Gnulib. (BITSET_WORD_BITS): Now defined in terms of ULONG_WIDTH.
Diffstat (limited to 'posix')
-rw-r--r--posix/regex.c2
-rw-r--r--posix/regex_internal.h50
2 files changed, 22 insertions, 30 deletions
diff --git a/posix/regex.c b/posix/regex.c
index 815e2ec769..991eedc826 100644
--- a/posix/regex.c
+++ b/posix/regex.c
@@ -17,6 +17,8 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#define __STDC_WANT_IEC_60559_BFP_EXT__
+
#ifndef _LIBC
# include <libc-config.h>
diff --git a/posix/regex_internal.h b/posix/regex_internal.h
index 6f761c6ed6..e9aa74bf33 100644
--- a/posix/regex_internal.h
+++ b/posix/regex_internal.h
@@ -141,6 +141,24 @@
#ifndef SSIZE_MAX
# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
#endif
+#ifndef ULONG_WIDTH
+# define ULONG_WIDTH REGEX_UINTEGER_WIDTH (ULONG_MAX)
+/* The number of usable bits in an unsigned integer type with maximum
+ value MAX, as an int expression suitable in #if. Cover all known
+ practical hosts. This implementation exploits the fact that MAX is
+ 1 less than a power of 2, and merely counts the number of 1 bits in
+ MAX; "COBn" means "count the number of 1 bits in the low-order n bits". */
+# define REGEX_UINTEGER_WIDTH(max) REGEX_COB128 (max)
+# define REGEX_COB128(n) (REGEX_COB64 ((n) >> 31 >> 31 >> 2) + REGEX_COB64 (n))
+# define REGEX_COB64(n) (REGEX_COB32 ((n) >> 31 >> 1) + REGEX_COB32 (n))
+# define REGEX_COB32(n) (REGEX_COB16 ((n) >> 16) + REGEX_COB16 (n))
+# define REGEX_COB16(n) (REGEX_COB8 ((n) >> 8) + REGEX_COB8 (n))
+# define REGEX_COB8(n) (REGEX_COB4 ((n) >> 4) + REGEX_COB4 (n))
+# define REGEX_COB4(n) (!!((n) & 8) + !!((n) & 4) + !!((n) & 2) + ((n) & 1))
+# if ULONG_MAX / 2 + 1 != 1ul << (ULONG_WIDTH - 1)
+# error "ULONG_MAX out of range"
+# endif
+#endif
/* The type of indexes into strings. This is signed, not size_t,
since the API requires indexes to fit in regoff_t anyway, and using
@@ -164,36 +182,8 @@ typedef __re_size_t re_hashval_t;
typedef unsigned long int bitset_word_t;
/* All bits set in a bitset_word_t. */
#define BITSET_WORD_MAX ULONG_MAX
-
-/* Number of bits in a bitset_word_t. For portability to hosts with
- padding bits, do not use '(sizeof (bitset_word_t) * CHAR_BIT)';
- instead, deduce it directly from BITSET_WORD_MAX. Avoid
- greater-than-32-bit integers and unconditional shifts by more than
- 31 bits, as they're not portable. */
-#if BITSET_WORD_MAX == 0xffffffffUL
-# define BITSET_WORD_BITS 32
-#elif BITSET_WORD_MAX >> 31 >> 4 == 1
-# define BITSET_WORD_BITS 36
-#elif BITSET_WORD_MAX >> 31 >> 16 == 1
-# define BITSET_WORD_BITS 48
-#elif BITSET_WORD_MAX >> 31 >> 28 == 1
-# define BITSET_WORD_BITS 60
-#elif BITSET_WORD_MAX >> 31 >> 31 >> 1 == 1
-# define BITSET_WORD_BITS 64
-#elif BITSET_WORD_MAX >> 31 >> 31 >> 9 == 1
-# define BITSET_WORD_BITS 72
-#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 3 == 1
-# define BITSET_WORD_BITS 128
-#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 7 == 1
-# define BITSET_WORD_BITS 256
-#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 7 > 1
-# define BITSET_WORD_BITS 257 /* any value > SBC_MAX will do here */
-# if BITSET_WORD_BITS <= SBC_MAX
-# error "Invalid SBC_MAX"
-# endif
-#else
-# error "Add case for new bitset_word_t size"
-#endif
+/* Number of bits in a bitset_word_t. */
+#define BITSET_WORD_BITS ULONG_WIDTH
/* Number of bitset_word_t values in a bitset_t. */
#define BITSET_WORDS ((SBC_MAX + BITSET_WORD_BITS - 1) / BITSET_WORD_BITS)