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| author | Ben Pfaff <blp@gnu.org> | 2007-08-15 03:37:54 +0000 |
|---|---|---|
| committer | Ben Pfaff <blp@gnu.org> | 2007-08-15 03:37:54 +0000 |
| commit | 6684d992bfedd21bf8dea1fbb52392c1d7c8159b (patch) | |
| tree | 4d9507b4b9c43b766795921d329434407a68f85d | |
| parent | 50236f7a99ae6442f6235451da1e345ca0fe7b18 (diff) | |
| download | gnulib-6684d992bfedd21bf8dea1fbb52392c1d7c8159b.tar.gz | |
* lib/count-one-bits.h: Add comments. (From Bruno Haible.)
* lib/count-one-bits.h: Don't include <limits.h>; no longer needed
given the changes below.
(COUNT_ONE_BITS): Use 'verify' rather than 'verify_true'. Work
even on hosts that have padding bits beyond the supported 64.
(From Paul Eggert.)
| -rw-r--r-- | ChangeLog | 11 | ||||
| -rw-r--r-- | lib/count-one-bits.h | 14 |
2 files changed, 19 insertions, 6 deletions
@@ -1,3 +1,14 @@ +2007-08-14 Ben Pfaff <blp@gnu.org> + + * lib/count-one-bits.h: Add comments. From Bruno Haible. + +2007-08-14 Paul Eggert <eggert@cs.ucla.edu> + + * lib/count-one-bits.h: Don't include <limits.h>; no longer needed + given the changes below. + (COUNT_ONE_BITS): Use 'verify' rather than 'verify_true'. Work + even on hosts that have padding bits beyond the supported 64. + 2007-08-10 Paul Eggert <eggert@cs.ucla.edu> * NEWS: In xstrtol, remove STRTOL_FATAL_ERROR and add xstrtol_fatal. diff --git a/lib/count-one-bits.h b/lib/count-one-bits.h index 7553bec4ec..e4a477b19d 100644 --- a/lib/count-one-bits.h +++ b/lib/count-one-bits.h @@ -20,19 +20,21 @@ #ifndef COUNT_ONE_BITS_H # define COUNT_ONE_BITS_H 1 -#include <limits.h> #include <stdlib.h> #include "verify.h" +/* Expand the code which computes the number of 1-bits of the local + variable 'x' of type TYPE (an unsigned integer type) and returns it + from the current function. */ #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR >= 4) #define COUNT_ONE_BITS(BUILTIN, TYPE) \ return BUILTIN (x); #else -#define COUNT_ONE_BITS(BUILTIN, TYPE) \ - int count = count_one_bits_32 (x); \ - if (CHAR_BIT * sizeof (TYPE) > 32) \ - count += count_one_bits_32 (x >> 31 >> 1); \ - (void) verify_true (CHAR_BIT * sizeof (TYPE) <= 64); \ +#define COUNT_ONE_BITS(BUILTIN, TYPE) \ + verify ((TYPE) -1 >> 31 >> 31 <= 3); /* TYPE has at most 64 bits */ \ + int count = count_one_bits_32 (x); \ + if (1 < (TYPE) -1 >> 31) /* TYPE has more than 32 bits? */ \ + count += count_one_bits_32 (x >> 31 >> 1); \ return count; /* Compute and return the the number of 1-bits set in the least |