emacs/lib/count-trailing-zeros.c, branch scratch/org-sync Emacs is the extensible, customizable, self-documenting real-time display editor. Improve support for popcount and counting trailing zeros. 2013-10-07T21:37:19+00:00 Paul Eggert 2013-10-07T21:37:19+00:00 595e113b15e2ce80b95d39d1851ce78f25ffa1f4 Do this by using the Gnulib modules for this. This should generate faster code on non-GCC, non-MSC platforms, and make the code a bit more portable, at least in theory. * admin/merge-gnulib (GNULIB_MODULES): Add count-one-bits and count-trailing-zeros. * lib/count-one-bits.c, lib/count-one-bits.h: * lib/count-trailing-zeros.c, lib/count-trailing-zeros.h: * m4/count-one-bits.m4, m4/count-trailing-zeros.m4: New files, copied from gnulib. * lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate. * nt/gnulib.mk: Merge changes from lib/gnulib.mk. * src/data.c: Include <count-one-bits.h>, <count-trailing-zeros.h>. (USE_MSC_POPCOUNT, POPCOUNT_STATIC_INLINE) (NEED_GENERIC_POPCOUNT, popcount_size_t_generic) (popcount_size_t_msc, popcount_size_t_gcc): Remove; now done by Gnulib. (popcount_size_t): Now a macro that defers to Gnulib. (count_trailing_zero_bits): Return int, for consistency with Gnulib and because Emacs prefers signed to unsigned int. Don't assume that size_t is either unsigned int or unsigned long or unsigned long long. (size_t_to_host_endian): Do not assume that size_t is either exactly 32 or exactly 64 bits wide. * src/lisp.h (BITS_PER_SIZE_T): Define consistently with BITS_PER_LONG etc., so that it's now an enum constant, not a macro. No need to assume that it's either 32 or 64. Fixes: debbugs:15550 
Do this by using the Gnulib modules for this.
This should generate faster code on non-GCC, non-MSC platforms,
and make the code a bit more portable, at least in theory.
* admin/merge-gnulib (GNULIB_MODULES): Add count-one-bits
and count-trailing-zeros.
* lib/count-one-bits.c, lib/count-one-bits.h:
* lib/count-trailing-zeros.c, lib/count-trailing-zeros.h:
* m4/count-one-bits.m4, m4/count-trailing-zeros.m4:
New files, copied from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* nt/gnulib.mk: Merge changes from lib/gnulib.mk.
* src/data.c: Include <count-one-bits.h>, <count-trailing-zeros.h>.
(USE_MSC_POPCOUNT, POPCOUNT_STATIC_INLINE)
(NEED_GENERIC_POPCOUNT, popcount_size_t_generic)
(popcount_size_t_msc, popcount_size_t_gcc):
Remove; now done by Gnulib.
(popcount_size_t): Now a macro that defers to Gnulib.
(count_trailing_zero_bits): Return int, for consistency with
Gnulib and because Emacs prefers signed to unsigned int.
Don't assume that size_t is either unsigned int or unsigned long
or unsigned long long.
(size_t_to_host_endian): Do not assume that size_t is either
exactly 32 or exactly 64 bits wide.
* src/lisp.h (BITS_PER_SIZE_T): Define consistently with BITS_PER_LONG
etc., so that it's now an enum constant, not a macro.
No need to assume that it's either 32 or 64.

Fixes: debbugs:15550