emacs/m4/count-trailing-zeros.m4

# count-trailing-zeros.m4
dnl Copyright (C) 2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_COUNT_TRAILING_ZEROS],
[
  dnl We don't need (and can't compile) count_trailing_zeros_ll
  dnl unless the type 'unsigned long long int' exists.
  AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
])
Improve support for popcount and counting trailing zeros. 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 2013-10-07 14:37:19 -07:00			`# count-trailing-zeros.m4`
			`dnl Copyright (C) 2013 Free Software Foundation, Inc.`
			`dnl This file is free software; the Free Software Foundation`
			`dnl gives unlimited permission to copy and/or distribute it,`
			`dnl with or without modifications, as long as this notice is preserved.`

			`AC_DEFUN([gl_COUNT_TRAILING_ZEROS],`
			`[`
			`dnl We don't need (and can't compile) count_trailing_zeros_ll`
			`dnl unless the type 'unsigned long long int' exists.`
			`AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])`
			`])`