* lib/stdbit.in.h (_GL_STDC_*_INLINE): New macros.
Enclose function definitions in #if @GL_STDC_*@ conditionals.
* lib/stdc_leading_zeros.c: New file.
* lib/stdc_leading_ones.c: New file.
* lib/stdc_trailing_zeros.c: New file.
* lib/stdc_trailing_ones.c: New file.
* lib/stdc_first_leading_zero.c: New file.
* lib/stdc_first_leading_one.c: New file.
* lib/stdc_first_trailing_zero.c: New file.
* lib/stdc_first_trailing_one.c: New file.
* lib/stdc_count_zeros.c: New file.
* lib/stdc_count_ones.c: New file, based on lib/stdbit.c.
* lib/stdc_has_single_bit.c: New file.
* lib/stdc_bit_width.c: New file.
* lib/stdc_bit_floor.c: New file.
* lib/stdc_bit_ceil.c: New file.
* lib/stdbit.c (__gl_stdbit_popcount_support): Remove variable.
* m4/stdbit_h.m4 (gl_STDBIT_H): Initialize GL_STDC_* variables.
* modules/stdbit-h: New file, based on modules/stdbit.
(Depends-on): Add gen-header.
(Makefile.am): Substitute GL_STDC_* variables.
* modules/stdc_leading_zeros: New file.
* modules/stdc_leading_ones: New file.
* modules/stdc_trailing_zeros: New file.
* modules/stdc_trailing_ones: New file.
* modules/stdc_first_leading_zero: New file.
* modules/stdc_first_leading_one: New file.
* modules/stdc_first_trailing_zero: New file.
* modules/stdc_first_trailing_one: New file.
* modules/stdc_count_zeros: New file.
* modules/stdc_count_ones: New file.
* modules/stdc_has_single_bit: New file.
* modules/stdc_bit_width: New file.
* modules/stdc_bit_floor: New file.
* modules/stdc_bit_ceil: New file.
* modules/stdbit: Change to a pure composition module.
* modules/stdc_leading_zeros-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_leading_ones-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_trailing_zeros-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_trailing_ones-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_leading_zero-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_leading_one-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_trailing_zero-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_trailing_one-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_count_zeros-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_count_ones-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_has_single_bit-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_bit_width-tests: New file, based on modules/stdbit-tests.
* modules/stdc_bit_floor-tests: New file, based on modules/stdbit-tests.
* modules/stdc_bit_ceil-tests: New file, based on modules/stdbit-tests.
* modules/stdbit-tests: Remove file.
* doc/posix-functions/stdc_leading_zeros.texi: Update.
* doc/posix-functions/stdc_leading_ones.texi: Likewise.
* doc/posix-functions/stdc_trailing_zeros.texi: Likewise.
* doc/posix-functions/stdc_trailing_ones.texi: Likewise.
* doc/posix-functions/stdc_first_leading_zero.texi: Likewise.
* doc/posix-functions/stdc_first_leading_one.texi: Likewise.
* doc/posix-functions/stdc_first_trailing_zero.texi: Likewise.
* doc/posix-functions/stdc_first_trailing_one.texi: Likewise.
* doc/posix-functions/stdc_count_zeros.texi: Likewise.
* doc/posix-functions/stdc_count_ones.texi: Likewise.
* doc/posix-functions/stdc_has_single_bit.texi: Likewise.
* doc/posix-functions/stdc_bit_width.texi: Likewise.
* doc/posix-functions/stdc_bit_floor.texi: Likewise.
* doc/posix-functions/stdc_bit_ceil.texi: Likewise.
Port to theoretical platforms that C and POSIX allow but are not
likely to ever exist. This is mostly just to document the existing
source code: when optimizing, the machine code should be largely
unchanged even on platforms lacking __builtin_clz etc.
* lib/stdbit.in.h: Omit static_assert that checks for 8-bit bits.
stdbit-tests checks for this, and omitting the static_assert here
removes a module dependency.
(__gl_stdbit_clzll): Do not limit word size to 128 bits.
(__gl_stdbit_popcount255): Rename from __gl_stdbit_popcount255.
All uses changed. Do not limit word size to 255 bits. Correct
bugs on odd theoretical platforms where the word size is not a
power of 2.
* modules/stdbit (Depends-on): Remove assert-h.
Fix namespace pollution in substitute stdbit.h.
Clean up and simplify some of the non-GCC code, by preferring
inline functions to macros and substituting something
more straightforward than a de Bruijn hash (possibly faster?).
The non-GCC non-C23 substitutes should all compile to
branch-free code, if the compiler is good.
* lib/stdbit.c (COUNT_LEADING_ZEROS_INLINE)
(COUNT_TRAILING_ZEROS_INLINE, COUNT_ONE_BITS_INLINE): Remove.
(__gl_stdbit_clztab) [!_GL_STDBIT_HAS_BUILTIN_CLZ && !_MSC_VER]:
New constant array.
(__gl_stdbit_popcount_support): Adjust to stdbit.in.h changes.
* lib/stdbit.in.h: Do not include <limits.h> or <stdlib.h>.
Check that bytes are 8 bits.
(COUNT_LEADING_ZEROS_INLINE, COUNT_TRAILING_ZEROS_INLINE)
(COUNT_ONE_BITS_INLINE, COUNT_LEADING_ZEROS)
(count_leading_zeros_32, count_leading_zeros)
(count_leading_zeros_l, count_leading_zeros_ll)
(COUNT_TRAILING_ZEROS, count_trailing_zeros_32)
(count_trailing_zeros, count_trailing_zeros_l)
(count_trailing_zeros_ll, COUNT_ONE_BITS, count_one_bits_32)
(COUNT_ONE_BITS_GENERIC, count_one_bits, count_one_bits_l)
(count_one_bits_ll): Remove, replacing all uses with ...
(_GL_STDBIT_HAS_BUILTIN_CLZ)
(_GL_STDBIT_HAS_BUILTIN_CTZ, _GL_STDBIT_HAS_BUILTIN_POPCOUNT)
(__gl_stdbit_clz, __gl_stdbit_clzl, __gl_stdbit_clzll)
(__gl_stdbit_ctz, __gl_stdbit_ctzl, __gl_stdbit_ctzll)
(__gl_stdbit_popcount, __gl_stdbit_popcountl, __gl_stdbit_popcountll)
(__gl_stdbit_popcount255): ... these new functions and macros.
(__popcnt64): Omit unnecessary casts.
(__gl_stdbit_popcount_support): Rename from popcount_support
and make it a signed char since that’s all we need.
(__gl_stdbit_popcount_supported): Rename from popcount_supported.
All uses changed.
* modules/stdbit (Depends-on): Add assert-h, for static_assert.
Remove dependence of stdbit on the modules count-leading-zeros,
count-trailing-zeros, and count-one-bits. stdbit is part of C23
and in the long run is more likely to be more portable, so code
should start preferring it.
* lib/stdbit.c (popcount_support): New var, if needed.
* lib/stdbit.in.h: Contain contents of count-leading-zeros.h,
count-trailing-zeros.h, and count-one-bits.h instead of including
those files. In the long run those files should be stubs that are
implemented via stdbit.
* modules/stdbit (Depends-on): Do not depend on count-leading-zeros,
count-trailing-zeros, count-one-bits.
