Jonathan Wakely c03b53da91 libstdc++: Add lightweight replacement for std::numeric_limits (PR 92546)
Many uses of std::numeric_limits in C++17 and C++20 features only really
need the min(), max() and digits constants for integral types. By adding
__detail::__int_limits we can avoid including the whole <limits> header.

The <limits> header isn't especially large, but avoiding it still gives
small savings in compilation time and memory usage for the compiler.

There are also C++11 features that could benefit from this change (e.g.
<bits/hashtable_policy.h> and <bits/uniform_int_dist.h>) but I won't
change those until stage 1.

The implementation of __int_limits assumes two's complement integers,
which is true for all targets supported by GCC.

	PR libstdc++/92546 (partial)
	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/bits/int_limits.h: New header.
	* include/bits/parse_numbers.h (__select_int::_Select_int): Replace
	numeric_limits with __detail::__int_limits.
	* include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
	(__countr_zero, __countr_one, __popcount, __ceil2, __floor2, __log2p1):
	Likewise.
	* include/std/charconv (__to_chars_8, __from_chars_binary)
	(__from_chars_alpha_to_num, from_chars): Likewise.
	* include/std/memory_resource (polymorphic_allocator::allocate)
	(polymorphic_allocator::allocate_object): Likewise.
	* include/std/string_view (basic_string_view::_S_compare): Likewise.
	* include/std/utility (in_range): Likewise.
	* testsuite/20_util/integer_comparisons/in_range_neg.cc: Adjust for
	extra error about incomplete type __int_limits<bool>.
	* testsuite/26_numerics/bit/bit.count/countl_one.cc: Include <limits>.
	* testsuite/26_numerics/bit/bit.count/countl_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countr_one.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countr_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/popcount.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Likewise.
	* testsuite/26_numerics/bit/bit.rotate/rotl.cc: Likewise.
	* testsuite/26_numerics/bit/bit.rotate/rotr.cc: Likewise.
2020-02-17 15:11:04 +00:00
2020-02-17 13:21:34 +01:00
2020-01-21 23:53:22 -08:00
2020-02-14 22:00:13 +00:00
2020-02-17 13:20:06 +01:00
2020-01-15 14:29:53 +01:00

This directory contains the GNU Compiler Collection (GCC).

The GNU Compiler Collection is free software.  See the files whose
names start with COPYING for copying permission.  The manuals, and
some of the runtime libraries, are under different terms; see the
individual source files for details.

The directory INSTALL contains copies of the installation information
as HTML and plain text.  The source of this information is
gcc/doc/install.texi.  The installation information includes details
of what is included in the GCC sources and what files GCC installs.

See the file gcc/doc/gcc.texi (together with other files that it
includes) for usage and porting information.  An online readable
version of the manual is in the files gcc/doc/gcc.info*.

See http://gcc.gnu.org/bugs/ for how to report bugs usefully.

Copyright years on GCC source files may be listed using range
notation, e.g., 1987-2012, indicating that every year in the range,
inclusive, is a copyrightable year that could otherwise be listed
individually.
Description
No description provided
Readme 2.1 GiB
Languages
C++ 31.9%
C 31.3%
Ada 12%
D 6.5%
Go 6.4%
Other 11.5%