Per https://github.com/itanium-cxx-abi/cxx-abi/issues/24 and
https://github.com/itanium-cxx-abi/cxx-abi/pull/166
We need to mangle constraints to be able to distinguish between function
templates that only differ in constraints. From the latter link, we want to
use the template parameter mangling previously specified for lambdas to also
make explicit the form of a template parameter where the argument is not a
"natural" fit for it, such as when the parameter is constrained or deduced.
I'm concerned about how the latter link changes the mangling for some C++98
and C++11 patterns, so I've limited template_parm_natural_p to avoid two
cases found by running the testsuite with -Wabi forced on:
template <class T, T V> T f() { return V; }
int main() { return f<int,42>(); }
template <int i> int max() { return i; }
template <int i, int j, int... rest> int max()
{
int sub = max<j, rest...>();
return i > sub ? i : sub;
}
int main() { return max<1,2,3>(); }
A third C++11 pattern is changed by this patch:
template <template <typename...> class TT, typename... Ts> TT<Ts...> f();
template <typename> struct A { };
int main() { f<A,int>(); }
I aim to resolve these with the ABI committee before GCC 14.1.
We also need to resolve https://github.com/itanium-cxx-abi/cxx-abi/issues/38
(mangling references to dependent template-ids where the name is fully
resolved) as references to concepts in std:: will consistently run into this
area. This is why mangle-concepts1.C only refers to concepts in the global
namespace so far.
The library changes are to avoid trying to mangle builtins, which fails.
Demangler support and test coverage is not complete yet.
gcc/cp/ChangeLog:
* cp-tree.h (TEMPLATE_ARGS_TYPE_CONSTRAINT_P): New.
(get_concept_check_template): Declare.
* constraint.cc (combine_constraint_expressions)
(finish_shorthand_constraint): Use UNKNOWN_LOCATION.
* pt.cc (convert_generic_types_to_packs): Likewise.
* mangle.cc (write_constraint_expression)
(write_tparms_constraints, write_type_constraint)
(template_parm_natural_p, write_requirement)
(write_requires_expr): New.
(write_encoding): Mangle trailing requires-clause.
(write_name): Pass parms to write_template_args.
(write_template_param_decl): Factor out from...
(write_closure_template_head): ...here.
(write_template_args): Mangle non-natural parms
and requires-clause.
(write_expression): Handle REQUIRES_EXPR.
include/ChangeLog:
* demangle.h (enum demangle_component_type): Add
DEMANGLE_COMPONENT_CONSTRAINTS.
libiberty/ChangeLog:
* cp-demangle.c (d_make_comp): Handle
DEMANGLE_COMPONENT_CONSTRAINTS.
(d_count_templates_scopes): Likewise.
(d_print_comp_inner): Likewise.
(d_maybe_constraints): New.
(d_encoding, d_template_args_1): Call it.
(d_parmlist): Handle 'Q'.
* testsuite/demangle-expected: Add some constraint tests.
libstdc++-v3/ChangeLog:
* include/std/bit: Avoid builtins in requires-clauses.
* include/std/variant: Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/abi/mangle10.C: Disable compat aliases.
* g++.dg/abi/mangle52.C: Specify ABI 18.
* g++.dg/cpp2a/class-deduction-alias3.C
* g++.dg/cpp2a/class-deduction-alias8.C:
Avoid builtins in requires-clauses.
* g++.dg/abi/mangle-concepts1.C: New test.
* g++.dg/abi/mangle-ttp1.C: New test.
Using a type-constraint instead of enable_if_t in the return types of
these functions greatly reduces the size of their mangled names. And by
now it's probably safe to assume recent compilers have sufficient C++20
concepts support to handle such constraints.
libstdc++-v3/ChangeLog:
* include/std/bit: Include <concepts>.
(byteswap): Use a type-constraint instead of enable_if_t
inside the return type, and use std::integral.
(_If_is_unsigned_integer): Replace with ...
(__unsigned_integer): ... this.
(rotl): Use a type-constraint instead of enable_if_t inside
the return type.
(countl_zero): Likewise.
(countl_one): Likewise.
(countr_zero): Likewise.
(countr_one): Likewise.
(popcount): Likewise.
(has_single_bit): Likewise.
(bit_ceil): Likewise.
(bit_floor): Likewise.
(bit_width): Likewise.
This adds checks for _GLIBCXX_HOSTED to a number of headers which are
not currently installed for freestanding, but need to be for P1642R11
support. For example, <iterator> needs to be installed for C++23
freestanding mode, but without stream iterators and streambuf iterators.
Similarly, <memory> needs to be installed, but without std::allocator
and std::shared_ptr. This change disables the non-freestanding parts of
those headers.
libstdc++-v3/ChangeLog:
PR libstdc++/106953
* include/backward/auto_ptr.h [!_GLIBCXX_HOSTED]: Do not define
shared_ptr members.
* include/bits/alloc_traits.h [!_GLIBCXX_HOSTED]: Do not declare
std::allocator_traits<std::allocator<T>> specializations for
freestanding.
* include/bits/memoryfwd.h [!_GLIBCXX_HOSTED] (allocator): Do
not declare for freestanding.
* include/bits/stl_algo.h [!_GLIBCXX_HOSTED] (stable_partition):
Do not define for freestanding.
[!_GLIBCXX_HOSTED] (merge, stable_sort): Do not use temporary
buffers for freestanding.
* include/bits/stl_algobase.h [!_GLIBCXX_HOSTED]: Do not declare
streambuf iterators and overloaded algorithms using them.
* include/bits/stl_uninitialized.h [!_GLIBCXX_HOSTED]: Do not
define specialized overloads for std::allocator.
* include/bits/unique_ptr.h [!_GLIBCXX_HOSTED] (make_unique)
(make_unique_for_overwrite, operator<<): Do not define for
freestanding.
* include/c_global/cstdlib [!_GLIBCXX_HOSTED] (_Exit): Declare.
Use _GLIBCXX_NOTHROW instead of throw().
* include/debug/assertions.h [!_GLIBCXX_HOSTED]: Ignore
_GLIBCXX_DEBUG for freestanding.
* include/debug/debug.h [!_GLIBCXX_DEBUG]: Likewise.
* include/std/bit [!_GLIBCXX_HOSTED]: Do not use the custom
__int_traits if <ext/numeric_traits.h> is available.
* include/std/functional [!_GLIBCXX_HOSTED]: Do not include
headers that aren't valid for freestanding.
(boyer_moore_searcher, boyer_moore_horspool_searcher): Do not
define for freestanding.
* include/std/iterator [!_GLIBCXX_HOSTED]: Do not include
headers that aren't valid for freestanding.
* include/std/memory [!_GLIBCXX_HOSTED]: Likewise.
* include/std/ranges [!_GLIBCXX_HOSTED] (istream_view): Do not
define for freestanding.
(views::__detail::__is_basic_string_view) [!_GLIBCXX_HOSTED]:
Do not define partial specialization for freestanding.
Our std::bit_cast was relying on the compiler to check for errors inside
__builtin_bit_cast, instead of checking them as constraints. That means
std::bit_cast was not SFINAE-friendly.
This fix uses a requires-clause, so for old versions of Clang without
concepts support the function will still be unconstrained. At some point
in future we can remove the #ifdef __cpp_concepts check and rely on all
compilers having full concepts support in C++20 mode.
libstdc++-v3/ChangeLog:
PR libstdc++/105027
* include/std/bit (bit_cast): Add constraints.
* testsuite/26_numerics/bit/bit.cast/105027.cc: New test.
This adds std::__is_constant_evaluated() as a C++11 wrapper for
__builtin_is_constant_evaluated, but just returning false if the
built-in isn't supported by the compiler. This allows us to use it
throughout the library without checking __has_builtin every time.
Some uses in std::vector and std::string can only be constexpr when the
std::is_constant_evaluated() function actually works, so we might as
well guard them with a relevant macro and call that function directly,
rather than the built-in or std::__is_constant_evaluated().
The remaining checks of the __cpp_lib_is_constant_evaluated macro could
now be replaced by checking __cplusplus >= 202002 instead, but there's
no practical difference. We still need some kind of preprocessor check
there anyway.
libstdc++-v3/ChangeLog:
* doc/doxygen/user.cfg.in (PREDEFINED): Change macro name.
* include/bits/allocator.h (allocate, deallocate): Use
std::__is_constant_evaluated() unconditionally, instead of
checking whether std::is_constant_evaluated() (or the built-in)
can be used.
* include/bits/basic_string.h: Check new macro. call
std::is_constant_evaluated() directly in C++20-only code that is
guarded by a suitable macro.
* include/bits/basic_string.tcc: Likewise.
* include/bits/c++config (__is_constant_evaluated): Define.
(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED): Replace with ...
(_GLIBCXX_HAVE_IS_CONSTANT_EVALUATED): New macro.
* include/bits/char_traits.h (char_traits): Replace conditional
calls to std::is_constant_evaluated with unconditional calls to
std::__is_constant_evaluated.
* include/bits/cow_string.h: Use new macro.
* include/bits/ranges_algobase.h (__copy_or_move): Replace
conditional calls to std::is_constant_evaluated with unconditional
calls to std::__is_constant_evaluated.
(__copy_or_move_backward, __fill_n_fn): Likewise.
* include/bits/ranges_cmp.h (ranges::less): Likewise.
* include/bits/stl_algobase.h (lexicographical_compare_three_way):
Likewise.
* include/bits/stl_bvector.h: Call std::is_constant_evaluated
directly in C++20-only code that is guarded by a suitable macro.
* include/bits/stl_construct.h (_Construct, _Destroy, _Destroy_n):
Replace is_constant_evaluated with __is_constant_evaluated.
* include/bits/stl_function.h (greater, less, greater_equal)
(less_equal): Replace __builtin_is_constant_evaluated and
__builtin_constant_p with __is_constant_evaluated.
* include/bits/stl_vector.h: Call std::is_constant_evaluated()
in C++20-only code.
* include/debug/helper_functions.h (__check_singular): Use
__is_constant_evaluated instead of built-in, or remove check
entirely.
* include/std/array (operator<=>): Use __is_constant_evaluated
unconditionally.
* include/std/bit (__bit_ceil): Likewise.
* include/std/type_traits (is_constant_evaluated): Define using
'if consteval' if possible.
* include/std/version: Use new macro.
* libsupc++/compare: Use __is_constant_evaluated instead of
__builtin_is_constant_evaluated.
* testsuite/23_containers/array/tuple_interface/get_neg.cc:
Adjust dg-error lines.
This patch adds [[nodiscard]] to std::byteswap, because the function
template doesn't do anything useful if the result isn't used.
2021-11-30 Jakub Jelinek <jakub@redhat.com>
* include/std/bit (byteswap): Add [[nodiscard]].
This patch attempts to implement P1272R4 (except for the std::bit_cast
changes in there which seem quite unrelated to this and will need to be
fixed on the compiler side).
While at least for GCC __builtin_bswap{16,32,64,128} should work fine
in constant expressions, I wonder about other compilers, so I'm using
a fallback implementation for constexpr evaluation always.
If you think that is unnecessary, I can drop the
__cpp_if_consteval >= 202106L &&
if !consteval
{
and
}
and reformat.
The fallback implementation is an attempt to make it work even for integral
types that don't have number of bytes divisible by 2 or when __CHAR_BIT__
is e.g. 16.
2021-11-28 Jakub Jelinek <jakub@redhat.com>
* include/std/bit (__cpp_lib_byteswap, byteswap): Define.
* include/std/version (__cpp_lib_byteswap): Define.
* testsuite/26_numerics/bit/bit.byteswap/byteswap.cc: New test.
* testsuite/26_numerics/bit/bit.byteswap/version.cc: New test.
Add [[nodiscard]] to functions that are effectively just a static_cast,
as per P2351. Also add it to std::addressof.
libstdc++-v3/ChangeLog:
* include/bits/move.h (forward, move, move_if_noexcept)
(addressof): Add _GLIBCXX_NODISCARD.
* include/bits/ranges_cmp.h (identity::operator()): Add
nodiscard attribute.
* include/c_global/cstddef (to_integer): Likewise.
* include/std/bit (bit_cast): Likewise.
* include/std/utility (as_const, to_underlying): Likewise.
As can be seen on:
unsigned char f1 (unsigned char x, int y) { return std::rotl (x, y); }
unsigned char f2 (unsigned char x, int y) { return std::rotr (x, y); }
unsigned short f3 (unsigned short x, int y) { return std::rotl (x, y); }
unsigned short f4 (unsigned short x, int y) { return std::rotr (x, y); }
unsigned int f5 (unsigned int x, int y) { return std::rotl (x, y); }
unsigned int f6 (unsigned int x, int y) { return std::rotr (x, y); }
unsigned long int f7 (unsigned long int x, int y) { return std::rotl (x, y); }
unsigned long int f8 (unsigned long int x, int y) { return std::rotr (x, y); }
unsigned long long int f9 (unsigned long long int x, int y) { return std::rotl (x, y); }
unsigned long long int f10 (unsigned long long int x, int y) { return std::rotr (x, y); }
//unsigned __int128 f11 (unsigned __int128 x, int y) { return std::rotl (x, y); }
//unsigned __int128 f12 (unsigned __int128 x, int y) { return std::rotr (x, y); }
constexpr auto a = std::rotl (1234U, 0);
constexpr auto b = std::rotl (1234U, 5);
constexpr auto c = std::rotl (1234U, -5);
constexpr auto d = std::rotl (1234U, -__INT_MAX__ - 1);
the current <bit> definitions of std::__rot[lr] aren't pattern recognized
as rotates, they are too long/complex for that, starting with signed modulo,
special case for 0 and different cases for positive and negative.
For types with power of two bits the following patch adds definitions that
the compiler can pattern recognize and turn e.g. on x86_64 into ro[lr][bwlq]
instructions. For weirdo types like unsigned __int20 etc. it keeps the
current definitions.
2021-03-06 Jakub Jelinek <jakub@redhat.com>
PR libstdc++/99396
* include/std/bit (__rotl, __rotr): Add optimized variants for power of
two _Nd which the compiler can pattern match the rotates.
There's no need to explicitly check for the maximum value, because the
function we call handles it correctly anyway.
libstdc++-v3/ChangeLog:
PR libstdc++/98226
* include/std/bit (__countl_one, __countr_one): Remove redundant
branches.
Thanks to Jakub's addition of the built-in, we can add this to the
library now. The compiler tests for the built-in are quite extensive,
including verifying the constraints, so this only adds minimal tests to
the library testsuite.
This doesn't add a new _GLIBCXX_HAVE_BUILTIN_BIT_CAST because using
__has_builtin(__builtin_bit_cast) works for GCC and versions of Clang
that provide the built-in.
libstdc++-v3/ChangeLog:
PR libstdc++/93121
* include/std/bit (__cpp_lib_bit_cast, bit_cast): Define.
* include/std/version (__cpp_lib_bit_cast): Define.
* testsuite/26_numerics/bit/bit.cast/bit_cast.cc: New test.
* testsuite/26_numerics/bit/bit.cast/version.cc: New test.
The popcount built-ins work fine for zero, so there's no need to check
for it.
libstdc++-v3/ChangeLog:
* include/std/bit (__popcount): Remove redundant check for zero.
I recently added std::__detail::__int_limits as a lightweight
alternative to std::numeric_limits, forgetting that the values it
provides (digits, min and max) are already provided by
__gnu_cxx::__numeric_traits.
This change adds __int_traits as an alias for __numeric_traits_integer.
This avoids instantiating __numeric_traits to decide whether to use
__numeric_traits_integer or __numeric_traits_floating. Then all uses of
__int_limits can be replaced with __int_traits, and __int_limits can be
removed.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Remove bits/int_limits.h.
* include/Makefile.in: Regenerate.
* include/bits/int_limits.h: Removed.
* include/bits/parse_numbers.h (_Select_int_base): Replace
__int_limits with __int_traits.
* include/bits/range_access.h (_SSize::operator()): Likewise.
* include/ext/numeric_traits.h (__numeric_traits_integer): Add
static assertion.
(__int_traits): New alias template.
* include/std/bit (__rotl, __rotr, __countl_zero, __countl_one)
(__countr_zero, __countr_one, __popcount, __bit_ceil)
(__bit_floor, __bit_width) Replace __int_limits with
__int_traits.
* 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 (cmp_equal, cmp_less, in_range): Likewise.
Implement this change for C++20 that was just approved in Prague.
P1956R1 On the names of low-level bit manipulation functions
* include/bits/hashtable_policy.h: Update comment.
* include/std/bit (__ispow2, __ceil2, __floor2, __log2p1): Rename.
(ispow2, ceil2, floor2, log2p1): Likewise.
(__cpp_lib_int_pow2): Add feature test macro.
* include/std/charconv (__to_chars_len_2): Adjust use of __log2p1.
* include/std/memory (assume_aligned): Adjust use of ispow2.
* include/std/version (__cpp_lib_int_pow2): Add.
* libsupc++/new_opa.cc: Adjust use of __ispow2.
* src/c++17/memory_resource.cc: Likewise, and for __ceil2 and __log2p1.
* testsuite/17_intro/freestanding.cc: Adjust use of ispow2.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_ceil.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_ceil_neg.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_floor.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/bit_width.cc: ... here.
* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: Rename to ...
* testsuite/26_numerics/bit/bit.pow.two/has_single_bit.cc: ... here.
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.
* include/bits/alloc_traits.h (allocator_traits::construct)
(allocator_traits::destroy, allocator_traits::max_size): Add unused
attributes to parameters that are not used in C++20.
* include/std/bit (__ceil2): Add braces around assertion to avoid
-Wmissing-braces warning.
From-SVN: r278401
This macro was added as part of moving std::endian from <type_traits> to
<bit>.
* include/std/bit (__cpp_lib_endian): Define.
* include/std/version (__cpp_lib_endian): Define.
* testsuite/26_numerics/endian/2.cc: New.
* testsuite/26_numerics/endian/3.cc: New.
* testsuite/26_numerics/endian/4.cc: New.
From-SVN: r273828
This change to an early C++2a feature was just approved (P1612R1).
* include/std/bit (endian): Move definition here as per P1612R1.
* include/std/type_traits (endian): Remove definition from here.
* testsuite/20_util/endian/1.cc: Rename to ...
* testsuite/26_numerics/endian/1.cc: ... here. Adjust header.
From-SVN: r273816
This proposal has now been accepted for C++20, with a few changes. This
patch adjusts std::rotl and std::rotr to match the final specification
and declares the additions for C++2a mode even when __STRICT_ANSI__ is
defined.
* include/std/bit (__rotl, __rotr): Change second parameter from
unsigned int to int and handle negative values.
(rotl, rotr): Remove check for __STRICT_ANSI__. Change second
parameter from unsigned int to int. Add nodiscard attribute.
* testsuite/26_numerics/bit/bitops.rot/rotl.cc: Rename to ...
* testsuite/26_numerics/bit/bit.rotate/rotl.cc: Here. Test negative
shifts.
* testsuite/26_numerics/bit/bitops.rot/rotr.cc: Rename to ...
* testsuite/26_numerics/bit/bit.rotate/rotr.cc: Here. Test negative
shifts.
From-SVN: r273706
* include/std/bit (__ceil2): Make unrepresentable results undefined,
as per P1355R2. Add debug assertion. Perform one left shift, not two,
so that out of range values cause undefined behaviour. Ensure that
shift will still be undefined if left operand is promoted.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Replace checks for
unrepresentable values with checks that they are not core constant
expressions.
* testsuite/26_numerics/bit/bit.pow.two/ceil2_neg.cc: New test.
From-SVN: r273705
Reuse the __is_one_of alias in additional places, and define traits to
check for signed/unsigned integer types so we don't have to duplicate
those checks elsewhere.
The additional overloads for std::byte in <bit> were reviewed by LEWG
and considered undesirable, so this patch removes them.
* include/bits/fs_path.h (path::__is_encoded_char): Use __is_one_of.
* include/std/bit (_If_is_unsigned_integer_type): Remove.
(_If_is_unsigned_integer): Use __is_unsigned_integer.
(rotl(byte, unsigned), rotr(byte, unsigned), countl_zero(byte))
(countl_one(byte), countr_zero(byte), countr_one(byte))
(popcount(byte), ispow2(byte), ceil2(byte), floor2(byte))
(log2p1(byte)): Remove.
* include/std/charconv (__detail::__is_one_of): Move to <type_traits>.
(__detail::__is_int_to_chars_type): Remove.
(__detail::__integer_to_chars_result_type): Use __is_signed_integer
and __is_unsigned_integer.
* include/std/type_traits (__is_one_of): Move here from <charconv>.
(__is_signed_integer, __is_unsigned_integer): New helpers.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Remove test for
std::byte overload.
* 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/bitops.count/countl_one.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countl_zero.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countr_one.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/countr_zero.cc: Likewise.
* testsuite/26_numerics/bit/bitops.count/popcount.cc: Likewise.
* testsuite/26_numerics/bit/bitops.rot/rotl.cc: Likewise.
* testsuite/26_numerics/bit/bitops.rot/rotr.cc: Likewise.
From-SVN: r272695
For values where the result cannot be represented the shift width would
be equal to the width of the type, which is undefined. Perform two
well-defined shifts instead of one possible undefined shift.
* include/bits/hashtable_policy.h (__clp2): Fix calculation for LLP64
targets where sizeof(size_t) > sizeof(long). Avoid undefined shifts
of the number of bits in the type.
* include/std/bit (__ceil2): Avoid undefined shifts.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: Test values with
the most signifiant bit set.
From-SVN: r263986
* include/std/bit (__countl_zero, __countr_zero, __popcount): Use
local variables for number of digits instead of type aliases.
(__log2p1): Remove redundant branch also checked in __countl_zero.
From-SVN: r262947
2018-07-04 Jonathan Wakely <jwakely@redhat.com>
Jakub Jelinek <jakub@redhat.com>
* include/std/bit (__rotl, __rotr): Fix for non-power of two sizes.
Co-Authored-By: Jakub Jelinek <jakub@redhat.com>
From-SVN: r262414
P0553R2 is not in the C++2a working draft yet, but is likely to be
approved soon. Neither proposal supports std::byte but this adds
overloads of each function for std::byte, assuming that will also get
added.
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/precompiled/stdc++.h: Include new header.
* include/std/bit: New header.
(__rotl, __rotr, __countl_zero, __countl_one, __countr_zero)
(__countr_one, __popcount, __ispow2, __ceil2, __floor2, __log2p1):
Define for C++14.
[!__STRICT_ANSI__] (rotl, rotr, countl_zero, countl_one, countr_zero)
(countr_one, popcount): Define for C++2a. Also overload for std::byte.
(ispow2, ceil2, floor2, log2p1): Define for C++2a.
[!__STRICT_ANSI__] (ispow2, ceil2, floor2, log2p1): Overload for
std::byte.
* testsuite/26_numerics/bit/bit.pow.two/ceil2.cc: New.
* testsuite/26_numerics/bit/bit.pow.two/floor2.cc: New.
* testsuite/26_numerics/bit/bit.pow.two/ispow2.cc: New.
* testsuite/26_numerics/bit/bit.pow.two/log2p1.cc: New.
* testsuite/26_numerics/bit/bitops.rot/rotl.cc: New.
* testsuite/26_numerics/bit/bitops.rot/rotr.cc: New.
* testsuite/26_numerics/bit/bitops.count/countl_one.cc: New.
* testsuite/26_numerics/bit/bitops.count/countl_zero.cc: New.
* testsuite/26_numerics/bit/bitops.count/countr_one.cc: New.
* testsuite/26_numerics/bit/bitops.count/countr_zero.cc: New.
From-SVN: r262360
Jason Merrill