[PATCH] libstdc++: Implement integer-class types as defined in [iterator.concept.winc]
Patrick Palka
ppalka@redhat.com
Tue Aug 11 15:38:41 GMT 2020
On Thu, 7 May 2020, Patrick Palka wrote:
> On Mon, 2 Mar 2020, Patrick Palka wrote:
>
> > On Mon, 24 Feb 2020, Patrick Palka wrote:
> >
> > > On Mon, 24 Feb 2020, Patrick Palka wrote:
> > >
> > > > This implements signed and unsigned integer-class types, whose width is one bit
> > > > larger than the widest native signed and unsigned integral type respectively.
> > > > In our case this is either __int128 and unsigned __int128, or long long and
> > > > unsigned long long.
> > > >
> > > > Internally, the two integer-class types are represented as a largest native
> > > > unsigned integral type plus one extra bit. The signed integer-class type is
> > > > represented in two's complement form with the extra bit acting as the sign bit.
> > > >
> > > > libstdc++-v3/ChangeLog:
> > > >
> > > > * include/bits/iterator_concepts.h (ranges::__detail::__max_diff_type):
> > > > Remove definition, replace with forward declaration of class
> > > > __max_diff_type.
> > > > (ranges::__detail::__max_size_type): Remove definition, replace with
> > > > forward declaration of class __max_size_type.
> > > > (__detail::__is_integer_like): Accept __int128 and unsigned __int128.
> > > > (__detail::__is_signed_integer_like): Accept __int128.
> > > > * include/bits/range_access.h (__detail::__max_size_type): New class.
> > > > (__detail::__max_diff_type): New class.
> > > > (__detail::__max_size_type::__max_size_type): Define this constructor
> > > > out-of-line to break the cycle.
> > > > (__detail::__to_unsigned_like): New function.
> > > > (numeric_limits<__detail::__max_size_type>): New explicit specialization.
> > > > (numeric_limits<__detail::__max_diff_type>): New explicit specialization.
> > > > * testsuite/std/ranges/iota/differenc_type.cc: New test.
> > >
> > > Here's v2 of the patch that splits out __max_size_type and
> > > __max_diff_type into a dedicated header, along with other misc
> > > improvements and fixes.
> > >
> > > -- >8 --
> >
> > Here's v3 of the patch. Changes from v2:
> >
> > * The arithmetic tests in difference_type.cc have been split out to a
> > separate file.
> >
> > * The arithmetic tests now run successfully in strict ANSI mode. The
> > issue was that __int128 does not model the integral concept in strict
> > ANSI mode, which we use to make operations on this type behave as
> > integer operations do. But for that we need to always treat __int128 as
> > an integer type in this API. So a new concept __integralish which is
> > always modelled by __int128 is introduced and used in the API instead.
> >
> > * Comments have been added explaining why __int128 is always used as the
> > underlying type even when the widest integer type in strict ANSI mode is
> > long long.
> >
> > * New tests, some minor code clean-ups, and added comments to the
> > unsigned division and multiplication routines.
> >
> > Tested on x86_64-pc-linux-gnu in both strict and GNU compilation modes,
> > with and without -U__SIZEOF_INT128__.
>
> Ping (now that stage 1 is open). Here's the latest rebased of version
> of the patch:
Here's the patch rebased against today's trunk. Compared to the
previous version, this version resolves some trivial merge conflicts in
include/bits/{iterator_concepts.h,range_access.h} and it replaces the
use of the removed trait __detail::__int_limits<unsigned long long>::digits
with __gnu_cxx::__int_traits<unsigned long long>::__digits.
Tested with and without -U__SIZEOF_INT128__, and in both strict and GNU
c++20 modes.
-- >8 --
Subject: [PATCH] libstdc++: integer-class types as per [iterator.concept.winc]
This implements signed and unsigned integer-class types, whose width is
one bit larger than the widest supported signed and unsigned integral
type respectively. In our case this is either __int128 and unsigned
__int128, or long long and unsigned long long.
Internally, the two integer-class types are represented as a largest
supported unsigned integral type plus one extra bit. The signed
integer-class type is represented in two's complement form with the
extra bit acting as the sign bit.
libstdc++-v3/ChangeLog:
* include/Makefile.am (bits_headers): Add new header
<bits/max_size_type.h>.
* include/Makefile.in: Regenerate.
* include/bits/iterator_concepts.h
(ranges::__detail::__max_diff_type): Remove definition, replace
with forward declaration of class __max_diff_type.
(__detail::__max_size_type): Remove definition, replace with
forward declaration of class __max_size_type.
(__detail::__is_unsigned_int128, __is_signed_int128,
__is_int128): New concepts.
(__detail::__is_integer_like): Accept __int128 and unsigned
__int128.
(__detail::__is_signed_integer_like): Accept __int128.
* include/bits/max_size_type.h: New header.
* include/bits/range_access.h: Include <bits/max_size_type.h>.
(__detail::__to_unsigned_like): Two new overloads.
* testsuite/std/ranges/iota/difference_type.cc: New test.
* testsuite/std/ranges/iota/max_size_type.cc: New test.
---
libstdc++-v3/include/Makefile.am | 1 +
libstdc++-v3/include/Makefile.in | 1 +
libstdc++-v3/include/bits/iterator_concepts.h | 24 +-
libstdc++-v3/include/bits/max_size_type.h | 753 ++++++++++++++++++
libstdc++-v3/include/bits/range_access.h | 11 +
.../std/ranges/iota/difference_type.cc | 57 ++
.../std/ranges/iota/max_size_type.cc | 376 +++++++++
7 files changed, 1219 insertions(+), 4 deletions(-)
create mode 100644 libstdc++-v3/include/bits/max_size_type.h
create mode 100644 libstdc++-v3/testsuite/std/ranges/iota/difference_type.cc
create mode 100644 libstdc++-v3/testsuite/std/ranges/iota/max_size_type.cc
diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index e131ce04f8c..1dff3862e35 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -143,6 +143,7 @@ bits_headers = \
${bits_srcdir}/locale_facets_nonio.tcc \
${bits_srcdir}/localefwd.h \
${bits_srcdir}/mask_array.h \
+ ${bits_srcdir}/max_size_type.h \
${bits_srcdir}/memoryfwd.h \
${bits_srcdir}/move.h \
${bits_srcdir}/node_handle.h \
diff --git a/libstdc++-v3/include/Makefile.in b/libstdc++-v3/include/Makefile.in
index c0b71e13a32..16371015071 100644
--- a/libstdc++-v3/include/Makefile.in
+++ b/libstdc++-v3/include/Makefile.in
@@ -489,6 +489,7 @@ bits_headers = \
${bits_srcdir}/locale_facets_nonio.tcc \
${bits_srcdir}/localefwd.h \
${bits_srcdir}/mask_array.h \
+ ${bits_srcdir}/max_size_type.h \
${bits_srcdir}/memoryfwd.h \
${bits_srcdir}/move.h \
${bits_srcdir}/node_handle.h \
diff --git a/libstdc++-v3/include/bits/iterator_concepts.h b/libstdc++-v3/include/bits/iterator_concepts.h
index aad6c2dcd91..5033f2bddc3 100644
--- a/libstdc++-v3/include/bits/iterator_concepts.h
+++ b/libstdc++-v3/include/bits/iterator_concepts.h
@@ -511,12 +511,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace ranges::__detail
{
+ class __max_diff_type;
+ class __max_size_type;
+
+ template<typename _Tp>
+ concept __is_signed_int128
#if __SIZEOF_INT128__
- using __max_diff_type = __int128;
- using __max_size_type = unsigned __int128;
+ = same_as<_Tp, __int128>;
#else
- using __max_diff_type = long long;
- using __max_size_type = unsigned long long;
+ = false;
+#endif
+
+ template<typename _Tp>
+ concept __is_unsigned_int128
+#if __SIZEOF_INT128__
+ = same_as<_Tp, unsigned __int128>;
+#else
+ = false;
#endif
template<typename _Tp>
@@ -525,12 +536,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
concept __integral_nonbool = integral<_Tp> && !__cv_bool<_Tp>;
+ template<typename _Tp>
+ concept __is_int128 = __is_signed_int128<_Tp> || __is_unsigned_int128<_Tp>;
+
template<typename _Tp>
concept __is_integer_like = __integral_nonbool<_Tp>
+ || __is_int128<_Tp>
|| same_as<_Tp, __max_diff_type> || same_as<_Tp, __max_size_type>;
template<typename _Tp>
concept __is_signed_integer_like = signed_integral<_Tp>
+ || __is_signed_int128<_Tp>
|| same_as<_Tp, __max_diff_type>;
} // namespace ranges::__detail
diff --git a/libstdc++-v3/include/bits/max_size_type.h b/libstdc++-v3/include/bits/max_size_type.h
new file mode 100644
index 00000000000..951cd6e93a8
--- /dev/null
+++ b/libstdc++-v3/include/bits/max_size_type.h
@@ -0,0 +1,753 @@
+// <max_size_type.h> -*- C++ -*-
+
+// Copyright (C) 2019-2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/max_size_type.h.
+ * This is an internal header file, included by other library headers.
+ * Do not attempt to use it directly. @headername{iterator}
+ */
+
+#ifndef _GLIBCXX_MAX_SIZE_TYPE_H
+#define _GLIBCXX_MAX_SIZE_TYPE_H 1
+
+#pragma GCC system_header
+
+#if __cplusplus > 201703L && __cpp_lib_concepts
+#include <ext/numeric_traits.h>
+#include <numbers>
+
+// This header implements unsigned and signed integer-class types (as per
+// [iterator.concept.winc]) that are one bit wider than the widest supported
+// integer type.
+//
+// The set of integer types we consider includes __int128 and unsigned __int128
+// (when they exist), even though they are really integer types only in GNU
+// mode. This is to obtain a consistent ABI for these integer-class types
+// across strict mode and GNU mode.
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+template<typename _Tp>
+ struct numeric_limits;
+
+namespace ranges
+{
+ namespace __detail
+ {
+ class __max_size_type
+ {
+ public:
+ __max_size_type() = default;
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ constexpr
+ __max_size_type(_Tp __i) noexcept
+ : _M_val(__i), _M_msb(__i < 0)
+ { }
+
+ constexpr explicit
+ __max_size_type(const __max_diff_type& __d) noexcept;
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ constexpr explicit operator _Tp() const noexcept
+ { return _M_val; }
+
+ constexpr explicit
+ operator bool() const noexcept
+ { return _M_val != 0 || _M_msb != 0; }
+
+ constexpr __max_size_type
+ operator+() const noexcept
+ { return *this; }
+
+ constexpr __max_size_type
+ operator~() const noexcept
+ { return __max_size_type{~_M_val, !_M_msb}; }
+
+ constexpr __max_size_type
+ operator-() const noexcept
+ { return operator~() + 1; }
+
+ constexpr __max_size_type&
+ operator+=(const __max_size_type& __r) noexcept
+ {
+ const auto __sum = _M_val + __r._M_val;
+ const bool __overflow = (__sum < _M_val);
+ _M_msb = _M_msb ^ __r._M_msb ^ __overflow;
+ _M_val = __sum;
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator-=(const __max_size_type& __r) noexcept
+ { return *this += -__r; }
+
+ constexpr __max_size_type&
+ operator*=(__max_size_type __r) noexcept
+ {
+ constexpr __max_size_type __threshold
+ = __rep(1) << (_S_rep_bits / 2 - 1);
+ if (_M_val < __threshold && __r < __threshold) [[likely]]
+ // When both operands are below this threshold then the
+ // multiplication can be safely computed in the base precision.
+ _M_val = _M_val * __r._M_val;
+ else
+ {
+ // Otherwise, perform the multiplication in four steps, by
+ // decomposing the LHS and the RHS into 2*x+a and 2*y+b,
+ // respectively, and computing 4*x*y + 2*x*b + 2*y*a + a*b.
+ const bool __lsb = _M_val & 1;
+ const bool __rlsb = __r._M_val & 1;
+ *this >>= 1;
+ __r >>= 1;
+ _M_val = (2 * _M_val * __r._M_val
+ + _M_val * __rlsb + __r._M_val * __lsb);
+ *this <<= 1;
+ *this += __rlsb * __lsb;
+ }
+
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator/=(const __max_size_type& __r) noexcept
+ {
+ __glibcxx_assert(__r != 0);
+
+ if (!_M_msb && !__r._M_msb) [[likely]]
+ _M_val /= __r._M_val;
+ else if (_M_msb && __r._M_msb)
+ {
+ _M_val = (_M_val >= __r._M_val);
+ _M_msb = 0;
+ }
+ else if (!_M_msb && __r._M_msb)
+ _M_val = 0;
+ else if (_M_msb && !__r._M_msb)
+ {
+ // The non-trivial case: the dividend has its MSB set and the
+ // divisor doesn't. In this case we compute ((LHS/2)/RHS)*2
+ // in the base precision. This quantity is either the true
+ // quotient or one less than the true quotient.
+ const auto __orig = *this;
+ *this >>= 1;
+ _M_val /= __r._M_val;
+ *this <<= 1;
+ if (__orig - *this * __r >= __r)
+ ++_M_val;
+ }
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator%=(const __max_size_type& __r) noexcept
+ {
+ if (!_M_msb && !__r._M_msb) [[likely]]
+ _M_val %= __r._M_val;
+ else
+ *this -= (*this / __r) * __r;
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator<<=(const __max_size_type& __r) noexcept
+ {
+ __glibcxx_assert(__r <= _S_rep_bits);
+ if (__r != 0)
+ {
+ _M_msb = (_M_val >> (_S_rep_bits - __r._M_val)) & 1;
+
+ if (__r._M_val == _S_rep_bits) [[unlikely]]
+ _M_val = 0;
+ else
+ _M_val <<= __r._M_val;
+ }
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator>>=(const __max_size_type& __r) noexcept
+ {
+ __glibcxx_assert(__r <= _S_rep_bits);
+ if (__r != 0)
+ {
+ if (__r._M_val == _S_rep_bits) [[unlikely]]
+ _M_val = 0;
+ else
+ _M_val >>= __r._M_val;
+
+ if (_M_msb) [[unlikely]]
+ {
+ _M_val |= __rep(1) << (_S_rep_bits - __r._M_val);
+ _M_msb = 0;
+ }
+ }
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator&=(const __max_size_type& __r) noexcept
+ {
+ _M_val &= __r._M_val;
+ _M_msb &= __r._M_msb;
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator|=(const __max_size_type& __r) noexcept
+ {
+ _M_val |= __r._M_val;
+ _M_msb |= __r._M_msb;
+ return *this;
+ }
+
+ constexpr __max_size_type&
+ operator^=(const __max_size_type& __r) noexcept
+ {
+ _M_val ^= __r._M_val;
+ _M_msb ^= __r._M_msb;
+ return *this;
+ }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator+=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a + b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator-=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a - b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator*=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a * b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator/=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a / b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator%=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a % b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator&=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a & b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator|=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a | b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator^=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a ^ b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator<<=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a << b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator>>=(_Tp& a, const __max_size_type& b) noexcept
+ { return (a = static_cast<_Tp>(a >> b)); }
+
+ friend constexpr __max_size_type
+ operator+(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l += __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator-(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l -= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator*(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l *= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator/(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l /= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator%(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l %= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator<<(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l <<= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator>>(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l >>= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator&(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l &= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator|(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l |= __r;
+ return __l;
+ }
+
+ friend constexpr __max_size_type
+ operator^(__max_size_type __l, const __max_size_type& __r) noexcept
+ {
+ __l ^= __r;
+ return __l;
+ }
+
+ friend constexpr bool
+ operator==(const __max_size_type& __l, const __max_size_type& __r) noexcept
+ { return __l._M_val == __r._M_val && __l._M_msb == __r._M_msb; }
+
+ friend constexpr bool
+ operator!=(const __max_size_type& __l, const __max_size_type& __r) noexcept
+ { return !(__l == __r); }
+
+ friend constexpr bool
+ operator<(const __max_size_type& __l, const __max_size_type& __r) noexcept
+ {
+ if (__l._M_msb == __r._M_msb)
+ return __l._M_val < __r._M_val;
+ else
+ return __r._M_msb;
+ }
+
+ friend constexpr bool
+ operator>(const __max_size_type& __l, const __max_size_type& __r) noexcept
+ { return __r < __l; }
+
+ friend constexpr bool
+ operator<=(const __max_size_type& __l, const __max_size_type& __r) noexcept
+ { return !(__l > __r); }
+
+ friend constexpr bool
+ operator>=(const __max_size_type& __l, const __max_size_type& __r) noexcept
+ { return __r <= __l; }
+
+#if __SIZEOF_INT128__
+ using __rep = unsigned __int128;
+#else
+ using __rep = unsigned long long;
+#endif
+ static constexpr size_t _S_rep_bits = sizeof(__rep) * __CHAR_BIT__;
+ private:
+ __rep _M_val = 0;
+ unsigned _M_msb:1 = 0;
+
+ constexpr explicit
+ __max_size_type(__rep __val, int __msb) noexcept
+ : _M_val(__val), _M_msb(__msb)
+ { }
+
+ friend __max_diff_type;
+ friend std::numeric_limits<__max_size_type>;
+ friend std::numeric_limits<__max_diff_type>;
+ };
+
+ class __max_diff_type
+ {
+ public:
+ __max_diff_type() = default;
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ constexpr
+ __max_diff_type(_Tp __i) noexcept
+ : _M_rep(__i)
+ { }
+
+ constexpr explicit
+ __max_diff_type(const __max_size_type& __d) noexcept
+ : _M_rep(__d)
+ { }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ constexpr explicit operator _Tp() const noexcept
+ { return static_cast<_Tp>(_M_rep); }
+
+ constexpr explicit
+ operator bool() const noexcept
+ { return _M_rep != 0; }
+
+ constexpr __max_diff_type
+ operator+() const noexcept
+ { return *this; }
+
+ constexpr __max_diff_type
+ operator-() const noexcept
+ { return __max_diff_type(-_M_rep); }
+
+ constexpr __max_diff_type
+ operator~() const noexcept
+ { return __max_diff_type(~_M_rep); }
+
+ constexpr __max_diff_type&
+ operator+=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep += __r._M_rep;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator-=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep -= __r._M_rep;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator*=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep *= __r._M_rep;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator/=(const __max_diff_type& __r) noexcept
+ {
+ __glibcxx_assert (__r != 0);
+ const bool __neg = *this < 0;
+ const bool __rneg = __r < 0;
+ if (!__neg && !__rneg)
+ _M_rep = _M_rep / __r._M_rep;
+ else if (__neg && __rneg)
+ _M_rep = -_M_rep / -__r._M_rep;
+ else if (__neg && !__rneg)
+ _M_rep = -(-_M_rep / __r._M_rep);
+ else
+ _M_rep = -(_M_rep / -__r._M_rep);
+ return *this ;
+ }
+
+ constexpr __max_diff_type&
+ operator%=(const __max_diff_type& __r) noexcept
+ {
+ __glibcxx_assert (__r != 0);
+ if (*this >= 0 && __r > 0)
+ _M_rep %= __r._M_rep;
+ else
+ *this -= (*this / __r) * __r;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator<<=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep.operator<<=(__r._M_rep);
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator>>=(const __max_diff_type& __r) noexcept
+ {
+ // Arithmetic right shift.
+ const auto __msb = _M_rep._M_msb;
+ _M_rep >>= __r._M_rep;
+ _M_rep._M_msb |= __msb;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator&=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep &= __r._M_rep;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator|=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep |= __r._M_rep;
+ return *this;
+ }
+
+ constexpr __max_diff_type&
+ operator^=(const __max_diff_type& __r) noexcept
+ {
+ _M_rep ^= __r._M_rep;
+ return *this;
+ }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator+=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a + b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator-=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a - b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator*=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a * b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator/=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a / b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator%=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a % b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator&=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a & b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator|=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a | b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator^=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a ^ b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator<<=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a << b)); }
+
+ template<typename _Tp> requires integral<_Tp> || __is_int128<_Tp>
+ friend constexpr _Tp&
+ operator>>=(_Tp& a, const __max_diff_type& b) noexcept
+ { return (a = static_cast<_Tp>(a >> b)); }
+
+ friend constexpr __max_diff_type
+ operator+(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l += __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator-(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l -= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator*(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l *= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator/(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l /= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator%(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l %= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator<<(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l <<= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator>>(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l >>= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator&(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l &= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator|(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l |= __r;
+ return __l;
+ }
+
+ friend constexpr __max_diff_type
+ operator^(__max_diff_type __l, const __max_diff_type& __r) noexcept
+ {
+ __l ^= __r;
+ return __l;
+ }
+
+ friend constexpr bool
+ operator==(const __max_diff_type& __l, const __max_diff_type& __r) noexcept
+ { return __l._M_rep == __r._M_rep; }
+
+ friend constexpr bool
+ operator!=(const __max_diff_type& __l, const __max_diff_type& __r) noexcept
+ { return !(__l == __r); }
+
+ constexpr bool
+ operator<(const __max_diff_type& __r) const noexcept
+ {
+ const auto __lsign = _M_rep._M_msb;
+ const auto __rsign = __r._M_rep._M_msb;
+ if (__lsign ^ __rsign)
+ return __lsign;
+ else
+ return _M_rep < __r._M_rep;
+ }
+
+ friend constexpr bool
+ operator>(const __max_diff_type& __l, const __max_diff_type& __r) noexcept
+ { return __r < __l; }
+
+ friend constexpr bool
+ operator<=(const __max_diff_type& __l, const __max_diff_type& __r) noexcept
+ { return !(__r < __l); }
+
+ friend constexpr bool
+ operator>=(const __max_diff_type& __l, const __max_diff_type& __r) noexcept
+ { return !(__l < __r); }
+
+ private:
+ __max_size_type _M_rep = 0;
+
+ friend class __max_size_type;
+ };
+
+ constexpr
+ __max_size_type::__max_size_type(const __max_diff_type& __d) noexcept
+ : __max_size_type(__d._M_rep)
+ { }
+
+ } // namespace __detail
+} // namespace ranges
+
+ template<>
+ struct numeric_limits<ranges::__detail::__max_size_type>
+ {
+ using _Sp = ranges::__detail::__max_size_type;
+ static constexpr bool is_specialized = true;
+ static constexpr bool is_signed = false;
+ static constexpr bool is_integer = true;
+ static constexpr bool is_exact = true;
+#if __SIZEOF_INT128__
+ static_assert(same_as<_Sp::__rep, unsigned __int128>);
+ static constexpr int digits = 129;
+#else
+ static_assert(same_as<_Sp::__rep, unsigned long long>);
+ static constexpr int digits
+ = __gnu_cxx::__int_traits<unsigned long long>::__digits + 1;
+#endif
+ static constexpr int digits10
+ = static_cast<int>(digits * numbers::ln2 / numbers::ln10);
+
+ static constexpr _Sp
+ min() noexcept
+ { return 0; }
+
+ static constexpr _Sp
+ max() noexcept
+ { return _Sp(static_cast<_Sp::__rep>(-1), 1); }
+
+ static constexpr _Sp
+ lowest() noexcept
+ { return min(); }
+ };
+
+ template<>
+ struct numeric_limits<ranges::__detail::__max_diff_type>
+ {
+ using _Dp = ranges::__detail::__max_diff_type;
+ using _Sp = ranges::__detail::__max_size_type;
+ static constexpr bool is_specialized = true;
+ static constexpr bool is_signed = true;
+ static constexpr bool is_integer = true;
+ static constexpr bool is_exact = true;
+ static constexpr int digits = numeric_limits<_Sp>::digits - 1;
+ static constexpr int digits10
+ = static_cast<int>(digits * numbers::ln2 / numbers::ln10);
+
+ static constexpr _Dp
+ min() noexcept
+ { return _Dp(_Sp(0, 1)); }
+
+ static constexpr _Dp
+ max() noexcept
+ { return _Dp(_Sp(static_cast<_Sp::__rep>(-1), 0)); }
+
+ static constexpr _Dp
+ lowest() noexcept
+ { return min(); }
+ };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+
+#endif // C++20 && library concepts
+#endif // _GLIBCXX_MAX_SIZE_TYPE_H
diff --git a/libstdc++-v3/include/bits/range_access.h b/libstdc++-v3/include/bits/range_access.h
index 3919183c5b4..3eb1f2fd272 100644
--- a/libstdc++-v3/include/bits/range_access.h
+++ b/libstdc++-v3/include/bits/range_access.h
@@ -36,6 +36,9 @@
#include <initializer_list>
#include <bits/iterator_concepts.h>
#include <ext/numeric_traits.h>
+#if __cplusplus > 201703L
+#include <bits/max_size_type.h>
+#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
@@ -352,6 +355,14 @@ namespace ranges
namespace __detail
{
+ constexpr __max_size_type
+ __to_unsigned_like(__max_size_type __t) noexcept
+ { return __t; }
+
+ constexpr __max_size_type
+ __to_unsigned_like(__max_diff_type __t) noexcept
+ { return __max_size_type(__t); }
+
template<integral _Tp>
constexpr make_unsigned_t<_Tp>
__to_unsigned_like(_Tp __t) noexcept
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/difference_type.cc b/libstdc++-v3/testsuite/std/ranges/iota/difference_type.cc
new file mode 100644
index 00000000000..4a342deae74
--- /dev/null
+++ b/libstdc++-v3/testsuite/std/ranges/iota/difference_type.cc
@@ -0,0 +1,57 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <ranges>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ using I = unsigned long long;
+ auto imax = std::numeric_limits<I>::max();
+ std::ranges::iota_view<I, I> i(0, imax);
+ auto begin = i.begin();
+ static_assert( std::input_or_output_iterator<decltype(begin)> );
+ auto size = std::ranges::end(i) - std::ranges::begin(i);
+ VERIFY( size > 0 );
+ VERIFY( size == imax );
+}
+
+void
+test02()
+{
+#if __SIZEOF_INT128__
+ using I = unsigned __int128;
+ auto imax = std::numeric_limits<I>::max();
+ std::ranges::iota_view<I, I> i(0, imax);
+ auto begin = i.begin();
+ static_assert( std::input_or_output_iterator<decltype(begin)> );
+ auto size = std::ranges::end(i) - std::ranges::begin(i);
+ VERIFY( size > 0 );
+ VERIFY( size == imax );
+#endif
+}
+
+int
+main()
+{
+ test01();
+ test02();
+}
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/max_size_type.cc b/libstdc++-v3/testsuite/std/ranges/iota/max_size_type.cc
new file mode 100644
index 00000000000..cb9444074fc
--- /dev/null
+++ b/libstdc++-v3/testsuite/std/ranges/iota/max_size_type.cc
@@ -0,0 +1,376 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <limits>
+#include <ranges>
+#include <testsuite_hooks.h>
+
+using max_size_t = std::ranges::__detail::__max_size_type;
+using max_diff_t = std::ranges::__detail::__max_diff_type;
+using rep_t = max_size_t::__rep;
+
+static_assert(sizeof(max_size_t) == sizeof(max_diff_t));
+
+static_assert(std::regular<max_size_t>);
+static_assert(std::totally_ordered<max_size_t>);
+
+static_assert(std::regular<max_diff_t>);
+static_assert(std::totally_ordered<max_diff_t>);
+
+// We can't use numeric_limits<rep_t>::max() here because __int128 is an
+// integral type only in GNU mode.
+constexpr max_size_t mu = max_size_t(~rep_t(0));
+constexpr max_size_t ou = 1;
+constexpr max_diff_t ns = -1;
+
+void
+test01()
+{
+ static_assert(max_size_t(7) % 3 == 1);
+ static_assert(max_size_t(7) % 4 == 3);
+
+ static_assert(-max_diff_t(1) == max_diff_t(-1));
+ static_assert(max_diff_t(3) % 2 == 1);
+ static_assert(max_diff_t(-3) / 2 == -1);
+ static_assert(max_diff_t(-3) % 2 == -1);
+ static_assert(max_diff_t(3) % -2 == 1);
+ static_assert(max_diff_t(-3) << 1 == -6);
+ static_assert(max_diff_t(-3) >> 1 == -2);
+ static_assert(max_diff_t(3) >> 1 == 1);
+ static_assert(max_diff_t(3) >> 2 == 0);
+
+ static_assert(max_diff_t(-5) / 3 == -1);
+ static_assert(max_diff_t(5) / -3 == -1);
+ static_assert(max_diff_t(-5) / -3 == 1);
+ static_assert(max_diff_t(5) / 3 == 1);
+
+ static_assert(max_diff_t(-6) / 3 == -2);
+ static_assert(max_diff_t(6) / -3 == -2);
+ static_assert(max_diff_t(-6) / -3 == 2);
+ static_assert(max_diff_t(6) / 3 == 2);
+
+ static_assert(~max_size_t(-3) == 2);
+ static_assert(~max_diff_t(-3) == 2);
+
+ static_assert(max_diff_t(1) < max_diff_t(3));
+ static_assert(max_diff_t(-1) < max_diff_t(3));
+ static_assert(max_diff_t(1) > max_diff_t(-3));
+ static_assert(max_diff_t(-1) > max_diff_t(-3));
+
+ static_assert(max_diff_t(mu)/-1 == -max_diff_t(mu));
+ static_assert(-max_diff_t(mu)/1 == -max_diff_t(mu));
+ static_assert(max_diff_t(mu)>>1 == max_diff_t(mu)/2);
+ static_assert(-max_diff_t(mu+1) == max_diff_t(mu+1));
+ static_assert(-(mu+1) == mu+1);
+ static_assert((mu+1)<<1 == 0);
+ static_assert(max_diff_t(mu+1)<<1 == 0);
+ static_assert(max_diff_t(mu+1)>>1 < 0);
+
+ static_assert(int(max_diff_t(mu+1)) == 0);
+ static_assert(rep_t(max_diff_t(mu+1)) == 0);
+ static_assert(int(max_diff_t(mu)) == -1);
+ static_assert(rep_t(max_diff_t(mu)) == rep_t(-1));
+
+ static_assert(2*mu+1 > 2*mu);
+ static_assert(~(2*mu+1) == 0);
+ static_assert(mu/mu == 1);
+ static_assert(2*mu > mu);
+ static_assert(2*mu-mu == mu);
+ static_assert((2*mu)/mu == 2);
+ static_assert((2*mu+1)/mu == 2);
+ static_assert((2*mu-1)/(mu-1) == 2);
+ static_assert((2*mu-1)/mu == 1);
+ static_assert((2*mu+-1)/mu == 1);
+ static_assert(2*mu-1 < 2*mu);
+ static_assert(2*mu-1 <= 2*mu);
+ static_assert(2*mu+1 > 2*mu);
+ static_assert(2*mu+1 >= 2*mu);
+ static_assert((2*mu)/1 == 2*mu);
+ static_assert(mu/mu-1 == 0);
+ static_assert(mu*0 == 0);
+ static_assert((2*mu-1)*0 == 0);
+ static_assert((2*mu-1)>>1 == mu-1);
+ static_assert(mu+-1+1 == mu);
+ static_assert(mu+1+-1 == mu);
+ static_assert(mu+1);
+ static_assert((2*mu)/2 == mu);
+ static_assert((2*mu)>>1 == mu);
+ static_assert((mu<<1)>>1 == mu);
+ static_assert(1/mu == 0);
+ static_assert(mu/1 == mu);
+ static_assert(((mu+1)|mu) == -1);
+ static_assert((mu+1)+(mu+1) < mu+1);
+
+ static_assert(max_size_t(ns) == -1);
+ static_assert(-max_diff_t(ou) == -1);
+ static_assert(-max_diff_t(-ou) == 1);
+ static_assert(max_size_t(-max_diff_t(-ou)) == 1);
+ static_assert(ns*ns == max_diff_t(ou));
+ static_assert(max_size_t(ns)*max_size_t(ns) == ou);
+ static_assert(-max_diff_t(0) == max_diff_t(0));
+ static_assert(-ou-ou == -2*ou);
+
+ static_assert(int(ns) == -1);
+ static_assert(rep_t(ns) == rep_t(-1));
+
+ static_assert(max_size_t() == 0);
+ static_assert(max_diff_t() == 0);
+
+ auto f = [] (auto a) { a /= a; return a; };
+ static_assert(f(max_size_t(5)) == 1);
+ static_assert(f(max_size_t(-5)) == 1);
+ static_assert(f(max_diff_t(5)) == 1);
+
+ auto g = [] (auto a) { a >>= a; return a; };
+ static_assert(g(max_size_t(5)) == 0);
+ static_assert(g(max_diff_t(5)) == 0);
+
+ auto h = [] (auto a) { a <<= a; return a; };
+ static_assert(h(max_size_t(3)) == 24);
+ static_assert(h(max_diff_t(3)) == 24);
+}
+
+template<bool signed_p, bool shorten_p>
+void
+test02()
+{
+ using hw_type = std::conditional_t<signed_p, signed rep_t, rep_t>;
+ using max_type = std::conditional_t<signed_p, max_diff_t, max_size_t>;
+ using shorten_type = std::conditional_t<shorten_p, hw_type, max_type>;
+ const int hw_type_bit_size = sizeof(hw_type) * __CHAR_BIT__;
+ const int limit = 1000;
+ const int log2_limit = 10;
+ static_assert((1 << log2_limit) >= limit);
+ const int min = (signed_p ? -limit : 0);
+ const int max = limit;
+ for (hw_type i = min; i <= max; i++)
+ {
+ bool ok = true;
+ if (signed_p || shorten_p)
+ {
+ ok &= (~i == shorten_type(~max_type(i)));
+ ok &= (-i == shorten_type(-max_type(i)));
+ }
+ for (hw_type j = min; j <= max; j++)
+ {
+ ok &= (i*j == shorten_type(max_type(i)*j));
+ ok &= (i+j == shorten_type(max_type(i)+j));
+ if (j != 0)
+ {
+ ok &= (i/j == shorten_type(max_type(i)/j));
+ ok &= (i%j == shorten_type(max_type(i)%j));
+ }
+ if (signed_p || shorten_p)
+ ok &= (i-j == shorten_type(max_type(i)-j));
+ ok &= ((i&j) == shorten_type(max_type(i)&j));
+ ok &= ((i|j) == shorten_type(max_type(i)|j));
+ ok &= ((i^j) == shorten_type(max_type(i)^j));
+ if (j >= 0 && j < hw_type(hw_type_bit_size)
+ && (shorten_p || j < hw_type(hw_type_bit_size) - log2_limit))
+ {
+ ok &= ((i>>j) == shorten_type(max_type(i)>>j));
+ ok &= ((i<<j) == shorten_type(max_type(i)<<j));
+ }
+ ok &= (i>j) == (max_type(i) > j);
+ ok &= (i<j) == (max_type(i) < j);
+ ok &= (i>=j) == (max_type(i) >= j);
+ ok &= (i<=j) == (max_type(i) <= j);
+ ok &= (i==j) == (max_type(i) == j);
+ ok &= (i!=j) == (max_type(i) != j);
+ if (!ok)
+ {
+ fprintf(stderr,
+ "Inconsistency found: %d %d %lld %lld\n",
+ signed_p, shorten_p, (long long)i, (long long)j) ;
+ VERIFY(0);
+ }
+ }
+ }
+}
+
+template<bool signed_p, bool toggle_base_p>
+void
+test03()
+{
+ using hw_type = std::conditional_t<signed_p, signed rep_t, rep_t>;
+ using max_type = std::conditional_t<signed_p, max_diff_t, max_size_t>;
+ using base_type = std::conditional_t<toggle_base_p, hw_type, max_type>;
+ constexpr int hw_type_bit_size = sizeof(hw_type) * __CHAR_BIT__;
+ constexpr int limit = 1000;
+ constexpr int log2_limit = 10;
+ static_assert((1 << log2_limit) >= limit);
+ const int min = (signed_p ? -limit : 0);
+ const int max = limit;
+ for (hw_type i = min; i <= max; i++)
+ {
+ bool ok = true;
+ base_type k;
+ for (hw_type j = min; j <= max; j++)
+ {
+ k = i; k *= j;
+ ok &= (k == (max_type(i)*j));
+ k = i; k += j;
+ ok &= (k == (max_type(i)+j));
+ if (j != 0)
+ {
+ k = i; k /= j;
+ ok &= (k == (max_type(i)/j));
+ k = i; k %= j;
+ ok &= (k == (max_type(i)%j));
+ }
+ if (signed_p)
+ {
+ k = i; k -= j;
+ ok &= (k == (max_type(i)-j));
+ }
+ k = i; k &= j;
+ ok &= (k == (max_type(i)&j));
+ k = i; k |= j;
+ ok &= (k == (max_type(i)|j));
+ k = i; k ^= j;
+ ok &= (k == (max_type(i)^j));
+ if (j >= 0 && j < hw_type(hw_type_bit_size)
+ && (!toggle_base_p || j < hw_type(hw_type_bit_size) - log2_limit))
+ {
+ k = i; k >>= j;
+ ok &= (k == (max_type(i)>>j));
+ k = i; k <<= j;
+ ok &= (k == (max_type(i)<<j));
+ }
+ if (!ok)
+ {
+ fprintf(stderr,
+ "Inconsistency found: %d %d %lld %lld\n",
+ signed_p, toggle_base_p, (long long)i, (long long)j) ;
+ VERIFY(0);
+ }
+ }
+ }
+}
+
+void
+test04()
+{
+ constexpr int limit = 1000;
+ for (int i = -limit; i <= limit; i++)
+ {
+ VERIFY( -max_size_t(-i) == i );
+ for (int j = i; j <= limit; j++)
+ {
+ VERIFY( max_size_t(-i) * max_size_t(-j) == i*j );
+ VERIFY( max_size_t(-j) * max_size_t(-i) == j*i );
+ VERIFY( rep_t(((mu+1)+i)*((mu+1)+j)) == rep_t(i*j) );
+ VERIFY( rep_t(((mu+1)+j)*((mu+1)+i)) == rep_t(j*i) );
+ if (i >= 0 && j > 0)
+ {
+ auto r = (mu+i)-((mu+i)/j)*j;
+ VERIFY( r >= 0 && r < j );
+ VERIFY( r == (mu+i)%j );
+ }
+ }
+ }
+}
+
+void
+test05()
+{
+#if __SIZEOF_INT128__
+ max_size_t x = 0;
+ x = static_cast<__int128>(0);
+ x = static_cast<unsigned __int128>(0);
+
+ max_diff_t y = 0;
+ y = static_cast<__int128>(0);;
+ y = static_cast<unsigned __int128>(0);
+#endif
+}
+
+using std::numeric_limits;
+
+static_assert(numeric_limits<max_size_t>::is_specialized);
+static_assert(!numeric_limits<max_size_t>::is_signed);
+static_assert(numeric_limits<max_size_t>::is_integer);
+static_assert(numeric_limits<max_size_t>::is_exact);
+// We can't unconditionally use numeric_limits here because __int128 is an
+// integral type only in GNU mode.
+#if __SIZEOF_INT128__
+static_assert(numeric_limits<max_size_t>::digits == 129);
+static_assert(numeric_limits<max_size_t>::digits10 == 38);
+static_assert(numeric_limits<max_size_t>::max()
+ == 2*max_size_t(~rep_t(0)) + 1);
+#else
+static_assert(numeric_limits<max_size_t>::digits
+ == numeric_limits<rep_t>::digits + 1);
+static_assert(numeric_limits<max_size_t>::digits10
+ == numeric_limits<rep_t>::digits10);
+static_assert(numeric_limits<max_size_t>::max()
+ == 2*max_size_t(numeric_limits<rep_t>::max())+1);
+#endif
+static_assert(numeric_limits<max_size_t>::min() == 0);
+static_assert(numeric_limits<max_size_t>::max()
+ == max_size_t(-1));
+static_assert((numeric_limits<max_size_t>::max()
+ >> (numeric_limits<max_size_t>::digits-1)) == 1);
+static_assert(numeric_limits<max_size_t>::lowest()
+ == numeric_limits<max_size_t>::min());
+
+static_assert(numeric_limits<max_diff_t>::is_specialized);
+static_assert(numeric_limits<max_diff_t>::is_signed);
+static_assert(numeric_limits<max_diff_t>::is_integer);
+static_assert(numeric_limits<max_diff_t>::is_exact);
+static_assert(numeric_limits<max_diff_t>::digits
+ == numeric_limits<max_size_t>::digits - 1);
+static_assert(numeric_limits<max_diff_t>::digits10
+ == numeric_limits<max_size_t>::digits10);
+// We can't unconditionally use numeric_limits here because __int128 is an
+// integral type only in GNU mode.
+#if __SIZEOF_INT128__
+static_assert(numeric_limits<max_diff_t>::min() == -max_diff_t(~rep_t(0))-1);
+static_assert(numeric_limits<max_diff_t>::max() == ~rep_t(0));
+#else
+static_assert(numeric_limits<max_diff_t>::min()
+ == -max_diff_t(numeric_limits<rep_t>::max())-1);
+static_assert(numeric_limits<max_diff_t>::max()
+ == numeric_limits<rep_t>::max());
+#endif
+static_assert(numeric_limits<max_diff_t>::lowest()
+ == numeric_limits<max_diff_t>::min());
+static_assert(max_diff_t(max_size_t(1)
+ << (numeric_limits<max_size_t>::digits-1))
+ == numeric_limits<max_diff_t>::min());
+
+int
+main()
+{
+ test01();
+
+ test02<false,false>();
+ test02<false,true>();
+ test02<true,false>();
+ test02<true,true>();
+
+ test03<false,false>();
+ test03<false,true>();
+ test03<true,false>();
+ test03<true,true>();
+
+ test04();
+ test05();
+}
--
2.28.0.97.gdc04167d37
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