On Tue, 05 Aug 2025 at 09:21 +0000, 1nfocalypse wrote:
Implements Philox Engine (P2075R6) and associated tests.
Implements additional feedback from v5 from Patrick Palka.
Also cut some trailing whitespace from the limb propagation
fix in v5.
Apologies for the delay from v5 - I had to finish writing some
CTF challenges for DEFCON this week. Thank you for the
feedback, and please let me know if anything further needs
to be changed.
Built/tested on x86_64-pc-linux-gnu.
From 23ffd0ca595c27e8721d6d73ac746293aace7771 Mon Sep 17 00:00:00 2001
From: 1nfocalypse <1nfocaly...@protonmail.com>
Date: Tue, 5 Aug 2025 01:37:18 +0000
Subject: [PATCH] [PATCH v6] libstdc++: Implement Philox Engine (PR119794)
Implemented additional changes from Patrick Palka.
Also removed some trailing whitespace in random.tcc.
replaced alias of __ios_base with ios_base
included <iomanip> in random.h
altered line number in pr60037-neg.cc to be accurate
Refactored iterator/index loops to be range-based for
in istream/ostream operator overloads
include <random> in philox_engine/cons/seed_seq.cc
Conforms with errata LWG4143, LWG4153 for Philox Engine.
PR libstdc++/119794
---
libstdc++-v3/include/bits/random.h | 283 ++++++++++++++++++
libstdc++-v3/include/bits/random.tcc | 191 ++++++++++++
libstdc++-v3/include/bits/version.def | 9 +
libstdc++-v3/include/bits/version.h | 10 +
libstdc++-v3/include/std/random | 3 +
.../26_numerics/random/philox4x32.cc | 23 ++
.../26_numerics/random/philox4x64.cc | 23 ++
.../random/philox_engine/cons/119794.cc | 39 +++
.../random/philox_engine/cons/copy.cc | 25 ++
.../random/philox_engine/cons/default.cc | 27 ++
.../random/philox_engine/cons/seed.cc | 20 ++
.../random/philox_engine/cons/seed_seq.cc | 24 ++
.../random/philox_engine/operators/equal.cc | 30 ++
.../random/philox_engine/operators/inequal.cc | 30 ++
.../philox_engine/operators/serialize.cc | 49 +++
.../philox_engine/requirements/constants.cc | 26 ++
.../requirements/constexpr_data.cc | 50 ++++
.../requirements/constexpr_functions.cc | 41 +++
.../philox_engine/requirements/typedefs.cc | 26 ++
.../26_numerics/random/pr60037-neg.cc | 4 +-
20 files changed, 931 insertions(+), 2 deletions(-)
create mode 100644 libstdc++-v3/testsuite/26_numerics/random/philox4x32.cc
create mode 100644 libstdc++-v3/testsuite/26_numerics/random/philox4x64.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/119794.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/copy.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/default.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed_seq.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/equal.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/inequal.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/serialize.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constants.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_data.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_functions.cc
create mode 100644
libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/typedefs.cc
diff --git a/libstdc++-v3/include/bits/random.h
b/libstdc++-v3/include/bits/random.h
index 1fdaf51934f..e74b7bd75c0 100644
--- a/libstdc++-v3/include/bits/random.h
+++ b/libstdc++-v3/include/bits/random.h
@@ -33,6 +33,7 @@
#include <vector>
#include <bits/uniform_int_dist.h>
+#include <iomanip>
namespace std _GLIBCXX_VISIBILITY(default)
{
@@ -1688,6 +1689,270 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ return !(__lhs == __rhs); }
#endif
+#if __cpp_lib_philox_engine
This should check __glibcxx_philox_engine (just in case this code is
moved to a separate header that ends up being included somewhere
withou all of <random>).
+ /**
+ * @brief: A discrete pseudorandom number generator based off of weakened
+ * cryptographic primitives.
Can we say "based on" instead of "based off of" which is an informal
American English term that sounds wrong to me.
I'm also not sure what this is telling me as a non-export user. Would
it be clearer to talk about it having weak cryptographic properties,
rather than being based on weakened cryptographic primitives?
+ *
+ * This algorithm was intended to be used for highly parallel random number
"was intended to be used" sounds like it refers to something in the
past that is no longer true. Maybe "was designed to be used" instead?
+ * generation, and is capable of immensely long periods. It provides "Crush-
I was going to ask whether immensely is a bit hyperbolic and could be
just "very long periods (e.g. ...)" but since we're talking at least
2^128 I think "immensely" is fine :-)
+ * resistance", denoting an ability to pass the TestU01 Suite's "Big Crush"
+ * test, demonstrating significant apparent entropy. It is not intended for
+ * cryptographic use and should not be used for such, despite being based on
+ * cryptographic primitives.
+ *
+ * The two four-word definitions are likely the best use for this algorithm,
+ * and are given below as defaults.
Can we refer to those as aliases or typedefs rather than definitions?
Or specializations?
Maybe even say it like this:
* The typedefs `philox4x32` and `philox4x64` are provided as
* suitable defaults for most use cases, providing high-quality
* random numbers at reasonable performance.
+ *
+ * This algorithm was created by John Salmon, Mark Moraes, Ron Dror, and
+ * David Shaw as a product of D.E. Shaw Research.
+ *
+ * @tparam __w Word size
+ * @tparam __n Buffer size
+ * @tparam __r Rounds
+ * @tparam __consts Multiplication and round constant pack, ordered as
+ * M_{0}, C_{0}, M_{1}, C_{1}, ... , M_{N/2-1}, C_{N/2-1}
+ *
+ * @headerfile random
+ * @since C++26
+ */
+ template<class _UIntType, size_t __w,
Our convention in libstdc++ code is to type 'typename' for template
parameters instead of 'class'
+ size_t __n, size_t __r,
+ _UIntType... __consts>
+ class philox_engine
+ {
+ static_assert(__n == 2 || __n == 4,
+ "template argument N must be either 2 or 4");
+ static_assert(sizeof...(__consts) == __n,
+ "length of consts array must match specified N");
+ static_assert(0 < __r, "a number of rounds must be specified");
+ static_assert((0 < __w && __w <= numeric_limits<_UIntType>::digits),
+ "specified bitlength must match input type");
The static assert messages all use the preferred "must" form, thanks!
+ template<typename _Sseq>
+ using _If_seed_seq
+ = __detail::_If_seed_seq_for<_Sseq, philox_engine, _UIntType>;
+
+ private:
This access specifier is redundant because everything above it is
already private.
+ // the ordering here is essential to functionality.
Does this refer to the ordering of the _S_popArray member in the
class, because it needs to be declared before it's used?
If so, I think we can drop the comment. If somebody fails to notice
that when reading the class definition, they'd find out pretty quickly
if they tried to reorder it and got errors.
The style recommendations to put private internal members last is not
a hard requirement, for cases like this where the order is significant
putting them first is obviously fine (since you have no choice! :-)
+ /** @brief an internal unpacking function for %philox_engine. */
We don't need a doxygen comment for private member functions, they
won't get included in the docs anyway.
+ template <size_t __ind0, size_t __ind1>
+ static constexpr
+ array<_UIntType, __n / 2>
+ _S_popArray()
+ {
+ if constexpr (__n == 4)
+ return {__consts...[__ind0], __consts...[__ind1]};
+ else
+ return {__consts...[__ind0]};
+ }
+
+ public:
+ /** Type of template param. */
+ using result_type = _UIntType;
+ // public members
+ static constexpr size_t word_size = __w;
+ static constexpr size_t word_count = __n;
+ static constexpr size_t round_count = __r;
+ static constexpr array<result_type, __n / 2> multipliers =
+ philox_engine::_S_popArray<0,2>();
+ static constexpr array<result_type, __n / 2> round_consts =
+ philox_engine::_S_popArray<1,3>();
+
+ /** @brief returns the minimum value possible. */
+ static constexpr result_type
+ min()
+ { return 0; }
+
+ /** @brief returns the maximum value possible. */
+ static constexpr result_type
+ max()
+ {
+ return ((1ull << (__w - 1)) | ((1ull << (__w - 1)) - 1));
+ }
+ // default key value
+ static constexpr result_type default_seed = 20111115u;
I wonder if we have a defect in the C++26 draft here, because
20111115u won't fit in a 16-bit int. We fixed that for
std::subtract_with_carry_engine via:
https://cplusplus.github.io/LWG/issue3809
and then fixed what I broke via:
https://cplusplus.github.io/LWG/issue4014
Since the value of default_seed is only used as the argument to the
default ctor (or the equivalent of calling seed() with no argument)
and the ctor reduces value by mod 2^w, I think we could define the
default seed as 20111115u & max().
But let's leave it for now, I'll raise this with LWG.
+
+ // constructors
+ philox_engine()
+ : philox_engine(default_seed)
+ {}
+
+ explicit
+ philox_engine(result_type __value);
+
+ /** @brief seed sequence constructor for %philox_engine
+ *
+ * @params __q the seed sequence
+ */
+ template<typename _Sseq, typename = _If_seed_seq<_Sseq>>
+ explicit
+ philox_engine(_Sseq& __q)
+ {
+ seed(__q);
+ }
+
+ void
+ seed(result_type value = default_seed);
+
+ /** @brief seeds %philox_engine by seed sequence
+ *
+ * @params __q the seed sequence
+ */
+ template<typename _Sseq>
+ _If_seed_seq<_Sseq>
+ seed(_Sseq& __q);
+
+ /** @brief sets the internal counter "cleartext"
+ *
+ * @params __counter std::array of len N
+ */
+ void
+ set_counter(const array<result_type, __n>& __counter);
+
+ /** @brief compares two %philox_engine objects
+ *
+ * @params __x A %philox_engine object
+ * @params __y A %philox_engine object
+ *
+ * @returns true if the objects will produce an identical stream, false
+ * otherwise
+ */
+ friend bool
+ operator==(const philox_engine& __x, const philox_engine& __y)
+ {
+ return (std::equal(__x._M_x.begin(), __x._M_x.end(),
+ __y._M_x.begin(), __y._M_x.end())
+ && std::equal(__x._M_y.begin(), __x._M_y.end(),
+ __y._M_y.begin(), __y._M_y.end())
+ && std::equal(__x._M_k.begin(), __x._M_k.end(),
+ __y._M_k.begin(), __y._M_k.end())
+ && __x._M_i == __y._M_i);
+ }
+
+ /** @brief outputs a single w-bit number and handles state advancement
+ *
+ * @returns return_type
+ */
+ _UIntType
+ operator()();
+
+ /** @brief discards __z numbers
+ *
+ * @params __z number of iterations to discard
+ */
+ void
+ discard(unsigned long long __z);
+
+ /** @brief outputs the state of the generator
+ *
+ * @param __os An output stream.
+ * @param __x A %philox_engine object reference
+ *
+ * @returns the state of the Philox Engine in __os
+ */
+ template<typename _CharT, typename _Traits>
+ friend basic_ostream<_CharT, _Traits>&
+ operator<<(basic_ostream<_CharT, _Traits>& __os,
+ const philox_engine& __x)
+ {
The "operator<<" and "{" lines should be lined up with "friend"
+ const typename ios_base::fmtflags __flags = __os.flags();
+ const _CharT __fill = __os.fill();
+ __os.flags(ios_base::dec | ios_base::left);
+ __os.fill(__os.widen(' '));
+ for (auto &__subkey : __x._M_k)
auto& rather than putting the space before the & please (and below as
well).
+ __os << __subkey << ' ';
+ for (auto &__ctr : __x._M_x)
+ __os << __ctr << ' ';
Inserting ' ' will get widened if __os is a wide stream, but since
you've already called __os.widen(' ') above you could save the result
of that in a local variable and then insert that character instead of
' '. That will avoid calling widen again on every iteration of the
loop.
+ __os << __x._M_i;
+ __os.flags(__flags);
If writing to the stream throws an exception we won't restore the
flags and fill character, but I think that's consistent with all our
operator<< overloads in <random>.
+ __os.fill(__fill);
+ return __os;
+ }
+
+ /** @brief takes input to set the state of the %philox_engine object
+ *
+ * @param __is An input stream.
+ * @param __x A %philox_engine object reference
+ *
+ * @returns %philox_engine object is set with values from instream
+ */
+ template <typename _CharT, typename _Traits>
+ friend basic_istream<_CharT, _Traits>&
+ operator>>(basic_istream<_CharT, _Traits>& __is,
+ philox_engine& __x)
+ {
Same comment about aligning to "friend".
+ const typename ios_base::fmtflags __flags = __is.flags();
+ __is.flags(ios_base::dec | ios_base::skipws);
+ for (auto &__subkey : __x._M_k)
+ __is >> __subkey;
+ for (auto &__ctr : __x._M_x)
+ __is >> __ctr;
+ array<_UIntType, __n> __tmpCtr = __x._M_x;
+ unsigned char __setIndex = 0;
+ for (size_t __j = 0; __j < __x._M_x.size(); ++__j)
+ {
+ if (__x._M_x[__j] > 0)
+ {
+ __setIndex = __j;
+ break;
+ }
+ }
+ for (size_t __j = 0; __j <= __setIndex; ++__j)
+ {
+ if (__j != __setIndex)
+ __x._M_x[__j] = max();
+ else
+ --__x._M_x[__j];
+ }
+ __x._M_philox();
+ __x._M_x = __tmpCtr;
+ __is >> __x._M_i;
+ __is.flags(__flags);
+ return __is;
+ }
+ private:
+ // private state variables
+ array<_UIntType, __n> _M_x;
+ array<_UIntType, __n / 2> _M_k;
+ array<_UIntType, __n> _M_y;
+ unsigned long long _M_i = 0;
+ }
+
+ template<class _UIntType,
+ size_t __w, size_t __n,
+ size_t __r, _UIntType... __consts>
+ philox_engine<_UIntType,
+ __w, __n, __r, __consts...>::philox_engine(result_type __value)
+ {
+ std::fill(_M_x.begin(), _M_x.end(), 0);
+ std::fill(_M_k.begin(), _M_k.end(), 0);
+ std::fill(_M_y.begin(), _M_y.end(), 0);
Can we just initialize these in a mem-initializer-list?
: _M_x{}, _M_k{}, _M_y{}
The compiler is more likely to optimize that well.
+ _M_k[0] = __value & max();
+ _M_i = __n - 1;
+ }
+
+ template<class _UIntType,
+ size_t __w, size_t __n,
+ size_t __r, _UIntType... __consts>
+ void
+ philox_engine<_UIntType,
+ __w, __n, __r, __consts...>::seed(result_type __value)
+ {
+ std::fill(_M_x.begin(), _M_x.end(), 0);
This can use std::array::fill, i.e. _M_x.fill(0);
Or would this whole function be simpler as:
*this = philox_engine(__value);
?
+ std::fill(_M_k.begin(), _M_k.end(), 0);
+ std::fill(_M_y.begin(), _M_y.end(), 0);
+ _M_k[0] = __value & max();
+ _M_i = __n - 1;
+ }
+
+ template<class _UIntType,
+ size_t __w, size_t __n,
+ size_t __r, _UIntType... __consts>
+ void
+ philox_engine<_UIntType, __w,
+ __n, __r, __consts...>::set_counter(const array<result_type, __n>& __counter)
+ {
+ for (unsigned long long __j = 0; __j < __n; ++__j)
+ _M_k[__k] = __precalc;
+ }
+ std::fill(_M_x.begin(), _M_x.end(), 0);
+ std::fill(_M_y.begin(), _M_y.end(), 0);
+ _M_i = __n - 1;
+ }
+
+ template<class _UIntType,
+ size_t __w, size_t __n,
+ size_t __r, _UIntType... __consts>
+ void
+ philox_engine<_UIntType,
+ __w, __n, __r, __consts...>::discard(unsigned long long __z)
+ {
+ for (unsigned long long __j = 0; __j < __z; ++__j)
+ _M_transition();
+ }
+
+ template<class _UIntType,
+ size_t __w, size_t __n,
+ size_t __r, _UIntType... __consts>
+ _UIntType
+ philox_engine<_UIntType, __w, __n, __r, __consts...>::operator()()
+ {
+ _M_transition();
+ return _M_y[_M_i];
+ }
+
+#endif
template<typename _IntType, typename _CharT, typename _Traits>
std::basic_ostream<_CharT, _Traits>&
diff --git a/libstdc++-v3/include/bits/version.def
b/libstdc++-v3/include/bits/version.def
index dbe2cb8f175..4c21fa187c8 100644
--- a/libstdc++-v3/include/bits/version.def
+++ b/libstdc++-v3/include/bits/version.def
@@ -2069,6 +2069,15 @@ ftms = {
};
};
+ftms = {
+ name = philox_engine;
+ values = {
+ v = 202406;
+ cxxmin = 26;
+ extra_cond = "__SIZEOF_INT128__";
+ };
+};
+
// Standard test specifications.
stds[97] = ">= 199711L";
stds[03] = ">= 199711L";
diff --git a/libstdc++-v3/include/bits/version.h
b/libstdc++-v3/include/bits/version.h
index 7bb6016df68..75a9946adce 100644
--- a/libstdc++-v3/include/bits/version.h
+++ b/libstdc++-v3/include/bits/version.h
@@ -2318,4 +2318,14 @@
#endif /* !defined(__cpp_lib_constexpr_exceptions) &&
defined(__glibcxx_want_constexpr_exceptions) */
#undef __glibcxx_want_constexpr_exceptions
+#if !defined(__cpp_lib_philox_engine)
+# if (__cplusplus > 202302L) && (__SIZEOF_INT128__)
+# define __glibcxx_philox_engine 202406L
+# if defined(__glibcxx_want_all) || defined(__glibcxx_want_philox_engine)
+# define __cpp_lib_philox_engine 202406L
+# endif
+# endif
+#endif /* !defined(__cpp_lib_philox_engine) &&
defined(__glibcxx_want_philox_engine) */
+#undef __glibcxx_want_philox_engine
+
#undef __glibcxx_want_all
diff --git a/libstdc++-v3/include/std/random b/libstdc++-v3/include/std/random
index 0e058a04bd9..8a02ade4b75 100644
--- a/libstdc++-v3/include/std/random
+++ b/libstdc++-v3/include/std/random
@@ -39,6 +39,9 @@
# include <bits/c++0x_warning.h>
#else
+#define __glibcxx_want_philox_engine
+#include <bits/version.h>
+
#include <cmath>
#include <cstdint> // For uint_fast32_t, uint_fast64_t, uint_least32_t
#include <cstdlib>
diff --git a/libstdc++-v3/testsuite/26_numerics/random/philox4x32.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox4x32.cc
new file mode 100644
index 00000000000..d5a8ca078ef
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox4x32.cc
@@ -0,0 +1,23 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
Please identify the document where these references are from, because
29.5.4 might be a different subclause in C++29, i.e.
+// N5014 29.5.4 Random Number Engine Class Templates
+// N5014 29.5.4.5 Class Template philox_engine
(Ideally we'd say "C++26 29.5.4 ..." but we don't know if that
subclause number will be correct in the final standard.)
+
+#include <random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ std::philox4x32 a;
+ a.discard(9999);
+
+ VERIFY( a() == 1955073260 );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git a/libstdc++-v3/testsuite/26_numerics/random/philox4x64.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox4x64.cc
new file mode 100644
index 00000000000..131f094cb28
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox4x64.cc
@@ -0,0 +1,23 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ std::philox4x64 a;
+ a.discard(9999);
+
+ VERIFY( a() == 3409172418970261260 );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/119794.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/119794.cc
new file mode 100644
index 00000000000..c3a5a0eb754
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/119794.cc
@@ -0,0 +1,39 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+#include <random>
+#include <testsuite_hooks.h>
+
+int f(int x)
+{
+ std::seed_seq sq(&x, &x + 1);
+ auto rnd = std::philox4x32(sq);
+ return std::uniform_int_distribution<int>()(rnd);
+}
+
+int g(int x)
+{
+ std::seed_seq sq(&x, &x + 1);
+ auto rnd = std::philox4x32();
+ rnd.seed(sq);
+ return std::uniform_int_distribution<int>()(rnd);
+}
+
+void test01()
+{
+ const int f1 = f(0);
+ const int f2 = f(0);
+
+ const int g1 = g(0);
+ const int g2 = g(0);
+
+ VERIFY( f1 == f2 );
+ VERIFY( g1 == g2 );
+ VERIFY( f1 == g1 );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/copy.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/copy.cc
new file mode 100644
index 00000000000..4f61928a157
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/copy.cc
@@ -0,0 +1,25 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+
+void
+test01()
+{
+
+ std::philox_engine<std::uint_fast32_t, 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53, 0xBB67AE85> e(1ul);
+
+ const auto f(e);
+ auto g(f);
+ g = g; // Suppress unused warning
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/default.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/default.cc
new file mode 100644
index 00000000000..9f9ae94db0f
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/default.cc
@@ -0,0 +1,27 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> philox4x32nullkey(0);
+
+ VERIFY( philox4x32nullkey.min() == 0 );
+ VERIFY( philox4x32nullkey.max() == (1ul << 31 | (1ul << 31) - 1) );
+ VERIFY( philox4x32nullkey() == 0x6627e8d5ul );
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed.cc
new file mode 100644
index 00000000000..5cb914f4b45
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed.cc
@@ -0,0 +1,20 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+#include <random>
+
+void
+test01()
+{
+ unsigned long seed = 2;
+ std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> philox4x32seeded(seed);
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed_seq.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed_seq.cc
new file mode 100644
index 00000000000..7d9e3e6540d
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/cons/seed_seq.cc
@@ -0,0 +1,24 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+
+void
+test01()
+{
+ std::seed_seq sseq{ 1, 2, 3, 4 };
+ std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> philox4x32sseq(sseq);
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/equal.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/equal.cc
new file mode 100644
index 00000000000..4f62bfbbd88
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/equal.cc
@@ -0,0 +1,30 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> x, y;
+
+ VERIFY ( x == y);
+ x.discard(100);
+ y.discard(100);
+
+ VERIFY (x == y);
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/inequal.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/inequal.cc
new file mode 100644
index 00000000000..86d757db904
--- /dev/null
+++
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/inequal.cc
@@ -0,0 +1,30 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> x, y;
+
+ VERIFY ( !(x != y) );
+ x.discard(100);
+ y.discard(100);
+
+ VERIFY ( !(x != y) );
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/serialize.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/serialize.cc
new file mode 100644
index 00000000000..bec4b172512
--- /dev/null
+++
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/operators/serialize.cc
@@ -0,0 +1,49 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <sstream>
+#include <random>
+#include <testsuite_hooks.h>
+#include <iostream>
+
+void
+test01()
+{
+ std::stringstream str;
+ std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> x, y;
+
+ x();
+ str << x;
+
+ VERIFY ( !(x == y) );
+ str >> y;
+ VERIFY ( x == y );
+ for (unsigned long i = 0; i < 100; ++i)
+ {
+ VERIFY (x() == y());
+ }
+ str.clear();
+ str << y;
+ x();
+ x();
+ x();
+ str >> x;
+ VERIFY ( x == y );
+ for (unsigned long i = 0; i < 1000; ++i)
+ {
+ VERIFY (x() == y());
+ }
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constants.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constants.cc
new file mode 100644
index 00000000000..c242056e0a4
--- /dev/null
+++
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constants.cc
@@ -0,0 +1,26 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+
+void test01()
+{
+ std::philox4x32 philox;
+ const void* p = &philox.word_size;
+ p = &philox.word_count;
+ p = &philox.round_count;
+ p = &philox.multipliers;
+ p = &philox.round_consts;
+ p = &philox.default_seed;
+ p = p; // Suppress unused warning.
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_data.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_data.cc
new file mode 100644
index 00000000000..5be0108c88c
--- /dev/null
+++
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_data.cc
@@ -0,0 +1,50 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+#include <testsuite_common_types.h>
+
+namespace __gnu_test
+{
+ struct constexpr_member_data
+ {
+ template<typename _Ttesttype>
+ void
+ operator()()
+ {
+ struct _Concept
+ {
+ void __constraint()
+ {
+ constexpr auto v1 __attribute__((unused))
+ = _Ttesttype::word_size;
+ constexpr auto v2 __attribute__((unused))
+ = _Ttesttype::word_count;
+ constexpr auto v3 __attribute__((unused))
+ = _Ttesttype::round_count;
+ constexpr auto v4 __attribute__((unused))
+ = _Ttesttype::multipliers;
+ constexpr auto v5 __attribute__((unused))
+ = _Ttesttype::round_consts;
+ constexpr auto v6 __attribute__((unused))
+ = _Ttesttype::default_seed;
+ }
+ };
+
+ _Concept c;
+ c.__constraint();
+ }
+ };
+};
+
+int
+main()
+{
+ __gnu_test::constexpr_member_data test;
+ typedef std::philox4x32 type;
+ test.operator()<type>();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_functions.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_functions.cc
new file mode 100644
index 00000000000..eb61d15568a
--- /dev/null
+++
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/constexpr_functions.cc
@@ -0,0 +1,41 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+#include <random>
+#include <testsuite_common_types.h>
+
+namespace __gnu_test
+{
+ struct constexpr_member_functions
+ {
+ template<typename _Ttesttype>
+ void
+ operator()()
+ {
+ struct _Concept
+ {
+ void __constraint()
+ {
+ constexpr auto v1 __attribute__((unused))
+ = _Ttesttype::min();
+ constexpr auto v2 __attribute__((unused))
+ = _Ttesttype::max();
+ }
+ };
+ _Concept c;
+ c.__constraint();
+ }
+ };
+}
+
+int
+main()
+{
+ __gnu_test::constexpr_member_functions test;
+ typedef std::philox4x32 type;
+ test.operator()<type>();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/typedefs.cc
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/typedefs.cc
new file mode 100644
index 00000000000..b368ee74106
--- /dev/null
+++
b/libstdc++-v3/testsuite/26_numerics/random/philox_engine/requirements/typedefs.cc
@@ -0,0 +1,26 @@
+// { dg-do run { target c++26 } }
+// { dg-require-cstdint "" }
+
+// 29.5.4 Random Number Engine Class Templates
+// 29.5.4.5 Class Template philox_engine
+
+
+#include <random>
+
+void
+test01()
+{
+ typedef std::philox_engine<std::uint_fast32_t,
+ 32, 4, 10, 0xCD9E8D57,
+ 0x9E3779B9, 0xD2511F53,
+ 0xBB67AE85> testType;
+
+ typedef testType::result_type result_type;
+}
+
+int
+main()
+{
+ test01();
+ return 0;
+}
diff --git a/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
b/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
index 0afba654152..13a0b8947b0 100644
--- a/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
+++ b/libstdc++-v3/testsuite/26_numerics/random/pr60037-neg.cc
@@ -10,6 +10,6 @@ std::__detail::_Adaptor<std::mt19937, unsigned long>
aurng(urng);
auto x = std::generate_canonical<std::size_t,
std::numeric_limits<std::size_t>::digits>(urng);
-// { dg-error "static assertion failed: template argument must be a floating point type"
"" { target *-*-* } 270 }
+// { dg-error "static assertion failed: template argument must be a floating point type"
"" { target *-*-* } 271 }
-// { dg-error "static assertion failed: template argument must be a floating point type"
"" { target *-*-* } 3357 }
+// { dg-error "static assertion failed: template argument must be a floating point type"
"" { target *-*-* } 3548 }
--
2.49.0
