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From: "hiraditya at msn dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/94823] modulo arithmetic bug in random.tcc
Date: Tue, 28 Apr 2020 20:56:34 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94823

AK <hiraditya at msn dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hiraditya at msn dot com

--- Comment #1 from AK <hiraditya at msn dot com> ---
Here's the partial stack trace in case it helps

```
in bits/random.tcc:3274:20: runtime error: unsigned integer overflow: 0 - 1
cannot be represented in type 'unsigned long'

in void std::seed_seq::generate<unsigned int*>(unsigned int*, unsigned int*=
)=20

in std::enable_if<std::is_class<std::seed_seq>::value, void>::type
__gnu_cxx::simd_fast_mersenne_twister_engine<unsigned int, 19937ul, 122ul,
18ul, 1ul, 11ul, 1ul, 3758096367u, 3724462975u, 3220897791u, 3221225462u, 1=
u,
0u, 0u, 331998852u>::seed<std::seed_seq>(std::seed_seq&) ext/random.tcc:110

in __gnu_cxx::simd_fast_mersenne_twister_engine<unsigned int, 19937ul, 122u=
l,
18ul, 1ul, 11ul, 1ul, 3758096367u, 3724462975u, 3220897791u, 3221225462u, 1=
u,
0u, 0u, 331998852u>::simd_fast_mersenne_twister_engine<std::seed_seq,
void>(std::seed_seq&) ext/random:104
```=