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| author | Jonathan Wakely <jwakely@redhat.com> | 2024-03-18 13:22:17 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2024-03-19 15:59:44 +0000 |
| commit | 07e03761a7fc1626a6a74ed957e117f56981558c (patch) | |
| tree | 6b66bbf3ca7e2cc3331d1d2c83c20f580f198267 /libstdc++-v3/include | |
| parent | c608b57f77a47179899666940c3b8b6a2e5435b2 (diff) | |
| download | gcc-07e03761a7fc1626a6a74ed957e117f56981558c.zip gcc-07e03761a7fc1626a6a74ed957e117f56981558c.tar.gz gcc-07e03761a7fc1626a6a74ed957e117f56981558c.tar.bz2 | |
libstdc++: Fix infinite loop in std::binomial_distribution [PR114359]
The multiplication (4 * _M_t * __1p) can wraparound to zero if _M_t is
unsigned and 4 * _M_t wraps to zero. The third operand has type double,
so do the second multiplication first, so that we aren't multiplying
integers.
libstdc++-v3/ChangeLog:
PR libstdc++/114359
* include/bits/random.tcc (binomial_distribution::param_type):
Ensure arithmetic is done as type double.
* testsuite/26_numerics/random/binomial_distribution/114359.cc: New test.
Diffstat (limited to 'libstdc++-v3/include')
| -rw-r--r-- | libstdc++-v3/include/bits/random.tcc | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc index ade4163..8216883 100644 --- a/libstdc++-v3/include/bits/random.tcc +++ b/libstdc++-v3/include/bits/random.tcc @@ -1503,7 +1503,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // sqrt(pi / 2) const double __spi_2 = 1.2533141373155002512078826424055226L; _M_s1 = std::sqrt(__np * __1p) * (1 + _M_d1 / (4 * __np)); - _M_s2 = std::sqrt(__np * __1p) * (1 + _M_d2 / (4 * _M_t * __1p)); + _M_s2 = std::sqrt(__np * __1p) * (1 + _M_d2 / (4 * (_M_t * __1p))); _M_c = 2 * _M_d1 / __np; _M_a1 = std::exp(_M_c) * _M_s1 * __spi_2; const double __a12 = _M_a1 + _M_s2 * __spi_2; |