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| author | Jonathan Wakely <jwakely@redhat.com> | 2023-08-11 18:10:29 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2023-08-11 18:20:48 +0100 |
| commit | 9e33d71834416b7eddadae2b0f68e85f04cd0c7f (patch) | |
| tree | 9788f08737983c7263cf0806c9441cfd1e9a5fba /libstdc++-v3/include | |
| parent | 20db5cab7a5ca9ac2928d10efca85e80a3d8630b (diff) | |
| download | gcc-9e33d71834416b7eddadae2b0f68e85f04cd0c7f.zip gcc-9e33d71834416b7eddadae2b0f68e85f04cd0c7f.tar.gz gcc-9e33d71834416b7eddadae2b0f68e85f04cd0c7f.tar.bz2 | |
libstdc++: Do not call log10(0.0) in std::format [PR110860]
Calling log10(0.0) returns -inf which has undefined behaviour when
converted to an integer. We only need to use log10 for large values
anyway. If the value is zero then the larger buffer is only needed due
to a large precision, so we don't need to use log10 to estimate the
number of digits for the significand.
libstdc++-v3/ChangeLog:
PR libstdc++/110860
* include/std/format (__formatter_fp::format): Do not call log10
with zero values.
Diffstat (limited to 'libstdc++-v3/include')
| -rw-r--r-- | libstdc++-v3/include/std/format | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 2fe430f..23da6b0 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -1490,7 +1490,7 @@ namespace __format // If the buffer is too small it's probably because of a large // precision, or a very large value in fixed format. size_t __guess = 8 + __prec; - if (__fmt == chars_format::fixed) // +ddd.prec + if (__fmt == chars_format::fixed && __v != 0) // +ddd.prec { if constexpr (is_same_v<_Fp, float>) __guess += __builtin_log10f(__v < 0.0f ? -__v : __v); |