diff options
| -rw-r--r-- | libstdc++-v3/include/std/format | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 60e5364..f68308e 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -1487,9 +1487,20 @@ 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 = __prec + sizeof(__buf); - if (__fmt == chars_format::fixed) - __guess += max((int)__builtin_log10(__builtin_abs(__v)) / 2, 1); + size_t __guess = 8 + __prec; + if (__fmt == chars_format::fixed) // +ddd.prec + { + if constexpr (is_same_v<_Fp, float>) + __guess += __builtin_log10f(__v < 0.0f ? -__v : __v); + else if constexpr (is_same_v<_Fp, double>) + __guess += __builtin_log10(__v < 0.0 ? -__v : __v); + else if constexpr (is_same_v<_Fp, long double>) + __guess += __builtin_log10l(__v < 0.0l ? -__v : __v); + else + __guess += numeric_limits<_Fp>::max_exponent10; + } + if (__guess <= sizeof(__buf)) [[unlikely]] + __guess = sizeof(__buf) * 2; __dynbuf.reserve(__guess); do |