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Niels Lohmann
32ca00cdfa
The contiguous number fast path validated a token byte by byte, copied it into token_buffer, and then converted it in out-of-line functions that scanned the digits a second time: parse_float_native() called parse_float_significand(), which returned its result through memory and called std::any_of (out of line with GCC) twice per number, and parse_integer_signed() divided by ten on every digit for its overflow check. scan_number_bulk_contiguous() now accumulates the significand while it validates the digits, eight at a time where at least eight bytes remain (is_eight_digits() and parse_eight_digits(), after fast_float). Floats with at most 19 digits go straight to decimal_to_float(); integers with at most 18 digits are stored without an overflow check (a narrower number type still rejects values that do not round-trip). Longer tokens take the existing path. has_nonzero_digit() is a plain loop and parse_float_significand() is always inlined, which helps that path. Signed-off-by: Niels Lohmann <mail@nlohmann.me>