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Niels Lohmann
aecbef3949
* Binary readers: swap the bytes of floats with a single byteswap byte_swap reversed float and double values byte by byte. GCC does not merge that loop into one bswap, and C++23's std::byteswap accepts only integers. Overloads for float and double now copy the bits into a uint32_t/uint64_t, call detail::byteswap, and copy them back. This applies to every binary reader that uses get_number. In the CBOR reader, the single- and double-precision float cases call a non-inlined helper. Without it, GCC stopped inlining the stream adapter's get_character() into parse_cbor_internal, which made reading from a std::istream about 0.5 % slower. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * CBOR reader: inline get_cbor_float() and always inline get() instead The never-inlined get_cbor_float() costs a call for every float read from input without bulk access: reading canada.json from CBOR through a FILE* became 5.6 % slower on Apple clang in the benchmark suite. The helper existed only because GCC 13 stopped inlining the stream adapter's get_character() into parse_cbor_internal. Always inlining binary_reader::get() fixes that as well. callgrind, all binary formats on buffer, std::istringstream and FILE* input (canada and citm_catalog): GCC 13 0.986-1.003, GCC 16 0.994-1.006, Clang 23 identical. Apple clang suite: FromBinaryFile/cbor/canada 0.939, geomean of the 53 binary reader rows 0.998. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>