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Niels Lohmann
606c1e710b
The vector UTF-8 check of json_view needed SSSE3 at compile time (JSON_VIEW_USE_SSSE3 with -mssse3), so default x86-64 builds validated non-ASCII text one sequence at a time. The check is now compiled for SSSE3 with a function attribute (GCC 4.9 and later, Clang; MSVC compiles the intrinsics anyway) and used where CPUID reports SSSE3. The answer is kept in an atomic that is initialized at compile time, so neither a guard nor a global constructor is needed. The definitions do not depend on compiler flags, so there is no ODR issue. JSON_VIEW_USE_SSSE3 now only skips the CPU check. On x86-64 Linux (Haswell), twitter.json parses 23% faster with Clang 18 and 25-34% faster with GCC 13, now ahead of yyjson. Also always inline read_eight_bytes() and parse_eight_digits(): GCC called both in the number loops of the lexer and of json_view (52 call sites), which cost about 10% on citm_catalog.json at -O2. Document that reusing a document with read() avoids the page faults of a fresh node index (about 40% of a 55 MB parse on x86-64 Linux). Signed-off-by: Niels Lohmann <mail@nlohmann.me>