Niels Lohmann 2f817b9174 SWAR: test for special bytes in the reduced form ...

The usual test for a zero byte, (x - ones) & ~x & high, needs `& ~x` only
to keep bytes from 0x80 out. The tests for quotes, backslashes and control
characters in string_scan.hpp and the serializer also flag every byte from
0x80 with `v & high`, so the `& ~x` terms can be dropped. Clang finds this
reduction itself; GCC does not and emits 24 instead of 16 instructions.

The masks are the same for 1.3 billion random words and for every pair of
adjacent byte values. With GCC 15 on x86-64: accept() -2 to -4 %,
sax_parse() -2 %, dump() -3 %. Clang is unchanged.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

2026-11-06 12:17:57 +01:00

..

conversions

Raise line coverage to 99.9 %: fix the measurement, remove unreachable code, add tests (#5997)

2026-11-02 17:54:38 +01:00

input

SWAR: test for special bytes in the reduced form

2026-11-06 12:17:57 +01:00

iterators

Restore the two commits of #6005 that the stack merge dropped (fixes the build of develop) (#6012)

2026-11-02 18:23:44 +01:00

meta

json_view: from_json() of the macros reads views directly (#5922)

2026-10-26 20:13:31 +01:00

output

SWAR: test for special bytes in the reduced form

2026-11-06 12:17:57 +01:00

view

Fix the MSVC and GCC builds of develop (C4127, -Weffc++) (#6016)

2026-11-02 20:07:00 +01:00

abi_config.hpp

Add json_document and json_view: node index, parser, and document (#5620)

2026-10-21 10:21:27 +02:00

abi_macros.hpp

json_view: one SIMD macro set with the library (#5921)

2026-10-26 20:13:31 +01:00

bit_ops.hpp

Use standard library helpers where available, with C++11 fallbacks (#5876)

2026-10-21 20:14:59 +02:00

exceptions.hpp

Keep the byte range in exceptions about the root value (#5990)

2026-11-02 17:50:40 +01:00

hash.hpp

Make std::hash<basic_json> consistent with operator== for numbers (#5772)

2026-10-07 19:18:51 +02:00

json_custom_base_class.hpp

Fix ADL leak of nlohmann::detail through basic_json's default base class (#5238)

2026-07-06 12:47:24 +02:00

json_pointer.hpp

Raise line coverage to 99.9 %: fix the measurement, remove unreachable code, add tests (#5997)

2026-11-02 17:54:38 +01:00

json_ref.hpp

Copy a pair-shaped array value under JSON_BRACE_INIT_COPY_SEMANTICS (#5701)

2026-10-07 07:39:05 +02:00

macro_scope.hpp

json_view: exceptions name the path and the bytes of the value (#5974)

2026-11-01 17:25:26 +01:00

macro_unscope.hpp

Use standard library helpers where available, with C++11 fallbacks (#5876)

2026-10-21 20:14:59 +02:00

recursion_depth_limit.hpp

Share one nesting depth limit between all bounded descents (#5637)

2026-09-30 20:06:43 +02:00

string_concat.hpp

Raise line coverage to 99.9 %: fix the measurement, remove unreachable code, add tests (#5997)

2026-11-02 17:54:38 +01:00

string_escape.hpp

Raise line coverage to 99.9 %: fix the measurement, remove unreachable code, add tests (#5997)

2026-11-02 17:54:38 +01:00

string_utils.hpp

Raise line coverage to 99.9 %: fix the measurement, remove unreachable code, add tests (#5997)

2026-11-02 17:54:38 +01:00

value_t.hpp

Consolidate duplicated detail helpers and bodies (#5891) (#5901)

2026-10-25 06:17:50 +01:00