json_mlake · API · cpu
json.cpu.simd_clmulprefix_xor64def prefix_xor64(x: UInt64) -> UInt64Per-bit prefix XOR over 64 bits.
Equivalent to clmul(x, ~UInt64(0)).low_64() (one PCLMULQDQ on x86
or one PMULL on ARM64 with CLMUL). The shift-based form below
compiles to six xor+shl pairs, ~6 cycles on a modern OoO core
-- well within the per-chunk budget for 64-byte stage 1 work
units, and free of any ISA feature gating.
find_escape_mask64def find_escape_mask64(backslash: UInt64, mut prev_escape: UInt64) -> UInt64Returns the bit-mask of bytes that are escaped within this chunk.
prev_escape carries the "byte 0 of this chunk is escaped by a
backslash from the previous chunk" flag (0 or 1). After the call,
prev_escape is updated to be the carry into the NEXT chunk -- 1
iff this chunk ended with a backslash whose escape lands on byte 0
of the chunk after.
Mirrors simdjson's json_escape_scanner::next.