9f3bfb8f
wire: inline decode_varint 1-byte fast path at all decoders (~2× decode)
decode_tag, decode_len, decode_int32/uint32/int64/uint64/sint32/sint64/
bool, and the VARINT/LEN branches of skip_field each now read the first
byte directly, handle 0..127 in straight-line code, and call into
decode_varint only for multi-byte values. The duplicated 3 lines per
call site are the cost of avoiding LuaJIT 2.1's side-trace-returning-
from-inlined-call limitation: with the fast path inlined, side traces
off the parent decoder's hot guard stay in the caller's own frame and
stitch back cleanly instead of bridging to interpreter dispatch.
Effect (bench/bench.lua, hello.Person across 5 sizes):
full mode decode: 2.1×–2.4× throughput (104→220 .. 14→33 MB/s)
runtime mode decode: 2.0×–2.1× throughput (90→175 .. 12→25 MB/s)
encode: unchanged (only decode paths were touched)
alloc/op: unchanged (bench-compare clean)
bridges: 27 → 7 across 10 jit-trace runs (-74%);
remaining are encoder-side (codec.lua:41/110 in runtime mode)
Eugene Blikh <bigbes@gmail.com> — 2026-05-15 10:52:29 UTC
Commit 9f3bfb8f9b5fa2942f8256831b0ad26c34ff6704 —
view raw patch
Parent(s):
aff3ee42
| File | Status | + | − |
|---|---|---|---|
runtime/pb/wire.lua
|
M | +56 | -2 |