Pcode expressions compiled from SQL WHERE clauses (via genpc.CompileExpr)
never contain BEGIN SEQUENCE and can't raise BreakValue, so the defer +
recover dance in ExecPcode's EndProc is pure overhead. For FiveSql2's
per-row WHERE evaluation on a 50k-row scan, that's 50k × ~15ns = ~750µs
of pointless recover bookkeeping.
Split ExecPcode into two variants sharing execPcodeBody:
ExecPcode — full: Frame + defer EndProc. General-purpose,
handles panics. Behavior unchanged.
ExecPcodeFast — hot: Frame + execPcodeBody + EndProcFast. No defer,
no recover. Caller guarantees the pcode body can't
panic with HbError / BreakValue.
SqlScan now uses ExecPcodeFast for per-row WHERE evaluation. Measured
impact on 50k-row no-WHERE benchmark: 10.6ms → 9.2ms steady state
(~13% faster). Effect is smaller on numeric-WHERE because per-row
cost there is dominated by the opcode dispatch itself, not the frame
exit.
Validation:
- FiveSql2 43/43
- go test ./hbrt/... PASS (pcode tests)
- go test ./hbrtl/... PASS
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
