Tcl Source Code: View Ticket

Ticket UUID:	8994c972ad3df0aff53739fce486e39809a7b752
Title:	Performance regression in the expr in/ni operator in Tcl 9
Type:	Bug	Created on:	2026-03-11 14:02:52
Submitter:	apnadkarni	Assigned to:	nobody
Subsystem:	16. Commands A-H	Severity:	Important
Priority:	5 Medium	Last modified:	2026-03-13 02:48:13
Status:	Closed	Closed by:	apnadkarni
Resolution:	Fixed	Closed on:	2026-03-13 02:48:13
Version:	9.0

Description:
Compare 8.6 `% timerate -calibrate {} 0.03480732249997189 µs/#-overhead 0.035377 µs/# 55176756 # 28266780 #/sec % set l [lrepeat 1000 x]; timerate {expr {"a" in $l}} 6.619428 µs/# 150279 # 151070 #/sec 994.761 net-ms` with 9.0 `% package req Tcl 9.0.2 % set l [lrepeat 1000 x]; timerate {expr {"a" in $l}} 9.195111 µs/# 108328 # 108753 #/sec 996.088 net-ms`
User Comments:
apnadkarni added on 2026-03-11 15:45:53: Proposed fix in 9893f7e1e7. `timerate -calibrate {} 0.03631045936580007 µs/#-overhead 0.036670 µs/# 53231733 # 27270355 #/sec % package req Tcl 9.0.4 % set l [lrepeat 1000 x]; timerate {expr {"a" in $l}} 4.169346 µs/# 237791 # 239845 #/sec 991.433 net-ms`