Re: [TCLCORE] New Bytecode Branch Ready for Review

[Donal F. <don...@ma...>]

A side note: the INST_JUMP_TABLE_NUM instruction will enable the addition of a new mode of operation for [switch] that I've been thinking about for a while: switching on integer equality, which I've seen the need for in handling things like switching on the number of arguments passed to a procedure. (It can't be safely done now because we use the wrong sort of equality testing.) I'll TIP that up once the instruction to make it practical hits the trunk.

Donal.

________________________________
From: Donal Fellows
Sent: Friday, May 02, 2025 17:24
To: Tcl Core
Subject: [TCLCORE] New Bytecode Branch Ready for Review

The branch for the new bytecodes (with the wonderfully wieldy name no-variable-width-instruction-issue) is ready for someone to give it a bit of a review.  It's quite a large one, so here's a summary:

[...]

The replacement for INST_RETURN_CODE_BRANCH is INST_JUMP_TABLE_NUM that is a general numeric-keyed jump table. (Take note for the Tcl Compiler and TBCLoad: there's a new AUX type).

[...]

Some of the operations are made available to [tcl::unsupported::assemble]. Only the error prefix comparator isn't; that's got safety requirements on its argument that I'm not bothering to make the assembler understand.