[EMAIL PROTECTED] wrote: > Bill KING <[EMAIL PROTECTED]> wrote: > >> A colleague brought up a very good point. At least for the first few >> revisions, is the old engine/code still going to be available until the >> new engine code base settles down? >> >> > > You can always pull the old code frm CVS and run it against > the newer code. We started making the switch with check-in [4652] > on 2008-01-02. So any CVS verious prior to that will be a pure > stack-based machine. > As expected, will be setting up a set of auto-tests for our particular use-case, but that's just being a good software engineer ;) > The changes consist of slowly adding capability to the existing > VM so that it can work with operands on the stack or in registers. > This continued through check-in [4700] on 2008-01-09. After [4700], > all operations can be done using register operands, though the > code generator still uses the stack for many things. Since then > and moving forward, we are converting the code generator to use > registers rather than the stack, and we are removing stack > capabilities from the VM as those abilities lapse from use. > Toward the end of the process, we will completely remove the > operand stack from the VM. > One hell of a challenge, but in the end, I do agree with you, there's been a lot of knowledge around for a long time on register based optimisations, and with an infinite register machine, some really amazing optimizations can occur, agreed. Besides, all the cool kids are doing it too ;) > During the conversion process, SQLite will likely be slower and > use more memory. But all regression tests are suppose to pass > after each check-in. So we hope to avoid introducing any bugs. > Once the conversion is complete, we hope to be able to reduce > the memory footprint of each sqlite3_stmt object and make them > run a little faster too. But we need to get a correctly functioning > pure register VM first. > This part I'm happy with "all regression tests are supposed to pass" :) I'm still going to wait a point or two before production tho, but that's again just careful management. Looking forward to this tho in the long run. > -- > D. Richard Hipp <[EMAIL PROTECTED]> > > > ----------------------------------------------------------------------------- > To unsubscribe, send email to [EMAIL PROTECTED] > ----------------------------------------------------------------------------- > > >
-- Bill King, Software Engineer Trolltech, Brisbane Technology Park 26 Brandl St, Eight Mile Plains, QLD, Australia, 4113 Tel + 61 7 3219 9906 (x137) Fax + 61 7 3219 9938 mobile: 0423 532 733 ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
