RE: What can we optimize (was Re: Schwartzian transforms)

2001-03-31 Thread Dan Sugalski
At 03:38 PM 3/29/2001 -0800, David Whipp wrote: > > From: Dan Sugalski [mailto:[EMAIL PROTECTED]] > > I'm hoping to have this stage of optimization in perl. Off by > > default with > > a normal parse-and-go run (though certainly enableable if you > > want), on by > > default with the bytecode comp

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-30 Thread David L. Nicol
Dan Sugalski wrote: > > At 02:52 PM 3/29/2001 -0800, Russ Allbery wrote: > >James Mastros <[EMAIL PROTECTED]> writes: > > > > > Ahh, bingo. That's what a number of people (inculding me) are > > > suggesting -- a :functional / :pure / :stateless / > > > :somthingelseIdontrecall attribute attachab

RE: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread David Whipp
> From: Dan Sugalski [mailto:[EMAIL PROTECTED]] > I'm hoping to have this stage of optimization in perl. Off by > default with > a normal parse-and-go run (though certainly enableable if you > want), on by > default with the bytecode compiler. Don't forget about run-time information: You coul

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dan Sugalski
At 06:22 PM 3/29/2001 -0500, Uri Guttman wrote: > > "DS" == Dan Sugalski <[EMAIL PROTECTED]> writes: > > >> This will probably be harder in Perl than in C because C can afford to > >> take more time to do global optimization passes. > > DS> I'm hoping to have this stage of optimization i

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Uri Guttman
> "DS" == Dan Sugalski <[EMAIL PROTECTED]> writes: >> This will probably be harder in Perl than in C because C can afford to >> take more time to do global optimization passes. DS> I'm hoping to have this stage of optimization in perl. Off by DS> default with a normal parse-and-go ru

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dan Sugalski
At 02:52 PM 3/29/2001 -0800, Russ Allbery wrote: >James Mastros <[EMAIL PROTECTED]> writes: > > > Ahh, bingo. That's what a number of people (inculding me) are > > suggesting -- a :functional / :pure / :stateless / > > :somthingelseIdontrecall attribute attachable to a sub. > >The experience from

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Russ Allbery
James Mastros <[EMAIL PROTECTED]> writes: > Ahh, bingo. That's what a number of people (inculding me) are > suggesting -- a :functional / :pure / :stateless / > :somthingelseIdontrecall attribute attachable to a sub. The experience from gcc, which has a similar attribute, is that such an attrib

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Russ Allbery
Dan Sugalski <[EMAIL PROTECTED]> writes: > Aliasing is actually one of the bigger problems with C, or so I'm lead > to believe. It gets in the way of a number of optimizations rather > badly. (So say some of Compaq's C and Fortran compiler folks, and I have > no reason to doubt them. The Fortran

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dan Sugalski
At 10:57 PM 3/29/2001 +0100, Piers Cawley wrote: >How painful would an 'potential' optimization that marked that area in >the bytecode/optree/whatever, with something along the lines of the >following be? > > If you get to this point and $i is not tied, and '=' is not > overridden for $i's

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Piers Cawley
Dan Sugalski <[EMAIL PROTECTED]> writes: > True enough. This is a small subset of general optimizations. For example, > this: > > >$i = 0; >foreach (1..1000) { > $i++; >} > > can be easily optimized to: > >$i = 1000; > > and most language implementations with any sort of o

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Juanma Barranquero
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Thu, 29 Mar 2001 10:36:48 -0800, "Hong Zhang" <[EMAIL PROTECTED]> wrote: > The function in Ada can not have any side effect, i.e. no change to > globals. Unless my reading of the Ada 95 standard is wrong, there's nothing that precludes function

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread James Mastros
On Thu, Mar 29, 2001 at 10:36:48AM -0800, Hong Zhang wrote: > I have to say that I agree to disagree. Since it has been so controversal, > I just don't think this optimization is a good one. Hmm, we aren't talking sort() specificly anymore. Look at the subject line. > The function in Ada can no

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Hong Zhang
> >Who really needs this kind of optimization for Perl? > > I do. Lots of people with web apps do. Pretty much anyone with a large or > long-running perl program does. I have to say that I agree to disagree. Since it has been so controversal, I just don't think this optimization is a good one. >

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Jarkko Hietaniemi
On Thu, Mar 29, 2001 at 11:29:16AM -0500, Dan Sugalski wrote: > At 05:19 PM 3/29/2001 +0100, Dave Mitchell wrote: > >Jarkko Hietaniemi <[EMAIL PROTECTED]> wrote: > > > Somewhat tangentially: this reminds me of a message a week ago or so > > > (can't find it anymore in my inbox) which proposed writ

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dan Sugalski
At 03:41 PM 3/28/2001 -0800, Hong Zhang wrote: >Are we over-optimizing? The Perl is just an interpreter language. Perl's not just an interpreter language, and hasn't been for a while. (Granted the bytecode compiler's not fully functional, but it does work in some cases) >Who really needs this

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dan Sugalski
At 05:19 PM 3/29/2001 +0100, Dave Mitchell wrote: >Jarkko Hietaniemi <[EMAIL PROTECTED]> wrote: > > Somewhat tangentially: this reminds me of a message a week ago or so > > (can't find it anymore in my inbox) which proposed writing C (or C++) > > code for Perl 6 so that "modern CPU architectures a

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dan Sugalski
At 10:25 AM 3/29/2001 -0500, James Mastros wrote: >On Wed, Mar 28, 2001 at 03:41:42PM -0800, Hong Zhang wrote: > > Are we over-optimizing? The Perl is just an interpreter language. > > Who really needs this kind of optimization for Perl? Even C does > > not provide this feature. >Umm, art thou sur

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread John Porter
Dave Mitchell wrote: > The main thrust of that was whether a PDD on coding conventions > should have sections on: >... > * Performance guidelines > > ...I guess we can safely dispense with that last entry. No, performance guidelines are probably still appropriate; but doing hand-coded peephole o

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Dave Mitchell
Jarkko Hietaniemi <[EMAIL PROTECTED]> wrote: > Somewhat tangentially: this reminds me of a message a week ago or so > (can't find it anymore in my inbox) which proposed writing C (or C++) > code for Perl 6 so that "modern CPU architectures are happy" (no > pipeline stalls because of "if"-s, etc.)

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread John Porter
Jarkko Hietaniemi wrote: > ... proposed writing C (or C++) > code for Perl 6 so that "modern CPU architectures are happy" (no > pipeline stalls because of "if"-s, etc.) ... in > general, for large codebases, the C compilers are much, much, > better in optimizing than humans. I totally agree. Th

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread Jarkko Hietaniemi
On Thu, Mar 29, 2001 at 10:25:06AM -0500, James Mastros wrote: > On Wed, Mar 28, 2001 at 03:41:42PM -0800, Hong Zhang wrote: > > Are we over-optimizing? The Perl is just an interpreter language. > > Who really needs this kind of optimization for Perl? Even C does > > not provide this feature. > U

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-29 Thread James Mastros
On Wed, Mar 28, 2001 at 03:41:42PM -0800, Hong Zhang wrote: > Are we over-optimizing? The Perl is just an interpreter language. > Who really needs this kind of optimization for Perl? Even C does > not provide this feature. Umm, art thou sure? C can optimize better then we currently do many times

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-28 Thread Hong Zhang
ki" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Wednesday, March 28, 2001 3:01 PM Subject: Re: What can we optimize (was Re: Schwartzian transforms) > On Wed, Mar 28, 2001 at 05:57:30PM -0500, James Mastros wrote: > > [A bunch of stuff] > Oh, and I agree with

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-28 Thread James Mastros
On Wed, Mar 28, 2001 at 05:57:30PM -0500, James Mastros wrote: > [A bunch of stuff] Oh, and I agree with sombody else on this thread that unless otherwise stated, the sort should always assume statelessness (and thus the ability to cache at will). If it's trivial to see that the sort function isn

Re: What can we optimize (was Re: Schwartzian transforms)

2001-03-28 Thread James Mastros
On Wed, Mar 28, 2001 at 04:36:58PM -0500, Dan Sugalski wrote: > With perl, though, this does > potentially unexpected things if $i is tied. Do we still optimize it away? > Do we only do it if we can tell that $i's not tied? Yep. And in non-trivial cases, the only way to do that might be for $i

What can we optimize (was Re: Schwartzian transforms)

2001-03-28 Thread Dan Sugalski
At 01:22 PM 3/28/2001 -0800, Russ Allbery wrote: >Dan Sugalski <[EMAIL PROTECTED]> writes: > > > I'm actually considering whether we even need to care what the > > programmer's said. If we can just flat-out say "We may optimize your > > sort function, and we make no guarantees as to the number of