Mail Archives: djgpp-workers/1998/05/07/23:06:14
Nate Eldredge wrote:
> At 11:23 5/7/1998 +0200, Vik Heyndrickx wrote:
> >....
> >``FIXME string operations'' remarks: FYI they are not generally slow
> >when they are
> >repz/repnz-ed. Intel knows where they are used for (I hope ;-)
>
> I seem to recall from looking at some glibc sources that on newer
> processors, Intel had put more work into speeding up the more RISC-ish
> instructions than the string ones. The result was that they could sometimes
> be slower than their simpleminded equivalents. I don't know enough to know
> whether that applies here, hence the comment. But you may well be right.
A pretty good rule of thumb is that "move"s are faster, "load"s and
"store"s are not [for the Pentium]. I think "REPZ CMPD" might be slower
too, but I'm not sure. Ppros and P-IIs are a lot more complicated,
but they look more like 486s than Pentiums (that is, the dual pipe
tricks no longer help, so REPs may start helping more again). Not
a lot has been written (that I've read, at least) on P6 string
optimization, though, so I stand to learn a lot about these cases if
anyone else has a bit to say.
>....
> Btw, can somebody tell me the following about LFN's:
> * Is case significant with LFN's enabled? i.e. will open("FooBar") fail if
> the file is really `foobar'?
Nope, case is only sorta significant. Case is preserved (and returned)
but two file names differing only in case will match. And Win95 seems
to preserve the existing file name more than I would think possible (my
version of MicroEMACS, for example, is set up to build a temporary, then
when the write takes place, the original is deleted and the temporary is
renamed -- usually, but not always, the updated file will have the same
case as the original in spite of the fact that the program is not LFN aware
and the original file should have been flushed before the rename takes
place!).
> * If so, is there a way to make Info-Zip store names as what you tell it,
> instead of the actual file names?
>
> I ask because my distribution includes some .S files, and GCC interprets
> that differently from .s, and I only have SFNs. Previously I made the zip on
> Linux, but rebooting all the time is a pain. For paranoia I am now including
> a fixlfn.bat file which will rename them to the appropriate cases, but if
> there is a better solution I would like to know it. (I'm also considering
> just naming them .s, and passing GCC `-x assembler-with-cpp', but that's not
> pretty.)
I, too, would like to know the answer to this question!
> Thanks again
>
> Nate Eldredge
> nate AT cartsys DOT com
--Charles
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