Re: a.out binaries that are 66% faster than ELF

Bryn Paul Arnold Jones (bpaj@gytha.demon.co.uk)
Wed, 26 Feb 1997 11:44:27 +0000 (GMT)


On Wed, 26 Feb 1997, Keith Rohrer wrote:

> > I'd say that the performance difference between the ELF and a.out versions
> > warrants an investigation of some sort. Comparing the "gcc -S" would be
> > a good start I guess...
> The a.out assembly uses smaller alignments (2 vs. 4 for variables, 4 vs.
> 16 for code); it uses leading underscores where the elf assembly does
> not. I would've put copies of the .s files on the web, but there's
> that pesky ITAR thing. Still, given the 386 was hardest hit, I expect
> that the smaller alignment padding wasn't the problem, and the underscore
> convention is purely a cosmetic naming thing. My bet is still on cache
> conflict misses. Anyone tried this on an MMX Pentium (bigger cache)?
>
> Keith
>

Hmm, on an MMX 200, I get "Complete in 6.699 seconds. (149281.92
keys/sec)" for the ELF executable as from the 2.01 source, if anyone
want's to send me a a.out/elf pair, I'll test them ... (I'd participate,
but I can't afford to keep my ppp link up, and I really don't want to
come prod it every 27 minutes)

Bryn

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