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

Keith Rohrer (
Wed, 26 Feb 1997 01:50:50 -0600 (CST)

> 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)?