[Python-Dev] Re: Python 2.1 slower than 2.0

Jeremy Hylton jeremy@alum.mit.edu
Mon, 29 Jan 2001 12:27:08 -0500 (EST)

>>>>> "ESR" == Eric S Raymond <esr@thyrsus.com> writes:

  ESR> Jeremy Hylton <jeremy@alum.mit.edu>:
  >> The strange thing is that I notice a difference between -O2 and
  >> -O3 with 2.1a1, but in the opposite direction.  On pystone,
  >> python -O2 runs consistently faster than -O3; the difference is
  >> .05 sec on my machine.

  ESR> Bizarre.  Make me wonder if we have a C compiler problem.

Depends on your defintion of "compiler problem" <wink>.  If you mean,
it compiles our code so it runs slower, then, yes, we've got one :-).

One of the differences between -O2 and -O3, according to the man page,
is that -O3 will perform optimizations that involve a space-speed
tradeoff.  It also include -finline-functions.  I can imagine that
some of these optimizations hurt memory performance enough to make a

not-really-understanding-but-not-really-expecting-too-ly y'rs,