Bug fixes (was: "Recursion, need more stack space.")_(re)

Tue, 17 Jun 1997 18:29:39 +0300 (LDT)

17-Jun-97 16:11 Frank Heckenbach wrote:
>> Or else: Loading the memory reference into a register and
>> pushing that *might* be faster than a direct push (don't know).
>
>That might be a reason. But I don't know, either. I would suppose not --
>why should the extra loading a register be faster? I tried some ways to
>measure the actual time (system clock, ps, /proc/..., even gprof), but
>they were all terribly inaccurate (+/- 5..10%), so there's no chance to
>check which is faster. :-( Anyone knows a way to measure runtime
>presicsely (Linux or DJGPP)?

I'm not an expert in Pentium optimizing, but I have seen somewhere that
  mov  reg, mem
  push reg
is faster than
  push mem
on a 486 and can be paired better on Pentium. I've seen it in one of the
texts about Pentium optimization at http://www.quantasm.com. I think it was
called 'Pentium(r) Optimization Cross-Reference by Instruction'.

--
Marius Gedminas
E-mail: mgedmin@pub.osf.lt
WWW: http://www-public.osf.lt/~mgedmin

Marius Gedminas (mgedmin@pub.osf.lt)