>> %esi is almost used for IP but use %eax for fetching the next byte,
>> jmp also seems to use %eax so right before it is spilled and the
>> destination address is brought into %eax.
> 
> Sounds more like the static register assignments get ignored.

It does not really get ignored, but the compiler performs more 
aggressive live range splitting (because it uses SSA in 4.x so live 
range splitting comes from free -- sometimes even if you don't want 
it...).  OTOH the optimizer is better, which is why sends are faster.

GCC 3.x should be in the same ballpark as 2.95.

Paolo