Thorsten Froehlich wrote:

> In article <chr### [at] netplexaussieorg> ,
> Christopher James Huff <chr### [at] maccom>  wrote:
> 
>>> You are running a compile for PIII on a PII? Why are you surprised that
>>> it doesn't work?
>>
>> Read it again...the PIII optimized compile is the faster one on his
>> machine.
> 
> Yes, but as the Pentium II does not support the SSE instructions it is
> surprising that it works at all!  Apparently the compiler used doesn't add
> a lot of SSE instructions...

gcc 3.1 does not use the SSE instruction by itself, you would have to use 
inline assembler to make it use them. So there is porbably only a few 
PIII-specific instructions left that it uses at all. This explains why it 
sometimes works on a PII as well. I had even turned off the SSE 
optimization when I compiled with the Intel compiler (only some of the 
5-components colour calculations could have been vectorized anyways) 
because it did not result in a speed-up, but rather a slow-down.

- Micha

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