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Re: 64-bit integers - long long (only on x86?)


Jan Hubicka wrote:
>>In my own experience, gcc does poorer than other good compilers when 
>>dealing with long long 64-bit integers on x86. I have also talked to 
>>others experiencing the same, and just the other day, Jack Lloyd posted 
>>a link to some results which indicated the same. Is there a wellknown 
>>reason for this, and what is it? If it's not wellknown, I will produce 
> 
> 
> It is well known.  The GCC register allocator assumes that the both parts
> of long long needs to be stored in consetuctive registers limiting the
> amount of choices it have resulting in  ugly code.
> Sadly changing this design decision is nontrivial, but some steps are being
> worked on.
> 
> Honza
> 

OK. I am glad it is at least a known problem. Are there any concrete 
goals for, say, 3.2 that addresses this? Or will it take longer than that?

/David



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