[Bug target/16961] Poor x86-64 performance with 128bit ints

["jh at suse dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From jh at suse dot cz  2005-07-18 12:45 -------
Subject: Re:  Poor x86-64 performance with 128bit ints

> 
> ------- Additional Comments From steven at gcc dot gnu dot org  2005-07-18 07:47 -------
> The 128 bits arithmetic has improved now: 
>  
> typedef unsigned long      mp_word __attribute__ ((mode(TI)));  
> mp_word a, b;  
> void test(void) { a += b; }  
>  
> test: 
>         movq    a(%rip), %rax 
>         addq    b(%rip), %rax 
>         movq    a+8(%rip), %rdx 
>         adcq    b+8(%rip), %rdx 
>         movq    %rax, a(%rip) 
>         movq    %rdx, a+8(%rip) 
>         ret 

I think the PR should be closed now when Jan added the 128bit arithmetic
patterns I originally skipped in the x86-64 port as it was killing my
32bit cross compiler at that time :)
At lest we should now perofrm no worse than i386 on 64bit math (that
sucks of course ;)

Honza
>  
> 
> -- 
> 
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16961
> 
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16961