[Bug tree-optimization/22041] Reverse loop order for increased efficiency

[rakdver at atrey dot karlin dot mff dot cuni dot cz]

------- Comment #5 from rakdver at atrey dot karlin dot mff dot cuni dot cz  2006-05-28 14:25 -------
Subject: Re:  Reverse loop order for increased efficiency

> ------- Comment #4 from tkoenig at gcc dot gnu dot org  2006-05-28 14:10 -------
> (In reply to comment #3)
> > Dunno if tree loop reversal is already there, but Zdenek probably likes to know
> > what bugs he is fixing...
> 
> Loop reversal doesn't occur yet.
> 
> gcc version 4.2.0 20060521 (experimental) gives us:
> 
> L4:
>         movl    (%ecx), %eax
>         addl    $1, %ebx
>         addl    %edi, %ecx
>         movl    %eax, (%edx)
>         addl    %esi, %edx
>         cmpl    16(%ebp), %ebx
>         jne     L4

loop reversal was removed with the old loop optimizer; the tree level
loop reversal patch
(http://gcc.gnu.org/ml/gcc-patches/2006-01/msg01851.html) was not
reviewed.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22041