[llvm-commits] [PATCH] AndOrXor Chain Optimization

[Eli Friedman]

2011/8/16 Daniel Nicácio <dnicacios at gmail.com>:
> ping
> Updated patch with revision 137728

This is a lot of code for a rather obscure optimization; I don't see
how it is worthwhile.

-Eli

> 2011/8/5 Daniel Nicácio <dnicacios at gmail.com>
>>
>> New unified diff file attached.
>> Daniel Nicacio
>>
>> 2011/8/4 Eli Friedman <eli.friedman at gmail.com>
>>>
>>> 2011/8/4 Daniel Nicácio <dnicacios at gmail.com>
>>>>
>>>> Hi, this patch increments the instcombiner pass.
>>>> It adds a new XOR, OR, AND optimization, trying to find a chain of
>>>> logical instructions (xor, and, or) operating on different bits of the same
>>>> word. If this chain is found, it is collapsed into a single logical
>>>> instruction.
>>>> The figure below shows a generic example:
>>>> Any comments and critics are welcome.
>>>
>>> Please attach a single diff containing all the changes, and please use
>>> "svn diff" or some other tool that makes a unified diff.
>>> -Eli
>
>