[LLVMdev] XOR optimization

[Rafael Auler]

I think he mean the intermediate steps:

%rem.1 = or i32 %rem, 1
%rem.2 = or i32 %rem, 2
%rem.3 = or i32 %rem, 3

When calculating bit_addr % 32. Inside the loop, %rem should be incremented
because of the loop unrolling, but instead, the optimizer thought it's
easier to OR it. This gives the same result, but it's weird.

2011/7/26 FlyLanguage <flylanguage at gmail.com>

> Den 26.07.2011 03:25, skrev Daniel Nicácio:
> >   - Do you know why a OR instruction is used for increments? instead of
> > using a INC or ADD?
>
> You mean "bit_addr++;" ?
>
> It's add'ing (+4 due to loop unrolling i guess)
>
>   %inc.3 = add i32 %0, 4
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