[LLVMdev] missed optimizations

[Nuno Lopes]

> On Tue, Sep 16, 2008 at 1:59 PM, Nuno Lopes <nunoplopes at sapo.pt> wrote:
>> Hi,
>> This kind of transformation isn't currently done by LLVM (note that here
>> this pass is only removing case statements. other transformations are not 
>> of
>> my responsibility :).
>> The patch is available at
>> http://web.ist.utl.pt/nuno.lopes/llvm_function_ret_infer.txt
>> I would love to ear some feedback, so that this pass can eventually be
>> merged to the LLVM tree. In particular I'm not sure if there's a better 
>> way
>> to track the possible return values of each function (e.g. is there any 
>> code
>> that I can reuse?)
>
> AnalyzeFunction can use BB->getTerminator() rather than iterating over
> all instructions to find the terminator.
>
> After you Analyze all the functions, why not just iterator on the uses
> of the functions you found you could transform rather than on ever
> instruction in the module?
>
> It seems you should be able to handle any comparison with a constant
> by using the min or max of your set as appropriate to the cmp.

Hi,

Thank you for your review. I've updated the patch to reflect your 
suggestions.
I've also completed the ICmp instruction folding.

Regards,
Nuno