[llvm-dev] PHI nodes and connected ICMp

[Anastasiya Ruzhanskaya via llvm-dev]

Sorry,  I just saw this enumeration with SCEV types - all operations should
be possible then...

2017-08-11 15:55 GMT+02:00 Anastasiya Ruzhanskaya <
anastasiya.ruzhanskaya at frtk.ru>:

> Thank you for your answer! I tested your example, yes, perhaps I should
> preserve some kind of tree to parse this start and end expressions for
> induction variable... I was surprised, that SCEV cannot compute the
> tripcount here. I thought, that all linear and maybe expressions with
> multiplication are suitable for analysis.
>
> 2017-08-10 19:30 GMT+02:00 Sanjoy Das <sanjoy at google.com>:
>
>> Hi Anastasiya,
>>
>> If you're looking for the exit value of a PHI node, please take a look
>> at what IndVarSimplify does here:
>> https://github.com/llvm-mirror/llvm/blob/master/lib/Transfor
>> ms/Scalar/IndVarSimplify.cpp#L516
>>
>> On Thu, Aug 10, 2017 at 12:55 AM, Anastasiya Ruzhanskaya
>> <anastasiya.ruzhanskaya at frtk.ru> wrote:
>> > By only two cases I mean , that in exiting block when computing the
>> > condition related to PHI node I can expect only icmp on one of incoming
>> > values or on phi node itself... I tried to come up with some more
>> complex
>> > examples but I always receive only these two cases, that is why I am
>> asking.
>>
>> So you could have cases like this: https://godbolt.org/g/j4zcWy
>>
>> -- Sanjoy
>>
>
>
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