[llvm-commits] [llvm] r49928 - /llvm/trunk/lib/Analysis/ScalarEvolution.cpp

[Dale Johannesen]

On Apr 19, 2008, at 6:41 PM, Dale Johannesen wrote:
> On Apr 19, 2008, at 6:38 PM, Chris Lattner wrote:
>> On Apr 19, 2008, at 6:22 PM, Dale Johannesen wrote:
>>>>>
>>>> This may be true for while/for loops, but isn't true for do+while
>>>> loops.
>>>>
>>>> do {
>>>> ...
>>>> } while (cond);
>>>>
>>>> Has no dominating check.
>>>
>>> But those are not executed 0 times, so the failing case can't arise.
>>> It works in practice, too.
>>
>> The count is for the number of times the backedge is executed, not  
>> the
>> number of times the loop is executed, right?
>
> The current code works in the case where the backedge is executed 0  
> times.  I believe it always works.  I will change my mind if  
> somebody constructs a case that doesn't work.

Which I did, and have checked in Nick's patch.  Thanks all.