[LLVMdev] IntervalPartition and Intervals per function

Chris Lattner clattner at apple.com
Wed Aug 27 13:41:40 PDT 2008


On Aug 27, 2008, at 1:35 PM, Prakash Prabhu wrote:

> Hi,
>
> I wrote a Function pass that requires the IntervalPartition pass in
> order to obtain the set of intervals for every function:
>
> However when i access the intervals vector for a particular call of
> runOnFunction, it seems that alll intervals computed for the earlier
> functions are still in the
> vector. To verify this, I added some debug in addIntervalToPartition:

Sounds like a bug.  Interval analysis is some of the oldest code in  
LLVM and was never widely used (once I implemented the first dominator  
info, it became unneeded).

> As seen above, the intervals computed for lresurrect are still present
> in the intervals vector, when function ldndate is accessed. Is this
> expected ? Or maybe I am missing something here ?

I wouldn't be surprised if interval analysis was totally broken.  Are  
you interested in tracking it down and fixing the problem?   
Alternatively, maybe we should remove the code from LLVM.

-Chris



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