[llvm-commits] [llvm] r73866 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolution.h lib/Analysis/ScalarEvolution.cpp test/Analysis/ScalarEvolution/trip-count5.ll

[Duncan Sands]

Hi Dan,

>> thanks for doing this.  Does the loop unroller make any use of it?
>> The loop in PR2624 is still not unrolled for example.
> 
> I believe LLVM's current loop unroller only works if an
> exact trip count is known. If ScalarEvolution finds the
> trip count is either 1 or 2, the loop won't be unrolled.

in the testcase scalar evolution finds that the trip count
is 3 for the backedge.  Perhaps the unroller skips loops
with more than one exit.

Ciao,

Duncan.