the loop exiting block dominates the latch block; if ScalarEvolution
can prove that the trip-count is finite, that's sufficient.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85165 91177308-0d34-0410-b5e6-96231b3b80d8
exact backedge taken count, when checking for infinite loops. This allows
it to delete loops with multiple exit conditions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84952 91177308-0d34-0410-b5e6-96231b3b80d8
This way ScalarEvolution can examine the loop to determine what state
it needs to update, if it chooses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75029 91177308-0d34-0410-b5e6-96231b3b80d8
the optimizers about this. For example, a readonly
function with no uses cannot be removed unless it is
also marked nounwind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71071 91177308-0d34-0410-b5e6-96231b3b80d8
CallbackVH, with fixes. allUsesReplacedWith need to
walk the def-use chains and invalidate all users of a
value that is replaced. SCEVs of users need to be
recalcualted even if the new value is equivalent. Also,
make forgetLoopPHIs walk def-use chains, since any
SCEV that depends on a PHI should be recalculated when
more information about that PHI becomes available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70927 91177308-0d34-0410-b5e6-96231b3b80d8
makes ScalarEvolution::deleteValueFromRecords, and it's code that
subtly needed to be called before ReplaceAllUsesWith, unnecessary.
It also makes ValueDeletionListener unnecessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70645 91177308-0d34-0410-b5e6-96231b3b80d8
to more accurately describe what it does. Expand its doxygen comment
to describe what the backedge-taken count is and how it differs
from the actual iteration count of the loop. Adjust names and
comments in associated code accordingly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65382 91177308-0d34-0410-b5e6-96231b3b80d8
so that ScalarEvolution doesn't hang onto a dangling Loop*, which
could be a problem if another Loop happens to get allocated at the
same address.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65323 91177308-0d34-0410-b5e6-96231b3b80d8
LoopPass*.
- Although less precise, this means they can be used in clients
without RTTI (who would otherwise need to include LoopPass.h, which
eventually includes things using dynamic_cast). This was the
simplest solution that presented itself, but I am happy to use a
better one if available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58010 91177308-0d34-0410-b5e6-96231b3b80d8
Also, use SCEV to determine the trip count of the loop, which is more powerful
and accurate that Loop::getTripCount.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51179 91177308-0d34-0410-b5e6-96231b3b80d8
several things that were neither in an anonymous namespace nor static
but not intended to be global.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
