dependence on DominanceFrontier. Instead, add an explicit DominanceFrontier
pass in StandardPasses.h to ensure that it gets scheduled at the right
time.

Declare that loop unrolling preserves ScalarEvolution, and shuffle some
getAnalysisUsages.

This eliminates one LoopSimplify and one LCCSA run in the standard
compile opts sequence.

llvm-svn: 109413

llvm-svn: 109045

llvm-svn: 106542

llvm-svn: 86180

clears out more information than just the stored backedge taken count.

llvm-svn: 85664

the loop exiting block dominates the latch block; if ScalarEvolution
can prove that the trip-count is finite, that's sufficient.

llvm-svn: 85165

exact backedge taken count, when checking for infinite loops. This allows
it to delete loops with multiple exit conditions.

llvm-svn: 84952

llvm-svn: 80766

and use this to simplify more code.

llvm-svn: 75722

This way ScalarEvolution can examine the loop to determine what state
it needs to update, if it chooses.

llvm-svn: 75029

llvm-svn: 74918

llvm-svn: 73906

the optimizers about this.  For example, a readonly
function with no uses cannot be removed unless it is
also marked nounwind.

llvm-svn: 71071

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.

llvm-svn: 70927

llvm-svn: 70661

makes ScalarEvolution::deleteValueFromRecords, and it's code that
subtly needed to be called before ReplaceAllUsesWith, unnecessary.

It also makes ValueDeletionListener unnecessary.

llvm-svn: 70645

deleting it.  This will let ScalarEvolution be more complete about
updating its records.

llvm-svn: 70632

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.

llvm-svn: 65382

llvm-svn: 65359

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.

llvm-svn: 65323

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.

llvm-svn: 58010

llvm-svn: 55779

llvm-svn: 52651

llvm-svn: 51666

Also, use SCEV to determine the trip count of the loop, which is more powerful
and accurate that Loop::getTripCount.

llvm-svn: 51179

several things that were neither in an anonymous namespace nor static
but not intended to be global.

llvm-svn: 51017

Patch by Matthijs Kooijman!

llvm-svn: 50861

We need to update PHIs containing the exiting block, not the exit block.  We really should come up with better names for these.

llvm-svn: 50770

llvm-svn: 50473

of this was suggested by Chris.

llvm-svn: 50441

llvm-svn: 50437

llvm-svn: 50436

llvm-svn: 50406

llvm-svn: 50384

llvm-svn: 50383

the trip count.

llvm-svn: 50382