Only create a canonical IV for backedge taken count if it will
actually be used by LinearFunctionTestReplace. And some related
cleanup, preparing to reduce dependence on canonical IVs.
No significant effect on x86 or arm in the test-suite.

llvm-svn: 130799

llvm-svn: 130408

llvm-svn: 130350

Modified LinearFunctionTestReplace to push the condition on the dead
list instead of eagerly deleting it. This can cause unnecessary
IV rewrites, which should have no effect on codegen and will not be an
issue once we stop generating canonical IVs.

llvm-svn: 130340

PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128537

llvm-svn: 128535

llvm-svn: 127842

SCEV may generate expressions composed of multiple pointers, which can
lead to invalid GEP expansion. Until we can teach SCEV to follow strict
pointer rules, make sure no bad GEPs creep into IR.
Fixes rdar://problem/9038671.

llvm-svn: 127839

llvm-svn: 127837

that have the bit set.

llvm-svn: 123104

functions of ScalarEvolution, in preparation for memoization and
other optimizations.

llvm-svn: 119562

Get rid of static constructors for pass registration.  Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820

perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.

llvm-svn: 116334

llvm-svn: 115996

llvm-svn: 114277

llvm-svn: 110460

llvm-svn: 110410

ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396

llvm-svn: 109103

llvm-svn: 109045

use getIncomingValueForBlock instead of
LoopInfo::getCanonicalInductionVariableIncrement.

llvm-svn: 108865

llvm-svn: 107976

This fixes PR7333.

llvm-svn: 106267

same, now that getConstant has overloads consistent with ConstantInt::get.

llvm-svn: 102965

numerator is an induction variable. For example, with code like this:

  for (i=0;i<n;++i)
    x[i%n] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the remainder.

llvm-svn: 101113

expression is a UDiv and it doesn't appear that the UDiv came from
the user's source.

ScalarEvolution has recently figured out how to compute a tripcount
expression for the inner loop in
SingleSource/Benchmarks/Shootout/sieve.c, using a udiv. Emitting a
udiv instruction dramatically slows down the enclosing loop.

llvm-svn: 101068

a ScalarEvolution bug with overflow handling is fixed, the normal analysis
code will automatically decline to operate on the icmp instructions which
are responsible for the loop exit.

llvm-svn: 101032

instead of deleting just the user. This makes it more consistent with
other code in IndVarSimplify, and theoretically can eliminate more users
earlier.

llvm-svn: 101027

the loop exit test. This usually doesn't come up for a variety of
reasons, but it isn't impossible, so make IndVarSimplify handle it
conservatively.

llvm-svn: 101008

llvm-svn: 101002

variables. For example, with code like this:

  for (i=0;i<n;++i)
    if (i<n)
      x[i] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.

llvm-svn: 101000

that it's only testing for the entry condition, not full loop-invariant
conditions.

llvm-svn: 100979

explicitly split into stride-and-offset pairs. Also, add the
ability to track multiple post-increment loops on the same expression.

This refines the concept of "normalizing" SCEV expressions used for
to post-increment uses, and introduces a dedicated utility routine for
normalizing and denormalizing expressions.

This fixes the expansion of expressions which are post-increment users
of more than one loop at a time. More broadly, this takes LSR another
step closer to being able to reason about more than one loop at a time.

llvm-svn: 100699

exits the loop.  With this information we can guarantee 
the iteration count of the loop is bounded by the 
compare.  I think this xforms is finally safe now.

llvm-svn: 100285

checker.  Amusingly, we already had tests that we should
have rejects because they would be miscompiled in the
testsuite.

The remaining issue with this is that we don't check that
the branch causes us to exit the loop if it fails, so we
don't actually know if we remain in bounds.

llvm-svn: 100284

to a signed vs unsigned value depending on the sign of the
constant fp means that we can't distinguish between a 
truly negative number and a positive number so large the
32nd bit is set.  So, do don't this!

llvm-svn: 100283

stuff.  More bugs remain though.

llvm-svn: 100282

the required validity checks in the first place, and supporting
a condition large enough to require the 32'nd bit isn't worth it.

llvm-svn: 100280

of llvm.

llvm-svn: 100276

no uses, it would have been deleted by 
RecursivelyDeleteTriviallyDeadInstructions

llvm-svn: 100275