cannot be folded into target cmp instruction.
- Avoid a phase ordering issue where early cmp optimization would prevent the
  later count-to-zero optimization.
- Add missing checks which could cause LSR to reuse stride that does not have
  users.
- Fix a bug in count-to-zero optimization code which failed to find the pre-inc
  iv's phi node.
- Remove, tighten, loosen some incorrect checks disable valid transformations.
- Quite a bit of code clean up.

llvm-svn: 86969

llvm-svn: 86761

llvm-svn: 86715

llvm-svn: 86193

LoopSimplify form may not be available.

llvm-svn: 86175

strides for now, because it doesn't handle them correctly. This fixes a
miscompile of SingleSource/Benchmarks/Misc-C++/ray.

This problem was usually hidden because indvars transforms such induction
variables into negations of canonical induction variables.

llvm-svn: 85118

CmpInst::isSigned.

llvm-svn: 85037

update all the callers.

llvm-svn: 82889

that get created during loop unswitching, and fix SplitBlockPredecessors'
LCSSA updating code to create new PHIs instead of trying to just move
existing ones.

Also, optimize Loop::verifyLoop, since it gets called a lot. Use
searches on a sorted list of blocks instead of calling the "contains"
function, as is done in other places in the Loop class, since "contains"
does a linear search. Also, don't call verifyLoop from LoopSimplify or
LCSSA, as the PassManager is already calling verifyLoop as part of
LoopInfo's verifyAnalysis.

llvm-svn: 81221

llvm-svn: 81101

that these passes are properly preserved.

Fix several transformation passes that claimed to preserve LoopSimplify
form but weren't.

llvm-svn: 80926

llvm-svn: 80766

This required converting a bunch of stuff off DOUT and other cleanups.

llvm-svn: 79819

llvm-svn: 78948

llvm-svn: 78610

matches what the comment says, and it avoids spurious BitCast
instructions for Argument values.

llvm-svn: 78121

metadata related, which I'm waiting on to avoid conflicting with Devang.

llvm-svn: 77721

llvm-svn: 77519

llvm-svn: 77516

llvm-svn: 77494

llvm-svn: 77247

llvm-svn: 77152

Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types.  More to come.

llvm-svn: 77011

llvm-svn: 76702

using the Curiously Recurring Template Pattern with LoopBase.

This will help further refactoring, and future functionality for
Loop. Also, Headers can now foward-declare Loop, instead of pulling
in LoopInfo.h or doing tricks.

llvm-svn: 75519

This started as a small change, I swear.  Unfortunately, lots of things call the [I|F]CmpInst constructors.  Who knew!?

llvm-svn: 75200

llvm-svn: 74918

llvm-svn: 74753

trip counts in more cases.

Generalize ScalarEvolution's isLoopGuardedByCond code to recognize
And and Or conditions, splitting the code out into an
isNecessaryCond helper function so that it can evaluate Ands and Ors
recursively, and make SCEVExpander be much more aggressive about
hoisting instructions out of loops.

test/CodeGen/X86/pr3495.ll has an additional instruction now, but
it appears to be due to an arbitrary register allocation difference.

llvm-svn: 74048

preheader is already an instruction.

llvm-svn: 74031

llvm-svn: 73906

terminology that LoopInfo uses.

llvm-svn: 73863

llvm-svn: 73796

hand-crafted testcase which demonstrates the bug that was exposed
in 254.gap.

llvm-svn: 73793

which it isn't prepared to handle.

llvm-svn: 73787

llvm-svn: 73783

as signed max tests. Along with r73717, this helps CodeGen avoid
emitting code for a maximum operation for this class of loop.

llvm-svn: 73718

casted induction variables in cases where the cast
isn't foldable. It ended up being a pessimization in
many cases. This could be fixed, but it would require
a bunch of complicated code in IVUsers' clients. The
advantages of this approach aren't visible enough to
justify it at this time.

llvm-svn: 73706

llvm-svn: 73621

failures.

To support this, add some utility functions to Type to help support
vector/scalar-independent code. Change ConstantInt::get and
ConstantFP::get to support vector types, and add an overload to
ConstantInt::get that uses a static IntegerType type, for
convenience.

Introduce a new getConstant method for ScalarEvolution, to simplify
common use cases.

llvm-svn: 73431