two are weak, we make them thunks to a new strong function) so don't iterate
through the function list as we're modifying it.

Also add back the outermost loop which got removed during the cleanups.

llvm-svn: 112595

Don't perform an extra traversal of the function just to do cleanup.  We can safely simplify instructions after each block has been processed without worrying about iterator invalidation.

llvm-svn: 112594

llvm-svn: 112591

llvm-svn: 112590

More Chris-inspired JumpThreading fixes: use ConstantExpr to correctly constant-fold undef, and be more careful with its return value.
This actually exposed an infinite recursion bug in ComputeValueKnownInPredecessors which theoretically already existed (in JumpThreading's
handling of and/or of i1's), but never manifested before.  This patch adds a tracking set to prevent this case.

llvm-svn: 112589

where we hash, compare and fold, instead of one iteration where we build up
the hash buckets and a second one to fold.

llvm-svn: 112582

Remove r111665, which implemented store-narrowing in InstCombine.  Chris discovered a miscompilation in it, and it's not easily
fixable at the optimizer level. I'll investigate reimplementing it in DAGCombine.

llvm-svn: 112575

llvm-svn: 112560

llvm-svn: 112553

Re-apply r112539, being more careful to respect the return values of the constant folding methods.  Additionally,
use the ConstantExpr::get*() methods to simplify some constant folding.

llvm-svn: 112550

llvm-svn: 112545

llvm-svn: 112543

Fixes and cleanups pointed out by Chris.  In general, be careful to handle 0 results from ComputeValueKnownInPredecessors
(indicating undef), and re-use existing constant folding APIs.

llvm-svn: 112539

instead of PromoteMemToReg.  This allows it to stop using DF and DT,
eliminating a computation of DT and DF from clang -O3.  Clang is now
down to 2 runs of DomFrontier.

llvm-svn: 112457

assertingvh so we get a violent explosion if the pointer dangles.

2) Fix AliasSetTracker::deleteValue to remove call sites with
   by-pointer comparisons instead of by-alias queries.  Using
   findAliasSetForCallSite can cause alias sets to get merged
   when they shouldn't, and can also miss alias sets when the
   call is readonly.

#2 fixes PR6889, which only repros with a .c file :(

llvm-svn: 112452

out of loops, just delete them.

llvm-svn: 112451

symtab manipulation, so its faster (in addition to being
more elegant)

llvm-svn: 112450

llvm-svn: 112449

of AST to remove the hoisted instruction from the AST, since it
is no longer in the loop.

llvm-svn: 112448

LICM correctly.  When sinking an instruction, it should not add
entries for the sunk instruction to the AST, it should remove
the entry for the sunk instruction.  The blocks being sunk to
are not in the loop, so their instructions shouldn't be in the
AST (yet)!

llvm-svn: 112447

keeping them around until the pass is destroyed, keep them
around a) just when useful (not for outer loops) and b) destroy
them right after we use them.  This should reduce memory use
and fixes potential bugs where a loop is deleted and another
loop gets allocated to the same address.

llvm-svn: 112446

claims that it preserves domfrontier if it doesn't really.

llvm-svn: 112445

for the unroller to pretend it supports updating it.  It still
has a horrible hack for DomTree.

llvm-svn: 112444

other filtering techniques, as those may allow it to filter
out more obviously unprofitable candidates.

llvm-svn: 112441

LSRInstance data structures up to date. This fixes some
pessimizations caused by stale data which will be exposed
in an upcoming change.

llvm-svn: 112440

NarrowSearchSpaceUsingHeuristics into separate functions.

llvm-svn: 112439

llvm-svn: 112438

llvm-svn: 112437

the high-level logic.

llvm-svn: 112436

llvm-svn: 112435

llvm-svn: 112434

preserves domfrontier.  It does preserve AA though.

llvm-svn: 112419

require DomFrontier.  Dropping this doesn't actually save any runs
of the pass though.

llvm-svn: 112418

Among other things, this uses SSAUpdater instead of 
PromoteMemToReg.

llvm-svn: 112417

llvm-svn: 112412

This leads to much simpler code.

llvm-svn: 112410

llvm-svn: 112409

llvm-svn: 112408

getUniqueExitBlocks instead of getExitBlocks and a manual
set to eliminate dupes.

llvm-svn: 112405

llvm-svn: 112404