Next step is to recalculate the threshold values given this new heuristic.

llvm-svn: 113525

Relax the "don't unroll loops containing calls" rule.  Instead, when a loop contains a call, lower the
unrolling threshold to the optimize-for-size threshold.  Basically, for loops containing calls, unrolling
can still be profitable as long as the loop is REALLY small.

llvm-svn: 113439

The threshold value of 50 is arbitrary, and I chose it simply by analogy to the inlining thresholds, where
the baseline unrolling threshold is slightly smaller than the baseline inlining threshold.  This could
undoubtedly use some tuning.

llvm-svn: 113306

llvm-svn: 113146

in the duplicated block instead of duplicating them.  

Duplicating them into the end of the loop and the preheader 
means that we got a phi node in the header of the loop, 
which prevented LICM from hoisting them.  GVN would
usually come around later and merge the duplicated 
instructions so we'd get reasonable output... except that
anything dependent on the shoulda-been-hoisted value can't
be hoisted.  In PR5319 (which this fixes), a memory value
didn't get promoted.

llvm-svn: 113134

Loop::hasLoopInvariantOperands method. Remove
a useless and confusing Loop::isLoopInvariant(Instruction)
method, which didn't do what you thought it did.

No functionality change.

llvm-svn: 113133

llvm-svn: 113115

llvm-svn: 113114

llvm-svn: 113113

llvm-svn: 113073

location is being re-stored to the memory location.  We would get
a dangling pointer from the SSAUpdate data structure and miss a 
use.  This fixes PR8068

llvm-svn: 113042

llvm-svn: 113025

is provable that they're equivalent.  This fixes PR4855.

llvm-svn: 112994

llvm-svn: 112878

I'm sure it is harmless.  Original commit message:
If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.

llvm-svn: 112810

llvm-svn: 112763

infinite loops or exits will eventually exit. This fixes PR5373.

llvm-svn: 112745

if we schedule another LVI-using pass afterwards.

llvm-svn: 112722

self host errors on clang-x86-64.

llvm-svn: 112719

then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.

llvm-svn: 112699

on llvmdev: SRoA is introducing MMX datatypes like <1 x i64>,
which then cause random problems because the X86 backend is
producing mmx stuff without inserting proper emms calls.

In the short term, force off MMX datatypes.  In the long term,
the X86 backend should not select generic vector types to MMX
registers.  This is being worked on, but won't be done in time
for 2.8.  rdar://8380055

llvm-svn: 112696

by 112440 are resolved.

llvm-svn: 112692

instead of hoisting them, just fold them away.  This occurs in the
testcase for PR8041, for example.

llvm-svn: 112669

llvm-svn: 112643

More cleanups of my JumpThreading transforms, including extracting some duplicated code into a helper function.

llvm-svn: 112634

llvm-svn: 112628

llvm-svn: 112625

llvm-svn: 112620

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

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