offset applied to it.

llvm-svn: 153493

register that's read by the preheader terminator.

rdar://11095580

llvm-svn: 153492

cleared. No functionality change.

llvm-svn: 153491

copies being considered for removal. Make sure to track all of the copies,
rather than just the most recent encountered, by holding a DenseSet instead of
an unsigned in SrcMap.

No test case - couldn't reduce something with a sane size.

llvm-svn: 153487

llvm-svn: 153486

produces a 32-bit immediate which is consumed by the use. It tries to 
fold the immediate by breaking it into two parts and fold them into the
immmediate fields of two uses. e.g
       movw    r2, #40885
       movt    r3, #46540
       add     r0, r0, r3
=>
       add.w   r0, r0, #3019898880
       add.w   r0, r0, #30146560
;
However, this transformation is incorrect if the user produces a flag. e.g.
       movw    r2, #40885
       movt    r3, #46540
       adds    r0, r0, r3
=>
       add.w   r0, r0, #3019898880
       adds.w  r0, r0, #30146560
Note the adds.w may not set the carry flag even if the original sequence
would.

rdar://11116189

llvm-svn: 153484

llvm-svn: 153483

Fixes PR11882: NULL dereference in ComputeLoadConstantCompareExitLimit.

llvm-svn: 153480

backtrace locations.

Testcase forthcoming, but I wanted to get some testing here.

Should fix:

PR12323
PR12314
rdar://11091100

llvm-svn: 153471

153465 was incorrect. In this code we wanted to check that the pointer operand is of pointer type (and not vector type).

llvm-svn: 153468

relocations.  The algorithm is the same as
that for x86_64.  Scattered relocations, a
feature present in i386 but not on x86_64,
are not yet supported.

llvm-svn: 153466

llvm-svn: 153465

Fixes PR11950.

llvm-svn: 153463

llvm-svn: 153462

llvm-svn: 153458

llvm-svn: 153456

llvm-svn: 153455

Original commit message:
Use the new range metadata in computeMaskedBits and add a new optimization to
instruction simplify that lets us remove an and when loading a boolean value.

llvm-svn: 153452

Thanks Andrey.

llvm-svn: 153451

[tsan] treat vtable pointer updates in a special way (requires tbaa); fix a bug (forgot to return true after instrumenting); make sure the tsan tests are run

llvm-svn: 153448

llvm-svn: 153438

llvm-svn: 153436

Patch by Sylvestre Ledru!

llvm-svn: 153435

llvm-svn: 153429

llvm-svn: 153428

instruction simplify that lets us remove an and when loding a boolean value.

llvm-svn: 153423

llvm-svn: 153422

llvm-svn: 153421

constant-offsets of a common base using the generic GEP-walking logic
I added for computing pointer differences in the same situation.

llvm-svn: 153419

inbounds GEPs. This isn't really necessary for simplifying pointer
differences, but I'm planning to re-use the same code to simplify
pointer comparisons where it is necessary. Since real code almost
exclusively uses inbounds GEPs, it doesn't seem worth it to support the
extra complexity of turning it on and off. If anyone would like that
back, feel free to shout. Note that instcombine will still catch any of
these patterns.

llvm-svn: 153418

llvm-svn: 153415

aggressively. There are lots of dire warnings about this being expensive
that seem to predate switching to the TrackingVH-based value remapper
that is automatically updated on RAUW. This makes it easy to not just
prune single-entry PHIs, but to fully simplify PHIs, and to recursively
simplify the newly inlined code to propagate PHINode simplifications.

This introduces a bit of a thorny problem though. We may end up
simplifying a branch condition to a constant when we fold PHINodes, and
we would like to nuke any dead blocks resulting from this so that time
isn't wasted continually analyzing them, but this isn't easy. Deleting
basic blocks *after* they are fully cloned and mapped into the new
function currently requires manually updating the value map. The last
piece of the simplification-during-inlining puzzle will require either
switching to WeakVH mappings or some other piece of refactoring. I've
left a FIXME in the testcase about this.

llvm-svn: 153410

to instead rely on much more generic and powerful instruction
simplification in the function cloner (and thus inliner).

This teaches the pruning function cloner to use instsimplify rather than
just the constant folder to fold values during cloning. This can
simplify a large number of things that constant folding alone cannot
begin to touch. For example, it will realize that 'or' and 'and'
instructions with certain constant operands actually become constants
regardless of what their other operand is. It also can thread back
through the caller to perform simplifications that are only possible by
looking up a few levels. In particular, GEPs and pointer testing tend to
fold much more heavily with this change.

This should (in some cases) have a positive impact on compile times with
optimizations on because the inliner itself will simply avoid cloning
a great deal of code. It already attempted to prune proven-dead code,
but now it will be use the stronger simplifications to prove more code
dead.

llvm-svn: 153403

fire if anything ever invalidates the assumption of a terminator
instruction being unchanged throughout the routine.

I've convinced myself that the current definition of simplification
precludes such a transformation, so I think getting some asserts
coverage that we don't violate this agreement is sufficient to make this
code safe for the foreseeable future.

Comments to the contrary or other suggestions are of course welcome. =]
The bots are now happy with this code though, so it appears the bug here
has indeed been fixed.

llvm-svn: 153401

list. This is a bad idea. ;] I'm hopeful this is the bug that's showing
up with the MSVC bots, but we'll see.

It is definitely unnecessary. InstSimplify won't do anything to
a terminator instruction, we don't need to even include it in the
iteration range. We can also skip the now dead terminator check,
although I've made it an assert to help document that this is an
important invariant.

I'm still a bit queasy about this because there is an implicit
assumption that the terminator instruction cannot be RAUW'ed by the
simplification code. While that appears to be true at the moment, I see
no guarantee that would ensure it remains true in the future. I'm
looking at the cleanest way to solve that...

llvm-svn: 153399

spotted by inspection, and I've crafted no test case that triggers it on
my machine, but some of the windows builders are hitting what looks like
memory corruption, so *something* is amiss here.

This patch takes a more generalized approach to eliminating
double-visits. Imagine code such as:

  %x = ...
  %y = add %x, 1
  %z = add %x, %y

You can imagine that if we simplify %x, we would add %y and %z to the
list. If the use-chain order happens to cause us to add them in reverse
order, we could pull %y off first, and simplify it, adding %z to the
list. We now have %z on the list twice, and will reference it after it
is deleted.

Currently, all my test cases happen to not trigger this, likely due to
the use-chain ordering, but there seems no guarantee that such
a situation could not occur, so we should handle it correctly.

Again, if anyone knows how to craft a testcase that actually triggers
this, please let me know.

llvm-svn: 153397

worklist. This can happen in theory when an instruction uses itself,
such as a PHI node. This was spotted by inspection, and unfortunately
I've not been able to come up with a test case that would trigger it. If
anyone has ideas, let me know...

llvm-svn: 153396

llvm-svn: 153395

bit simpler by handling a common case explicitly.

Also, refactor the implementation to use a worklist based walk of the
recursive users, rather than trying to use value handles to detect and
recover from RAUWs during the recursive descent. This fixes a very
subtle bug in the previous implementation where degenerate control flow
structures could cause mutually recursive instructions (PHI nodes) to
collapse in just such a way that From became equal to To after some
amount of recursion. At that point, we hit the inf-loop that the assert
at the top attempted to guard against. This problem is defined away when
not using value handles in this manner. There are lots of comments
claiming that the WeakVH will protect against just this sort of error,
but they're not accurate about the actual implementation of WeakVHs,
which do still track RAUWs.

I don't have any test case for the bug this fixes because it requires
running the recursive simplification on unreachable phi nodes. I've no
way to either run this or easily write an input that triggers it. It was
found when using instruction simplification inside the inliner when
running over the nightly test-suite.

llvm-svn: 153393

llvm-svn: 153392