is returned through a bitcast.

llvm-svn: 137402

the retains and releases all use the same SSA pointer value.

Also, don't let CFG hazards disrupt nested retain+release pair
optimizations.

llvm-svn: 137399

rather than plain postorder, so that CFG constructs like single-exit loops
are reliably visited in a sensible order.

llvm-svn: 137398

SCEV unrolling can unroll loops with arbitrary induction variables. It
is a prerequisite for -disable-iv-rewrite performance. It is also
easily handles loops of arbitrary structure including multiple exits
and is generally more robust.

This is under a temporary option to avoid affecting default
behavior for the next couple of weeks. It is needed so that I can
checkin unit tests for updateUnloop.

llvm-svn: 137384

llvm-svn: 137352

Distinguish between two copies of one inlined variable. Take 2.

llvm-svn: 137253

Also, my apologies for spoiling the autocomplete on SimplifyInstructions.cpp. I couldn't think of a better filename.

llvm-svn: 137229

llvm-svn: 137203

SimplifyIndVar utility since it is required.

llvm-svn: 137202

llvm-svn: 137199

llvm-svn: 137198

based on ScalarEvolution without changing the induction variable phis.

This utility is the main tool of IndVarSimplifyPass, but the pass also
restructures induction variables in strange ways that are sensitive to
pass ordering. This provides a way for other loop passes to simplify
new uses of induction variables created during transformation. The
utility may be used by any pass that preserves ScalarEvolution. Soon
LoopUnroll will use it.

The net effect in this checkin is to cleanup the IndVarSimplify pass
by factoring out the SimplifyIndVar algorithm into a standalone utility.

llvm-svn: 137197

llvm-svn: 137195

These are not individual bug fixes. I had to rewrite a good chunk of
the unroller to make it sane. I think it was getting lucky on trivial
completely unrolled loops with no early exits. I included some fairly
simple unit tests for partial unrolling. I didn't do much stress
testing, so it may not be perfect, but should be usable now.

llvm-svn: 137190

llvm-svn: 137170

functionality since in the C api a pass is created and added to a pass
manager in a single call.

llvm-svn: 137159

LoopUnroll looks like it has some stale code. Remove it to prove my sanity and avoid further confusion.

llvm-svn: 137106

instead of a vector.

llvm-svn: 137099

The 'unwind' instruction was acting essentially as a placeholder, because it
would be replaced at the end of this function by a branch to the "unwind
handler". The 'unwind' instruction is going away, so use 'unreachable' instead,
which serves the same purpose as a placeholder.

llvm-svn: 137098

recurrence, the initial values low bits can sometimes be ignored.

To take advantage of this, added FoldIVUser to IndVarSimplify to fold
an IV operand into a udiv/lshr if the operator doesn't affect the
result.

-indvars -disable-iv-rewrite now transforms

i = phi i4
i1 = i0 + 1
idx = i1 >> (2 or more)
i4 = i + 4

into

i = phi i4
idx = i0 >> ...
i4 = i + 4

llvm-svn: 137013

inlined variable, based on the discussion in PR10542.

This explodes the runtime of several passes down the pipeline due to
a large number of "copies" remaining live across a large function. This
only shows up with both debug and opt, but when it does it creates
a many-minute compile when self-hosting LLVM+Clang. There are several
other cases that show these types of regressions.

All of this is tracked in PR10542, and progress is being made on fixing
the issue. Once its addressed, the re-instated, but until then this
restores the performance for self-hosting and other opt+debug builds.

Devang, let me know if this causes any trouble, or impedes fixing it in
any way, and thanks for working on this!

llvm-svn: 136953

We need to map DebugLoc. It leads to Fuction * (through subprogram entry node) which should be appropriately mapped.

llvm-svn: 136910

llvm-svn: 136900

This is some of my original LLVM code. *wipes tear*

llvm-svn: 136821

to notify SCEV of a change. Add forgetLoop in a couple of those places.

llvm-svn: 136797

llvm-svn: 136795

  - use SmallVectorImpl& for the function argument.
  - ignore the operands on the GEP, even if they aren't constant! Much as we
    pretend the malloc succeeds, we pretend that malloc + whatever-you-GEP'd-by
    is not null. It's magic!

llvm-svn: 136757

Don't replace a gep/bitcast with 'undef' because that will form a "free(undef)"
which in turn means "unreachable". What we wanted was a no-op. Instead, analyze
the whole tree and look for all the instructions we need to delete first, then
delete them second, not relying on the use_list to stay consistent.

llvm-svn: 136752

malloc call.

llvm-svn: 136732

llvm-svn: 136727

llvm-svn: 136723

llvm-svn: 136722

Revert r136503 and r136480 in an effort to fix non-determinism in the llvm-gcc buildbots on i386.  Devang is looking into the root cause.

llvm-svn: 136674

This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).

llvm-svn: 136589

llvm-svn: 136585

r136339, r136341, r136369, r136387, r136392, r136396, r136429, r136430, r136444,
r136445, r136446, r136253 pending review.

llvm-svn: 136556

llvm-svn: 136503

llvm-svn: 136480

working on x86 (at least for trivial testcases); other architectures will
need more work so that they actually emit the appropriate instructions for
orderings stricter than 'monotonic'. (As far as I can tell, the ARM, PPC,
Mips, and Alpha backends need such changes.)

llvm-svn: 136457

Make sure to correctly clear the exact/nuw/nsw flags off of shifts when they are combined together. <rdar://problem/9859829>

llvm-svn: 136435