where a chain outside of the loop block-set ended up in the worklist for
scheduling as part of the contiguous loop. However, asserting the first
block in the chain is in the loop-set isn't a valid check -- we may be
forced to drag a chain into the worklist due to one block in the chain
being part of the loop even though the first block is *not* in the loop.
This occurs when we have been forced to form a chain early due to
un-analyzable branches.

No test case here as I have no idea how to even begin reducing one, and
it will be hopelessly fragile. We have to somehow end up with a loop
header of an inner loop which is a successor of a basic block with an
unanalyzable pair of branch instructions. Ow. Self-host triggers it so
it is unlikely it will regress.

This at least gets block placement back to passing selfhost and the test
suite. There are still a lot of slowdown that I don't like coming out of
block placement, although there are now also a lot of speedups. =[ I'm
seeing swings in both directions up to 10%. I'm going to try to find
time to dig into this and see if we can turn this on for 3.1 as it does
a really good job of cleaning up after some loops that degraded with the
inliner changes.

llvm-svn: 154287

debugging.

llvm-svn: 154286

GEPs, bit casts, and stores reaching it but no other instructions. These
often show up during the iterative processing of the inliner, SROA, and
DCE. Once we hit this point, we can completely remove the alloca. These
were actually showing up in the final, fully optimized code in a bunch
of inliner tests I've been working on, and notably they show up after
LLVM finishes optimizing away all function calls involved in
hash_combine(a, b).

llvm-svn: 154285

Previously we used three instructions to broadcast an immediate value into a
vector register.
On Sandybridge we continue to load the broadcasted value from the constant pool.

llvm-svn: 154284

llvm-svn: 154283

llvm-svn: 154282

llvm-svn: 154281

An MDNode has a list of MDNodeOperands allocated directly after it as part of
its allocation. Therefore, the Parent of the MDNodeOperands can be found by
walking back through the operands to the beginning of that list. Mark the first
operand's value pointer as being the 'first' operand so that we know where the
beginning of said list is.

This saves a *lot* of space during LTO with -O0 -g flags.

llvm-svn: 154280

value pointer by making the value pointer into a pointer-int pair with 2 bits
available for flags.

llvm-svn: 154279

converting from std::nullptr_t, the subexpression might have side-effects.

llvm-svn: 154278

llvm-svn: 154277

llvm-svn: 154276

llvm-svn: 154275

llvm-svn: 154274

ext_reserved_user_defined_literal must not default to Error in MicrosoftMode. Hence create ext_ms_reserved_user_defined_literal that doesn't default to Error; otherwise MSVC headers won't parse. 

Fixes PR12383.

llvm-svn: 154273

Turn avx2 vinserti128 intrinsic calls into INSERT_SUBVECTOR DAG nodes and remove patterns for selecting the intrinsic. Similar was already done for avx1.

llvm-svn: 154272

llvm-svn: 154270

llvm-svn: 154269

Move vinsertf128 patterns near the instruction definitions. Add AddedComplexity to AVX2 vextracti128 patterns to give them priority over the integer versions of vextractf128 patterns.

llvm-svn: 154268

llvm-svn: 154267

   shuffle node because it could introduce new shuffle nodes that were not
   supported efficiently by the target.

2. Add a more restrictive shuffle-of-shuffle optimization for cases where the
   second shuffle reverses the transformation of the first shuffle.

llvm-svn: 154266

reciprocal if converting to the reciprocal is exact.  Do it even if inexact
if -ffast-math.  This substantially speeds up ac.f90 from the polyhedron
benchmarks.

llvm-svn: 154265

optimizers could do this for us, but expecting partial SROA of classes
with template methods through cloning is probably expecting too much
heroics. With this change, the begin/end pointer pairs which indicate
the status of each loop iteration are actually passed directly into each
layer of the combine_data calls, and the inliner has a chance to see
when most of the combine_data function could be deleted by inlining.
Similarly for 'length'.

We have to be careful to limit the places where in/out reference
parameters are used as those will also defeat the inliner / optimizers
from properly propagating constants.

With this change, LLVM is able to fully inline and unroll the hash
computation of small sets of values, such as two or three pointers.
These now decompose into essentially straight-line code with no loops or
function calls.

There is still one code quality problem to be solved with the hashing --
LLVM is failing to nuke the alloca. It removes all loads from the
alloca, leaving only lifetime intrinsics and dead(!!) stores to the
alloca. =/ Very unfortunate.

llvm-svn: 154264

speculate. Without this, loop rotate (among many other places) would
suddenly stop working in the presence of debug info. I found this
looking at loop rotate, and have augmented its tests with a reduction
out of a very hot loop in yacr2 where failing to do this rotation costs
sometimes more than 10% in runtime performance, perturbing numerous
downstream optimizations.

This should have no impact on performance without debug info, but the
change in performance when debug info is enabled can be extreme. As
a consequence (and this how I got to this yak) any profiling of
performance problems should be treated with deep suspicion -- they may
have been wildly innacurate of debug info was enabled for profiling. =/
Just a heads up.

llvm-svn: 154263

Found by inspection.

llvm-svn: 154262

The tLDRr instruction with the last register operand set to the zero register
prints in assembly as if no register was specified, and the assembler encodes
it as a tLDRi instruction with a zero immediate.  With the integrated assembler,
that zero register gets emitted as "r0", so we get "ldr rx, [ry, r0]" which
is broken.  Emit the instruction as tLDRi with a zero immediate.  I don't
know if there's a good way to write a testcase for this.  Suggestions welcome.

Opportunities for follow-up work:
1) The asm printer should complain if a non-optional register operand is set
   to the zero register, instead of silently dropping it.
2) The integrated assembler should complain in the same situation, instead of
   silently emitting the operand as "r0".

llvm-svn: 154261

  performance, patched by Johannes Doerfert <johannes@jdoerfert.de>.

llvm-svn: 154260

llvm-svn: 154259

  patched by Johannes Doerfert <johannes@jdoerfert.de>.

llvm-svn: 154258

llvm-svn: 154255

llvm-svn: 154254

llvm-svn: 154252

Grouped unrolling means that we unroll a loop such that the different instances
of a certain statement are scheduled right after each other, but we do
not generate any vector code. The idea here is that we can schedule the
bb vectorizer right afterwards and use it heuristics to decide when
vectorization should be performed.

llvm-svn: 154251

nanoseconds in 32-bit expression would cause pthread_cond_timedwait
to time out immediately.  Add explicit casts to the TimeValue::TimeValue
ctor that takes a struct timeval and change the NanoSecsPerSec etc
constants defined in TimeValue to be uint64_t so any other calculations
involving these should be promoted to 64-bit even when lldb is built
for 32-bit.

<rdar://problem/11204073>, <rdar://problem/11179821>, <rdar://problem/11194705>.

llvm-svn: 154250

llvm-svn: 154249

  - The [class.protected] restriction is non-trivial for any instance
    member, even if the access lacks an object (for example, if it's
    a pointer-to-member constant).  In this case, it is equivalent to
    requiring the naming class to equal the context class.
  - The [class.protected] restriction applies to accesses to constructors
    and destructors.  A protected constructor or destructor can only be
    used to create or destroy a base subobject, as a direct result.
  - Several places were dropping or misapplying object information.

The standard could really be much clearer about what the object type is
supposed to be in some of these accesses.  Usually it's easy enough to
find a reasonable answer, but still, the standard makes a very confident
statement about accesses to instance members only being possible in
either pointer-to-member literals or member access expressions, which
just completely ignores concepts like constructor and destructor
calls, using declarations, unevaluated field references, etc.

llvm-svn: 154248

Cygwin-1.7 supports dw2. Some recent mingw distros support one, too.
I have confirmed test-suite/SingleSource/Benchmarks/Shootout-C++/except.cpp can pass on Cygwin.

llvm-svn: 154247

llvm-svn: 154246

string.

llvm-svn: 154243

a hello world executable from atoms.  There is still much to be flushed out.
Added one test case, test/darwin/hello-world.objtxt, which exercises the
darwin platform.

Added -platform option to lld-core tool to dynamically select platform.

llvm-svn: 154242