This checkin also adds in some tests that utilize these paths and updates some of the
clients.

llvm-svn: 166578

over the implicitly-formed-and-nesting CGSCC pass manager and function
pass managers, especially when using them on the opt commandline or
using extension points in the module builder. The '-barrier' opt flag
(or the pass itself) will create a no-op module pass in the pipeline,
resetting the pass manager stack, and allowing the creation of a new
pipeline of function passes or CGSCC passes to be created that is
independent from any previous pipelines.

For example, this can be used to test running two CGSCC passes in
independent CGSCC pass managers as opposed to in the same CGSCC pass
manager. It also allows us to introduce a further hack into the
PassManagerBuilder to separate the O0 pipeline extension passes from the
always-inliner's CGSCC pass manager, which they likely do not want to
participate in... At the very least none of the Sanitizer passes want
this behavior.

This fixes a bug with ASan at O0 currently, and I'll commit the ASan
test which covers this pass. I'm happy to add a test case that this pass
exists and works, but not sure how much time folks would like me to
spend adding test cases for the details of its behavior of partition
pass managers.... The whole thing is just vile, and mostly intended to
unblock ASan, so I'm hoping to rip this all out in a brave new pass
manager world.

llvm-svn: 166172

llvm-svn: 166112

Use the Attributes::get method which takes an AttrVal value directly to simplify the code a bit. No functionality change.

llvm-svn: 166009

llvm-svn: 166004

Move the Attributes::Builder outside of the Attributes class and into its own class named AttrBuilder. No functionality change.

llvm-svn: 165960

Add an enum for the return and function indexes into the AttrListPtr object. This gets rid of some magic numbers.

llvm-svn: 165924

Convert the internal representation of the Attributes class into a pointer to an
opaque object that's uniqued by and stored in the LLVMContext object. The
Attributes class then becomes a thin wrapper around this opaque
object. Eventually, the internal representation will be expanded to include
attributes that represent code generation options, etc.

llvm-svn: 165917

llvm-svn: 165899

Remove the bitwise AND operators from the Attributes class. Replace it with the equivalent from the builder class.

llvm-svn: 165896

Remove the bitwise assignment OR operator from the Attributes class. Replace it with the equivalent from the builder class.

llvm-svn: 165895

Remove the bitwise NOT operator from the Attributes class. Replace it with the equivalent from the builder class.

llvm-svn: 165892

namespace. Use the attribute's enum value instead. No functionality change
intended.

llvm-svn: 165610

Have 'addFnAttr' take the attribute enum value. Then have it build the attribute object and add it appropriately. No functionality change.

llvm-svn: 165595

llvm-svn: 165550

llvm-svn: 165498

llvm-svn: 165494

DeadArgumentElimination pass can replace one LLVM function with another,
invalidating a pointer stored in debug info metadata entry for this function.
To fix this, we collect debug info descriptors for functions before
running a DeadArgumentElimination pass and "patch" pointers in metadata nodes
if we replace a function.

llvm-svn: 165490

We use the enums to query whether an Attributes object has that attribute. The
opaque layer is responsible for knowing where that specific attribute is stored.

llvm-svn: 165488

llvm-svn: 165468

the same thing. No functionality change.

llvm-svn: 165435

llvm-svn: 165402

llvm-svn: 165209

llvm-svn: 165208

llvm-svn: 165207

llvm-svn: 165206

Again, let me know if anything breaks due to this!

llvm-svn: 164986

Fun fact: The CBE learned how to deal with this situation before it was removed.

llvm-svn: 164918

llvm-svn: 164850

Fixes PR13968.

llvm-svn: 164815

Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767

llvm-svn: 164768

llvm-svn: 164767

have testcases for the current problems.

llvm-svn: 164731

The hasFnAttr method has been replaced by querying the Attributes explicitly. No
intended functionality change.

llvm-svn: 164725

llvm-svn: 164629

Queue the fallout. ;]

llvm-svn: 164480

llvm-svn: 164124

FCAs. This is essential in order to promote allocas that are used in
struct returns by frontends like Clang. The FCA load would block the
rest of the pass from firing, resulting is significant regressions with
the bullet benchmark in the nightly test suite.

Thanks to Duncan for repeated discussions about how best to do this, and
to both him and Benjamin for review.

This appears to have blocked many places where the pass tries to fire,
and so I'm expect somewhat different results with this fix added.

As with the last big patch, I'm including a change to enable the SROA by
default *temporarily*. Ben is going to remove this as soon as the LNT
bots pick up the patch. I'm just trying to get a round of LNT numbers
from the stable machines in the lab.

NOTE: Four clang tests are expected to fail in the brief window where
this is enabled. Sorry for the noise!

llvm-svn: 164119

What we have so far:
- Some clang test failures (these were known already)

- Perf results are mixed, some big regressions
  http://llvm.org/perf/db_default/v4/nts/3844
  http://llvm.org/perf/db_default/v4/nts/3845

  bullet suffers a lot. matmul is interesting: slower scalar code, faster with -vectorize.

- Some dragonegg selfhost bots crash in SROA during selfhost now
  http://lab.llvm.org:8011/builders/dragonegg-x86_64-linux-gcc-4.6-self-host-checks/builds/1632
  http://lab.llvm.org:8011/builders/dragonegg-x86_64-linux-gcc-4.5-self-host/builds/1891

llvm-svn: 163968

new one, and add support for running the new pass in that mode and in
that slot of the pass manager. With this the new pass can completely
replace the old one within the pipeline.

The strategy for enabling or disabling the SSAUpdater logic is to do it
by making the requirement of the domtree analysis optional. By default,
it is required and we get the standard mem2reg approach. This is usually
the desired strategy when run in stand-alone situations. Within the
CGSCC pass manager, we disable requiring of the domtree analysis and
consequentially trigger fallback to the SSAUpdater promotion.

In theory this would allow the pass to re-use a domtree if one happened
to be available even when run in a mode that doesn't require it. In
practice, it lets us have a single pass rather than two which was
simpler for me to wrap my head around.

There is a hidden flag to force the use of the SSAUpdater code path for
the purpose of testing. The primary testing strategy is just to run the
existing tests through that path. One notable difference is that it has
custom code to handle lifetime markers, and one of the tests has been
enhanced to exercise that code.

This has survived a bootstrap and the test suite without serious
correctness issues, however my run of the test suite produced *very*
alarming performance numbers. I don't entirely understand or trust them
though, so more investigation is on-going.

To aid my understanding of the performance impact of the new SROA now
that it runs throughout the optimization pipeline, I'm enabling it by
default in this commit, and will disable it again once the LNT bots have
picked up one iteration with it. I want to get those bots (which are
much more stable) to evaluate the impact of the change before I jump to
any conclusions.

NOTE: Several Clang tests will fail because they run -O3 and check the
result's order of output. They'll go back to passing once I disable it
again.

llvm-svn: 163965