llvm-svn: 219975

A second instance of attributed types escaped the previous change, identified
thanks to Richard Smith!  When deducing the void case, we would also assume that
the type would not be attributed.  Furthermore, properly handle multiple
attributes being applied to a single TypeLoc.

Properly handle this case and future-proof a bit by ignoring parenthesis
further.  The test cases do use the additional parenthesis to ensure that this
case remains properly handled.

Addresses post-commit review comments from Richard Smith to SVN r219851.

llvm-svn: 219974

llvm-svn: 219973

llvm-svn: 219972

llvm-svn: 219971

llvm-svn: 219970

llvm-svn: 219969

This is in preparation for another patch that makes patchpoints invokable.

Reviewers: atrick, ributzka
Reviewed By: ributzka
Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5657

llvm-svn: 219967

pointer contains something.

llvm-svn: 219966

llvm-svn: 219965

llvm-svn: 219964

'AS'.

Using 'S' as this was a terrible idea. Arguably, 'AS' is not much
better, but it at least follows the idea of using initialisms and
removes active confusion about the AllocaSlices variable and a Slice
variable.

llvm-svn: 219963

clang-modernize.

I did have to clean up the variable types and whitespace a bit because
the use of auto made the code much less readable here.

llvm-svn: 219962

Insert poisoned paddings between fields in C++ classes so that AddressSanitizer can find intra-object-overflow bugs

Summary:
The general approach is to add extra paddings after every field
in AST/RecordLayoutBuilder.cpp, then add code to CTORs/DTORs that poisons the paddings
(CodeGen/CGClass.cpp).

Everything is done under the flag -fsanitize-address-field-padding. 
The blacklist file (-fsanitize-blacklist) allows to avoid the transformation 
for given classes or source files. 

See also https://code.google.com/p/address-sanitizer/wiki/IntraObjectOverflow

Test Plan: run SPEC2006 and some of the Chromium tests with  -fsanitize-address-field-padding

Reviewers: samsonov, rnk, rsmith

Reviewed By: rsmith

Subscribers: majnemer, cfe-commits

Differential Revision: http://reviews.llvm.org/D5687

llvm-svn: 219961

They cannot be written to, so marking them const makes sense and may improve
optimisation.

As a side-effect, SectionInfos has to be moved from Sema to ASTContext.

It also fixes this problem, that occurs when compiling ATL:

  warning LNK4254: section 'ATL' (C0000040) merged into '.rdata' (40000040) with different attributes

The ATL headers are putting variables in a special section that's marked
read-only. However, Clang currently can't model that read-onlyness in the IR.
But, by making the variables const, the section does become read-only, and
the linker warning is avoided.

Differential Revision: http://reviews.llvm.org/D5812

llvm-svn: 219960

First, add a comment to support more variation in FDE formats. Second, refactor
fde -> function handling into a separate function living in the ArchHandler.

llvm-svn: 219959

ArrayRef accessors.

I think this even came up in review that this was over-engineered, and
indeed it was. Time to un-build it.

llvm-svn: 219958

Summary:
Backends can use setInsertFencesForAtomic to signal to the middle-end that
montonic is the only memory ordering they can accept for
stores/loads/rmws/cmpxchg. The code lowering those accesses with a stronger
ordering to fences + monotonic accesses is currently living in
SelectionDAGBuilder.cpp. In this patch I propose moving this logic out of it
for several reasons:
- There is lots of redundancy to avoid: extremely similar logic already
  exists in AtomicExpand.
- The current code in SelectionDAGBuilder does not use any target-hooks, it
  does the same transformation for every backend that requires it
- As a result it is plain *unsound*, as it was apparently designed for ARM.
  It happens to mostly work for the other targets because they are extremely
  conservative, but Power for example had to switch to AtomicExpand to be
  able to use lwsync safely (see r218331).
- Because it produces IR-level fences, it cannot be made sound ! This is noted
  in the C++11 standard (section 29.3, page 1140):
```
Fences cannot, in general, be used to restore sequential consistency for atomic
operations with weaker ordering semantics.
```
It can also be seen by the following example (called IRIW in the litterature):
```
atomic<int> x = y = 0;
int r1, r2, r3, r4;
Thread 0:
  x.store(1);
Thread 1:
  y.store(1);
Thread 2:
  r1 = x.load();
  r2 = y.load();
Thread 3:
  r3 = y.load();
  r4 = x.load();
```
r1 = r3 = 1 and r2 = r4 = 0 is impossible as long as the accesses are all seq_cst.
But if they are lowered to monotonic accesses, no amount of fences can prevent it..

This patch does three things (I could cut it into parts, but then some of them
would not be tested/testable, please tell me if you would prefer that):
- it provides a default implementation for emitLeadingFence/emitTrailingFence in
terms of IR-level fences, that mimic the original logic of SelectionDAGBuilder.
As we saw above, this is unsound, but the best that can be done without knowing
the targets well (and there is a comment warning about this risk).
- it then switches Mips/Sparc/XCore to use AtomicExpand, relying on this default
implementation (that exactly replicates the logic of SelectionDAGBuilder, so no
functional change)
- it finally erase this logic from SelectionDAGBuilder as it is dead-code.

Ideally, each target would define its own override for emitLeading/TrailingFence
using target-specific fences, but I do not know the Sparc/Mips/XCore memory model
well enough to do this, and they appear to be dealing fine with the ARM-inspired
default expansion for now (probably because they are overly conservative, as
Power was). If anyone wants to compile fences more agressively on these
platforms, the long comment should make it clear why he should first override
emitLeading/TrailingFence.

Test Plan: make check-all, no functional change

Reviewers: jfb, t.p.northover

Subscribers: aemerson, llvm-commits

Differential Revision: http://reviews.llvm.org/D5474

llvm-svn: 219957

These haven't been necessary since allowing
selecting SALU instructions in non-entry blocks
was enabled.

llvm-svn: 219956

iterators.

There are a ton of places where it essentially wants ranges
rather than just iterators. This is just the first step that adds the
core slice range typedefs and uses them in a couple of places. I still
have to explicitly construct them because they've not been punched
throughout the entire set of code. More range-based cleanups incoming.

llvm-svn: 219955

No longer emit diagnostics about unused results (comparisons, etc) from unevaluated contexts. Fixes PR18571.

llvm-svn: 219954

This was resulting in invalid simplifications of sdiv

llvm-svn: 219953

llvm-svn: 219952

These days -std-compile-opts was just a silly alias for -O3.

llvm-svn: 219951

Summary:
Currently, call slot optimization requires that if the destination is an
argument, the argument has the sret attribute. This is to ensure that
the memory access won't trap. In addition to sret, we can also allow the
optimization to happen for arguments that have the new dereferenceable
attribute, which gives the same guarantee.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5832

llvm-svn: 219950

To deal with cycles in shared library dependencies, the darwin linker supports
marking specific link dependencies as "upward".  An upward link is when a
lower level library links against a higher level library.

llvm-svn: 219949

This patch creates the import address table and sets its
address to the delay-load import table. This also creates
wrapper functions for __delayLoadHelper2.

x86 only for now.

llvm-svn: 219948

llvm-svn: 219947

llvm-svn: 219946

llvm-svn: 219945

If a square root call has an FP multiplication argument that can be reassociated,
then we can hoist a repeated factor out of the square root call and into a fabs().

In the simplest case, this:

   y = sqrt(x * x);

becomes this:

   y = fabs(x);

This patch relies on an earlier optimization in instcombine or reassociate to put the
multiplication tree into a canonical form, so we don't have to search over
every permutation of the multiplication tree.

Because there are no IR-level FastMathFlags for intrinsics (PR21290), we have to
use function-level attributes to do this optimization. This needs to be fixed
for both the intrinsics and in the backend.

Differential Revision: http://reviews.llvm.org/D5787

llvm-svn: 219944

DebugInfo: Follow up to r219736, also test/demonstrate that we emit the constant value in this case as well.

llvm-svn: 219943

llvm-svn: 219942

llvm-svn: 219941

llvm-svn: 219940

Summary:
Fix code to follow the "Don’t use else after a return" rule.
This is a followup from rL219792.

Reviewers: alexfh

Subscribers: klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D5826

llvm-svn: 219939

(also, the code executed once the element was found was split half
inside the loop and half after it - now put it all together after the
find operation)

I'm a bit concerned that this code is rather untested (commenting out
this whole function and running check-clang doesn't fail any tests)...

And I wish I had polymorphic lambdas.

llvm-svn: 219938

The final goal is to get rid of all the rest overloads that
accept LLVM objects (llvm::Function and llvm::GlobalVariable),
and pass in source-level entities instead.

llvm-svn: 219937

was able to create itself before returning the shared
pointer to it.
clang warning.

llvm-svn: 219936

llvm-svn: 219935