I thought that I had fixed this problem in r216818, but I did not do a very
good job. The underlying issue is that when we add alias.scope metadata we are
asserting that this metadata completely describes the aliasing relationships
within the current aliasing scope domain, and so in the context of translating
noalias argument attributes, the pointers must all be based on noalias
arguments (as underlying objects) and have no other kind of underlying object.
In r216818 excluding appropriate accesses from getting alias.scope metadata is
done by looking for underlying objects that are not identified function-local
objects -- but that's wrong because allocas, etc. are also function-local
objects and we need to explicitly check that all underlying objects are the
noalias arguments for which we're adding metadata aliasing scopes.

This fixes the underlying-object check for adding alias.scope metadata, and
does some refactoring of the related capture-checking eligibility logic (and
adds more comments; hopefully making everything a bit clearer).

Fixes self-hosting on x86_64 with -mllvm -enable-noalias-to-md-conversion (the
feature is still disabled by default).

llvm-svn: 216863

Summary:
Fixes a FIXME in MachineSinking. Instead of using the simple heuristics
in isPostDominatedBy, use the real MachinePostDominatorTree. The old
heuristics caused instructions to sink unnecessarily, and might create
register pressure.

Test Plan:
Added a NVPTX codegen test to verify that our change is in effect. It also
shows the unnecessary register pressure caused by over-sinking. Updated
affected tests in AArch64 and X86.

Reviewers: eliben, meheff, Jiangning

Reviewed By: Jiangning

Subscribers: jholewinski, aemerson, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D4814

llvm-svn: 216862

DW_TAG_lexical_scopes inform debuggers about the instruction range for
which a given variable (or imported declaration/module/etc) is valid. If
the scope doesn't itself contain any such entities, it's a waste of
space and should be omitted.

We were correctly doing this for entirely empty leaves, but not for
intermediate nodes.

Reduces total (not just debug sections) .o file size for a bootstrap
-gmlt LLVM by 22% and bootstrap -gmlt clang executable by 13%. The wins
for a full -g build will be less as a % (and in absolute terms), but
should still be substantial - with some of that win being fewer
relocations, thus more substantiall reducing link times than fewer bytes
alone would have.

llvm-svn: 216861

Make this conservatively correct and report false for different
address spaces, which might require a nontrivial translation.

Based on the few uses of this, I don't think this currently
breaks anything.

llvm-svn: 216846

DebugInfo: Move argument creation up into the caller that's unambiguously handling the subprogram scope (replacing a conditional with an assertion in the process)

llvm-svn: 216845

Delay adding imported entity DIEs to the lexical scope, streamlining the check for "this scope has nothing in it"

This makes the emptiness of the scope with regards to variables and
nested scopes is the same as with regards to imported entities. Just
check if we had nothing at all before we build the node.

llvm-svn: 216840

Another step towards improving lexical_scope handling

llvm-svn: 216839

Refactor constructImportedEntityDIE(DwarfUnit, DIImportedEntity) to return a DIE rather than inserting it into a specified context.

First of many steps to improve lexical scope construction (to omit
trivial lexical scopes - those without any direct variables). To that
end it's easier not to create imported entities directly into the
lexical scope node, but to build them, then add them if necessary.

llvm-svn: 216838

llvm-svn: 216833

Summary:
This extends the work done in [1], adding missing intrinsic lowering for floor, trunc, round and copysign.

[1] http://comments.gmane.org/gmane.comp.compilers.llvm.cvs/199372

Test Plan: Extended `test/ExecutionEngine/Interpreter/intrinsics.ll` to test the additional missing intrinsics. All tests pass.

Reviewers: dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5120

llvm-svn: 216827

llvm-svn: 216823

Fix some cases where StringRef was being passed by const reference. Remove const from some other StringRefs since its implicitly const already.

llvm-svn: 216820

llvm-svn: 216819

The previous implementation of AddAliasScopeMetadata, which adds noalias
metadata to preserve noalias parameter attribute information when inlining had
a flaw: it would add alias.scope metadata to accesses which might have been
derived from pointers other than noalias function parameters. This was
incorrect because even some access known not to alias with all noalias function
parameters could easily alias with an access derived from some other pointer.
Instead, when deriving from some unknown pointer, we cannot add alias.scope
metadata at all. This fixes a miscompile of the test-suite's tramp3d-v4.
Furthermore, we cannot add alias.scope to functions unless we know they
access only argument-derived pointers (currently, we know this only for
memory intrinsics).

Also, we fix a theoretical problem with using the NoCapture attribute to skip
the capture check. This is incorrect (as explained in the comment added), but
would not matter in any code generated by Clang because we get only inferred
nocapture attributes in Clang-generated IR.

This functionality is not yet enabled by default.

llvm-svn: 216818

llvm-svn: 216817

consider: (and (icmp X, Y), (and Z, (icmp A, B)))
It may be possible to combine (icmp X, Y) with (icmp A, B).
If we successfully combine, create an 'and' instruction with Z.

This fixes PR20814.

N.B. There is room for improvement after this change but I'm not
convinced it's worth chasing yet.

llvm-svn: 216814

I think this broke the build bot. Reverting it for now until I have time to take a closer look.

llvm-svn: 216813

llvm-svn: 216809

MachOObjectFile in lib/Object currently has no support for parsing the rebase, 
binding, and export information from the LC_DYLD_INFO load command in final 
linked mach-o images. This patch adds support for parsing the exports trie data
structure. It also adds an option to llvm-objdump to dump that export info.

I did the exports parsing first because it is the hardest. The information is 
encoded in a trie structure, but the standard ObjectFile way to inspect content 
is through iterators. So I needed to make an iterator that would do a 
non-recursive walk through the trie and maintain the concatenation of edges 
needed for the current string prefix.

I plan to add similar support in MachOObjectFile and llvm-objdump to 
parse/display the rebasing and binding info too.

llvm-svn: 216808

Select the correct register class for the various instructions that are
generated when combining instructions and constrain the registers to the
appropriate register class.

This fixes rdar://problem/18183707.

llvm-svn: 216805

Also constrain the register class for branches.

This fixes rdar://problem/18181496.

llvm-svn: 216804

When sinking an instruction it might be moved past the original last use of one
of its operands. This last use has the kill flag set and the verifier will
obviously complain about this.

Before Machine Sinking (AArch64):
%vreg3<def> = ASRVXr %vreg1, %vreg2<kill>
%XZR<def> = SUBSXrs %vreg4, %vreg1<kill>, 160, %NZCV<imp-def>
...

After Machine Sinking:
%XZR<def> = SUBSXrs %vreg4, %vreg1<kill>, 160, %NZCV<imp-def>
...
%vreg3<def> = ASRVXr %vreg1, %vreg2<kill>

This fix clears all the kill flags in all instruction that use the same operands
as the instruction that is being sunk.

This fixes rdar://problem/18180996.

llvm-svn: 216803

RuntimeDyldImpl.

These are platform independent, and moving them to the base class allows
RuntimeDyldChecker to use them too.

llvm-svn: 216801

specifier and change the default behavior to only emit the
DW_AT_accessibility(public) attribute when the isPublic() is explicitly
set.

rdar://problem/18154959

llvm-svn: 216799

llvm-svn: 216798

llvm-svn: 216797

llvm-svn: 216794

llvm-svn: 216793

Rushed when I realized I hadn't committed the FreeDeleter for a clang
change I'd committed, and didn't check that I had things lying around in
my client.

Apologies for the noise.

llvm-svn: 216792

llvm-svn: 216789

llvm-svn: 216788

llvm-svn: 216787

Summary: Just fixing comments, no functional change.

Test Plan: N/A

Reviewers: jfb

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D5130

llvm-svn: 216784

llvm-svn: 216781

Summary:
If a variadic function body contains a musttail call, then we copy all
of the remaining register parameters into virtual registers in the
function prologue. We track the virtual registers through the function
body, and add them as additional registers to pass to the call. Because
this is all done in virtual registers, the register allocator usually
gives us good code. If the function does a call, however, it will have
to spill and reload all argument registers (ew).

Forwarding regparms on x86_32 is not implemented because most compilers
don't support varargs in 32-bit with regparms.

Reviewers: majnemer

Subscribers: aemerson, llvm-commits

Differential Revision: http://reviews.llvm.org/D5060

llvm-svn: 216780

We've rejected these kinds of functions since r28405 in 2006 because
it's impossible to lower the return of a callee cleanup varargs
function. However there are lots of legal ways to leave such a function
without returning, such as aborting. Today we can leave a function with
a musttail call to another function with the correct prototype, and
everything works out.

I'm removing the verifier check declaring that a normal return from such
a function is UB.

Reviewed By: nlewycky

Differential Revision: http://reviews.llvm.org/D5059

llvm-svn: 216779

This patch checks for DAG patterns that are an add or a sub followed by a
compare on 16 and 8 bit inputs. Since AArch64 does not support those types
natively they are legalized into 32 bit values, which means that mask operations
are inserted into the DAG to emulate overflow behaviour. In many cases those
masks do not change the result of the processing and just introduce a dependent
operation, often in the middle of a hot loop.

This patch detects the relevent DAG patterns and then tests to see if the
transforms are equivalent with and without the mask, removing the mask if
possible. The exact mechanism of this patch was discusses in
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-July/074444.html

There is a reasonably good chance there are missed oppurtunities due to similiar
(but not identical) DAG patterns that could be funneled into this test, adding
them should be simple if we see test cases.

Tests included.

rdar://13754426

llvm-svn: 216776

The new solution is to not use this lowering if there are any dynamic
allocas in the current function. We know up front if there are dynamic
allocas, but we don't know if we'll need to create stack temporaries
with large alignment during lowering. Conservatively assume that we will
need such temporaries.

Reviewed By: hans

Differential Revision: http://reviews.llvm.org/D5128

llvm-svn: 216775

Even loads/stores that have a stronger ordering than monotonic can be safe.
The rule is no release-acquire pair on the path from the QueryInst, assuming that
the QueryInst is not atomic itself.

llvm-svn: 216771

Summary:
Mostly renaming the (not very explicit) variables Tmp0, .. Tmp4, and grouping
related statements together, along with a few lines of comments for the
surprising parts.

No functional change intended.

Test Plan: make check-all

Reviewers: jfb

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5088

llvm-svn: 216768