Commit Graph

119669 Commits

Author SHA1 Message Date
Rafael Espindola
6624afccc6 Start adding documentation for llvm-lib.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242557 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 18:49:26 +00:00
Adam Nemet
fadee632e1 Revert "ARM: Enable MachineScheduler and disable PostRAScheduler for swift."
This reverts commit r242500.

It broke some internal tests and Matthias asked me to revert it while he
is investigating.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242553 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 18:14:19 +00:00
Matthias Braun
63f73d7b80 Use llvm_unreachable() instead of report_fatal_error() if the machine model is incomplete
This error is for developers only so it makes sense to abort and get a
backtrace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242551 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 17:50:11 +00:00
Peter Zotov
7b9a628414 [OCaml] Do not use -warn-error in tests.
This -warn-error flag invariably gets into release tarballs
and breaks builds on distributions that run tests as a part
of release process. The OCaml binding tests are especially
critical, since they often expose lingering toolchain bugs,
and so it is replaced with -w +A (equivalent to -Wall).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242550 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 17:33:23 +00:00
James Molloy
f5bdd93ff8 [ARM] Use [SU]ABSDIFF nodes instead of intrinsics for VABD/VABA
No functional change, but it preps codegen for the future when SABSDIFF
will start getting generated in anger.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242546 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 17:10:55 +00:00
James Molloy
126ab2389e [AArch64] Use [SU]ABSDIFF nodes instead of intrinsics for ABD/ABA
No functional change, but it preps codegen for the future when SABSDIFF
will start getting generated in anger.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242545 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 17:10:45 +00:00
Hans Wennborg
8a8582d6e9 Add libunwind to the release scripts
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242543 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 16:49:59 +00:00
Eli Bendersky
27bd1ca0d9 Use inbounds GEPs for memcpy and memset lowering
Follow-up on discussion in http://reviews.llvm.org/D11220


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242542 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 16:42:33 +00:00
Rafael Espindola
f82375c972 Add support for producing thin archives in llvm-lib.
I will send an entry in docs/CommandGuide for review today.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242533 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 16:01:11 +00:00
Alexandros Lamprineas
96ac935e6d Edited the CPUNames table of TargetParser
- Changed the default FPU of cortex-m4.
- Removed "cortex-m4f" entry. Currently not supported.

Change-Id: I73121e358aa9e7ba68eb001c2143df390ff2352a
Phabricator: http://reviews.llvm.org/D11100

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242528 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 15:49:32 +00:00
John Brawn
591adee23b Make global aliases have symbol size equal to their type
This is mainly for the benefit of GlobalMerge, so that an alias into a
MergedGlobals variable has the same size as the original non-merged
variable.

Differential Revision: http://reviews.llvm.org/D10837


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242520 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 12:12:03 +00:00
Daniel Sanders
fe6ad9692a test-release.sh: Add ability to do a test build using the trunk or branches.
Summary:
Adds '--svn-path BRANCH' that causes the script to export the specified path
from each project. Otherwise the tag specified by -release, -rc, etc. will be
used. The version portion of the package name will be 'test-$path' (any forward
slashes in the branch name are replaced with underscores), for example:
  -svn-path trunk => clang+llvm-test-trunk-mips-linux-gnu.tar.xz
  -svn-path branches/release_35 => clang+llvm-test-branches_release_35-mips-linux-gnu.tar.xz

This is primarily useful for bringing new release packages up to standard
without needing to create and maintain a tag for the purpose.

Reviewers: tstellarAMD, hans

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6563



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242518 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 10:40:40 +00:00
Chandler Carruth
81f4bf79a1 [PM/AA] Disable the core unsafe aspect of GlobalsModRef in the face of
basic changes to the IR such as folding pointers through PHIs, Selects,
integer casts, store/load pairs, or outlining.

This leaves the feature available behind a flag. This flag's default
could be flipped if necessary, but the real-world performance impact of
this particular feature of GMR may not be sufficiently significant for
many folks to want to run the risk.

Currently, the risk here is somewhat mitigated by half-hearted attempts
to update GlobalsModRef when the rest of the optimizer changes
something. However, I am currently trying to remove that update
mechanism as it makes migrating the AA infrastructure to a form that can
be readily shared between new and old pass managers very challenging.
Without this update mechanism, it is possible that this still unlikely
failure mode will start to trip people, and so I wanted to try to
proactively avoid that.

There is a lengthy discussion on the mailing list about why the core
approach here is flawed, and likely would need to look totally different
to be both reasonably effective and resilient to basic IR changes
occuring. This patch is essentially the first of two which will enact
the result of that discussion. The next patch will remove the current
update mechanism.

Thanks to lots of folks that helped look at this from different angles.
Especial thanks to Michael Zolotukhin for doing some very prelimanary
benchmarking of LTO without GlobalsModRef to get a rough idea of the
impact we could be facing here. So far, it looks very small, but there
are some concerns lingering from other benchmarking. The default here
may get flipped if performance results end up pointing at this as a more
significant issue.

Also thanks to Pete and Gerolf for reviewing!

Differential Revision: http://reviews.llvm.org/D11213

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242512 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 06:58:24 +00:00
Peter Zotov
2fd32b4a0f [OCaml] Use a nicer style for documentation than OCaml default.
In particular, it's much easier to read, as it doesn't expand all
the way on wide-screen displays.

CSS committed under LLVM license with explicit permission from
Daniel Bünzli <daniel.buenzli@erratique.ch>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242511 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 06:37:59 +00:00
Kuba Brecka
d71b7d01e8 [asan] Fix invalid debug info for promotable allocas
Since r230724 ("Skip promotable allocas to improve performance at -O0"), there is a regression in the generated debug info for those non-instrumented variables. When inspecting such a variable's value in LLDB, you often get garbage instead of the actual value. ASan instrumentation is inserted before the creation of the non-instrumented alloca. The only allocas that are considered standard stack variables are the ones declared in the first basic-block, but the initial instrumentation setup in the function breaks that invariant.

This patch makes sure uninstrumented allocas stay in the first BB.

Differential Revision: http://reviews.llvm.org/D11179



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242510 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 06:29:57 +00:00
Davide Italiano
ac018543f8 [llvm-cxxdump] Don't rely on global state
Differential Revision:	http://reviews.llvm.org/D11227


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242509 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 06:18:36 +00:00
Tim Northover
b974e0babe AArch64: add comment missed out from earlier patch.
Helps explain some of the background behind this bit of code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242503 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 03:31:50 +00:00
Matthias Braun
c8fe2bf3a4 ARM: Enable MachineScheduler and disable PostRAScheduler for swift.
This is mostly done to disable the PostRAScheduler which optimizes for
instruction latencies which isn't a good fit for out-of-order
architectures. This also allows to leave out the itinerary table in
swift in favor of the SchedModel ones.

This change leads to performance improvements/regressions by as much as
10% in some benchmarks, in fact we loose 0.4% performance over the
llvm-testsuite for reasons that appear to be unknown or out of the
compilers control. rdar://20803802 documents the investigation of
these effects.

While it is probably a good idea to perform the same switch for the
other ARM out-of-order CPUs, I limited this change to swift as I cannot
perform the benchmark verification on the other CPUs.

Differential Revision: http://reviews.llvm.org/D10513

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242500 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 01:44:31 +00:00
Matt Arsenault
ac69d5205b Only do fmul (fadd x, x), c combine if the fadd only has one use
This was increasing the instruction count if the fadd has multiple uses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242498 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 01:14:35 +00:00
Rafael Espindola
7c91cefac5 Use small encodings for constants when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242493 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 00:57:52 +00:00
Alex Lorenz
2744189c46 MIR Serialization: Serialize the frame setup machine instruction flag.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242491 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 00:24:15 +00:00
Alex Lorenz
ed2032f17a MIR Serialization: Serialize the frame index machine operands.
Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242487 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 23:37:45 +00:00
Cong Hou
1dd3d83c5e Add new constructors for LoopInfo/DominatorTree/BFI/BPI
Those new constructors make it more natural to construct an object for a function. For example, previously to build a LoopInfo for a function, we need four statements:

DominatorTree DT;
LoopInfo LI;
DT.recalculate(F);
LI.analyze(DT);

Now we only need one statement:

LoopInfo LI(DominatorTree(F));

http://reviews.llvm.org/D11274



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242486 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 23:23:35 +00:00
Matthias Braun
650d9427f0 Arm: Don't define a label twice with two setjmps in a function.
Constructing a name based on the function name didn't give us a unique
symbol if we had more than one setjmp in a function. Using
MCContext::createTempSymbol() always gives us a unique name.

Differential Revision: http://reviews.llvm.org/D9314

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242482 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 22:34:20 +00:00
Matthias Braun
9e4654db1a Fix __builtin_setjmp in combination with sjlj exception handling.
llvm.eh.sjlj.setjmp was used as part of the SjLj exception handling
style but is also used in clang to implement __builtin_setjmp.  The ARM
backend needs to output additional dispatch tables for the SjLj
exception handling style, these tables however can't be emitted if
llvm.eh.sjlj.setjmp is simply used for __builtin_setjmp and no actual
landing pad blocks exist.

To solve this issue a new llvm.eh.sjlj.setup_dispatch intrinsic is
introduced which is used instead of llvm.eh.sjlj.setjmp in the SjLj
exception handling lowering, so we can differentiate between the case
where we actually need to setup a dispatch table and the case where we
just need the __builtin_setjmp semantic.

Differential Revision: http://reviews.llvm.org/D9313

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242481 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 22:34:16 +00:00
Mehdi Amini
ec56faaa64 Fix ffiInvoke() use of DataLayout, broken in 242414
From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242456 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 22:23:09 +00:00
Sanjoy Das
cb19d4c525 [SCEV][NFC] Use triple-slash (///) for comment.
Makes the comments for proveNoWrapByVaryingStart consistent with the
rest of ScalarEvolution.h

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242451 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 22:08:37 +00:00
Simon Pilgrim
6757a44d2d Fix spelling. NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242448 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 21:44:53 +00:00
Tim Northover
c5cc2e1a5a AArch64: make inexact signalling on round Darwin-specific
C11 leaves the choice on whether round-to-integer operations set the inexact
flag implementation-defined. Darwin does expect it to be set, but this seems to
be against the intent of the IEEE document and slower to implement anyway. So
it should be opt-in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242446 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 21:30:21 +00:00
Simon Pilgrim
eee548ab0c [X86][SSE] Added nounwind attribute to vector shift tests.
Stop i686 codegen from generating cfi directives.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242443 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 21:14:26 +00:00
Bill Schmidt
7be3a33a0b [PowerPC] v4i32 is a VSRCRegClass
I was looking at some vector code generation and kept seeing
unnecessary vector copies into the Altivec half of the VSX registers.
I discovered that we overlooked v4i32 when adding the register classes
for VSX; we only added v4f32 and v2f64.  This means that anything that
canonicalizes into v4i32 (which is a LOT of stuff) ends up being
forced into VRRC on its way to VSRC.

The fix is one line.  The rest of the patch is fixing up some test
cases whose code generation has changed as a result.

This seems like it would be a good candidate for backport to 3.7.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242442 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 21:14:07 +00:00
Philip Reames
edcb51fd4c List supported architectures for StackMap section and related intrinsics
Not having this documented led to some confusion in a recent review thread.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242441 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 21:10:46 +00:00
Simon Pilgrim
cc89d5ab31 [X86][SSE] Updated vector conversion test names.
I'll be adding further tests shortly so need a more thorough naming convention.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242440 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 21:00:57 +00:00
Eli Bendersky
ccd3aa85a9 Streamline the coding style in NVPTXLowerAggrCopies
Make the style consistent with LLVM style throughout and clang-format.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242439 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 20:42:38 +00:00
Matthias Braun
da787addf3 MachineInstr: Explain the subtle semantics of uses()/defs()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242438 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 20:27:01 +00:00
Jingyue Wu
1241b83d61 [NVPTX] enable SpeculativeExecution in NVPTX
Summary:
SpeculativeExecution enables a series straight line optimizations (such
as SLSR and NaryReassociate) on conditional code. For example,

  if (...)
    ... b * s ...
  if (...)
    ... (b + 1) * s ...

speculative execution can hoist b * s and (b + 1) * s from then-blocks,
so that we have

  ... b * s ...
  if (...)
    ...
  ... (b + 1) * s ...
  if (...)
    ...

Then, SLSR can rewrite (b + 1) * s to (b * s + s) because after
speculative execution b * s dominates (b + 1) * s.

The performance impact of this change is significant. It speeds up the
benchmarks running EigenFloatContractionKernelInternal16x16
(ba68f42fa6/unsupported/Eigen/CXX11/src/Tensor/TensorContractionCuda.h (cl-526))
by roughly 2%. Some internal benchmarks that have the above code pattern
are improved by up to 40%. No significant slowdowns are observed on
Eigen CUDA microbenchmarks.

Reviewers: jholewinski, broune, eliben

Subscribers: llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11201

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242437 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 20:13:48 +00:00
Matthias Braun
66b12088cb AArch64: Implement conditional compare sequence matching.
This is a new iteration of the reverted r238793 /
http://reviews.llvm.org/D8232 which wrongly assumed that any and/or
trees can be represented by conditional compare sequences, however there
are some restrictions to that. This version fixes this and adds comments
that explain exactly what types of and/or trees can actually be
implemented as conditional compare sequences.

Related to http://llvm.org/PR20927, rdar://18326194

Differential Revision: http://reviews.llvm.org/D10579

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242436 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 20:02:37 +00:00
Tom Stellard
104dab3e04 AMDPGU/SI: Negative offsets aren't allowed in MUBUF's vaddr operand
Reviewers: arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11226

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242434 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 19:40:09 +00:00
Tom Stellard
cac05d9b58 AMDPGU/SI: Use AssertZext node to mask high bit for scratch offsets
Summary:
We can safely assume that the high bit of scratch offsets will never
be set, because this would require at least 128 GB of GPU memory.

Reviewers: arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11225

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242433 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 19:40:07 +00:00
Matthias Braun
0219a272ec LiveInterval: Document and enforce rules about empty subranges.
Empty subranges are not allowed in a LiveInterval and must be removed
instead: Check this in the verifiers, put a reminder for this in the
comment of the shrinkToUses variant for a single lane and make it
automatic for the shrinkToUses variant for a LiveInterval.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242431 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:55:35 +00:00
Matthias Braun
ac40c926aa Do not duplicate method name in comment, remove duplicate comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242430 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:55:32 +00:00
Rafael Espindola
5404f6983a Delete an unused function.
Patch by Xan López!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242429 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:41:41 +00:00
Pete Cooper
5cfac0ef44 Revert "Add missing load/store flags to thumb2 instructions."
This reverts commit r242300.

This is causing buildbot failures which we are investigating.
I'll reapply once we know whats going on, but for now want to
get the bots green.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242428 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:38:13 +00:00
Cong Hou
204b59072d Rename LoopInfo::Analyze() to LoopInfo::analyze() and turn its parameter type to const&.
The benefit of turning the parameter of LoopInfo::analyze() to const& is that it now can accept a rvalue.

http://reviews.llvm.org/D11250



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242426 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:23:57 +00:00
Peter Collingbourne
4a6d99b0a9 Internalize: internalize comdat members as a group, and drop comdat on such members.
Internalizing an individual comdat group member without also internalizing
the other members of the comdat can break comdat semantics. For example,
if a module contains a reference to an internalized comdat member, and the
linker chooses a comdat group from a different object file, this will break
the reference to the internalized member.

This change causes the internalizer to only internalize comdat members if all
other members of the comdat are not externally visible. Once a comdat group
has been fully internalized, there is no need to apply comdat rules to its
members; later optimization passes (e.g. globaldce) can legally drop individual
members of the comdat. So we drop the comdat attribute from all comdat members.

Differential Revision: http://reviews.llvm.org/D10679

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242423 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 17:42:21 +00:00
Benjamin Kramer
fc0d94c8ec [NVPTX] Don't leak dead instructions after unlinking them from the BasicBlock
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242417 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 16:51:48 +00:00
Mehdi Amini
965883ad85 Fix Kaleidoscope tuto: ExecutionEngine->getDataLayout() returns a ref
From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242416 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 16:47:18 +00:00
Mehdi Amini
e02fce0ac9 Make ExecutionEngine owning a DataLayout
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

The ExecutionEngine will act as an exception and will be unsafe to
be reused across context. We don't enforce this rule but undefined
behavior can occurs if the user tries to do it.

Reviewers: lhames

Subscribers: echristo, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11110

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242414 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 16:34:23 +00:00
Eli Bendersky
9e05109e11 Correct lowering of memmove in NVPTX
This fixes https://llvm.org/bugs/show_bug.cgi?id=24056

Also a bit of refactoring along the way.

Differential Revision: http://reviews.llvm.org/D11220


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242413 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 16:27:19 +00:00
Tom Stellard
2da44c31e3 AMDGPU/R600: Remove unused variable
This fixes a warning introduced by r242410.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242412 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 16:13:34 +00:00