Commit Graph

108366 Commits

Author SHA1 Message Date
Chandler Carruth
b3ce94707a [x86] Add AVX1 and AVX2 testing to all of the 128-bit shuffle test
cases.

While clearly we don't need the AVX vector width, these ISA extensions
often cause us to select different instructions and we should cover them
even with the narrow vector width.

Also, while here, nuke the stress_test2 contents. There is no reason to
try to FileCheck this entire body when it is mostly a test for
successfully surviving the code generator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218710 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 22:16:23 +00:00
Chandler Carruth
3a926b9b5c [x86] Update the exact FileCheck syntax of the 256-bit and 512-bit
shuffle tests to match that used in the script I posted and now used
consistently in 128-bit tests.

Nothing interesting changing here, just using the label name as the
FileCheck label and a slightly more general comment marker consumption
strategy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218709 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 22:04:45 +00:00
David Blaikie
f0fd2f855e Adjust test case addition in r218702 so as not to fail when the X86 target isn't built.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218708 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 22:02:27 +00:00
Chandler Carruth
8b6f2eee07 [x86] Rework all of the 128-bit vector shuffle tests with my handy test
updating script so that they are more thorough and consistent.

Specific fixes here include:
- Actually test VEX-encoded AVX mnemonics.
- Actually use an SSE 4.1 run to test SSE 4.1 features!
- Correctly check instructions sequences from the start of the function.
- Elide the shuffle operands and comment designator in a consistent way.
- Test all of the architectures instead of just the ones I was motivated
  to manually author.

I've gone back through and fixed up any egregious issues I spotted. Let
me know if I missed something you really dislike.

One downside to this is that we're now not as diligently using FileCheck
variables for registers. I would be much more concerned with this if we
had larger register usage, but there just aren't that interesting of
register choices here and most of the registers are constrained by the
ABI. Ultimately, I don't think this is likely to be the maintenance
burden for these tests and updating them again should be staright
forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218707 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 21:44:34 +00:00
David Blaikie
76ff19ffa7 Disable the -gmlt optimization implemented in r218129 under Darwin due to issues with dsymutil.
r218129 omits DW_TAG_subprograms which have no inlined subroutines when
emitting -gmlt data. This makes -gmlt very low cost for -O0 builds.

Darwin's dsymutil reasonably considers a CU empty if it has no
subprograms (which occurs with the above optimization in -O0 programs
without any force_inline function calls) and drops the line table, CU,
and everything in this situation, making backtraces impossible.

Until dsymutil is modified to account for this, disable this
optimization on Darwin to preserve the desired functionality.
(see r218545, which should be reverted after this patch, for other
discussion/details)

Footnote:
In the long term, it doesn't look like this scheme (of simplified debug
info to describe inlining to enable backtracing) is tenable, it is far
too size inefficient for optimized code (the DW_TAG_inlined_subprograms,
even once compressed, are nearly twice as large as the line table
itself (also compressed)) and we'll be considering things like Cary's
two level line table proposal to encode all this information directly in
the line table.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218702 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 21:28:32 +00:00
Sanjay Patel
73a335f7f6 Use the target-specified iteration count to opt out of any further refinement of an estimate. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218700 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 20:44:23 +00:00
Sanjay Patel
cafc85bf1e Split the estimate() interface into separate functions for each type. NFC.
It was hacky to use an opcode as a switch because it won't always match
(rsqrte != sqrte), and it looks like we'll need to add more special casing
per arch than I had hoped for. Eg, x86 will prefer a different NR estimate
implementation. ARM will want to use it's 'step' instructions. There also
don't appear to be any new estimate instructions in any arch in a long,
long time. Altivec vloge and vexpte may have been the first and last in
that field...



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218698 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 20:28:48 +00:00
Juergen Ributzka
9952c922c2 Recommit r218010 [FastISel][AArch64] Fold bit test and branch into TBZ and TBNZ.
Note: This version fixed an issue with the TBZ/TBNZ instructions that were
generated in FastISel. The issue was that the 64bit version of TBZ (TBZX)
automagically sets the upper bit of the immediate field that is used to specify
the bit we want to test. To test for any of the lower 32bits we have to first
extract the subregister and use the 32bit version of the TBZ instruction (TBZW).

Original commit message:
Teach selectBranch to fold bit test and branch into a single instruction (TBZ or
TBNZ).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218693 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 19:59:35 +00:00
Matt Arsenault
28233d3a63 R600/SI: Fix printing of clamp and omod
No tests for omod since nothing uses it yet, but
this should get rid of the remaining annoying trailing
zeros after some instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218692 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 19:49:48 +00:00
Matt Arsenault
532a5c7dc6 R600/SI: Update VOP3b to not include obsolete operands
abs / neg are now part of the srcN_modifiers operands

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218691 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 19:49:43 +00:00
Bradley Smith
95b3e168c5 Extend C disassembler API to allow specifying target features
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218682 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 16:31:40 +00:00
Reed Kotler
8a6f79e58d Add numeric extend, trunctate to mips fast-isel
Summary:
 Add numeric extend, trunctate to mips fast-isel

 Reactivates D4827



Test Plan:
fpext.ll
loadstoreconv.ll

Reviewers: dsanders

Subscribers: mcrosier

Differential Revision: http://reviews.llvm.org/D5251

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218681 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 16:30:13 +00:00
Tom Coxon
8a23890385 [AArch64] Remove unnecessary whitespace. (Test commit)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218680 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 16:23:16 +00:00
Andrea Di Biagio
9e6df85d39 [DAG] Check in advance if a build_vector has a legal type before attempting to convert it into a shuffle.
Currently, the DAG Combiner only tries to convert type-legal build_vector nodes
into shuffles. This patch simply moves the logic that checks if a
build_vector has a legal value type up before we even start analyzing the
operands. This allows to early exit immediately from method
'visitBUILD_VECTOR' if the node type is known to be illegal.

No functional change intended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218677 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 15:30:22 +00:00
Alex Lorenz
a66e3bbf7a Revert r218673 'llvm-cov: add test for report's function & file association.'
Test causes buildbot failures.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218676 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 14:48:12 +00:00
Alex Lorenz
c174931a77 llvm-cov: add test for report's function & file association.
This commit adds a test which checks that the functions defined in header files will get associated with the header files rather than the source files in the reports.

Differential Revision: http://reviews.llvm.org/D5489


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218673 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 12:52:31 +00:00
Alex Lorenz
38c59de6b1 llvm-cov: Use the number of executed functions for the function coverage metric.
This commit fixes llvm-cov's function coverage metric by using the number of executed functions instead of the number of fully covered functions.

Differential Revision: http://reviews.llvm.org/D5196


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218672 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 12:45:13 +00:00
Lorenzo Martignoni
f49592dddc Introduce support for custom wrappers for vararg functions.
Differential Revision: http://reviews.llvm.org/D5412



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218671 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 12:33:16 +00:00
Robert Khasanov
8acdc5232d [AVX512] Added intrinsics for 128-, 256- and 512-bit versions of VCMPGT{BWDQ}.
Patch by Sergey Lisitsyn <sergey.lisitsyn@intel.com>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218670 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 12:15:52 +00:00
Robert Khasanov
175ff01f0f [AVX512] Added intrinsics for 128- and 256-bit versions of VCMPEQ{BWDQ}
Fixed lowering of this intrinsics in case when mask is v2i1 and v4i1.
Now cmp intrinsics lower in the following way:
 (i8 (int_x86_avx512_mask_pcmpeq_q_128
             (v2i64 %a), (v2i64 %b), (i8 %mask))) ->
 (i8 (bitcast
   (v8i1 (insert_subvector undef,
           (v2i1 (and (PCMPEQM %a, %b),
                      (extract_subvector
                         (v8i1 (bitcast %mask)), 0))), 0))))


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218669 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 11:41:54 +00:00
Robert Khasanov
cfa5724d50 [AVX512] Added intrinsics for VPCMPEQB and VPCMPEQW.
Added new operand type for intrinsics (IIT_V64)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218668 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 11:32:22 +00:00
Robert Khasanov
58da66b2bf [AVX512] Enabled intrinsics for VPCMPEQD and VPCMPEQQ.
Added CMP_MASK intrinsic type


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218667 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 11:19:50 +00:00
Job Noorman
deb16c9eac Make sure aggregates are properly alligned on MSP430.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218665 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 11:15:44 +00:00
Chad Rosier
ecea7ba518 [IndVarSimplify] Widen loop unsigned compares.
This patch extends r217953 to handle unsigned comparison.
Phabricator revision: http://reviews.llvm.org/D5526

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218659 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 03:17:42 +00:00
Chandler Carruth
4abb04a65c [x86] Revert r218588, r218589, and r218600. These patches were pursuing
a flawed direction and causing miscompiles. Read on for details.

Fundamentally, the premise of this patch series was to map
VECTOR_SHUFFLE DAG nodes into VSELECT DAG nodes for all blends because
we are going to *have* to lower to VSELECT nodes for some blends to
trigger the instruction selection patterns of variable blend
instructions. This doesn't actually work out so well.

In order to match performance with the existing VECTOR_SHUFFLE
lowering code, we would need to re-slice the blend in order to fit it
into either the integer or floating point blends available on the ISA.
When coming from VECTOR_SHUFFLE (or other vNi1 style VSELECT sources)
this works well because the X86 backend ensures that these types of
operands to VSELECT get sign extended into '-1' and '0' for true and
false, allowing us to re-slice the bits in whatever granularity without
changing semantics.

However, if the VSELECT condition comes from some other source, for
example code lowering vector comparisons, it will likely only have the
required bit set -- the high bit. We can't blindly slice up this style
of VSELECT. Reid found some code using Halide that triggers this and I'm
hopeful to eventually get a test case, but I don't need it to understand
why this is A Bad Idea.

There is another aspect that makes this approach flawed. When in
VECTOR_SHUFFLE form, we have very distilled information that represents
the *constant* blend mask. Converting back to a VSELECT form actually
can lose this information, and so I think now that it is better to treat
this as VECTOR_SHUFFLE until the very last moment and only use VSELECT
nodes for instruction selection purposes.

My plan is to:
1) Clean up and formalize the target pre-legalization DAG combine that
   converts a VSELECT with a constant condition operand into
   a VECTOR_SHUFFLE.
2) Remove any fancy lowering from VSELECT during *legalization* relying
   entirely on the DAG combine to catch cases where we can match to an
   immediate-controlled blend instruction.

One additional step that I'm not planning on but would be interested in
others' opinions on: we could add an X86ISD::VSELECT or X86ISD::BLENDV
which encodes a fully legalized VSELECT node. Then it would be easy to
write isel patterns only in terms of this to ensure VECTOR_SHUFFLE
legalization only ever forms the fully legalized construct and we can't
cycle between it and VSELECT combining.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218658 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 02:52:28 +00:00
Chandler Carruth
52b072d73f [x86] Add some vector-register broadcast operations to the 256-bit v4
tests which were missing them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218657 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 02:32:36 +00:00
Matt Arsenault
cbb188bffc R600: Fix broken check lines, missing scalar case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218655 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 01:05:29 +00:00
Matt Arsenault
108eb07f61 Fix missing C++ mode comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218654 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 01:05:27 +00:00
Juergen Ributzka
a0af4b0271 [FastISel][AArch64] Fold sign-/zero-extends into the load instruction.
The sign-/zero-extension of the loaded value can be performed by the memory
instruction for free. If the result of the load has only one use and the use is
a sign-/zero-extend, then we emit the proper load instruction. The extend is
only a register copy and will be optimized away later on.

Other instructions that consume the sign-/zero-extended value are also made
aware of this fact, so they don't fold the extend too.

This fixes rdar://problem/18495928.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218653 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 00:49:58 +00:00
Juergen Ributzka
e8a9706eda [FastISel][AArch64] Factor out scale factor calculation. NFC.
Factor out the code that determines the implicit scale factor of memory
operations for a given value type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218652 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 00:49:54 +00:00
Nick Kledzik
c27ddda8ce [llvm-objdump] switch some uses of format() to format_hex() and left_justify()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218649 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-30 00:19:58 +00:00
Eric Christopher
11bea1bff3 Simplify conditional.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218643 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 23:31:13 +00:00
Adam Nemet
e3d2fcce41 [AVX512] Use X86VectorVTInfo in the masking helper classes and the FMAs
No functionality change.

Makes the code more compact (see the FMA part).

This needs a new type attribute MemOpFrag in X86VectorVTInfo.  For now I only
defined this in the simple cases.  See the commment before the attribute.

Diff of X86.td.expanded before and after is empty except for the appearance of
the new attribute.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218637 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 22:54:41 +00:00
Hans Wennborg
4edcbaec90 WinCOFFObjectWriter: optimize the string table for common suffices
This is a follow-up from r207670 which did the same for ELF.

Differential Revision: http://reviews.llvm.org/D5530

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218636 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 22:43:20 +00:00
Eric Christopher
6a2169eb6f Add soft-float to the key for the subtarget lookup in the TargetMachine
map, this makes sure that we can compile the same code for two different
ABIs (hard and soft float) in the same module.

Update one testcase accordingly (and fix some confusing naming) and
add a new testcase as well with the ordering swapped which would
highlight the problem.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218632 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 21:57:54 +00:00
Eric Christopher
200f3764bf Fix spelling and reflow comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218631 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 21:57:52 +00:00
Dave Estes
f657899174 [AArch64] Refines the Cortex-A57 Machine Model
Primarily refines all of the instructions with accurate latency
and micro-op information. Refinements largely focus on the NEON
instructions.

Additionally, a few advanced features are modeled, including
forwarding for MAC instructions and hazards for floating point SQRT
and DIV.

Lastly, the issue-width is reduced to three so that the scheduler
will better accommodate the narrower decode and dispatch width.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218627 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 21:27:36 +00:00
David Blaikie
03b4667e14 Unit test r218187, changing RTDyldMemoryManager::getSymbolAddress's behavior favor mangled lookup over unmangled lookup.
The contract of this function seems problematic (fallback in either
direction seems like it could produce bugs in one client or another),
but here's some tests for its current behavior, at least. See the
commit/review thread of r218187 for more discussion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218626 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 21:25:13 +00:00
Aaron Ballman
7b2aaade87 Fixing the build for compilers which do not yet have support for constexpr functions, NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218622 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 20:27:01 +00:00
Jordan Rose
88c0ed30da Add getValueOr to llvm::Optional<T>.
This takes a single argument convertible to T, and
- if the Optional has a value, returns the existing value,
- otherwise, constructs a T from the argument and returns that.

Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218618 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 18:56:08 +00:00
Jordan Rose
ede14e3e21 Add "typedef T value_type;" to llvm::Optional<T>.
Inspired by std::experimental::optional from the "Library Fundamentals" C++ TS.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218617 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 18:56:05 +00:00
Matt Arsenault
78beaa5d02 Fixing missing C++ mode comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218612 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 15:55:18 +00:00
Matt Arsenault
0db97bb9b4 Fix include order
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218611 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 15:53:15 +00:00
Matt Arsenault
1bcadc9b5c R600/SI: Fix hardcoded values for modifiers.
Move enums to SIDefines.h

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218610 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 15:50:26 +00:00
Matt Arsenault
49cbc1891b R600/SI: Also fix fsub + fadd a, a to mad combines
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218609 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 14:59:38 +00:00
Matt Arsenault
a5f45d5444 R600/SI: Fix using mad with multiplies by 2
These turn into fadds, so combine them into the target
mad node.

fadd (fadd (a, a), b) -> mad 2.0, a, b

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218608 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 14:59:34 +00:00
Chad Rosier
ea64dce261 [AArch64] Improve cost model to handle sdiv by a pow-of-two.
This patch improves the target-specific cost model to better handle signed
division by a power of two. The immediate result is that this enables the SLP
vectorizer to do a better job.

http://reviews.llvm.org/D5469
PR20714

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218607 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 13:59:31 +00:00
Frederic Riss
97552d7c1c Store TypeUnits in a SmallVector<DWARFUnitSection> instead of a single DWARFUnitSection.
There will be multiple TypeUnits in an unlinked object that will be extracted
from different sections. Now that we have DWARFUnitSection that is supposed
to represent an input section, we need a DWARFUnitSection<TypeUnit> per
input .debug_types section.

Once this is done, the interface is homogenous and we can move the Section
parsing code into DWARFUnitSection.

This is a respin of r218513 that got reverted because it broke some builders.
This new version features an explicit move constructor for the DWARFUnitSection
class to workaround compilers unable to generate correct C++11 default
constructors.

Reviewers: samsonov, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5482

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218606 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 13:56:39 +00:00
Kevin Qin
dbaeb6e7cb Use a loop to simplify the runtime unrolling prologue.
Runtime unrolling will create a prologue to execute the extra
iterations which is can't divided by the unroll factor. It
generates an if-then-else sequence to jump into a factor -1
times unrolled loop body, like

    extraiters = tripcount % loopfactor
    if (extraiters == 0) jump Loop:
    if (extraiters == loopfactor) jump L1
    if (extraiters == loopfactor-1) jump L2
    ...
    L1:  LoopBody;
    L2:  LoopBody;
    ...
    if tripcount < loopfactor jump End
    Loop:
    ...
    End:

It means if the unroll factor is 4, the loop body will be 7
times unrolled, 3 are in loop prologue, and 4 are in the loop.
This commit is to use a loop to execute the extra iterations
in prologue, like

        extraiters = tripcount % loopfactor
        if (extraiters == 0) jump Loop:
        else jump Prol
 Prol:  LoopBody;
        extraiters -= 1                 // Omitted if unroll factor is 2.
        if (extraiters != 0) jump Prol: // Omitted if unroll factor is 2.
        if (tripcount < loopfactor) jump End
 Loop:
 ...
 End:

Then when unroll factor is 4, the loop body will be copied by
only 5 times, 1 in the prologue loop, 4 in the original loop.
And if the unroll factor is 2, new loop won't be created, just
as the original solution.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218604 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 11:15:00 +00:00
Oliver Stannard
017c6111a8 [Thumb2] ldrexd and strexd are not defined on v7M
The Thumb2 ldrexd and strexd instructions are not defined for
M-class architectures.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218603 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-29 10:57:29 +00:00