Commit Graph

117690 Commits

Author SHA1 Message Date
Sanjay Patel
27b0e0b7de fix typo in comment; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238025 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 15:31:47 +00:00
Rafael Espindola
cc3f1db34c Detect invalid section indexes when we first read them.
We still detect the same errors, but now we do it earlier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238024 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 14:59:27 +00:00
John Brawn
8a95a5095d [ARM] Fix typo in subtarget feature list for 7em triple
The list of subtarget features for the 7em triple contains 't2xtpk',
which actually disables that subtarget feature. Correct that to
'+t2xtpk' and test that the instructions enabled by that feature do
actually work.

Differential Revision: http://reviews.llvm.org/D9936


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238022 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 14:16:22 +00:00
Rafael Espindola
05f7d4f508 Fix llvm-nm -S option.
It is explicitly documented to have no effect on object formats where symbols
don't have sizes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238019 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 13:28:35 +00:00
Rafael Espindola
c6174adb16 Make this test stricter. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238018 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 13:17:31 +00:00
NAKAMURA Takumi
25103832b2 Reapply part of r237975, "Fix Clang -Wmissing-override warning", except for DIContext.h, to apease g++-4.7.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238012 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 10:11:07 +00:00
Tamas Berghammer
c189633586 Revert "[X86] Fix a variable name for r237977 so that it works with every compilers."
Revert "[X86] Refactor the prologue emission to prepare for shrink-wrapping."

This reverts commit 6b3b93fc8b.
This reverts commit ab0b15dff8.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238011 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 10:01:56 +00:00
Puyan Lotfi
d9a08b08ac Compile time improvements to VirtRegRewriter.
This change to VirtRegRewriter::addMBBLiveIns adds live-in registers for each
MachineBasicBlock's LiveIns set without isLiveIn checks as they are being added
because doing so is expensive. After all live-in registers are added, the LiveIn
vectors are sorted and uniqued.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238008 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 08:11:26 +00:00
NAKAMURA Takumi
b6b98c12d5 Revert r237954, "Resubmit r237708 (MIR Serialization: print and parse LLVM IR using MIR format)."
It brought cyclic dependencies between LLVMCodeGen and LLVMMIR.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238007 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 07:17:07 +00:00
Duncan P. N. Exon Smith
f5e0674d06 MC: Shave a pointer off of MCSymbol::Name
Shave a pointer off of `MCSymbolName` by storing `StringMapEntry<bool>*`
instead of `StringRef`.  This brings `sizeof(MCSymbol)` down to 64 on
64-bit platforms, a nice round number.  My profile showed memory
dropping from 914 MB down to 908 MB, roughly 0.7%.  Other than memory
usage, no functionality change here.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238005 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 06:04:42 +00:00
Tobias Grosser
b7888bd5ea Revert "Fix Clang -Wmissing-override warning"
This reverts commit r237975. This seems also to break with gcc 4.7

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238004 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 06:01:04 +00:00
Duncan P. N. Exon Smith
005bf5f8b0 MC: Pack MCSymbol::Index in with the bitfield in MCSymbol
Save a pointer for each `MCSymbol`, bringing `llc` memory usage down
from 920 MB to 914 MB, around ~0.6%.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238003 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 05:59:05 +00:00
Duncan P. N. Exon Smith
6c3a7cbe54 MC: Lift MCSymbolData::Index up to MCSymbol::Index, NFC
Lift `MCSymbolData::Index` up a level to `MCSymbol`, as preparation for
packing it into the bitfield in `MCSymbol`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238001 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 05:54:01 +00:00
NAKAMURA Takumi
117f3a66e8 Revert part of r237975, "Fix Clang -Wmissing-override warning" in DIContext.h, to appease g++-4.7.
llvm/include/llvm/DebugInfo/DIContext.h:144:11: error:   overriding ‘virtual llvm::LoadedObjectInfo::~LoadedObjectInfo() noexcept (true)’

It seems the destructor in the base class may not be "default".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238000 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 05:52:50 +00:00
Duncan P. N. Exon Smith
ec8c491a06 SDAG: Give SDDbgValues their own allocator (and reset it)
Previously `SDDbgValue`s used the general allocator that lives for all
of `SelectionDAG`.  Instead, give them their own allocator, and reset it
whenever `SDDbgInfo::clear()` is called, plugging a spiritual leak.

This drops `SelectionDAGBuilder::visitIntrinsicCall()` off of my heap
profile (was at around 2% of `llc` for codegen of `-flto -g`).  Thanks
to Pete Cooper for spotting the problem and suggesting the fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237998 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 05:45:19 +00:00
Duncan P. N. Exon Smith
73993abb6c SDAG: Cleanup initialization of SDDbgValue, NFC
Cleanup how `SDDbgValue` is initialized, and rearrange the fields to
save two pointers in the struct layout.  No real functionality change
though (and I doubt the memory savings would show up in a profile).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237997 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 05:35:53 +00:00
Tobias Grosser
82967c0bcd Revert "unique_ptrify LoadedObjectInfo::clone"
This reverts commit r237976, which seems to break existing gcc 4.7 buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237996 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 05:33:54 +00:00
David Majnemer
fe0d65bcc6 [InstSimplify] Handle some overflow intrinsics in InstSimplify
This change does a few things:
- Move some InstCombine transforms to InstSimplify
- Run SimplifyCall from within InstCombine::visitCallInst
- Teach InstSimplify to fold [us]mul_with_overflow(X, undef) to 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237995 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 03:56:46 +00:00
Chandler Carruth
edcdc5cb6a [Unroll] Replace a hand-wavy FIXME with a FIXME that explains the actual
problem instead of suggesting doing something that is trivial to do but
incorrect given the current design of the libraries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237994 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 03:07:28 +00:00
Chandler Carruth
f5ed85b2c8 [Unroll] Extract the logic for caching SCEV-modeled GEPs with their
simplified model for use simulating each iteration into a separate
helper function that just returns the cache.

Building this cache had nothing to do with the rest of the unroll
analysis and so this removes an unnecessary coupling, etc. It should
also make it easier to think about the concept of providing fast cached
access to basic SCEV models as an orthogonal concept to the overall
unroll simulation.

I'd really like to see this kind of caching logic folded into SCEV
itself, it seems weird for us to provide it at this layer rather than
making repeated queries into SCEV fast all on their own.

No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237993 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 03:02:22 +00:00
Chandler Carruth
9233137390 [Unroll] Refactor the accumulation of optimized instruction costs into
a single location.

This reduces code duplication a bit and will also pave the way for
a better separation between the visitation algorithm and the unroll
analysis.

No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237990 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 02:47:29 +00:00
Philip Reames
2c78f9499c [LICM] Sinking doesn't involve the preheader
PR23608 pointed out that using the preheader to gain a context instruction isn't always legal because a loop might not have a preheader.  When looking into that, I realized that using the preheader to determine legality for sinking is questionable at best.  Given no test covers that case and the original commit didn't seem to intend it, I restructured the code to only ask context sensative queries for hoising of loads and stores.  This is effectively a partial revert of 237593.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237985 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 02:14:05 +00:00
Hans Wennborg
253c092e56 Revert r236894 "[BasicAA] Fix zext & sext handling"
This seems to have caused PR23626: Clang miscompiles webkit's base64 decoder

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237984 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 01:27:37 +00:00
Quentin Colombet
6b3b93fc8b [X86] Fix a variable name for r237977 so that it works with every compilers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237980 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 00:41:03 +00:00
Daniel Berlin
4ea24c84fb MergedLoadStoreMotion preserves MemoryDependenceAnalysis, it does not require it.
(It already was coded assuming it can sometimes be null, so no other changes are necessary)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237978 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 00:13:05 +00:00
Quentin Colombet
ab0b15dff8 [X86] Refactor the prologue emission to prepare for shrink-wrapping.
- Add a late pass to expand pseudo instructions (tail call and EH returns).
  Instead of doing it in the prologue emission.
- Factor some static methods in X86FrameLowering to ease code sharing.

NFC.

Related to <rdar://problem/20821487>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237977 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 00:12:31 +00:00
David Blaikie
fcf7993d4a unique_ptrify LoadedObjectInfo::clone
As noted in the original review, this is unused in tree & is used by
Julia... that's problematic. This API coudl easily be deleted/modified
by accident without any validation that it remains correct.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237976 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 00:05:05 +00:00
David Blaikie
a89d43a2ce Fix Clang -Wmissing-override warning
& remove the duplication by introducing a CRTP base to implement the
clone behavior.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237975 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 00:00:00 +00:00
Hal Finkel
afcd3e68a8 [PPC] Correct iterator bug in PPCTLSDynamicCall
Unfortunately, I can't reduce a small test case for this (although compiling
mpfr-3.1.2 with -O2 -mcpu=a2 would fairly reliably trigger a crash), but the
problem is fairly clear (at least once you know you're looking for one). If the
TLS instruction being replaced was at the end of the block, we'd increment the
iterator past it (so it would then point to MBB.end()), and then we'd increment
it again as part of the for statement, thus overrunning the end of the list.
Don't do that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237974 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 23:45:49 +00:00
Peter Collingbourne
66811d9817 Revert r237590, "ARM: allow jump tables to be placed as constant islands."
Caused a miscompile of the Android port of Chromium, details
forthcoming.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237972 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 23:20:55 +00:00
Jingyue Wu
41cf9ae1b8 [NaryReassoc] reassociate GEP for CSE
Summary:
x = &a[i];
y = &a[i + j];

=>

y = x + j;

along with some refactoring work such as extracting method
findClosestMatchingDominator.

Depends on D9786 which provides the ScalarEvolution::getGEPExpr interface.

Test Plan: nary-gep.ll

Reviewers: meheff, broune

Reviewed By: broune

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9802

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237971 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 23:17:30 +00:00
Michael J. Spencer
b86942cca4 [Support] Fix ErrorOr equality operator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237970 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 23:15:00 +00:00
Sanjay Patel
56409de6c4 fix typos, remove function names from comments, NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237969 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 23:04:44 +00:00
David Majnemer
41af60bdc0 [InstCombine] X - 0 is equal to X, not undef
A refactoring made @llvm.ssub.with.overflow.i32(i32 %X, i32 0) transform
into undef instead of %X.

This fixes PR23624.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237968 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 23:04:21 +00:00
Pete Cooper
1052042adf Use Op<0> accessor instead of OperandList for Instructions. NFC
This is consistent with other uses of the operand list.  I'm planning a future commit where this will actually matter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237967 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 22:48:54 +00:00
Chad Rosier
d525214b96 Use new MachineInstr mayLoadOrStore() API.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237965 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:59:57 +00:00
Quentin Colombet
3ad083f2cb [InlineSpiller] Fix rematerialization for bundles.
Prior to this patch, we could update the operand of another MI in the same
bundle.

Longer version:
Before InlineSpiller rematerializes a vreg, it iterates over operands of each MI
in a bundle, collecting all (MI, OpNo) pairs that reference that vreg.

Then if it does rematerialize, it goes through the pair list and replaces the
operands with the new (rematerialized) vreg.  The problem is, it tries to
replace all of these operands in the main MI ! This works fine for single MIs.
However, if we are processing a bundle of MIs and the list contains multiple
pairs - the rematerialization will either crash trying to access a non-existing
operand of the main MI, or silently corrupt one of the existing ones. It will
also ignore other MIs in the bundle.

The obvious fix is to use the MI pointers saved in collected (MI, OpNo) pairs.
This must have been the original intent of the pair list but somehow these
pointers got lost.

Patch by Dmitri Shtilman <dshtilman@icloud.com>!

Differential revision: http://reviews.llvm.org/D9904

<rdar://problem/21002163>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237964 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:41:55 +00:00
Chad Rosier
676efa4d56 [AArch64] Enhance the load/store optimizer with target-specific alias analysis.
Phabricator: http://reviews.llvm.org/D9863

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237963 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:36:46 +00:00
Sanjay Patel
a33f5160eb fix typo in comment; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237962 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:29:13 +00:00
Keno Fischer
b6976af3cd Make it easier to use DwarfContext with MCJIT
Summary:
This supersedes http://reviews.llvm.org/D4010, hopefully properly
dealing with the JIT case and also adds an actual test case.
DwarfContext was basically already usable for the JIT (and back when
we were overwriting ELF files it actually worked out of the box by
accident), but in order to resolve relocations correctly it needs
to know the load address of the section.
Rather than trying to get this out of the ObjectFile or requiring
the user to create a new ObjectFile just to get some debug info,
this adds the capability to pass in that info directly.
As part of this I separated out part of the LoadedObjectInfo struct
from RuntimeDyld, since it is now required at a higher layer.

Reviewers: lhames, echristo

Reviewed By: echristo

Subscribers: vtjnash, friss, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D6961

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237961 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:24:32 +00:00
David Blaikie
6777be3446 Put GEPOperator member function definition in the appropriate .cpp file
Last commit put it in Constants.cpp instead of Operator.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237960 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:17:12 +00:00
David Blaikie
bd75a9292e [opaque pointer type] Allow gep_type_iterator to work with the pointee type from the GEP instruction
The raw non-instruction/constant form of this is still relying on being
able to access the pointee type from a pointer type - those will be
cleaned up later. For now, just focus on the cases where the pointee
type is easily accessible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237958 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:12:43 +00:00
Rafael Espindola
477acf64d0 Stop forwarding (get|set)Aligment from MCSectionData to MCSection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237956 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:02:35 +00:00
Chad Rosier
f8330b43ee [MachineInstr] Add mayLoadOrStore API. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237955 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 21:00:30 +00:00
Alex Lorenz
3e5034d130 Resubmit r237708 (MIR Serialization: print and parse LLVM IR using MIR format).
This commit is a 2nd attempt at committing the initial MIR serialization patch.
The first commit (r237708) made the incremental buildbots unstable and was 
reverted in r237730. The original commit didn't add a terminating null 
character to the LLVM IR source which was passed to LLParser, and this 
sometimes caused the test 'llvmIR.mir' to fail with a parsing error because 
the LLVM IR source didn't have a null character immediately after the end 
and thus LLLexer encountered some garbage characters that ultimately caused 
the error.

This commit also includes the other test fixes I committed in
r237712 (llc path fix) and r237723 (remove target triple) which
also got reverted in r237730.

--Original Commit Message--

MIR Serialization: print and parse LLVM IR using MIR format.

This commit is the initial commit for the MIR serialization project.
It creates a new library under CodeGen called 'MIR'. This new
library adds a new machine function pass that prints out the LLVM IR 
using the MIR format. This pass is then added as a last pass when a 
'stop-after' option is used in llc. The new library adds the initial 
functionality for parsing of MIR files as well. This commit also 
extends the llc tool so that it can recognize and parse MIR input files.

Reviewers: Duncan P. N. Exon Smith, Matthias Braun, Philip Reames

Differential Revision: http://reviews.llvm.org/D9616


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237954 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 20:54:45 +00:00
Bill Schmidt
63292d1bba [PPC64] Handle vpkudum mask pattern correctly when vpkudum isn't available
My recent patch to add support for ISA 2.07 vector pack/unpack
instructions didn't properly check for availability of the vpkudum
instruction when recognizing it as a special vector shuffle case.
This causes us to leave the vector shuffle in place (rather than
converting it to a vector permute) so that it can be recognized later
as a vpkudum, but that pattern is invalid for processors prior to
POWER8.  Thus LLVM crashes with an "unable to select" message.  We
observed this since one of our buildbots is configured to generate
code for a POWER7.

This patch fixes the problem by checking for availability of the
vpkudum instruction during custom lowering of vector shuffles.

I've added a test case variant for the vpkudum pattern when the
instruction isn't available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237952 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 20:48:49 +00:00
Rafael Espindola
fabbc4985b Stop creating MCSectionData is the ELF writer.
Now is is just its use of MCSymbolData that requires it to take a non const
MCAssembler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237951 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 20:43:13 +00:00
Kostya Serebryany
c9389db422 [lib/Fuzzer] ignore flags that start with --; use git pull --rebase instead of just git pull
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237950 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 20:39:13 +00:00
Adrian Prantl
849c7601a0 IR / debug info: Add a DWOId field to DICompileUnit,
so DWARF skeleton CUs can be expression in IR. A skeleton CU is a
(typically empty) DW_TAG_compile_unit that has a DW_AT_(GNU)_dwo_name and
a DW_AT_(GNU)_dwo_id attribute. It is used to refer to external debug info.

This is a prerequisite for clang module debugging as discussed in
http://lists.cs.uiuc.edu/pipermail/cfe-dev/2014-November/040076.html.
In order to refer to external types stored in split DWARF (dwo) objects,
such as clang modules, we need to emit skeleton CUs, which identify the
dwarf object (i.e., the clang module) by filename (the SplitDebugFilename)
and a hash value, the dwo_id.

This patch only contains the IR changes. The idea is that a CUs with a
non-zero dwo_id field will be emitted together with a DW_AT_GNU_dwo_name
and DW_AT_GNU_dwo_id attribute.

http://reviews.llvm.org/D9488
rdar://problem/20091852

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237949 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 20:37:30 +00:00
Hal Finkel
5368a26e16 [PPC/LoopUnrollRuntime] Don't avoid high-cost trip count computation on the PPC/A2
On X86 (and similar OOO cores) unrolling is very limited, and even if the
runtime unrolling is otherwise profitable, the expense of a division to compute
the trip count could greatly outweigh the benefits. On the A2, we unroll a lot,
and the benefits of unrolling are more significant (seeing a 5x or 6x speedup
is not uncommon), so we're more able to tolerate the expense, on average, of a
division to compute the trip count.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237947 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 20:30:23 +00:00