Commit Graph

7498 Commits

Author SHA1 Message Date
Michael Kuperstein 2005a3f20e [DAGCombine] Fix divrem combine not to assume div/rem type is simple.
The divrem combine assumed the type of the div/rem is simple, which isn't
necessarily true. This probably worked fine until r250825, since it only
saw legal types, but now breaks when it runs as a pre-type-legalization 
combine.

This fixes PR26835.

Differential Revision: http://reviews.llvm.org/D17878

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262746 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-04 21:23:29 +00:00
Renato Golin 99ec266022 [ARM] Merging 64-bit divmod lib calls into one
When div+rem calls on the same arguments are found, the ARM back-end merges the
two calls into one __aeabi_divmod call for up to 32-bits values. However,
for 64-bit values, which also have a lib call (__aeabi_ldivmod), it wasn't
merging the calls, and thus calling ldivmod twice and spilling the temporary
results, which generated pretty bad code.

This patch legalises 64-bit lib calls for divmod, so that now all the spilling
and the second call are gone. It also relaxes the DivRem combiner a bit on the
legal type check, since it was already checking for isLegalOrCustom on every
value, so the extra check for isTypeLegal was redundant.

Second attempt, creating TLI.isOperationCustom like isOperationExpand, to make
sure we only emit valid types or the ones that were explicitly marked as custom.
Now, passing check-all and test-suite on x86, ARM and AArch64.

This patch fixes PR17193 (and a long time FIXME in the tests).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262738 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-04 19:19:36 +00:00
Simon Pilgrim 946e6cb363 [X86][SSE] Improve vector ZERO_EXTEND by combining to ZERO_EXTEND_VECTOR_INREG
Generalise the existing SIGN_EXTEND to SIGN_EXTEND_VECTOR_INREG combine to support zero extension as well and get rid of a lot of unnecessary ANY_EXTEND + mask patterns.

Differential Revision: http://reviews.llvm.org/D17691

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262599 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-03 09:43:28 +00:00
Renato Golin ff17c53224 Revert "[ARM] Merging 64-bit divmod lib calls into one"
This reverts commit r262507, which broke some ARM buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262594 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-03 08:57:44 +00:00
David Majnemer 767bd9b70f [X86] Don't give catch objects a displacement of zero
Catch objects with a displacement of zero do not initialize a catch
object.  The displacement is relative to %rsp at the end of the
function's prologue for x86_64 targets.

If we place an object at the top-of-stack, we will end up wit a
displacement of zero resulting in our catch object remaining
uninitialized.

Address this by creating our catch objects as fixed objects.  We will
ensure that the UnwindHelp object is created after the catch objects so
that no catch object will have a displacement of zero.

Differential Revision: http://reviews.llvm.org/D17823

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262546 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-03 00:01:25 +00:00
Renato Golin 4d7de4fa50 [ARM] Merging 64-bit divmod lib calls into one
When div+rem calls on the same arguments are found, the ARM back-end merges the
two calls into one __aeabi_divmod call for up to 32-bits values. However,
for 64-bit values, which also have a lib call (__aeabi_ldivmod), it wasn't
merging the calls, and thus calling ldivmod twice and spilling the temporary
results, which generated pretty bad code.

This patch legalises 64-bit lib calls for divmod, so that now all the spilling
and the second call are gone. It also relaxes the DivRem combiner a bit on the
legal type check, since it was already checking for isLegalOrCustom on every
value, so the extra check for isTypeLegal was redundant.

This patch fixes PR17193 (and a long time FIXME in the tests).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262507 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-02 19:35:45 +00:00
Justin Bogner 13724638d0 SelectionDAG: Use correctly sized allocation functions for SDNodes
The placement new calls here were all calling the allocation function
in RecyclingAllocator/Recycler for SDNode, instead of the function for
the specific subclass we were constructing.

Since this particular allocator always overallocates it more or less
worked, but would hide what we're actually doing from any memory
tools. Also, if you tried to change this allocator so something like a
BumpPtrAllocator or MallocAllocator, the compiler would crash horribly
all the time.

Part of llvm.org/PR26808.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262500 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-02 19:01:11 +00:00
Matt Arsenault 543afc9d41 DAGCombiner: Make sure an integer is being truncated
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262446 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-02 01:36:51 +00:00
Matt Arsenault d06f393d79 DAGCombiner: Turn truncate of a bitcasted vector to an extract
On AMDGPU where operations i64 operations are often bitcasted to v2i32
and back, this pattern shows up regularly where it breaks some
expected combines on i64, such as load width reducing.

This fixes some test failures in a future commit when i64 loads
are changed to promote.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262397 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 21:31:53 +00:00
Vasileios Kalintiris 6e09ce7e5f Revert "[mips] Promote the result of SETCC nodes to GPR width."
This reverts commit r262316.

It seems that my change breaks an out-of-tree chromium buildbot, so
I'm reverting this in order to investigate the situation further.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262387 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 20:25:43 +00:00
Justin Lebar e2c35f6c8b [NVPTX] Use different, convergent MIs for convergent calls.
Summary:
Calls sometimes need to be convergent.  This is already handled at the
LLVM IR level, but it also needs to be handled at the MI level.

Ideally we'd propagate convergence from instructions, down through the
selection DAG, and into MIs.  But this is Hard, and would affect
optimizations in the SDNs -- right now only SDNs with two operands have
any flags at all.

Instead, here's a much simpler hack: Add new opcodes for NVPTX for
convergent calls, and generate these when lowering convergent LLVM
calls.

Reviewers: jholewinski

Subscribers: jholewinski, chandlerc, joker.eph, jhen, tra, llvm-commits

Differential Revision: http://reviews.llvm.org/D17423

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262373 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 19:24:03 +00:00
Matt Arsenault 8ba165a405 DAGCombiner: Turn extract of bitcasted integer into truncate
This reduces the number of bitcast nodes and generally cleans up the
DAG when bitcasting between integers and vectors everywhere.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262358 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 18:01:37 +00:00
Vasileios Kalintiris ef35f84f09 [mips] Promote the result of SETCC nodes to GPR width.
Summary:
This patch modifies the existing comparison, branch, conditional-move
and select patterns, and adds new ones where needed. Also, the updated
SLT{u,i,iu} set of instructions generate a GPR width result.

The majority of the code changes in the Mips back-end fix the wrong
assumption that the result of SETCC nodes always produce an i32 value.
The changes in the common code path account for the fact that in 64-bit
MIPS targets, i1 is promoted to i32 instead of i64.

Reviewers: dsanders

Subscribers: dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D10970

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262316 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 10:08:01 +00:00
Matt Arsenault ffd2af79db LegalizeDAG: Use correct ptr type when expanding unaligned load/store
This fixes regressions exposed in existing AMDGPU tests in a
future commit when all loads are custom lowered.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262299 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-01 05:13:35 +00:00
Matt Arsenault 2bc40a1dbd DAGCombiner: Don't unnecessarily swap operands in ReassociateOps
In the case where op = add, y = base_ptr, and x = offset, this
transform:

(op y, (op x, c1)) -> (op (op x, y), c1)

breaks the canonical form of add by putting the base pointer in the
second operand and the offset in the first.

This fix is important for the R600 target, because for some address
spaces the base pointer and the offset are stored in separate register
classes. The old pattern caused the ISel code for matching addressing
modes to put the base pointer and offset in the wrong register classes,
which required no-trivial code transformations to fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262148 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-27 19:57:45 +00:00
Matt Arsenault f51a2196a5 DAGCombiner: Relax sqrt NaN folding check
This is OK for +0 since compares to +/-0 give the same result.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262125 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-27 09:38:05 +00:00
Cong Hou e2e3f26532 Fix a bug in isVectorReductionOp() in SelectionDAGBuilder.cpp that may cause assertion failure on AArch64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262091 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-26 23:25:30 +00:00
Cong Hou e4f9f1583a Detecte vector reduction operations just before instruction selection.
(This is the second attemp to commit this patch, after fixing pr26652 & pr26653).

This patch detects vector reductions before instruction selection. Vector
reductions are vectorized reduction operations, and for such operations we have
freedom to reorganize the elements of the result as long as the reduction of them
stay unchanged. This will enable some reduction pattern recognition during
instruction combine such as SAD/dot-product on X86. A flag is added to
SDNodeFlags to mark those vector reduction nodes to be checked during instruction
combine.

To detect those vector reductions, we search def-use chains starting from the
given instruction, and check if all uses fall into two categories:

1. Reduction with another vector.
2. Reduction on all elements.

in which 2 is detected by recognizing the pattern that the loop vectorizer
generates to reduce all elements in the vector outside of the loop, which
includes several ShuffleVector and one ExtractElement instructions.


Differential revision: http://reviews.llvm.org/D15250




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261804 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-24 23:40:36 +00:00
Artur Pilipenko ba9f09caee NFC. Move isDereferenceable to Loads.h/cpp
This is a part of the refactoring to unify isSafeToLoadUnconditionally and isDereferenceablePointer functions. In subsequent change I'm going to eliminate isDerferenceableAndAlignedPointer from Loads API, leaving isSafeToLoadSpecualtively the only function to check is load instruction can be speculated.   

Reviewed By: hfinkel

Differential Revision: http://reviews.llvm.org/D16180


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261736 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-24 12:49:04 +00:00
Matt Arsenault c97b66787e SelectionDAG: Use correct addrspace when lowering memcpy
This was causing assertions later from using the wrong pointer
size with LDS operations. getOptimalMemOpType should also have
address space arguments later.

This avoids assertions in existing tests exposed by
a future commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261580 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-22 22:01:42 +00:00
Duncan P. N. Exon Smith 8de6150816 ADT: Remove == and != comparisons between ilist iterators and pointers
I missed == and != when I removed implicit conversions between iterators
and pointers in r252380 since they were defined outside ilist_iterator.

Since they depend on getNodePtrUnchecked(), they indirectly rely on UB.
This commit removes all uses of these operators.  (I'll delete the
operators themselves in a separate commit so that it can be easily
reverted if necessary.)

There should be NFC here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261498 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-21 20:39:50 +00:00
Simon Pilgrim 01ad432bbe [DAGCombiner] Use getBitcast helper when possible. NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261437 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-20 15:05:29 +00:00
Sanjoy Das 8ba7696b97 [StatepointLowering] Minor non-semantic cleanups
Use auto, bring file up to coding standards etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261358 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 19:37:07 +00:00
Sanjoy Das 5a8841daf3 [StatepointLowering] Update StatepointMaxSlotsRequired correctly
Now that we don't always add an element to AllocatedStackSlots if we
don't find a pre-existing unallocated stack slot, bumping
StatepointMaxSlotsRequired to `NumSlots + 1` is not correct.  Instead
bump the statistic near the push_back, to
Builder.FuncInfo.StatepointStackSlots.size().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261348 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 18:15:56 +00:00
Sanjoy Das 2ad23171bd [StatepointLowering] Fix a mistake in rL261336
The check on MFI->getObjectSize() has to be on the FrameIndex, not on
the index of the FrameIndex in AllocatedStackSlots.  Weirdly, the tests
I added in rL261336 didn't catch this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261347 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 18:15:53 +00:00
Sanjoy Das d3b66593b0 [StatepointLowering] Change AllocatedStackSlots to use SmallBitVector
NFCI.  They key motivation here is that I'd like to use
SmallBitVector::all() in a later change.  Also, using a bit vector here
seemed better in general.

The only interesting change here is that in the failure case of
allocateStackSlot, we no longer (the equivalent of) push_back(true) to
AllocatedStackSlots.  As far as I can tell, this is fine, since we'd
never re-use those slots in the same StatepointLoweringState instance.

Technically there was no need to change the operator[] type accesses to
set() and test(), but I thought it'd be nice to make it obvious that
we're using something other than a std::vector like thing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261337 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 17:15:26 +00:00
Sanjoy Das fffaef16a2 [StatepointLowering] Fix bug in allocateStackSlot
allocateStackSlot did not consider the size of the value to be spilled
before deciding to re-use a spill slot.  This was originally okay (since
originally we'd only ever spill pointers), but it became not okay when
we changed our scheme to directly spill vectors of pointers.

While this change fixes the bug pointed out, it has two performance
caveats:

 - It matches spill slot and spillee size exactly, while in theory we
   can spill, e.g., an 8 byte pointer into a 16 byte slot.  This is
   slightly complicated to fix since in the stackmaps section, we report
   the size of the spill slot as the size of the "indirect value"; and
   if they're no longer equivalent, we'll have to keep track of the
   (indirect) value size separately from the stack slot size.

 - It will "spuriously run out" of reusable slots, since we now have an
   second check in the search loop in addition to the availablity
   check (e.g. you had two free scalar slots, and you first ask for a
   vector slot followed by a scalar slot).  I'll fix this in a later
   commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261336 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 17:15:22 +00:00
Sanjoy Das f08995153b [StatepointLowering] Clean up allocateStackSlot
This removes the unusual loop structure in allocateStackSlot in favor of
something more straightforward.  I've also removed the cautionary
comment in the function, which I suspect is historical cruft now, and
confuses more than it enlightens.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261335 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 17:15:17 +00:00
Matthias Braun 4f298ff508 LegalizeDAG: Fix ExpandFCOPYSIGN assuming the same type on both inputs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261306 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-19 04:44:19 +00:00
Richard Trieu 1b96cbe208 Remove uses of builtin comma operator.
Cleanup for upcoming Clang warning -Wcomma.  No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261270 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-18 22:09:30 +00:00
Nico Weber b512b02828 Revert r261070, it caused PR26652 / PR26653.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261127 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-17 18:47:29 +00:00
Cong Hou ff3f2ebae3 Detecte vector reduction operations just before instruction selection.
This patch detects vector reductions before instruction selection. Vector
reductions are vectorized reduction operations, and for such operations we have
freedom to reorganize the elements of the result as long as the reduction of them
stay unchanged. This will enable some reduction pattern recognition during
instruction combine such as SAD/dot-product on X86. A flag is added to
SDNodeFlags to mark those vector reduction nodes to be checked during instruction
combine.

To detect those vector reductions, we search def-use chains starting from the
given instruction, and check if all uses fall into two categories:

1. Reduction with another vector.
2. Reduction on all elements.

in which 2 is detected by recognizing the pattern that the loop vectorizer
generates to reduce all elements in the vector outside of the loop, which
includes several ShuffleVector and one ExtractElement instructions.


Differential revision: http://reviews.llvm.org/D15250



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261070 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-17 06:37:04 +00:00
Ahmed Bougacha 606927f7bb [CodeGen] Document and use getConstant's splat-building feature. NFC.
Differential Revision: http://reviews.llvm.org/D17229

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260901 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-15 18:07:29 +00:00
Pirama Arumuga Nainar d313df118a Don't combine fp_round (fp_round x) if f80 to f16 is generated
Summary:
This patch skips DAG combine of fp_round (fp_round x) if it results in
an fp_round from f80 to f16.

fp_round from f80 to f16 always generates an expensive (and as yet,
unimplemented) libcall to __truncxfhf2.  This prevents selection of
native f16 conversion instructions from f32 or f64.  Moreover, the first
(value-preserving) fp_round from f80 to either f32 or f64 may become a
NOP in platforms like x86.

Reviewers: ab

Subscribers: srhines, llvm-commits

Differential Revision: http://reviews.llvm.org/D17221

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260769 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-13 00:08:05 +00:00
Sanjay Patel a52e2127b6 [SelectionDAG] change getConstant() to use the input SDLoc when building splat vectors
The code change is simple enough: instead of attaching an anonymous SDLoc to splatted
vector constants, use the scalar constant's existing SDLoc since that is what is passed 
into getConstant() as a param. But this changes instruction scheduling, so I'll explain
why that happens.

The motivation for this patch starts near:
http://reviews.llvm.org/rL258833
...x86's getZeroVector() could be similarly cleaned up and I thought it would be 'NFC'.
But when I made that change locally, several x86 codegen tests wiggled.

It turns out that the lack of SDLoc consistency in getConstant() changes the way 
ScheduleDAGRRList behaves. This is because the SDLoc contains 'IROrder' and some DAG
scheduler algorithms use IROrder for tie-breaking.

Differential Revision: http://reviews.llvm.org/D16972



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260582 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 20:21:24 +00:00
Ahmed Bougacha 3248c624fa [CodeGen] Prefer "if (SDValue R = ...)" to "if (R.getNode())". NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260316 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-09 22:54:12 +00:00
Sanjay Patel 068c0ce5f1 [SelectionDAG] make getMemBasePlusOffset() accessible; NFCI
I reinvented this functionality in http://reviews.llvm.org/D16828 because it was
hidden away as a static function. The changes in x86 are not based on a complete
audit. I suspect there are other possible uses there, and there are almost certainly
more potential users in other targets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260295 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-09 21:42:04 +00:00
Hans Wennborg 7dfc3433f3 [X86] Don't zero/sign-extend i1, i8, or i16 return values to 32 bits (PR22532)
This matches GCC and MSVC's behaviour, and saves on code size.

We were already not extending i1 return values on x86_64 after r127766. This
takes that patch further by applying it to x86 target as well, and also for i8
and i16.

The ABI docs have been unclear about the required behaviour here. The new i386
psABI [1] clearly states (Table 2.4, page 14) that i1, i8, and i16 return
vales do not need to be extended beyond 8 bits. The x86_64 ABI doc is being
updated to say the same [2].

Differential Revision: http://reviews.llvm.org/D16907

 [1]. https://01.org/sites/default/files/file_attach/intel386-psabi-1.0.pdf
 [2]. https://groups.google.com/d/msg/x86-64-abi/E8O33onbnGQ/_RFWw_ixDQAJ

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260133 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-08 19:34:30 +00:00
Matt Arsenault 98d69cc318 SelectionDAG: Lower some range metadata to AssertZext
If a range has a lower bound of 0, add an AssertZext from the
nearest floor power of two.

This allows operations with some workitem intrinsics with known
maximum ranges to use fast 24-bit multiplies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260109 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-08 16:28:19 +00:00
Sanjoy Das 0ba13f53fe [StatepointLower] Use None instead of Optional<int>()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259956 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-05 23:40:04 +00:00
Petar Jovanovic 8ed0526e77 [Power PC] softening long double type
This patch implements softening of long double type (ppcf128) on ppc32
architecture and enables operations for this type for soft float.

Patch by Strahinja Petrovic.

Differential Revision: http://reviews.llvm.org/D15811


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259791 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-04 14:43:50 +00:00
Sanjay Patel 4b77eeb789 rangify; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259722 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 22:44:14 +00:00
Tim Shen 33bf0bd3ea [SelectionDAG] Fix CombineToPreIndexedLoadStore O(n^2) behavior
This patch consists of two parts: a performance fix in DAGCombiner.cpp
and a correctness fix in SelectionDAG.cpp.

The test case tests the bug that's uncovered by the performance fix, and
fixed by the correctness fix.

The performance fix keeps the containers required by the
hasPredecessorHelper (which is a lazy DFS) and reuse them. Since
hasPredecessorHelper is called in a loop, the overall efficiency reduced
from O(n^2) to O(n), where n is the number of SDNodes.

The correctness fix keeps iterating the neighbor list even if it's time
to early return. It will return after finishing adding all neighbors to
Worklist, so that no neighbors are discarded due to the original early
return.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259691 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 20:58:55 +00:00
Eugene Zelenko 380d47d651 Fix Clang-tidy readability-redundant-control-flow warnings; other minor fixes.
Differential revision: http://reviews.llvm.org/D16793


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259539 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 18:20:45 +00:00
Balaram Makam 60101204f1 AArch64: Implement missed conditional compare sequences.
Summary:
This is an extension to the existing implementation of r242436 which
restricts to only select inputs. This version fixes missed opportunities
in pr26084 by attempting to lower conditional compare sequences of
and/or trees with setcc leafs. This will additionaly handle the case
when a tree with select input is not a conjunction-disjunction tree
but some of the sub trees are conjunction-disjunction trees.

Reviewers: jmolloy, t.p.northover, mcrosier, MatzeB

Subscribers: mcrosier, llvm-commits, junbuml, haicheng, mssimpso, gberry

Differential Revision: http://reviews.llvm.org/D16291

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259387 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-01 19:13:07 +00:00
Tim Shen a750479355 [SelectionDAG] Eliminate exponential behavior in WalkChainUsers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259315 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-31 03:59:34 +00:00
Matthias Braun 5e08bd340a Avoid overly large SmallPtrSet/SmallSet
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259283 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-30 01:24:31 +00:00
Yaron Keren 55307987a1 Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment.
clang part in r259232, this is the LLVM part of the patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259240 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 20:50:44 +00:00
David Majnemer 98232aa5c9 [X86] Don't transform X << 1 to X + X during type legalization
While legalizing a 64-bit shift left by 1, the following occurs:

We split the shift operand in half: a high half and a low half.
We then create an ADDC with the low half and a ADDE with the high half +
the carry bit from the ADDC.

This is problematic if X is any_ext'd because the high half computation
is now undef + undef + carry bit and there is no way to ensure that the
two undef values had the same bitwise representation.  This results in
the lowest bit in the high half turning into garbage.

Instead, do not try to turn shifts into arithmetic during type
legalization.

This fixes PR26350.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259065 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-28 18:20:05 +00:00
Junmo Park 91de9d1201 [DAGCombiner] Don't add volatile or indexed stores to ChainedStores
Summary:
findBetterNeighborChains does not handle volatile or indexed stores.
However, it did not check when adding stores to ChainedStores.

Reviewers: arsenm

Differential Revision: http://reviews.llvm.org/D16463


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259024 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-28 06:23:33 +00:00