Commit Graph

701 Commits

Author SHA1 Message Date
Adam Nemet
bddcf8ba3a [LoopVectorize] Add accessors for Num{Stores,Loads,PredStores} in AccessAnalysis
These members are moving to LoopAccessAnalysis.  The accessors help to hide
this.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227750 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 16:56:02 +00:00
Adam Nemet
8a1d3fe962 [LoopVectorize] Rename the Report class to VectorizationReport
This class will become public in the new LoopAccessAnalysis header so the name
needs to be more global.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227749 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 16:56:00 +00:00
Adam Nemet
f986a7f39c [LoopVectorize] Factor out duplicated code into Report::emitAnalysis
The logic in emitAnalysis is duplicated across multiple functions.  This
splits it into a function.  Another use will be added by the patchset.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227748 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 16:55:58 +00:00
Adam Nemet
2659684fe3 [LoopVectorize] Split out RuntimePointerCheck from LoopVectorizationLegality
RuntimePointerCheck will be used through LoopAccessAnalysis in
LoopVectorizationLegality.  Later in the patchset it will become a local class
of LoopAccessAnalysis.

NFC.  This is part of the patchset that splits out the memory dependence logic
from LoopVectorizationLegality into a new class LoopAccessAnalysis.
LoopAccessAnalysis will be used by the new Loop Distribution pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227747 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 16:55:56 +00:00
Chandler Carruth
baceda736e [multiversion] Thread a function argument through all the callers of the
getTTI method used to get an actual TTI object.

No functionality changed. This just threads the argument and ensures
code like the inliner can correctly look up the callee's TTI rather than
using a fixed one.

The next change will use this to implement per-function subtarget usage
by TTI. The changes after that should eliminate the need for FTTI as that
will have become the default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227730 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 12:01:35 +00:00
Chandler Carruth
a6a87b595d [PM] Change the core design of the TTI analysis to use a polymorphic
type erased interface and a single analysis pass rather than an
extremely complex analysis group.

The end result is that the TTI analysis can contain a type erased
implementation that supports the polymorphic TTI interface. We can build
one from a target-specific implementation or from a dummy one in the IR.

I've also factored all of the code into "mix-in"-able base classes,
including CRTP base classes to facilitate calling back up to the most
specialized form when delegating horizontally across the surface. These
aren't as clean as I would like and I'm planning to work on cleaning
some of this up, but I wanted to start by putting into the right form.

There are a number of reasons for this change, and this particular
design. The first and foremost reason is that an analysis group is
complete overkill, and the chaining delegation strategy was so opaque,
confusing, and high overhead that TTI was suffering greatly for it.
Several of the TTI functions had failed to be implemented in all places
because of the chaining-based delegation making there be no checking of
this. A few other functions were implemented with incorrect delegation.
The message to me was very clear working on this -- the delegation and
analysis group structure was too confusing to be useful here.

The other reason of course is that this is *much* more natural fit for
the new pass manager. This will lay the ground work for a type-erased
per-function info object that can look up the correct subtarget and even
cache it.

Yet another benefit is that this will significantly simplify the
interaction of the pass managers and the TargetMachine. See the future
work below.

The downside of this change is that it is very, very verbose. I'm going
to work to improve that, but it is somewhat an implementation necessity
in C++ to do type erasure. =/ I discussed this design really extensively
with Eric and Hal prior to going down this path, and afterward showed
them the result. No one was really thrilled with it, but there doesn't
seem to be a substantially better alternative. Using a base class and
virtual method dispatch would make the code much shorter, but as
discussed in the update to the programmer's manual and elsewhere,
a polymorphic interface feels like the more principled approach even if
this is perhaps the least compelling example of it. ;]

Ultimately, there is still a lot more to be done here, but this was the
huge chunk that I couldn't really split things out of because this was
the interface change to TTI. I've tried to minimize all the other parts
of this. The follow up work should include at least:

1) Improving the TargetMachine interface by having it directly return
   a TTI object. Because we have a non-pass object with value semantics
   and an internal type erasure mechanism, we can narrow the interface
   of the TargetMachine to *just* do what we need: build and return
   a TTI object that we can then insert into the pass pipeline.
2) Make the TTI object be fully specialized for a particular function.
   This will include splitting off a minimal form of it which is
   sufficient for the inliner and the old pass manager.
3) Add a new pass manager analysis which produces TTI objects from the
   target machine for each function. This may actually be done as part
   of #2 in order to use the new analysis to implement #2.
4) Work on narrowing the API between TTI and the targets so that it is
   easier to understand and less verbose to type erase.
5) Work on narrowing the API between TTI and its clients so that it is
   easier to understand and less verbose to forward.
6) Try to improve the CRTP-based delegation. I feel like this code is
   just a bit messy and exacerbating the complexity of implementing
   the TTI in each target.

Many thanks to Eric and Hal for their help here. I ended up blocked on
this somewhat more abruptly than I expected, and so I appreciate getting
it sorted out very quickly.

Differential Revision: http://reviews.llvm.org/D7293

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227669 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-31 03:43:40 +00:00
Reid Kleckner
2389dc9d26 Silence "not all paths return a value" warning in MSVC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227614 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-30 21:30:57 +00:00
Chandler Carruth
2ec788d43f Fix a warning introduced by r227557 due to a default label in a fully
covering switch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227575 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-30 13:30:43 +00:00
Hao Liu
e7769db118 [LoopVectorize] Induction variables: support arbitrary constant step.
Previously, only -1 and +1 step values are supported for induction variables. This patch extends LV to support
arbitrary constant steps.
Initial patch by Alexey Volkov. Some bug fixes are added in the following version.

Differential Revision: http://reviews.llvm.org/D6051 and http://reviews.llvm.org/D7193


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227557 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-30 05:02:21 +00:00
Erik Eckstein
8f6e8cb4f6 SLPVectorizer: fix wrong scheduling of atomic load/stores.
This fixes PR22306.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227077 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 09:07:04 +00:00
Aaron Ballman
591e043a7a Silencing a -Wsign-compare warning (all uses of this constant are within unsigned expressions anyway); NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226826 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 13:57:41 +00:00
Erik Eckstein
5b657c48d8 SLPVectorizer: add a second limit for the number of alias checks.
Even with the current limit on the number of alias checks, the containing loop has quadratic complexity.
This begins to hurt for blocks containing > 1K load/store instructions.
This commit introduces a limit for the loop count. It reduces the runtime for such very large blocks.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226792 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 08:20:51 +00:00
Elena Demikhovsky
05e7ae1a7b Fixed a bug in masked load/store in reversed loop.
Added a test.

The bug was submitted to bugzilla:
http://llvm.org/bugs/show_bug.cgi?id=22225



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226791 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-22 08:20:06 +00:00
Karthik Bhat
7e9f120130 Fix Operandreorder logic in SLPVectorizer to generate longer vectorizable chain.
This patch fixes 2 issues in reorderInputsAccordingToOpcode
1) AllSameOpcodeLeft and AllSameOpcodeRight was being calculated incorrectly resulting in code not being vectorized in few cases.
2) Adds logic to reorder operands if we get longer chain of consecutive loads enabling vectorization. Handled the same for cases were we have AltOpcode.
Thanks Michael for inputs and review.
Review: http://reviews.llvm.org/D6677



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226547 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-20 06:11:00 +00:00
Erik Eckstein
04075c619b SLPVectorizer: limit the number of alias checks to reduce the runtime.
In case of blocks with many memory-accessing instructions, alias checking can take lot of time
(because calculating the memory dependencies has quadratic complexity).
I chose a limit which resulted in no changes when running the benchmarks.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226439 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-19 09:33:38 +00:00
Chandler Carruth
5a2d01e5b8 [PM] Now that LoopInfo isn't in the Pass type hierarchy, it is much
cleaner to derive from the generic base.

Thise removes a ton of boiler plate code and somewhat strange and
pointless indirections. It also remove a bunch of the previously needed
friend declarations. To fully remove these, I also lifted the verify
logic into the generic LoopInfoBase, which seems good anyways -- it is
generic and useful logic even for the machine side.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226385 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-18 01:25:51 +00:00
Chandler Carruth
de5df29556 [PM] Split the LoopInfo object apart from the legacy pass, creating
a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226373 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-17 14:16:18 +00:00
Alexander Kornienko
b4c6267f7c Replace size method call of containers to empty method where appropriate
This patch was generated by a clang tidy checker that is being open sourced.
The documentation of that checker is the following:

/// The emptiness of a container should be checked using the empty method
/// instead of the size method. It is not guaranteed that size is a
/// constant-time function, and it is generally more efficient and also shows
/// clearer intent to use empty. Furthermore some containers may implement the
/// empty method but not implement the size method. Using empty whenever
/// possible makes it easier to switch to another container in the future.

Patch by Gábor Horváth!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226161 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 11:41:30 +00:00
Chandler Carruth
eeeec3ce0d [PM] Separate the TargetLibraryInfo object from the immutable pass.
The pass is really just a means of accessing a cached instance of the
TargetLibraryInfo object, and this way we can re-use that object for the
new pass manager as its result.

Lots of delta, but nothing interesting happening here. This is the
common pattern that is developing to allow analyses to live in both the
old and new pass manager -- a wrapper pass in the old pass manager
emulates the separation intrinsic to the new pass manager between the
result and pass for analyses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226157 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 10:41:28 +00:00
NAKAMURA Takumi
20b033eae5 Update libdeps since TLI was moved from Target to Analysis in r226078.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226126 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-15 05:21:00 +00:00
Erik Eckstein
d6238e7b7e reapply: SLPVectorizer: Cache results from memory alias checking.
This speeds up the dependency calculations for blocks with many load/store/call instructions.
Beside the improved runtime, there is no functional change.

Compared to the original commit, this re-applied commit contains a bug fix which ensures that there are
no incorrect collisions in the alias cache.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225977 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 11:24:47 +00:00
Hao Liu
e928b4046a Fix a wrong comment in LoopVectorize.
I.E. more than two -> exactly two
Fix a typo function name in LoopVectorize.
  I.E. collectStrideAcccess() -> collectStrideAccess()


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225935 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 03:02:16 +00:00
Julien Lerouge
88e1d95d4d Fix non-determinism issue in SLP
The issue was introduced in r214638:

+  for (auto &BSIter : BlocksSchedules) {
+    scheduleBlock(BSIter.second.get());
+  }

Because BlocksSchedules is a DenseMap with BasicBlock* keys, blocks are
scheduled in non-deterministic order, resulting in unpredictable IR.

Patch by Daniel Reynaud!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225821 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 19:45:52 +00:00
Erik Eckstein
046c3e807d Revert "SLPVectorizer: Cache results from memory alias checking."
The alias cache has a problem of incorrect collisions in case a new instruction is allocated at the same address as a previously deleted instruction.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225790 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 14:36:46 +00:00
Erik Eckstein
5b23df7cd8 SLPVectorizer: Cache results from memory alias checking.
This speeds up the dependency calculations for blocks with many load/store/call instructions.
Beside the improved runtime, there is no functional change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225786 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-13 11:37:51 +00:00
Michael Zolotukhin
d23518097e Update comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225553 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 22:15:06 +00:00
Michael Zolotukhin
b2e5f58de0 Remove duplicating code. NFC.
The removed condition is checked in the previous loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225542 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 20:36:19 +00:00
Suyog Sarda
df970d6297 Assumption that "VectorizedValue" will always be an Instruction is not correct.
It can be a constant or a vector argument.

ex :

define i32 @hadd(<4 x i32> %a) #0 {
entry:
  %vecext = extractelement <4 x i32> %a, i32 0
  %vecext1 = extractelement <4 x i32> %a, i32 1
  %add = add i32 %vecext, %vecext1
  %vecext2 = extractelement <4 x i32> %a, i32 2
  %add3 = add i32 %add, %vecext2
  %vecext4 = extractelement <4 x i32> %a, i32 3
  %add5 = add i32 %add3, %vecext4
  ret i32 %add5
}



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225517 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 10:23:48 +00:00
Jiangning Liu
614fe873ce Fixed a bug in memory dependence checking module of loop vectorization. The following loop should not be vectorized with current algorithm.
{code}
// loop body
   ... = a[i]          (1)
    ... = a[i+1]       (2)
 .......
a[i+1] = ....          (3)
   a[i] = ...          (4)
{code}

The algorithm tries to collect memory access candidates from AliasSetTracker, and then check memory dependences one another. The memory accesses are unique in AliasSetTracker, and a single memory access in AliasSetTracker may map to multiple entries in AccessAnalysis, which could cover both 'read' and 'write'. Originally the algorithm only checked 'write' entry in Accesses if only 'write' exists. This is incorrect and the consequence is it ignored all read access, and finally some RAW and WAR dependence are missed.

For the case given above, if we ignore two reads, the dependence between (1) and (3) would not be able to be captured, and finally this loop will be incorrectly vectorized.

The fix simply inserts a new loop to find all entries in Accesses. Since it will skip most of all other memory accesses by checking the Value pointer at the very beginning of the loop, it should not increase compile-time visibly.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225159 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 10:08:58 +00:00
Chandler Carruth
5a9cd4d44e [PM] Split the AssumptionTracker immutable pass into two separate APIs:
a cache of assumptions for a single function, and an immutable pass that
manages those caches.

The motivation for this change is two fold. Immutable analyses are
really hacks around the current pass manager design and don't exist in
the new design. This is usually OK, but it requires that the core logic
of an immutable pass be reasonably partitioned off from the pass logic.
This change does precisely that. As a consequence it also paves the way
for the *many* utility functions that deal in the assumptions to live in
both pass manager worlds by creating an separate non-pass object with
its own independent API that they all rely on. Now, the only bits of the
system that deal with the actual pass mechanics are those that actually
need to deal with the pass mechanics.

Once this separation is made, several simplifications become pretty
obvious in the assumption cache itself. Rather than using a set and
callback value handles, it can just be a vector of weak value handles.
The callers can easily skip the handles that are null, and eventually we
can wrap all of this up behind a filter iterator.

For now, this adds boiler plate to the various passes, but this kind of
boiler plate will end up making it possible to port these passes to the
new pass manager, and so it will end up factored away pretty reasonably.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225131 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-04 12:03:27 +00:00
Elena Demikhovsky
cc794daa67 Some code improvements in Masked Load/Store.
No functional changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224986 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-30 14:28:14 +00:00
Elena Demikhovsky
b31322328a Masked Load/Store - Changed the order of parameters in intrinsics.
No functional changes.
The documentation is coming.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224829 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-25 07:49:20 +00:00
Tilmann Scheller
409585877a [BBVectorize] Remove two more redundant assignments.
Found by the Clang static analyzer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224590 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 17:21:38 +00:00
Tilmann Scheller
14ef1a43c2 [BBVectorize] Remove redundant assignment.
Found by the Clang static analyzer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224589 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 17:13:12 +00:00
Tilmann Scheller
b8b0b8f0a8 [LoopVectorize] Remove redundant assignment.
Found by the Clang static analyzer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224587 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-19 17:02:31 +00:00
Suyog Sarda
4bfc4f2e8c Revert 224119 "This patch recognizes (+ (+ v0, v1) (+ v2, v3)), reorders them for bundling into vector of loads,
and vectorizes it." 

This was re-ordering floating point data types resulting in mismatch in output.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224424 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-17 10:34:27 +00:00
Elena Demikhovsky
14fb445715 Masked Load and Store Intrinsics in loop vectorizer.
The loop vectorizer optimizes loops containing conditional memory
accesses by generating masked load and store intrinsics.
This decision is target dependent.

http://reviews.llvm.org/D6527



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-16 11:50:42 +00:00
Elena Demikhovsky
1c3a1516f8 Loop Vectorizer minor changes in the code -
some comments, function names, identation.

Reviewed here: http://reviews.llvm.org/D6527


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224218 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-14 09:43:50 +00:00
Suyog Sarda
1dea0dc279 This patch recognizes (+ (+ v0, v1) (+ v2, v3)), reorders them for bundling into vector of loads,
and vectorizes it. 
 
 Test case :
 
       float hadd(float* a) {
           return (a[0] + a[1]) + (a[2] + a[3]);
        }
 
 
 AArch64 assembly before patch :
 
        ldp	s0, s1, [x0]
 	ldp	s2, s3, [x0, #8]
 	fadd	s0, s0, s1
 	fadd	s1, s2, s3
 	fadd	s0, s0, s1
 	ret
 
 AArch64 assembly after patch :
 
        ldp	d0, d1, [x0]
 	fadd	v0.2s, v0.2s, v1.2s
 	faddp	s0, v0.2s
 	ret

Reviewed Link : http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20141208/248531.html



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224119 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-12 12:53:44 +00:00
Michael Zolotukhin
c9f47d8821 Remove redundant variable.
Tested by adding assert(LoopVectorPreHeader == VecPreheader) on LLVM
test suite and SPECs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223847 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 22:45:07 +00:00
Duncan P. N. Exon Smith
dad20b2ae2 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 18:38:53 +00:00
Duncan P. N. Exon Smith
5ed8a767a0 LoopVectorize: Remove unnecessary RAUW
Remove an unnecessary `MDNode::replaceAllUsesWith()`.  In the preceding
line, `TheLoop->setLoopID()` visits all backedges and sets the new loop
ID.  This sufficiently updates the loop metadata.

Metadata RAUW is going away as part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223210 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-03 05:41:20 +00:00
Michael Zolotukhin
97be10d98f PR21302. Vectorize only bottom-tested loops.
rdar://problem/18886083

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223171 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-02 22:59:06 +00:00
Duncan P. N. Exon Smith
54786a0936 Revert "Masked Vector Load and Store Intrinsics."
This reverts commit r222632 (and follow-up r222636), which caused a host
of LNT failures on an internal bot.  I'll respond to the commit on the
list with a reproduction of one of the failures.

Conflicts:
	lib/Target/X86/X86TargetTransformInfo.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222936 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-28 21:29:14 +00:00
Elena Demikhovsky
ae1ae2c3a1 Masked Vector Load and Store Intrinsics.
Introduced new target-independent intrinsics in order to support masked vector loads and stores. The loop vectorizer optimizes loops containing conditional memory accesses by generating these intrinsics for existing targets AVX2 and AVX-512. The vectorizer asks the target about availability of masked vector loads and stores.
Added SDNodes for masked operations and lowering patterns for X86 code generator.
Examples:
<16 x i32> @llvm.masked.load.v16i32(i8* %addr, <16 x i32> %passthru, i32 4 /* align */, <16 x i1> %mask)
declare void @llvm.masked.store.v8f64(i8* %addr, <8 x double> %value, i32 4, <8 x i1> %mask)

Scalarizer for other targets (not AVX2/AVX-512) will be done in a separate patch.

http://reviews.llvm.org/D6191



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222632 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-23 08:07:43 +00:00
Suyog Sarda
ca72befdb5 Vectorize a reduction chain feeding into a 'return' statement.
e.x 
return (a[0]+b[0]) + (a[1]+b[1])

Differential Revision: http://reviews.llvm.org/D6227



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222364 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 16:07:38 +00:00
David Blaikie
5401ba7099 Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222334 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-19 07:49:26 +00:00
Duncan P. N. Exon Smith
f4742f4c84 IR: Make MDString::getName() private
Hide the fact that `MDString`'s string is stored in `Value::Name` --
that's going to change soon.  Update the only in-tree client that was
using it instead of `Value::getString()`.

Part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221951 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-13 23:59:16 +00:00
Duncan P. N. Exon Smith
5bf8ade9d0 Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221711 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-11 21:30:22 +00:00
David Majnemer
bb642c4369 LoopVectorize: Don't assume pointees are sized
A pointer's pointee might not be sized: the pointee could be a function.

Report this as IK_NoInduction when calculating isInductionVariable.

This fixes PR21508.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221501 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-07 00:31:14 +00:00