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Commit Graph

1577 Commits

Author SHA1 Message Date
Hal Finkel
7469edb8f1 [LV] Extend InstWidening with CM_Widen_Recursive
Changes to the original scalar loop during LV code gen cause the return value
of Legal->isConsecutivePtr() to be inconsistent with the return value during
legal/cost phases (further analysis and information of the bug is in D39346).
This patch is an alternative fix to PR34965 following the CM_Widen approach
proposed by Ayal and Gil in D39346. It extends InstWidening enum with
CM_Widen_Reverse to properly record the widening decision for consecutive
reverse memory accesses and, consequently, get rid of the
Legal->isConsetuviePtr() call in LV code gen. I think this is a simpler/cleaner
solution to PR34965 than the one in D39346.

Fixes PR34965.

Patch by Diego Caballero, thanks!

Differential Revision: https://reviews.llvm.org/D40742

llvm-svn: 320913
2017-12-16 02:55:24 +00:00
Hal Finkel
b17cb3a5ce [LV] NFC patch for moving VP*Recipe class definitions from LoopVectorize.cpp to VPlan.h
This is a small step forward to move VPlan stuff to where it should belong (i.e., VPlan.*):

  1. VP*Recipe classes in LoopVectorize.cpp are moved to VPlan.h.
  2. Many of VP*Recipe::print() and execute() definitions are still left in
     LoopVectorize.cpp since they refer to things declared in LoopVectorize.cpp. To
     be moved to VPlan.cpp at a later time.
  3. InterleaveGroup class is moved from anonymous namespace to llvm namespace.
     Referencing it in anonymous namespace from VPlan.h ended up in warning.

Patch by Hideki Saito, thanks!

Differential Revision: https://reviews.llvm.org/D41045

llvm-svn: 320900
2017-12-16 01:12:50 +00:00
Guozhi Wei
8c380373f3 [SLPVectorizer] Don't ignore scalar extraction instructions of aggregate value
In SLPVectorizer, the vector build instructions (insertvalue for aggregate type) is passed to BoUpSLP.buildTree, it is treated as UserIgnoreList, so later in cost estimation, the cost of these instructions are not counted. 
For aggregate value, later usage are more likely to be done in scalar registers, either used as individual scalars or used as a whole for function call or return value. Ignore scalar extraction instructions may cause too aggressive vectorization for aggregate values, and slow down performance. So for vectorization of aggregate value, the scalar extraction instructions are required in cost estimation.

Differential Revision: https://reviews.llvm.org/D41139

llvm-svn: 320736
2017-12-14 19:35:43 +00:00
Dorit Nuzman
157ae50057 [LV] Support efficient vectorization of an induction with redundant casts
D30041 extended SCEVPredicateRewriter to improve handling of Phi nodes whose
update chain involves casts; PSCEV can now build an AddRecurrence for some
forms of such phi nodes, under the proper runtime overflow test. This means
that we can identify such phi nodes as an induction, and the loop-vectorizer
can now vectorize such inductions, however inefficiently. The vectorizer
doesn't know that it can ignore the casts, and so it vectorizes them.

This patch records the casts in the InductionDescriptor, so that they could
be marked to be ignored for cost calculation (we use VecValuesToIgnore for
that) and ignored for vectorization/widening/scalarization (i.e. treated as
TriviallyDead).

In addition to marking all these casts to be ignored, we also need to make
sure that each cast is mapped to the right vector value in the vector loop body
(be it a widened, vectorized, or scalarized induction). So whenever an
induction phi is mapped to a vector value (during vectorization/widening/
scalarization), we also map the respective cast instruction (if exists) to that
vector value. (If the phi-update sequence of an induction involves more than one
cast, then the above mapping to vector value is relevant only for the last cast
of the sequence as we allow only the "last cast" to be used outside the
induction update chain itself).

This is the last step in addressing PR30654.

llvm-svn: 320672
2017-12-14 07:56:31 +00:00
Michael Zolotukhin
5b96dc51f0 Remove redundant includes from lib/Transforms.
llvm-svn: 320628
2017-12-13 21:31:01 +00:00
Mohammad Shahid
ca62a8ef1a [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh

Reviewed By: Ayal

Subscribers: mgrang, dcaballe, hans, mzolotukhin

Differential Revision: https://reviews.llvm.org/D36130

llvm-svn: 320548
2017-12-13 03:08:29 +00:00
Dorit Nuzman
483596bd6f [LV] Ignore the cost of values that will not appear in the vectorized loop
VecValuesToIgnore holds values that will not appear in the vectorized loop.
We should therefore ignore their cost when VF > 1.

Differential Revision: https://reviews.llvm.org/D40883

llvm-svn: 320463
2017-12-12 08:57:43 +00:00
Adam Nemet
8c2b05ed44 [LV] Interleaved access vectorization: fix computing new alias info
As a new access is generated spanning across multiple fields, we need to
propagate alias info from all the fields to form the most generic alias info.

rdar://35602528

Differential Revision: https://reviews.llvm.org/D40617

llvm-svn: 319979
2017-12-06 22:42:24 +00:00
Hans Wennborg
4fca1b8552 Revert r319531 "[SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops."
It causes builds to fail with "Instruction does not dominate all uses" (PR35497).

> Patch tries to improve vectorization of the following code:
>
> void add1(int * __restrict dst, const int * __restrict src) {
>   *dst++ = *src++;
>   *dst++ = *src++ + 1;
>   *dst++ = *src++ + 2;
>   *dst++ = *src++ + 3;
> }
> Allows to vectorize even if the very first operation is not a binary add, but just a load.
>
> Fixed issues related to previous commit.
>
> Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev
>
> Reviewed By: ABataev, RKSimon
>
> Subscribers: llvm-commits, RKSimon
>
> Differential Revision: https://reviews.llvm.org/D28907

llvm-svn: 319550
2017-12-01 16:17:24 +00:00
Dinar Temirbulatov
9217bba7ab [SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops.
Patch tries to improve vectorization of the following code:
    
            void add1(int * __restrict dst, const int * __restrict src) {
              *dst++ = *src++;
              *dst++ = *src++ + 1;
              *dst++ = *src++ + 2;
              *dst++ = *src++ + 3;
            }
            Allows to vectorize even if the very first operation is not a binary add, but just a load.
    
            Fixed issues related to previous commit.
    
            Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev
    
            Reviewed By: ABataev, RKSimon
    
            Subscribers: llvm-commits, RKSimon
    
            Differential Revision: https://reviews.llvm.org/D28907

llvm-svn: 319531
2017-12-01 11:10:47 +00:00
Alina Sbirlea
77a10244b2 Add MemorySSA as loop dependency, disabled by default [NFC].
Summary:
First step in adding MemorySSA as dependency for loop pass manager.
Adding the dependency under a flag.

New pass manager: MSSA pointer in LoopStandardAnalysisResults can be null.
Legacy and new pass manager: Use cl::opt EnableMSSALoopDependency. Disabled by default.

Reviewers: sanjoy, davide, gberry

Subscribers: mehdi_amini, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D40274

llvm-svn: 318772
2017-11-21 15:45:46 +00:00
NAKAMURA Takumi
be536e28e1 SLPVectorizer.cpp: Avoid std::stable_sort(properlyDominates()).
properlyDominates() shouldn't be used as sort key. It causes different output between stdlibc++ and libc++.
Instead, I introduced RPOT. In most cases, it works for CSE.

llvm-svn: 318743
2017-11-21 09:41:01 +00:00
Gil Rapaport
b76bf11f90 [LV] Model masking in VPlan, introducing VPInstructions
This patch adds a new abstraction layer to VPlan and leverages it to model the planned
instructions that manipulate masks (AND, OR, NOT), introduced during predication.

The new VPValue and VPUser classes model how data flows into, through and out
of a VPlan, forming the vertices of a planned Def-Use graph. The new
VPInstruction class is a generic single-instruction Recipe that models a
planned instruction along with its opcode, operands and users. See
VectorizationPlan.rst for more details.

Differential Revision: https://reviews.llvm.org/D38676

llvm-svn: 318645
2017-11-20 12:01:47 +00:00
Adam Nemet
01d159b6a1 [SLP] Added more missed optimization remarks
Summary:
Added more remarks to SLP pass, in particular "missed" optimization remarks.
Also proposed several tests for new functionality.

Patch by Vladimir Miloserdov!

For reference you may look at: https://reviews.llvm.org/rL302811

Reviewers: anemet, fhahn

Reviewed By: anemet

Subscribers: javed.absar, lattner, petecoup, yakush, llvm-commits

Differential Revision: https://reviews.llvm.org/D38367

llvm-svn: 318307
2017-11-15 17:04:53 +00:00
Hans Wennborg
4937b695da Revert r318193 "[SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops."
It crashes building sqlite; see reply on the llvm-commits thread.

> [SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops.
>
>         Patch tries to improve vectorization of the following code:
>
>         void add1(int * __restrict dst, const int * __restrict src) {
>           *dst++ = *src++;
>           *dst++ = *src++ + 1;
>           *dst++ = *src++ + 2;
>           *dst++ = *src++ + 3;
>         }
>         Allows to vectorize even if the very first operation is not a binary add, but just a load.
>
>         Fixed issues related to previous commit.
>
>         Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev
>
>         Reviewed By: ABataev, RKSimon
>
>         Subscribers: llvm-commits, RKSimon
>
>         Differential Revision: https://reviews.llvm.org/D28907

llvm-svn: 318239
2017-11-15 00:38:13 +00:00
Dinar Temirbulatov
7ad2acdfcd [SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops.
Patch tries to improve vectorization of the following code:
    
        void add1(int * __restrict dst, const int * __restrict src) {
          *dst++ = *src++;
          *dst++ = *src++ + 1;
          *dst++ = *src++ + 2;
          *dst++ = *src++ + 3;
        }
        Allows to vectorize even if the very first operation is not a binary add, but just a load.
    
        Fixed issues related to previous commit.
    
        Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev
    
        Reviewed By: ABataev, RKSimon
    
        Subscribers: llvm-commits, RKSimon
    
        Differential Revision: https://reviews.llvm.org/D28907

llvm-svn: 318193
2017-11-14 20:55:08 +00:00
Gil Rapaport
b162077a3d [LV] Introduce VPBlendRecipe, VPWidenMemoryInstructionRecipe
This patch is part of D38676.

The patch introduces two new Recipes to handle instructions whose vectorization
involves masking. These Recipes take VPlan-level masks in D38676, but still rely
on ILV's existing createEdgeMask(), createBlockInMask() in this patch.

VPBlendRecipe handles intra-loop phi nodes, which are vectorized as a sequence
of SELECTs. Its execute() code is refactored out of ILV::widenPHIInstruction(),
which now handles only loop-header phi nodes.

VPWidenMemoryInstructionRecipe handles load/store which are to be widened
(but are not part of an Interleave Group). In this patch it simply calls
ILV::vectorizeMemoryInstruction on execute().

Differential Revision: https://reviews.llvm.org/D39068

llvm-svn: 318149
2017-11-14 12:09:30 +00:00
Alexey Bataev
827225754a [SLP] Fix PR23510: Try to find best possible vectorizable stores.
Summary:
The analysis of the store sequence goes in straight order - from the
first store to the last. Bu the best opportunity for vectorization will
happen if we're going to use reverse order - from last store to the
first. It may be best because usually users have some initialization
part + further processing and this first initialization may confuse
SLP vectorizer.

Reviewers: RKSimon, hfinkel, mkuper, spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39606

llvm-svn: 317821
2017-11-09 19:07:16 +00:00
Dan Gohman
39c48b9d3e Add an @llvm.sideeffect intrinsic
This patch implements Chandler's idea [0] for supporting languages that
require support for infinite loops with side effects, such as Rust, providing
part of a solution to bug 965 [1].

Specifically, it adds an `llvm.sideeffect()` intrinsic, which has no actual
effect, but which appears to optimization passes to have obscure side effects,
such that they don't optimize away loops containing it. It also teaches
several optimization passes to ignore this intrinsic, so that it doesn't
significantly impact optimization in most cases.

As discussed on llvm-dev [2], this patch is the first of two major parts.
The second part, to change LLVM's semantics to have defined behavior
on infinite loops by default, with a function attribute for opting into
potential-undefined-behavior, will be implemented and posted for review in
a separate patch.

[0] http://lists.llvm.org/pipermail/llvm-dev/2015-July/088103.html
[1] https://bugs.llvm.org/show_bug.cgi?id=965
[2] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118632.html

Differential Revision: https://reviews.llvm.org/D38336

llvm-svn: 317729
2017-11-08 21:59:51 +00:00
Mitch Phillips
796856de93 Revert rL317618
The implemented pass fails and is breaking a large number of unit tests.
Example:
http://lab.llvm.org:8011/builders/clang-with-lto-ubuntu/builds/5777/steps/build-stage3-compiler/logs/stdio

This reverts commit rL317618

llvm-svn: 317641
2017-11-08 00:20:53 +00:00
Dinar Temirbulatov
f950708f49 [SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops.
Patch tries to improve vectorization of the following code:

    void add1(int * __restrict dst, const int * __restrict src) {
      *dst++ = *src++;
      *dst++ = *src++ + 1;
      *dst++ = *src++ + 2;
      *dst++ = *src++ + 3;
    }
    Allows to vectorize even if the very first operation is not a binary add, but just a load.

    Fixed PR34619 and other issues related to previous commit.

    Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev

    Reviewed By: ABataev, RKSimon

    Subscribers: llvm-commits, RKSimon

    Differential Revision: https://reviews.llvm.org/D28907

llvm-svn: 317618
2017-11-07 21:25:34 +00:00
Sanjay Patel
fd69991264 [IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html
and again more recently:
http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html

...this is a step in cleaning up our fast-math-flags implementation in IR to better match
the capabilities of both clang's user-visible flags and the backend's flags for SDNode.

As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 
'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic 
reassociation - 'AllowReassoc'.

We're also adding a bit to allow approximations for library functions called 'ApproxFunc' 
(this was initially proposed as 'libm' or similar).

...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did 
look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), 
but that's apparently already used for other purposes. Also, I don't think we can just 
add a field to FPMathOperator because Operator is not intended to be instantiated. 
We'll defer movement of FMF to another day.

We keep the 'fast' keyword. I thought about removing that, but seeing IR like this:
%f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2
...made me think we want to keep the shortcut synonym.

Finally, this change is binary incompatible with existing IR as seen in the 
compatibility tests. This statement:
"Newer releases can ignore features from older releases, but they cannot miscompile 
them. For example, if nsw is ever replaced with something else, dropping it would be 
a valid way to upgrade the IR." 
( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility )
...provides the flexibility we want to make this change without requiring a new IR 
version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will 
fail to optimize some previously 'fast' code because it's no longer recognized as 
'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'.

Note: an inter-dependent clang commit to use the new API name should closely follow 
commit.

Differential Revision: https://reviews.llvm.org/D39304

llvm-svn: 317488
2017-11-06 16:27:15 +00:00
Benjamin Kramer
d6177e6458 [LoopVectorize] Replace manual VPlan memory management with unique_ptr.
No functionality change intended.

llvm-svn: 317003
2017-10-31 14:58:22 +00:00
Dehao Chen
91af01a4b7 Do not add discriminator encoding for debug intrinsics.
Summary: There are certain requirements for debug location of debug intrinsics, e.g. the scope of the DILocalVariable should be the same as the scope of its debug location. As a result, we should not add discriminator encoding for debug intrinsics.

Reviewers: dblaikie, aprantl

Reviewed By: aprantl

Subscribers: JDevlieghere, aprantl, bjope, sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D39343

llvm-svn: 316703
2017-10-26 21:20:52 +00:00
Bjorn Pettersson
6a9d0663f6 [LSV] Avoid adding vectors of pointers as candidates
Summary:
We no longer add vectors of pointers as candidates for
load/store vectorization. It does not seem to work anyway,
but without this patch we can end up in asserts when trying
to create casts between an integer type and the pointer of
vectors type.

The test case I've added used to assert like this when trying to
cast between i64 and <2 x i16*>:
opt: ../lib/IR/Instructions.cpp:2565: Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
#0 PrintStackTraceSignalHandler(void*)
#1 SignalHandler(int)
#2 __restore_rt
#3 __GI_raise
#4 __GI_abort
#5 __GI___assert_fail
#6 llvm::CastInst::Create(llvm::Instruction::CastOps, llvm::Value*, llvm::Type*, llvm::Twine const&, llvm::Instruction*)
#7 llvm::IRBuilder<llvm::ConstantFolder, llvm::IRBuilderDefaultInserter>::CreateBitOrPointerCast(llvm::Value*, llvm::Type*, llvm::Twine const&)
#8 Vectorizer::vectorizeStoreChain(llvm::ArrayRef<llvm::Instruction*>, llvm::SmallPtrSet<llvm::Instruction*, 16u>*)

Reviewers: arsenm

Reviewed By: arsenm

Subscribers: nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D39296

llvm-svn: 316665
2017-10-26 13:59:15 +00:00
Bjorn Pettersson
2a168cc880 [LSV] Skip all non-byte sizes, not only less than eight bits
Summary:
The code comments indicate that no effort has been spent on
handling load/stores when the size isn't a multiple of the
byte size correctly. However, the code only avoided types
smaller than 8 bits. So for example a load of an i28 could
still be considered as a candidate for vectorization.

This patch adjusts the code to behave according to the code
comment.

The test case used to hit the following assert when
trying to use "cast" an i32 to i28 using CreateBitOrPointerCast:

opt: ../lib/IR/Instructions.cpp:2565: Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
#0 PrintStackTraceSignalHandler(void*)
#1 SignalHandler(int)
#2 __restore_rt
#3 __GI_raise
#4 __GI_abort
#5 __GI___assert_fail
#6 llvm::CastInst::Create(llvm::Instruction::CastOps, llvm::Value*, llvm::Type*, llvm::Twine const&, llvm::Instruction*)
#7 llvm::IRBuilder<llvm::ConstantFolder, llvm::IRBuilderDefaultInserter>::CreateBitOrPointerCast(llvm::Value*, llvm::Type*, llvm::Twine const&)
#8 (anonymous namespace)::Vectorizer::vectorizeLoadChain(llvm::ArrayRef<llvm::Instruction*>, llvm::SmallPtrSet<llvm::Instruction*, 16u>*)

Reviewers: arsenm

Reviewed By: arsenm

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39295

llvm-svn: 316663
2017-10-26 13:42:55 +00:00
Eugene Zelenko
66256b9583 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316034
2017-10-17 21:27:42 +00:00
NAKAMURA Takumi
541dbb6cd5 Revert rL315894, "SLPVectorizer.cpp: Try to appease stage2-3 difference. (D38586)"
llvm-svn: 315896
2017-10-16 09:50:01 +00:00
NAKAMURA Takumi
44ac91f556 SLPVectorizer.cpp: Try to appease stage2-3 difference. (D38586)
llvm-svn: 315894
2017-10-16 09:15:23 +00:00
Eugene Zelenko
16fc947602 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 315640
2017-10-12 23:30:03 +00:00
Vivek Pandya
aa23fb5991 [NFC] Convert OptimizationRemarkEmitter old emit() calls to new closure
parameterized emit() calls

Summary: This is not functional change to adopt new emit() API added in r313691.

Reviewed By: anemet

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38285

llvm-svn: 315476
2017-10-11 17:12:59 +00:00
Adam Nemet
ec7409d86a Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*
Sync it up with the name of the class actually defined here.  This has been
bothering me for a while...

llvm-svn: 315249
2017-10-09 23:19:02 +00:00
Ayal Zaks
d3b59ba5b1 [LV] Fix PR34743 - handle casts that sink after interleaved loads
When ignoring a load that participates in an interleaved group, make sure to
move a cast that needs to sink after it.

Testcase derived from reproducer of PR34743.

Differential Revision: https://reviews.llvm.org/D38338

llvm-svn: 314986
2017-10-05 15:45:14 +00:00
Ayal Zaks
44ffc1b606 [LV] Fix PR34711 - widen instruction ranges when sinking casts
Instead of trying to keep LastWidenRecipe updated after creating each recipe,
have tryToWiden() retrieve the last recipe of the current VPBasicBlock and check
if it's a VPWidenRecipe when attempting to extend its range. This ensures that
such extensions, optimized to maintain the original instruction order, do so
only when the instructions are to maintain their relative order. The latter does
not always hold, e.g., when a cast needs to sink to unravel first order
recurrence (r306884).

Testcase derived from reproducer of PR34711.

Differential Revision: https://reviews.llvm.org/D38339

llvm-svn: 314981
2017-10-05 12:41:49 +00:00
Hans Wennborg
11d67365c5 Revert r314806 "[SLP] Vectorize jumbled memory loads."
All the buildbots are red, e.g.
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-lld/builds/2436/

> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask' of
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh
>
> Reviewed By: Ayal
>
> Subscribers: hans, mzolotukhin
>
> Differential Revision: https://reviews.llvm.org/D36130

llvm-svn: 314824
2017-10-03 18:32:29 +00:00
Mohammad Shahid
9bab937b54 [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh

Reviewed By: Ayal

Subscribers: hans, mzolotukhin

Differential Revision: https://reviews.llvm.org/D36130

llvm-svn: 314806
2017-10-03 15:28:48 +00:00
Matthew Simpson
7763474960 [LV] Use correct insertion point when type shrinking reductions
When type shrinking reductions, we should insert the truncations and extends at
the end of the loop latch block. Previously, these instructions were inserted
at the end of the loop header block. The difference is only a problem for loops
with predicated instructions (e.g., conditional stores and instructions that
may divide by zero). For these instructions, we create new basic blocks inside
the vectorized loop, which cause the loop header and latch to no longer be the
same block. This should fix PR34687.

Reference: https://bugs.llvm.org/show_bug.cgi?id=34687
llvm-svn: 314542
2017-09-29 18:07:39 +00:00
Sanjoy Das
3115e502f7 Use a BumpPtrAllocator for Loop objects
Summary:
And now that we no longer have to explicitly free() the Loop instances, we can
(with more ease) use the destructor of LoopBase to do what LoopBase::clear() was
doing.

Reviewers: chandlerc

Subscribers: mehdi_amini, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D38201

llvm-svn: 314375
2017-09-28 02:45:42 +00:00
Alexey Bataev
3637bc5aa5 [SLP] Fix crash on propagate IR flags for undef operands of min/max
reductions.

If both operands of the newly created SelectInst are Undefs the
resulting operation is also Undef, not SelectInst. It may cause crashes
when trying to propagate IR flags because function expects exactly
SelectInst instruction, nothing else.

llvm-svn: 314323
2017-09-27 17:42:49 +00:00
Sanjay Patel
0fd59b48d3 [SLP] fix typos/formatting; NFC
llvm-svn: 314315
2017-09-27 16:32:56 +00:00
Alexey Bataev
0b1859ac23 [SLP] Support for horizontal min/max reduction.
Summary:
SLP vectorizer supports horizontal reductions for Add/FAdd binary operations. Patch adds support for horizontal min/max reductions.
Function getReductionCost() is split to getArithmeticReductionCost() for binary operation reductions and getMinMaxReductionCost() for min/max reductions.
Patch fixes PR26956.

Reviewers: spatel, mkuper, hfinkel, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27846

llvm-svn: 314101
2017-09-25 13:34:59 +00:00
Hans Wennborg
44d1f6514a Revert r313771 "[SLP] Vectorize jumbled memory loads."
This broke the buildbots, e.g.
http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/391

> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask'
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Subscribers: mzolotukhin
>
> Reviewed By: ayal
>
> Differential Revision: https://reviews.llvm.org/D36130
>
> Review comments updated accordingly
>
> Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0
>
> Added a TODO for sortLoadAccesses API
>
> Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58
>
> Modified the TODO for sortLoadAccesses API
>
> Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565
>
> Review comment update for using OpdNum to insert the mask in respective location
>
> Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce
>
> Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase
>
> Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b

llvm-svn: 313781
2017-09-20 18:00:03 +00:00
Mohammad Shahid
5a29343ec1 [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask'
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Subscribers: mzolotukhin

Reviewed By: ayal

Differential Revision: https://reviews.llvm.org/D36130

Review comments updated accordingly

Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0

Added a TODO for sortLoadAccesses API

Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58

Modified the TODO for sortLoadAccesses API

Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565

Review comment update for using OpdNum to insert the mask in respective location

Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce

Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase

Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b
llvm-svn: 313771
2017-09-20 17:19:57 +00:00
Alexander Kornienko
694b27a0ce Revert r313736: "[SLP] Vectorize jumbled memory loads."
The revision breaks buildbots:
http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/6694/steps/test/logs/stdio

llvm-svn: 313758
2017-09-20 14:53:07 +00:00
Mohammad Shahid
33f617c7de [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh

Reviewed By: Ayal

Subscribers: mzolotukhin

Differential Revision: https://reviews.llvm.org/D36130

Commit after rebase for patch D36130

Change-Id: I8add1c265455669ef288d880f870a9522c8c08ab
llvm-svn: 313736
2017-09-20 08:18:28 +00:00
Adam Nemet
8d2be3fa7c Allow ORE.emit to take a closure to delay building the remark object
In the lambda we are now returning the remark by value so we need to preserve
its type in the insertion operator.  This requires making the insertion
operator generic.

I've also converted a few cases to use the new API.  It seems to work pretty
well.  See the LoopUnroller for a slightly more interesting case.

llvm-svn: 313691
2017-09-19 23:00:55 +00:00
Sanjay Patel
b7a2b50f6a [SLP] clean up for vector store case; NFCI
llvm-svn: 313541
2017-09-18 16:20:15 +00:00
Chandler Carruth
4a434efc2a [SLP] Revert r312791 and other necessary commits, except for TTI and
CostModel.

The original patch added support for horizontal min/max reductions to
the SLP vectorizer.

This patch causes LLVM to miscompile fairly simple signed min
reductions. I have attached a test progrom to http://llvm.org/PR34635
that shows the behavior change after this patch. We found this in a test
for the open source Eigen library, but also in other code.

Unfortunately, the revert is moderately challenging. It required
reverting:
r313042: [SLP] Test with multiple uses of conditional op and wrong parent.
r312853: [SLP] Fix buildbots, NFC.
r312793: [SLP] Fix the warning about paths not returning the value, NFC.
r312791: [SLP] Support for horizontal min/max reduction.

And even then, I had to completely skip reverting the changes to TTI and
CostModel because r312832 rewrote so much of this code. Plus, the cost
modeling changes aren implicated in the miscompile, so they should be
fine and will just not be used until this gets re-introduced.

llvm-svn: 313409
2017-09-15 22:23:27 +00:00
Vivek Pandya
dda17788af This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

llvm-svn: 313390
2017-09-15 20:10:09 +00:00
Vivek Pandya
d4e6d8ad49 This reverts r313381
llvm-svn: 313387
2017-09-15 19:53:54 +00:00
Vivek Pandya
8ef565859a This patch fixes https://bugs.llvm.org/show_bug.cgi?id=32352
It enables OptimizationRemarkEmitter::allowExtraAnalysis and MachineOptimizationRemarkEmitter::allowExtraAnalysis to return true not only for -fsave-optimization-record but when specific remarks are requested with
command line options.
The diagnostic handler used to be callback now this patch adds a class
DiagnosticHandler. It has virtual method to provide custom diagnostic handler
and methods to control which particular remarks are enabled. 
However LLVM-C API users can still provide callback function for diagnostic handler.

llvm-svn: 313382
2017-09-15 19:30:59 +00:00
Ilya Biryukov
51785ee0c4 Revert "[SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops."
This reverts commit r313348.

Reason: it caused buildbot failures.
llvm-svn: 313352
2017-09-15 10:15:00 +00:00
Dinar Temirbulatov
abd1b29772 [SLPVectorizer] Failure to beneficially vectorize 'copyable' elements in integer binary ops.
Patch tries to improve vectorization of the following code:

void add1(int * __restrict dst, const int * __restrict src) {
  *dst++ = *src++;
  *dst++ = *src++ + 1;
  *dst++ = *src++ + 2;
  *dst++ = *src++ + 3;
}
Allows to vectorize even if the very first operation is not a binary add, but just a load.

Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev, davide

Subscribers: llvm-commits, RKSimon

Differential Revision: https://reviews.llvm.org/D28907

llvm-svn: 313348
2017-09-15 06:56:39 +00:00
Dinar Temirbulatov
f74bdecbc6 [SLPVectorizer] Remove duplicated functionality code in initScheduleData function, NFCI.
llvm-svn: 313341
2017-09-15 04:31:54 +00:00
Alon Kom
f5b825ae49 [LV] Fix maximum legal VF calculation
This patch fixes pr34283, which exposed that the computation of
maximum legal width for vectorization was wrong, because it relied
on MaxInterleaveFactor to obtain the maximum stride used in the loop,
however not all strided accesses in the loop have an interleave-group
associated with them.
Instead of recording the maximum stride in the loop, which can be over
conservative (e.g. if the access with the maximum stride is not involved
in the dependence limitation), this patch tracks the actual maximum legal
width imposed by accesses that are involved in dependencies.

Differential Revision: https://reviews.llvm.org/D37507

llvm-svn: 313237
2017-09-14 07:40:02 +00:00
Dinar Temirbulatov
4f2a1f0cb0 [SLPVectorizer] Prefer auto over explicit type for VL0, NFCI.
llvm-svn: 313228
2017-09-14 04:28:35 +00:00
Anna Thomas
a8474917f4 [LV] Avoid computing the register usage for default VF. NFC
These are changes to reduce redundant computations when calculating a
feasible vectorization factor:
1. early return when target has no vector registers
2. don't compute register usage for the default VF.

Suggested during review for D37702.

llvm-svn: 313176
2017-09-13 19:35:45 +00:00
Ayal Zaks
303a302e55 [LV] Fix PR34523 - avoid generating redundant selects
When converting a PHI into a series of 'select' instructions to combine the
incoming values together according their edge masks, initialize the first
value to the incoming value In0 of the first predecessor, instead of
generating a redundant assignment 'select(Cond[0], In0, In0)'. The latter
fails when the Cond[0] mask is null, representing a full mask, which can
happen only when there's a single incoming value.

No functional changes intended nor expected other than surviving null Cond[0]'s.

This fix follows D35725, which introduced using null to represent full masks.

Differential Revision: https://reviews.llvm.org/D37619

llvm-svn: 313119
2017-09-13 06:28:37 +00:00
Anna Thomas
c739ce8170 [LV] Clamp the VF to the trip count
Summary:
When the MaxVectorSize > ConstantTripCount, we should just clamp the
vectorization factor to be the ConstantTripCount.
This vectorizes loops where the TinyTripCountThreshold >= TripCount < MaxVF.

Earlier we were finding the maximum vector width, which could be greater than
the trip count itself. The Loop vectorizer does all the work for generating a
vectorizable loop, but in the end we would always choose the scalar loop (since
the VF > trip count). This allows us to choose the VF keeping in mind the trip
count if available.

This is a fix on top of rL312472.

Reviewers: Ayal, zvi, hfinkel, dneilson

Reviewed by: Ayal

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D37702

llvm-svn: 313046
2017-09-12 16:32:45 +00:00
Alexey Bataev
521acd5aad [SLP] Fix for PHINode during horizontal reduction scanning, NFC.
Reduces number of loops during instructions analysis.

llvm-svn: 313035
2017-09-12 15:13:50 +00:00
Alexey Bataev
a8c33e3a37 [SLP] Fix buildbots, NFC.
llvm-svn: 312853
2017-09-09 02:08:45 +00:00
Dinar Temirbulatov
d6c1f050aa [SLPVectorizer] Add struct InstructionsState that holds information about analysis of vector to be vectorized.
Reviewers: spatel, mzolotukhin, mkuper, hfinkel, RKSimon, filcab, ABataev, davide

Subscribers: llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D37212

llvm-svn: 312802
2017-09-08 17:08:17 +00:00
Alexey Bataev
c263c4735c [SLP] Fix the warning about paths not returning the value, NFC.
llvm-svn: 312793
2017-09-08 14:32:20 +00:00
Alexey Bataev
182cf8e3c6 [SLP] Support for horizontal min/max reduction.
SLP vectorizer supports horizontal reductions for Add/FAdd binary
operations. Patch adds support for horizontal min/max reductions.
Function getReductionCost() is split to getArithmeticReductionCost() for
binary operation reductions and getMinMaxReductionCost() for min/max
reductions.
Patch fixes PR26956.

Differential revision: https://reviews.llvm.org/D27846

llvm-svn: 312791
2017-09-08 13:49:36 +00:00
Zvi Rackover
d91a5044bd LoopVectorize: MaxVF should not be larger than the loop trip count
Summary:
Improve how MaxVF is computed while taking into account that MaxVF should not be larger than the loop's trip count.

Other than saving on compile-time by pruning the possible MaxVF candidates, this patch fixes pr34438 which exposed the following flow:
1. Short trip count identified -> Don't bail out, set OptForSize:=True to avoid tail-loop and runtime checks.
2. Compute MaxVF returned 16 on a target supporting AVX512.
3. OptForSize -> choose VF:=MaxVF.
4. Bail out because TripCount = 8, VF = 16, TripCount % VF !=0 means we need a tail loop.

With this patch step 2. will choose MaxVF=8 based on TripCount.

Reviewers: Ayal, dorit, mkuper, hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, llvm-commits

Differential Revision: https://reviews.llvm.org/D37425

llvm-svn: 312472
2017-09-04 08:35:13 +00:00
Benjamin Kramer
3052672172 [LoopVectorize] Turn static DenseSet into switch.
LLVM transforms this into a bit test which is a lot faster and smaller.

llvm-svn: 312417
2017-09-02 16:41:55 +00:00
Eugene Zelenko
cbd8f32d28 [Analysis, Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 312383
2017-09-01 21:37:29 +00:00
Manoj Gupta
1bbda74bca [LoopVectorizer] Use two step casting for float to pointer types.
Summary:
LoopVectorizer is creating casts between vec<ptr> and vec<float> types
on ARM when compiling OpenCV. Since, tIs is illegal to directly cast a
floating point type to a pointer type even if the types have same size
causing a crash. Fix the crash using a two-step casting by bitcasting
to integer and integer to pointer/float.
Fixes PR33804.

Reviewers: mkuper, Ayal, dlj, rengolin, srhines

Reviewed By: rengolin

Subscribers: aemerson, kristof.beyls, mkazantsev, Meinersbur, rengolin, mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D35498

llvm-svn: 312331
2017-09-01 15:36:00 +00:00
Dinar Temirbulatov
727d1c6273 [SLPVectorizer] Move out Entry->NeedToGather check and assert of inner loop as invariant, NFCI.
llvm-svn: 312242
2017-08-31 14:10:07 +00:00
Sanjay Patel
4aeffc1bf9 [Instruction] add moveAfter() convenience function; NFCI
As suggested in D37121, here's a wrapper for removeFromParent() + insertAfter(),
but implemented using moveBefore() for symmetry/efficiency.

Differential Revision: https://reviews.llvm.org/D37239

llvm-svn: 312001
2017-08-29 14:07:48 +00:00
Ayal Zaks
995e9f83a6 [LV] Fix PR34248 - recommit D32871 after revert r311304
Original commit r311077 of D32871 was reverted in r311304 due to failures
reported in PR34248.

This recommit fixes PR34248 by restricting the packing of predicated scalars
into vectors only when vectorizing, avoiding doing so when unrolling w/o
vectorizing. Added a test derived from the reproducer of PR34248.

llvm-svn: 311849
2017-08-27 12:55:46 +00:00
Chandler Carruth
f802228b0f Revert r311077: [LV] Using VPlan ...
This causes LLVM to assert fail on PPC64 and crash / infloop in other
cases. Filed http://llvm.org/PR34248 with reproducer attached.

llvm-svn: 311304
2017-08-20 23:17:11 +00:00
Aditya Kumar
2eb341c166 [Loop Vectorize] Added a separate metadata
Added a separate metadata to indicate when the loop
has already been vectorized instead of setting width and count to 1.

Patch written by Divya Shanmughan and Aditya Kumar

Differential Revision: https://reviews.llvm.org/D36220

llvm-svn: 311281
2017-08-20 10:32:41 +00:00
Chandler Carruth
8d95cf5170 [SLP] Fix an unused variable warning in non-asserts builds.
llvm-svn: 311227
2017-08-19 05:06:23 +00:00
Dinar Temirbulatov
8641c659f9 [SLPVectorizer] Tighten up VLeft, VRight declaration, remove unnecessary testcase test/Transforms/SLPVectorizer/X86/reorder.ll, NFCI.
llvm-svn: 311223
2017-08-19 03:15:07 +00:00
Dinar Temirbulatov
58a3537457 [SLPVectorizer] Add opcode parameter to reorderAltShuffleOperands, reorderInputsAccordingToOpcode functions.
Reviewers: mkuper, RKSimon, ABataev, mzolotukhin, spatel, filcab

Subscribers: llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D36766

llvm-svn: 311221
2017-08-19 02:54:20 +00:00
Ayal Zaks
89896f022f [LV] Using VPlan to model the vectorized code and drive its transformation
VPlan is an ongoing effort to refactor and extend the Loop Vectorizer. This
patch introduces the VPlan model into LV and uses it to represent the vectorized
code and drive the generation of vectorized IR.

In this patch VPlan models the vectorized loop body: the vectorized control-flow
is represented using VPlan's Hierarchical CFG, with predication refactored from
being a post-vectorization-step into a vectorization planning step modeling
if-then VPRegionBlocks, and generating code inline with non-predicated code. The
vectorized code within each VPBasicBlock is represented as a sequence of
Recipes, each responsible for modelling and generating a sequence of IR
instructions. To keep the size of this commit manageable the Recipes in this
patch are coarse-grained and capture large chunks of LV's code-generation logic.
The constructed VPlans are dumped in dot format under -debug.

This commit retains current vectorizer output, except for minor instruction
reorderings; see associated modifications to lit tests.

For further details on the VPlan model see docs/Proposals/VectorizationPlan.rst
and its references.

Authors: Gil Rapaport and Ayal Zaks

Differential Revision: https://reviews.llvm.org/D32871

llvm-svn: 311077
2017-08-17 09:29:59 +00:00
Rui Ueyama
aaf73b4bf2 Fix -Wunused-lambda-capture for Release build.
`I` and `this` are used only in assert or DEBUG, so they are unused
in Release build.

llvm-svn: 310934
2017-08-15 17:39:35 +00:00
Ayal Zaks
43ce19524f [LV] Minor savings to Sink casts to unravel first order recurrence
Two minor savings: avoid copying the SinkAfter map and avoid moving a cast if it
is not needed.

Differential Revision: https://reviews.llvm.org/D36408

llvm-svn: 310910
2017-08-15 08:32:59 +00:00
Dinar Temirbulatov
4f1e6897ea [SLPVectorizer] Replace VL[0] to VL0 with assert, add propagateIRFlags extra parameter VL0,
replace E->Scalars[0] to VL0, NFCI.

llvm-svn: 310904
2017-08-15 00:31:49 +00:00
Dinar Temirbulatov
17df27f960 [SLPVectorizer] Schedule bundle with different opcodes.
This change let us schedule a bundle with different opcodes in it, for example : [ load, add, add, add ]

Reviewers: mkuper, RKSimon, ABataev, mzolotukhin, spatel, filcab

Subscribers: llvm-commits, rengolin

Differential Revision: https://reviews.llvm.org/D36518

llvm-svn: 310847
2017-08-14 15:40:16 +00:00
Anna Thomas
ce71877c5e [LoopVectorize] Fix assertion failure in Fcmp vectorization
Summary:
When vectorizing fcmps we can trip on incorrect cast assertion when setting the
FastMathFlags after generating the vectorized FCmp.
This can happen if the FCmp can be folded to true or false directly. The fix
here is to set the FastMathFlag using the FastMathFlagBuilder *before* creating
the FCmp Instruction. This is what's done by other optimizations such as
InstCombine.
Added a test case which trips on cast assertion without this patch.

Reviewers: Ayal, mssimpso, mkuper, gilr

Reviewed by: Ayal, mssimpso

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D36244

llvm-svn: 310389
2017-08-08 18:07:44 +00:00
Alexey Bataev
9f19665894 [SLP] General improvements of SLP vectorization process.
Patch tries to improve two-pass vectorization analysis, existing in SLP vectorizer. What it does:

1. Defines key nodes, that are the vectorization roots. Previously vectorization started if StoreInst or ReturnInst is found. For now, the vectorization started for all Instructions with no users and void types (Terminators, StoreInst) + CallInsts.
2. CmpInsts, InsertElementInsts and InsertValueInsts are stored in the
array. This array is processed only after the vectorization of the
first-after-these instructions key node is finished. Vectorization goes
in reverse order to try to vectorize as much code as possible.

Reviewers: mzolotukhin, Ayal, mkuper, gilr, hfinkel, RKSimon

Subscribers: ashahid, anemet, RKSimon, mssimpso, llvm-commits

Differential Revision: https://reviews.llvm.org/D29826

llvm-svn: 310260
2017-08-07 15:25:49 +00:00
Alexey Bataev
92afaf2479 Revert "[SLP] General improvements of SLP vectorization process."
This reverts commit r310255.

llvm-svn: 310257
2017-08-07 14:51:52 +00:00
Alexey Bataev
ec62fc0fc9 [SLP] General improvements of SLP vectorization process.
Summary:
Patch tries to improve two-pass vectorization analysis, existing in SLP vectorizer. What it does:
1. Defines key nodes, that are the vectorization roots. Previously vectorization started if StoreInst or ReturnInst is found. For now, the vectorization started for all Instructions with no users and void types (Terminators, StoreInst) + CallInsts.
2. CmpInsts, InsertElementInsts and InsertValueInsts are stored in the array. This array is processed only after the vectorization of the first-after-these instructions key node is finished. Vectorization goes in reverse order to try to vectorize as much code as possible.

Reviewers: mzolotukhin, Ayal, mkuper, gilr, hfinkel, RKSimon

Subscribers: ashahid, anemet, RKSimon, mssimpso, llvm-commits

Differential Revision: https://reviews.llvm.org/D29826

llvm-svn: 310255
2017-08-07 14:03:17 +00:00
Dinar Temirbulatov
a7733cfe8c [SLPVectorizer] Add extra parameter to setInsertPointAfterBundle to handle different opcodes, NFCI.
Differential Revision: https://reviews.llvm.org/D35769

llvm-svn: 310183
2017-08-05 18:43:52 +00:00
Matt Arsenault
3207fbe899 LV: Don't insert runtime ptr checks on divergent targets
llvm-svn: 309890
2017-08-02 21:43:08 +00:00
Alexey Bataev
6c386e33ac [SLPVectorizer] Generalize interface of functions, NFC.
llvm-svn: 309816
2017-08-02 14:38:07 +00:00
Alexey Bataev
abac065cef [SLP] Fix for PR31880: shuffle and vectorize repeated scalar ops on extracted elements
Summary:
Currently most of the time vectors of extractelement instructions are
treated as scalars that must be gathered into vectors. But in some
cases, like when we have extractelement instructions from single vector
with different constant indeces or from 2 vectors of the same size, we
can treat this operations as shuffle of a single vector or blending of 2
vectors.
```
define <2 x i8> @g(<2 x i8> %x, <2 x i8> %y) {
  %x0 = extractelement <2 x i8> %x, i32 0
  %y1 = extractelement <2 x i8> %y, i32 1
  %x0x0 = mul i8 %x0, %x0
  %y1y1 = mul i8 %y1, %y1
  %ins1 = insertelement <2 x i8> undef, i8 %x0x0, i32 0
  %ins2 = insertelement <2 x i8> %ins1, i8 %y1y1, i32 1
  ret <2 x i8> %ins2
}
```
can be converted to something like
```
define <2 x i8> @g(<2 x i8> %x, <2 x i8> %y) {
  %1 = shufflevector <2 x i8> %x, <2 x i8> %y, <2 x i32> <i32 0, i32 3>
  %2 = mul <2 x i8> %1, %1
  ret <2 x i8> %2
}
```
Currently this type of conversion is considered as high cost
transformation.

Reviewers: mzolotukhin, delena, mkuper, hfinkel, RKSimon

Subscribers: ashahid, RKSimon, spatel, llvm-commits

Differential Revision: https://reviews.llvm.org/D30200

llvm-svn: 309812
2017-08-02 13:25:26 +00:00
Davide Italiano
3c9ab0171a [SLPVectorizer] Unbreak the build with -Werror.
GCC was complaining about `&&` within `||` without explicit
parentheses. NFCI.

llvm-svn: 309606
2017-07-31 19:14:19 +00:00
Alexey Bataev
2aa430ee58 [SLP] Initial rework for min/max horizontal reduction vectorization, NFC.
Summary: All getReductionCost() functions are renamed to getArithmeticReductionCost() + added basic infrastructure to handle non-binary reduction operations.

Reviewers: spatel, mzolotukhin, Ayal, mkuper, gilr, hfinkel

Subscribers: RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D29402

llvm-svn: 309566
2017-07-31 14:36:05 +00:00
Alexey Bataev
55309303be [Cost] Rename getReductionCost() to getArithmeticReductionCost(), NFC.
llvm-svn: 309563
2017-07-31 14:19:32 +00:00
Ayal Zaks
dca1c68e5c [LV] Avoid redundant operations manipulating masks
The Loop Vectorizer generates redundant operations when manipulating masks:
AND with true, OR with false, compare equal to true. Instead of relying on
a subsequent pass to clean them up, this patch avoids generating them.

Use null (no-mask) to represent all-one full masks, instead of a constant
all-one vector, following the convention of masked gathers and scatters.

Preparing for a follow-up VPlan patch in which these mask manipulating
operations are modeled using recipes.

Differential Revision: https://reviews.llvm.org/D35725

llvm-svn: 309558
2017-07-31 13:21:42 +00:00
Alexey Bataev
078766df94 [SLP] Allow vectorization of the instruction from the same basic blocks only, NFC.
Summary:
After some changes in SLP vectorizer we missed some additional checks to
limit the instructions for vectorization. We should not perform analysis
of the instructions if the parent of instruction is not the same as the
parent of the first instruction in the tree or it was analyzed already.

Subscribers: mzolotukhin

Differential Revision: https://reviews.llvm.org/D34881

llvm-svn: 309425
2017-07-28 20:11:16 +00:00
Alexey Bataev
a5b418f4ae [SLP] Outline code for the check that instruction users are part of
vectorization tree, NFC.

llvm-svn: 309284
2017-07-27 15:48:44 +00:00
Dinar Temirbulatov
50b5e7be49 [SLPVectorizer] Replace E->Scalars to VL0 at vectorizeTree and move comment, NFCI.
llvm-svn: 308750
2017-07-21 16:02:56 +00:00
Dinar Temirbulatov
27a9d21730 [SLPVectorizer] buildTree_rec replace cast<Instruction>(VL[0]) to VL0, NFCI.
llvm-svn: 308745
2017-07-21 15:31:54 +00:00
Dinar Temirbulatov
030b7675c5 [SLPVectorizer] Change canReuseExtract function parameter Opcode from unsigned to Value *, NFCI.
llvm-svn: 308739
2017-07-21 13:32:36 +00:00
Ayal Zaks
fd3659df66 [LV] Test once if vector trip count is zero, instead of twice
Generate a single test to decide if there are enough iterations to jump to the
vectorized loop, or else go to the scalar remainder loop. This test compares the
Scalar Trip Count: if STC < VF * UF go to the scalar loop. If
requiresScalarEpilogue() holds, at-least one iteration must remain scalar; the
rest can be used to form vector iterations. So in this case the test checks
instead if (STC - 1) < VF * UF by comparing STC <= VF * UF, and going to the
scalar loop if so. Otherwise the vector loop is entered for at-least one vector
iteration.

This test covers the case where incrementing the backedge-taken count will
overflow leading to an incorrect trip count of zero. In this (rare) case we will
also avoid the vector loop and jump to the scalar loop.

This patch simplifies the existing tests and effectively removes the basic-block
originally named "min.iters.checked", leaving the single test in block
"vector.ph".

Original observation and initial patch by Evgeny Stupachenko.

Differential Revision: https://reviews.llvm.org/D34150

llvm-svn: 308421
2017-07-19 05:16:39 +00:00
Simon Pilgrim
994cf2550f Remove unnecessary cast. NFCI.
llvm-svn: 308166
2017-07-17 09:35:03 +00:00
Dinar Temirbulatov
1f7aa2cc6e [SLPVectorizer] Add an extra parameter to tryScheduleBundle function, NFCI.
llvm-svn: 308081
2017-07-15 05:43:54 +00:00
Dinar Temirbulatov
0919126046 [SLPVectorizer] Add an extra parameter to alreadyVectorized function, NFCI.
llvm-svn: 307996
2017-07-14 03:48:29 +00:00
Michael Kuperstein
2652e56b42 [LV] Don't allow outside uses of IVs if the SCEV is predicated on loop conditions.
This fixes PR33706.
Differential Revision: https://reviews.llvm.org/D35227

llvm-svn: 307837
2017-07-12 19:53:55 +00:00
Dinar Temirbulatov
bfdd0d2eb7 [SLPVectorizer] Revert change in cancelScheduling with referencing to FirstInBundle, NFCI.
llvm-svn: 307667
2017-07-11 15:54:50 +00:00
Dinar Temirbulatov
181c4e6396 [SLPVectorizer] Add an extra parameter to cancelScheduling function, NFCI.
llvm-svn: 307158
2017-07-05 13:53:03 +00:00
Teresa Johnson
5eaedef8eb Revert "r306473 - re-commit r306336: Enable vectorizer-maximize-bandwidth by default."
This still breaks PPC tests we have. I'll forward reproduction
instructions to dehao.

llvm-svn: 306936
2017-07-01 03:24:09 +00:00
Teresa Johnson
b943e549e8 re-commit r306336: Enable vectorizer-maximize-bandwidth by default.
Differential Revision: https://reviews.llvm.org/D33341

llvm-svn: 306935
2017-07-01 03:24:08 +00:00
Teresa Johnson
1221ff2f21 revert r306336 for breaking ppc test.
llvm-svn: 306934
2017-07-01 03:24:07 +00:00
Teresa Johnson
283d2c83b2 Enable vectorizer-maximize-bandwidth by default.
Summary:
vectorizer-maximize-bandwidth is generally useful in terms of performance. I've tested the impact of changing this to default on speccpu benchmarks on sandybridge machines. The result shows non-negative impact:

spec/2006/fp/C++/444.namd                 26.84  -0.31%
spec/2006/fp/C++/447.dealII               46.19  +0.89%
spec/2006/fp/C++/450.soplex               42.92  -0.44%
spec/2006/fp/C++/453.povray               38.57  -2.25%
spec/2006/fp/C/433.milc                   24.54  -0.76%
spec/2006/fp/C/470.lbm                    41.08  +0.26%
spec/2006/fp/C/482.sphinx3                47.58  -0.99%
spec/2006/int/C++/471.omnetpp             22.06  +1.87%
spec/2006/int/C++/473.astar               22.65  -0.12%
spec/2006/int/C++/483.xalancbmk           33.69  +4.97%
spec/2006/int/C/400.perlbench             33.43  +1.70%
spec/2006/int/C/401.bzip2                 23.02  -0.19%
spec/2006/int/C/403.gcc                   32.57  -0.43%
spec/2006/int/C/429.mcf                   40.35  +0.27%
spec/2006/int/C/445.gobmk                 26.96  +0.06%
spec/2006/int/C/456.hmmer                  24.4  +0.19%
spec/2006/int/C/458.sjeng                 27.91  -0.08%
spec/2006/int/C/462.libquantum            57.47  -0.20%
spec/2006/int/C/464.h264ref               46.52  +1.35%

geometric mean                                   +0.29%

The regression on 453.povray seems real, but is due to secondary effects as all hot functions are bit-identical with and without the flag.

I started this patch to consult upstream opinions on this. It will be greatly appreciated if the community can help test the performance impact of this change on other architectures so that we can decided if this should be target-dependent.

Reviewers: hfinkel, mkuper, davidxl, chandlerc

Reviewed By: chandlerc

Subscribers: rengolin, sanjoy, javed.absar, bjope, dorit, magabari, RKSimon, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D33341

llvm-svn: 306933
2017-07-01 03:24:06 +00:00
Dinar Temirbulatov
885eda0f81 [SLPVectorizer] Add isOdd() helper function, NFCI.
llvm-svn: 306887
2017-06-30 21:16:26 +00:00
Ayal Zaks
68a67b24b0 [LV] Sink casts to unravel first order recurrence
Check if a single cast is preventing handling a first-order-recurrence Phi,
because the scheduling constraints it imposes on the first-order-recurrence
shuffle are infeasible; but they can be made feasible by moving the cast
downwards. Record such casts and move them when vectorizing the loop.

Differential Revision: https://reviews.llvm.org/D33058

llvm-svn: 306884
2017-06-30 21:05:06 +00:00
Ayal Zaks
fbea2e7ae6 [LV] Optimize for size when vectorizing loops with tiny trip count
It may be detrimental to vectorize loops with very small trip count, as various
costs of the vectorized loop body as well as enclosing overheads including
runtime tests and scalar iterations may outweigh the gains of vectorizing. The
current cost model measures the cost of the vectorized loop body only, expecting
it will amortize other costs, and loops with known or expected very small trip
counts are not vectorized at all. This patch allows loops with very small trip
counts to be vectorized, but under OptForSize constraints, which ensure the cost
of the loop body is dominant, having no runtime guards nor scalar iterations.

Patch inspired by D32451.

Differential Revision: https://reviews.llvm.org/D34373

llvm-svn: 306803
2017-06-30 08:02:35 +00:00
Chandler Carruth
cd49bfab29 Remove the BBVectorize pass.
It served us well, helped kick-start much of the vectorization efforts
in LLVM, etc. Its time has come and past. Back in 2014:
http://lists.llvm.org/pipermail/llvm-dev/2014-November/079091.html

Time to actually let go and move forward. =]

I've updated the release notes both about the removal and the
deprecation of the corresponding C API.

llvm-svn: 306797
2017-06-30 07:09:08 +00:00
Daniel Jasper
27e8037308 Revert "r306473 - re-commit r306336: Enable vectorizer-maximize-bandwidth by default."
This still breaks PPC tests we have. I'll forward reproduction
instructions to dehao.

llvm-svn: 306792
2017-06-30 06:32:21 +00:00
Dinar Temirbulatov
27e2999beb [SLPVectorizer] Moving Entry->NeedToGather check out of inner loop,
since it is invariant there. NFCI.

llvm-svn: 306749
2017-06-29 21:56:33 +00:00
Dinar Temirbulatov
93e49735f5 [SLPVectorizer] Introducing getTreeEntry() helper function [NFC]
Differential Revision: https://reviews.llvm.org/D34756

llvm-svn: 306655
2017-06-29 08:46:18 +00:00
Ayal Zaks
10c351befb [LV] Fix PR33613 - retain order of insertelement per part
r306381 caused PR33613, by reversing the order in which insertelements were
generated per unroll part. This patch fixes PR33613 by retraining this order,
placing each set of insertelements per part immediately after the last scalar
being packed for this part. Includes a test case derived from PR33613.

Reference: https://bugs.llvm.org/show_bug.cgi?id=33613
Differential Revision: https://reviews.llvm.org/D34760

llvm-svn: 306575
2017-06-28 17:59:33 +00:00
Dehao Chen
482aa8cd57 re-commit r306336: Enable vectorizer-maximize-bandwidth by default.
Differential Revision: https://reviews.llvm.org/D33341

llvm-svn: 306473
2017-06-27 22:05:58 +00:00
Ayal Zaks
af4e296f51 Recommitting 306331.
Undoing revert 306338 after fixed bug: add metadata to the load instead of the
reverse shuffle added to it, retaining the original ValueMap implementation.

llvm-svn: 306381
2017-06-27 08:41:19 +00:00
Dehao Chen
57e415b733 revert r306336 for breaking ppc test.
llvm-svn: 306344
2017-06-26 23:05:35 +00:00
Ayal Zaks
45e68f8b0a reverting 306331.
Causes TBAA metadata to be generates on reverse shuffles, investigating.

llvm-svn: 306338
2017-06-26 22:26:54 +00:00
Dehao Chen
f2ec2d4e8b Enable vectorizer-maximize-bandwidth by default.
Summary:
vectorizer-maximize-bandwidth is generally useful in terms of performance. I've tested the impact of changing this to default on speccpu benchmarks on sandybridge machines. The result shows non-negative impact:

spec/2006/fp/C++/444.namd                 26.84  -0.31%
spec/2006/fp/C++/447.dealII               46.19  +0.89%
spec/2006/fp/C++/450.soplex               42.92  -0.44%
spec/2006/fp/C++/453.povray               38.57  -2.25%
spec/2006/fp/C/433.milc                   24.54  -0.76%
spec/2006/fp/C/470.lbm                    41.08  +0.26%
spec/2006/fp/C/482.sphinx3                47.58  -0.99%
spec/2006/int/C++/471.omnetpp             22.06  +1.87%
spec/2006/int/C++/473.astar               22.65  -0.12%
spec/2006/int/C++/483.xalancbmk           33.69  +4.97%
spec/2006/int/C/400.perlbench             33.43  +1.70%
spec/2006/int/C/401.bzip2                 23.02  -0.19%
spec/2006/int/C/403.gcc                   32.57  -0.43%
spec/2006/int/C/429.mcf                   40.35  +0.27%
spec/2006/int/C/445.gobmk                 26.96  +0.06%
spec/2006/int/C/456.hmmer                  24.4  +0.19%
spec/2006/int/C/458.sjeng                 27.91  -0.08%
spec/2006/int/C/462.libquantum            57.47  -0.20%
spec/2006/int/C/464.h264ref               46.52  +1.35%

geometric mean                                   +0.29%

The regression on 453.povray seems real, but is due to secondary effects as all hot functions are bit-identical with and without the flag.

I started this patch to consult upstream opinions on this. It will be greatly appreciated if the community can help test the performance impact of this change on other architectures so that we can decided if this should be target-dependent.

Reviewers: hfinkel, mkuper, davidxl, chandlerc

Reviewed By: chandlerc

Subscribers: rengolin, sanjoy, javed.absar, bjope, dorit, magabari, RKSimon, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D33341

llvm-svn: 306336
2017-06-26 21:41:09 +00:00
Ayal Zaks
b5aa1c975d [LV] Changing the interface of ValueMap, NFC.
Instead of providing access to the internal MapStorage holding all Values
associated with a given Key, used for setting or resetting them all together,
ValueMap keeps its MapStorage internal; its new interface allows getting,
setting or resetting a single Value, per part or per part-and-lane.
Follows the discussion in https://reviews.llvm.org/D32871.

Differential Revision: https://reviews.llvm.org/D34473

llvm-svn: 306331
2017-06-26 21:03:51 +00:00
Diana Picus
3f190b5619 Revert "Enable vectorizer-maximize-bandwidth by default."
This reverts commit r305960 because it broke self-hosting on AArch64.

llvm-svn: 305990
2017-06-22 10:00:28 +00:00
Dehao Chen
94af335d3b Enable vectorizer-maximize-bandwidth by default.
Summary:
vectorizer-maximize-bandwidth is generally useful in terms of performance. I've tested the impact of changing this to default on speccpu benchmarks on sandybridge machines. The result shows non-negative impact:

spec/2006/fp/C++/444.namd                 26.84  -0.31%
spec/2006/fp/C++/447.dealII               46.19  +0.89%
spec/2006/fp/C++/450.soplex               42.92  -0.44%
spec/2006/fp/C++/453.povray               38.57  -2.25%
spec/2006/fp/C/433.milc                   24.54  -0.76%
spec/2006/fp/C/470.lbm                    41.08  +0.26%
spec/2006/fp/C/482.sphinx3                47.58  -0.99%
spec/2006/int/C++/471.omnetpp             22.06  +1.87%
spec/2006/int/C++/473.astar               22.65  -0.12%
spec/2006/int/C++/483.xalancbmk           33.69  +4.97%
spec/2006/int/C/400.perlbench             33.43  +1.70%
spec/2006/int/C/401.bzip2                 23.02  -0.19%
spec/2006/int/C/403.gcc                   32.57  -0.43%
spec/2006/int/C/429.mcf                   40.35  +0.27%
spec/2006/int/C/445.gobmk                 26.96  +0.06%
spec/2006/int/C/456.hmmer                  24.4  +0.19%
spec/2006/int/C/458.sjeng                 27.91  -0.08%
spec/2006/int/C/462.libquantum            57.47  -0.20%
spec/2006/int/C/464.h264ref               46.52  +1.35%

geometric mean                                   +0.29%

The regression on 453.povray seems real, but is due to secondary effects as all hot functions are bit-identical with and without the flag.

I started this patch to consult upstream opinions on this. It will be greatly appreciated if the community can help test the performance impact of this change on other architectures so that we can decided if this should be target-dependent.

Reviewers: hfinkel, mkuper, davidxl, chandlerc

Reviewed By: chandlerc

Subscribers: rengolin, sanjoy, javed.absar, bjope, dorit, magabari, RKSimon, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D33341

llvm-svn: 305960
2017-06-21 22:01:32 +00:00
Taewook Oh
4440ca5fab Improve profile-guided heuristics to use estimated trip count.
Summary:
Existing heuristic uses the ratio between the function entry
frequency and the loop invocation frequency to find cold loops. However,
even if the loop executes frequently, if it has a small trip count per
each invocation, vectorization is not beneficial. On the other hand,
even if the loop invocation frequency is much smaller than the function
invocation frequency, if the trip count is high it is still beneficial
to vectorize the loop.

This patch uses estimated trip count computed from the profile metadata
as a primary metric to determine coldness of the loop. If the estimated
trip count cannot be computed, it falls back to the original heuristics.

Reviewers: Ayal, mssimpso, mkuper, danielcdh, wmi, tejohnson

Reviewed By: tejohnson

Subscribers: tejohnson, mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32451

llvm-svn: 305729
2017-06-19 18:48:58 +00:00
Dinar Temirbulatov
5ad6ab329c Remove brackets, NFC.
llvm-svn: 305706
2017-06-19 16:44:07 +00:00
George Burgess IV
5cb9a3f362 [LoopVectorize] Don't preserve nsw/nuw flags on shrunken ops.
If we're shrinking a binary operation, it may be the case that the new
operations wraps where the old didn't. If this happens, the behavior
should be well-defined. So, we can't always carry wrapping flags with us
when we shrink operations.

If we do, we get incorrect optimizations in cases like:

void foo(const unsigned char *from, unsigned char *to, int n) {
  for (int i = 0; i < n; i++)
    to[i] = from[i] - 128;
}

which gets optimized to:

void foo(const unsigned char *from, unsigned char *to, int n) {
  for (int i = 0; i < n; i++)
    to[i] = from[i] | 128;
}

Because:
- InstCombine turned `sub i32 %from.i, 128` into
  `add nuw nsw i32 %from.i, 128`.
- LoopVectorize vectorized the add to be `add nuw nsw <16 x i8>` with a
  vector full of `i8 128`s
- InstCombine took advantage of the fact that the newly-shrunken add
  "couldn't wrap", and changed the `add` to an `or`.

InstCombine seems happy to figure out whether we can add nuw/nsw on its
own, so I just decided to drop the flags. There are already a number of
places in LoopVectorize where we rely on InstCombine to clean up.

llvm-svn: 305053
2017-06-09 03:56:15 +00:00
Chandler Carruth
eb66b33867 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Ayal Zaks
89dc822b95 [LV] Make scalarizeInstruction() non-virtual. NFC.
Following the request made in https://reviews.llvm.org/D32871,
scalarizeInstruction() which is no longer overridden by InnerLoopUnroller is
hereby made non-virtual in InnerLoopVectorizer.

Should have been part of r297580 originally.

llvm-svn: 304685
2017-06-04 13:29:51 +00:00
Galina Kistanova
870ed0ecd4 Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.
llvm-svn: 304636
2017-06-03 05:18:46 +00:00
Alexey Bataev
2af32a5c46 [SLP] Improve comments and naming of functions/variables/members, NFC.
Fixed some comments, added an additional description of the algorithms,
improved readability of the code.

Differential revision: https://reviews.llvm.org/D33320

llvm-svn: 304616
2017-06-03 00:08:21 +00:00
Alexey Bataev
3c03fadd49 Revert "[SLP] Improve comments and naming of functions/variables/members, NFC."
This reverts commit 6e311de8b907aa20da9a1a13ab07c3ce2ef4068a.

llvm-svn: 304609
2017-06-02 23:09:15 +00:00
Alexey Bataev
a1a5c4aa73 [SLP] Improve comments and naming of functions/variables/members, NFC.
Summary:
Fixed some comments, added an additional description of the algorithms,
improved readability of the code.

Reviewers: anemet

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D33320

llvm-svn: 304593
2017-06-02 20:39:27 +00:00
Matthew Simpson
4dac882c99 [LV] Reapply r303763 with fix for PR33193
r303763 caused build failures in some out-of-tree tests due to an assertion in
TTI. The original patch updated cost estimates for induction variable update
instructions marked for scalarization. However, it didn't consider that the
incoming value of an induction variable phi node could be a cast instruction.
This caused queries for cast instruction costs with a mix of vector and scalar
types. This patch includes a fix for cast instructions and the test case from
PR33193.

The fix was suggested by Jonas Paulsson <paulsson@linux.vnet.ibm.com>.

Reference: https://bugs.llvm.org/show_bug.cgi?id=33193
Original Differential Revision: https://reviews.llvm.org/D33457

llvm-svn: 304235
2017-05-30 19:55:57 +00:00
Joerg Sonnenberger
037031dde3 Revert r303763, results in asserts i.e. while building Ruby.
llvm-svn: 304179
2017-05-29 22:52:17 +00:00
Matthew Simpson
fb2142e95d [LV] Update type in cost model for scalarization
For non-uniform instructions marked for scalarization, we should update
`VectorTy` when computing instruction costs to reflect the scalar type. In
addition to determining instruction costs, this type is also used to signal
that all instructions in the loop will be scalarized. This currently affects
memory instructions and non-pointer induction variables and their updates. (We
also mark GEPs scalar after vectorization, but their cost is computed together
with memory instructions.) For scalarized induction updates, this patch also
scales the scalar cost by the vectorization factor, corresponding to each
induction step.

llvm-svn: 303763
2017-05-24 15:26:15 +00:00
Jonas Paulsson
0437145b47 [LoopVectorizer] Let target prefer scalar addressing computations.
The loop vectorizer usually vectorizes any instruction it can and then
extracts the elements for a scalarized use. On SystemZ, all elements
containing addresses must be extracted into address registers (GRs). Since
this extraction is not free, it is better to have the address in a suitable
register to begin with. By forcing address arithmetic instructions and loads
of addresses to be scalar after vectorization, two benefits result:

* No need to extract the register
* LSR optimizations trigger (LSR isn't handling vector addresses currently)

Benchmarking show improvements on SystemZ with this new behaviour.

Any other target could try this by returning false in the new hook
prefersVectorizedAddressing().

Review: Renato Golin, Elena Demikhovsky, Ulrich Weigand
https://reviews.llvm.org/D32422

llvm-svn: 303744
2017-05-24 13:42:56 +00:00
Ayal Zaks
08b77c4665 [LV] Report multiple reasons for not vectorizing under allowExtraAnalysis
The default behavior of -Rpass-analysis=loop-vectorizer is to report only the
first reason encountered for not vectorizing, if one is found, at which time the
vectorizer aborts its handling of the loop. This patch allows multiple reasons
for not vectorizing to be identified and reported, at the potential expense of
additional compile-time, under allowExtraAnalysis which can currently be turned
on by Clang's -fsave-optimization-record and opt's -pass-remarks-missed.

Removed from LoopVectorizationLegality::canVectorize() the redundant checking
and reporting if we CantComputeNumberOfIterations, as LAI::canAnalyzeLoop() also
does that. This redundancy is caught by a lit test once multiple reasons are
reported.

Patch initially developed by Dror Barak.

Differential Revision: https://reviews.llvm.org/D33396

llvm-svn: 303613
2017-05-23 07:08:02 +00:00
Amara Emerson
7af0aadc40 Fix vector pass-through value being unused in IRBuilder::CreateMaskedGather
Also s/0/nullptr in the call site in LV.

llvm-svn: 303416
2017-05-19 10:40:18 +00:00
Reid Kleckner
73e1a13fdc [IR] De-virtualize ~Value to save a vptr
Summary:
Implements PR889

Removing the virtual table pointer from Value saves 1% of RSS when doing
LTO of llc on Linux. The impact on time was positive, but too noisy to
conclusively say that performance improved. Here is a link to the
spreadsheet with the original data:

https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing

This change makes it invalid to directly delete a Value, User, or
Instruction pointer. Instead, such code can be rewritten to a null check
and a call Value::deleteValue(). Value objects tend to have their
lifetimes managed through iplist, so for the most part, this isn't a big
deal.  However, there are some places where LLVM deletes values, and
those places had to be migrated to deleteValue.  I have also created
llvm::unique_value, which has a custom deleter, so it can be used in
place of std::unique_ptr<Value>.

I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which
derives from User outside of lib/IR. Code in IR cannot include MemorySSA
headers or call the MemoryAccess object destructors without introducing
a circular dependency, so we need some level of indirection.
Unfortunately, no class derived from User may have any virtual methods,
because adding a virtual method would break User::getHungOffOperands(),
which assumes that it can find the use list immediately prior to the
User object. I've added a static_assert to the appropriate OperandTraits
templates to help people avoid this trap.

Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv

Reviewed By: chandlerc

Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D31261

llvm-svn: 303362
2017-05-18 17:24:10 +00:00
Matthew Simpson
be5fce863d Revert 303174, 303176, and 303178
These commits are breaking the bots. Reverting to investigate.

llvm-svn: 303182
2017-05-16 15:50:30 +00:00
Matthew Simpson
fdeda43e2f [LV] Avoid potentential division by zero when selecting IC
llvm-svn: 303174
2017-05-16 14:43:55 +00:00
Adam Nemet
f9607f0660 [SLP] Enable 64-bit wide vectorization on AArch64
ARM Neon has native support for half-sized vector registers (64 bits).  This
is beneficial for example for 2D and 3D graphics.  This patch adds the option
to lower MinVecRegSize from 128 via a TTI in the SLP Vectorizer.

*** Performance Analysis

This change was motivated by some internal benchmarks but it is also
beneficial on SPEC and the LLVM testsuite.

The results are with -O3 and PGO.  A negative percentage is an improvement.
The testsuite was run with a sample size of 4.

** SPEC

* CFP2006/482.sphinx3  -3.34%

A pretty hot loop is SLP vectorized resulting in nice instruction reduction.
This used to be a +22% regression before rL299482.

* CFP2000/177.mesa     -3.34%
* CINT2000/256.bzip2   +6.97%

My current plan is to extend the fix in rL299482 to i16 which brings the
regression down to +2.5%.  There are also other problems with the codegen in
this loop so there is further room for improvement.

** LLVM testsuite

* SingleSource/Benchmarks/Misc/ReedSolomon               -10.75%

There are multiple small SLP vectorizations outside the hot code.  It's a bit
surprising that it adds up to 10%.  Some of this may be code-layout noise.

* MultiSource/Benchmarks/VersaBench/beamformer/beamformer -8.40%

The opt-viewer screenshot can be seen at F3218284.  We start at a colder store
but the tree leads us into the hottest loop.

* MultiSource/Applications/lambda-0.1.3/lambda            -2.68%
* MultiSource/Benchmarks/Bullet/bullet                    -2.18%

This is using 3D vectors.

* SingleSource/Benchmarks/Shootout-C++/Shootout-C++-lists +6.67%

Noise, binary is unchanged.

* MultiSource/Benchmarks/Ptrdist/anagram/anagram          +4.90%

There is an additional SLP in the cold code.  The test runs for ~1sec and
prints out over 2000 lines. This is most likely noise.

* MultiSource/Applications/aha/aha                        +1.63%
* MultiSource/Applications/JM/lencod/lencod               +1.41%
* SingleSource/Benchmarks/Misc/richards_benchmark         +1.15%

Differential Revision: https://reviews.llvm.org/D31965

llvm-svn: 303116
2017-05-15 21:15:01 +00:00
Craig Topper
be2ad5e5e7 [ValueTracking] Replace all uses of ComputeSignBit with computeKnownBits.
This patch finishes off the conversion of ComputeSignBit to computeKnownBits.

Differential Revision: https://reviews.llvm.org/D33166

llvm-svn: 303035
2017-05-15 06:39:41 +00:00
Simon Pilgrim
288ebc9253 [LoopOptimizer][Fix]PR32859, PR24738
The Loop vectorizer pass introduced undef value while it is fixing output of LCSSA form.
Here it is:

before: %e.0.ph = phi i32 [ 0, %for.inc.2.i ]
after: %e.0.ph = phi i32 [ 0, %for.inc.2.i ], [ undef, %middle.block ]

and after this change we have:

%e.0.ph = phi i32 [ 0, %for.inc.2.i ]
%e.0.ph = phi i32 [ 0, %for.inc.2.i ], [ 0, %middle.block ]

Committed on behalf of @dtemirbulatov

Differential Revision: https://reviews.llvm.org/D33055

llvm-svn: 302988
2017-05-13 13:25:57 +00:00
Craig Topper
7ebd2e3f5b [KnownBits] Add bit counting methods to KnownBits struct and use them where possible
This patch adds min/max population count, leading/trailing zero/one bit counting methods.

The min methods return answers based on bits that are known without considering unknown bits. The max methods give answers taking into account the largest count that unknown bits could give.

Differential Revision: https://reviews.llvm.org/D32931

llvm-svn: 302925
2017-05-12 17:20:30 +00:00
Adam Nemet
73703d12a4 [SLP] Emit optimization remarks
The approach I followed was to emit the remark after getTreeCost concludes
that SLP is profitable.  I initially tried emitting them after the
vectorizeRootInstruction calls in vectorizeChainsInBlock but I vaguely
remember missing a few cases for example in HorizontalReduction::tryToReduce.

ORE is placed in BoUpSLP so that it's available from everywhere (notably
HorizontalReduction::tryToReduce).

We use the first instruction in the root bundle as the locator for the remark.
In order to get a sense how far the tree is spanning I've include the size of
the tree in the remark.  This is not perfect of course but it gives you at
least a rough idea about the tree.  Then you can follow up with -view-slp-tree
to really see the actual tree.

llvm-svn: 302811
2017-05-11 17:06:17 +00:00
Ayal Zaks
4c2e1fba70 [LV] Refactor ILV.vectorize{Loop}() by introducing LVP.executePlan(); NFC
Introduce LoopVectorizationPlanner.executePlan(), replacing ILV.vectorize() and
refactoring ILV.vectorizeLoop(). Method collectDeadInstructions() is moved from
ILV to LVP. These changes facilitate building VPlans and using them to generate
code, following https://reviews.llvm.org/D28975 and its tentative breakdown.

Method ILV.createEmptyLoop() is renamed ILV.createVectorizedLoopSkeleton() to
improve clarity; it's contents remain intact.

Differential Revision: https://reviews.llvm.org/D32200

llvm-svn: 302790
2017-05-11 11:36:33 +00:00
Matthew Simpson
383f076bfc [AArch64] Consider widening instructions in cost calculations
The AArch64 instruction set has a few "widening" instructions (e.g., uaddl,
saddl, uaddw, etc.) that take one or more doubleword operands and produce
quadword results. The operands are automatically sign- or zero-extended as
appropriate. However, in LLVM IR, these extends are explicit. This patch
updates TTI to consider these widening instructions as single operations whose
cost is attached to the arithmetic instruction. It marks extends that are part
of a widening operation "free" and applies a sub-target specified overhead
(zero by default) to the arithmetic instructions.

Differential Revision: https://reviews.llvm.org/D32706

llvm-svn: 302582
2017-05-09 20:18:12 +00:00
Anna Thomas
3580c4d010 [LV] Fix insertion point for shuffle vectors in first order recurrence
Summary:
In first order recurrence vectorization, when the previous value is a phi node, we need to
set the insertion point to the first non-phi node.
We can have the previous value being a phi node, due to the generation of new
IVs as part of trunc optimization [1].

[1] https://reviews.llvm.org/rL294967

Reviewers: mssimpso, mkuper

Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32969

llvm-svn: 302532
2017-05-09 14:29:33 +00:00
Amara Emerson
59ff6c8c60 Introduce experimental generic intrinsics for horizontal vector reductions.
- This change allows targets to opt-in to using them instead of the log2
  shufflevector algorithm.
- The SLP and Loop vectorizers have the common code to do shuffle reductions
  factored out into LoopUtils, and now have a unified interface for generating
  reductions regardless of the preference of the target. LoopUtils now uses TTI
  to determine what kind of reductions the target wants to handle.
- For CodeGen, basic legalization support is added.

Differential Revision: https://reviews.llvm.org/D30086

llvm-svn: 302514
2017-05-09 10:43:25 +00:00
Jonas Paulsson
fd1a4ff9b5 Use right function in LoopVectorize.
-    unsigned AS = getMemInstAlignment(I);
+    unsigned AS = getMemInstAddressSpace(I);

Review: Hal Finkel
llvm-svn: 302114
2017-05-04 05:31:56 +00:00
Sanjoy Das
19757d9ec3 Rename WeakVH to WeakTrackingVH; NFC
This relands r301424.

llvm-svn: 301812
2017-05-01 17:07:49 +00:00
Craig Topper
c5d014c133 [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for computeKnownBits
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.

Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.

I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.

Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.

Differential Revision: https://reviews.llvm.org/D32376

llvm-svn: 301432
2017-04-26 16:39:58 +00:00
Sanjoy Das
732f091d68 Reverts commit r301424, r301425 and r301426
Commits were:

"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"

The changes assumed pointers are 8 byte aligned on all architectures.

llvm-svn: 301429
2017-04-26 16:37:05 +00:00
Matthew Simpson
1c83e0e38f [LV] Handle external uses of floating-point induction variables
Reference: https://bugs.llvm.org/show_bug.cgi?id=32758
Differential Revision: https://reviews.llvm.org/D32445

llvm-svn: 301428
2017-04-26 16:23:02 +00:00
Sanjoy Das
e226969b1c Rename WeakVH to WeakTrackingVH; NFC
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.

Reviewers: dblaikie, davide

Reviewed By: davide

Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D32266

llvm-svn: 301424
2017-04-26 16:20:52 +00:00
Stanislav Mekhanoshin
19be2234f0 Skip bitcasts while looking for GEP in LoadStoreVectorizer
Differential Revisison: https://reviews.llvm.org/D32101

llvm-svn: 301343
2017-04-25 18:00:08 +00:00
Craig Topper
d59a3da3b6 [APInt] Use isSubsetOf, intersects, and bit counting methods to reduce temporary APInts
This patch uses various APInt methods to reduce temporary APInt creation.

This should be all of the unrelated cleanups that got buried in D32376(creating a KnownBits struct) as well as some pointed out by Simon during the review of that. Plus a few improvements to use counting instead of masking.

I've left out any places where we do something like (KnownZero & KnownOne) != 0 as I plan to add a helper method to KnownBits to ask that question and didn't want to thrash that code an additional time.

Differential Revision: https://reviews.llvm.org/D32495

llvm-svn: 301338
2017-04-25 17:46:30 +00:00
Gil Rapaport
a2e72f19da [LV] Remove redundant basic block split
This patch is part of D28975's breakdown.

Genreating the control-flow to guard predicated instructions modified to
only use SplitBlockAndInsertIfThen() for producing the if-then construct.

Differential Revision: https://reviews.llvm.org/D32224

llvm-svn: 301293
2017-04-25 05:57:22 +00:00
Matthew Simpson
ca617e5f11 [LV] Model if-converted phi node costs
Phi nodes in non-header blocks are converted to select instructions after
if-conversion. This patch updates the cost model to account for the selects.

Differential Revision: https://reviews.llvm.org/D31906

llvm-svn: 300980
2017-04-21 14:14:54 +00:00
Easwaran Raman
7b83777c46 [SLP vectorizer] Allow phi node reordering in tryToVectorizeList.
In tryToVectorizeList, under a very limited circumstance (when entered
from tryToVectorizePair), the values may be reordered (swapped) and the
SLP tree is built with the new order. This extends that to the case when
starting from phis in vectorizeChainsInBlock when there are exactly two
phis. The textual order of phi nodes shouldn't really matter. Without
this change, the loop body in the accompnaying test case is fully vectorized
when we swap the orde of the phis but not with this order. While this
doesn't solve the phi-ordering problem in a general way (for more than 2
phis), this is simple fix that piggybacks on an existing mechanism and
is useful in cases like multiplying two complex numbers.

Differential revision: https://reviews.llvm.org/D32065

llvm-svn: 300574
2017-04-18 18:16:57 +00:00
Gil Rapaport
e43ac15a7c [LV] Cache block mask values
This patch is part of D28975's breakdown.

Add caching for block masks similar to the cache already used for edge masks,
replacing generation per user with reusing the first generated value which
dominates all uses.

Differential Revision: https://reviews.llvm.org/D32054

llvm-svn: 300557
2017-04-18 14:43:43 +00:00
Gil Rapaport
f30248c36d [LV] Remove implicit single basic block assumption
This patch is part of D28975's breakdown - no change in output intended.

LV's code currently assumes the vectorized loop is a single basic block up
until predicateInstructions() is called. This patch removes two manifestations
of this assumption (loop phi incoming values, dominator tree update) by
replacing the use of vectorLoopBody with the vectorized loop's latch/header.

Differential Revision: https://reviews.llvm.org/D32040

llvm-svn: 300310
2017-04-14 07:30:23 +00:00
Anna Thomas
926acfc84a [LV] Fix the vector code generation for first order recurrence
Summary:
In first order recurrences where phi's are used outside the loop,
we should generate an additional vector.extract of the second last element from
the vectorized phi update.
This is because we require the phi itself (which is the value at the second last
iteration of the vector loop) and not the phi's update within the loop.
Also fix the code gen when we just unroll, but don't vectorize.
Fixes PR32396.

Reviewers: mssimpso, mkuper, anemet

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D31979

llvm-svn: 300238
2017-04-13 18:59:25 +00:00
Ayal Zaks
25f1259181 [LV] Refactor ILV to provide vectorizeInstruction(); NFC
Refactoring InnerLoopVectorizer's vectorizeBlockInLoop() to provide
vectorizeInstruction(). Aligning DeadInstructions with its only user.
Facilitates driving the transformation by VPlan - follows
https://reviews.llvm.org/D28975 and its tentative breakdown.

Differential Revision: https://reviews.llvm.org/D31997

llvm-svn: 300183
2017-04-13 09:07:23 +00:00
Jonas Paulsson
eedad8c536 [SLPVectorizer] Pass the right type argument to getCmpSelInstrCost()
In getEntryCost(), make the scalar type for a compare instruction that of the
operands, not i1. This is needed in order to call getCmpSelInstrCost() for a
compare in a sensible way, the same way as the LoopVectorizer does.

New test: test/Transforms/SLPVectorizer/SystemZ/SLP-cmp-cost-query.ll

Review: Matthew Simpson
https://reviews.llvm.org/D31601

llvm-svn: 300061
2017-04-12 13:29:25 +00:00
Jonas Paulsson
a16794b9f4 [LoopVectorizer] Improve handling of branches during cost estimation.
The cost for a branch after vectorization is very different depending on if
the vectorizer will if-convert the block (branch is eliminated), or if
scalarized and predicated blocks will be produced (branch duplicated before
each block). There is also the case of remaining scalar branches, such as the
back-edge branch.

This patch handles these cases differently with TTI based cost estimates.

Review: Matthew Simpson
https://reviews.llvm.org/D31175

llvm-svn: 300058
2017-04-12 13:13:15 +00:00
Jonas Paulsson
b15d643e4a [LoopVectorizer, TTI] New method supportsEfficientVectorElementLoadStore()
Since SystemZ supports vector element load/store instructions, there is no
need for extracts/inserts if a vector load/store gets scalarized.

This patch lets Target specify that it supports such instructions by means of
a new TTI hook that defaults to false.

The use for this is in the LoopVectorizer getScalarizationOverhead() method,
which will with this patch produce a smaller sum for a vector load/store on
SystemZ.

New test: test/Transforms/LoopVectorize/SystemZ/load-store-scalarization-cost.ll

Review: Adam Nemet
https://reviews.llvm.org/D30680

llvm-svn: 300056
2017-04-12 12:41:37 +00:00
Jonas Paulsson
90b172efa0 [SystemZ] TargetTransformInfo cost functions implemented.
getArithmeticInstrCost(), getShuffleCost(), getCastInstrCost(),
getCmpSelInstrCost(), getVectorInstrCost(), getMemoryOpCost(),
getInterleavedMemoryOpCost() implemented.

Interleaved access vectorization enabled.

BasicTTIImpl::getCastInstrCost() improved to check for legal extending loads,
in which case the cost of the z/sext instruction becomes 0.

Review: Ulrich Weigand, Renato Golin.
https://reviews.llvm.org/D29631

llvm-svn: 300052
2017-04-12 11:49:08 +00:00
Anna Thomas
b2455558f1 [LV] Avoid vectorizing first order recurrence when phi uses are outside loop
In the vectorization of first order recurrence, we vectorize such
that the last element in the vector will be the one extracted to pass into the
scalar remainder loop. However, this is not true when there is a phi (other
than the primary induction variable) is used outside the loop.
In such a case, we need the value from the second last iteration (i.e.
the phi value), not the last iteration (which would be the phi update).
I've added a test case for this. Also see PR32396.

A follow up patch would generate the correct code gen for such cases,
and turn this vectorization on.

Differential Revision: https://reviews.llvm.org/D31910

Reviewers: mssimpso
llvm-svn: 299985
2017-04-11 21:02:00 +00:00
Matthew Simpson
7a552e6e70 Reapply r298620: [LV] Vectorize GEPs
This patch reapplies r298620. The original patch was reverted because of two
issues. First, the patch exposed a bug in InstCombine that caused the Chromium
builds to fail (PR32414). This issue was fixed in r299017. Second, the patch
introduced a bug in the vectorizer's scalars analysis that caused test suite
builds to fail on SystemZ. The scalars analysis was too aggressive and marked a
memory instruction scalar, even though it was going to be vectorized. This
issue has been fixed in the current patch and several new test cases for the
scalars analysis have been added.

llvm-svn: 299770
2017-04-07 14:15:34 +00:00
Matthew Simpson
a754d575fa [LV] Transform truncations of non-primary induction variables
The vectorizer tries to replace truncations of induction variables with new
induction variables having the smaller type. After r295063, this optimization
was applied to all integer induction variables, including non-primary ones.
When optimizing the truncation of a non-primary induction variable, we still
need to transform the new induction so that it has the correct start value.
This should fix PR32419.

Reference: https://bugs.llvm.org/show_bug.cgi?id=32419
llvm-svn: 298882
2017-03-27 20:07:38 +00:00
Ivan Krasin
2fef6ee778 Revert r298620: [LV] Vectorize GEPs
Reason: breaks linking Chromium with LLD + ThinLTO (a pass crashes)
LLVM bug: https://bugs.llvm.org//show_bug.cgi?id=32413

Original change description:

[LV] Vectorize GEPs

This patch adds support for vectorizing GEPs. Previously, we only generated
vector GEPs on-demand when creating gather or scatter operations. All GEPs from
the original loop were scalarized by default, and if a pointer was to be stored
to memory, we would have to build up the pointer vector with insertelement
instructions.

With this patch, we will vectorize all GEPs that haven't already been marked
for scalarization.

The patch refines collectLoopScalars to more exactly identify the scalar GEPs.
The function now more closely resembles collectLoopUniforms. And the patch
moves vector GEP creation out of vectorizeMemoryInstruction and into the main
vectorization loop. The vector GEPs needed for gather and scatter operations
will have already been generated before vectoring the memory accesses.

Original Differential Revision: https://reviews.llvm.org/D30710

llvm-svn: 298735
2017-03-24 20:49:43 +00:00
Matthew Simpson
6e2f8c9035 [LV] Vectorize GEPs
This patch adds support for vectorizing GEPs. Previously, we only generated
vector GEPs on-demand when creating gather or scatter operations. All GEPs from
the original loop were scalarized by default, and if a pointer was to be stored
to memory, we would have to build up the pointer vector with insertelement
instructions.

With this patch, we will vectorize all GEPs that haven't already been marked
for scalarization.

The patch refines collectLoopScalars to more exactly identify the scalar GEPs.
The function now more closely resembles collectLoopUniforms. And the patch
moves vector GEP creation out of vectorizeMemoryInstruction and into the main
vectorization loop. The vector GEPs needed for gather and scatter operations
will have already been generated before vectoring the memory accesses.

Differential Revision: https://reviews.llvm.org/D30710

llvm-svn: 298620
2017-03-23 16:29:58 +00:00
Matthew Simpson
0ed5ec7509 [LV] Delete unneeded scalar GEP creation code
The code for generating scalar base pointers in vectorizeMemoryInstruction is
not needed. We currently scalarize all GEPs and maintain the scalarized values
in VectorLoopValueMap. The GEP cloning in this unneeded code is the same as
that in scalarizeInstruction. The test cases that changed as a result of this
patch changed because we were able to reuse the scalarized GEP that we
previously generated instead of cloning a new one.

Differential Revision: https://reviews.llvm.org/D30587

llvm-svn: 298615
2017-03-23 16:07:21 +00:00
Yi Kong
9f5d4ec9d0 Test commit access
Remove some trailing whitespaces.

llvm-svn: 298379
2017-03-21 14:49:19 +00:00
Gil Rapaport
efbbc3ed40 [LV] Refactor cross-iteration phi's back-patching; NFC
This patch refactors the PHisToFix loop as follows:

- The loop itself now resides in its own method.
- The new method iterates on scalar-loop's header; the PHIsToFix map formerly
  propagated as an output parameter and filled during phi widening is removed.
- The code handling reductions is moved into its own method, similar to the
  existing fixFirstOrderRecurrence().

Differential Revision: https://reviews.llvm.org/D30755

llvm-svn: 297740
2017-03-14 13:50:47 +00:00
Ayal Zaks
91ca0c753e [LV] Refactor Cost Model's selectVectorizationFactor(); NFC
Refactoring Cost Model's selectVectorizationFactor() so that it handles only the
selection of the best VF from a pre-computed range of candidate VF's, extracting
early-exit criteria and the computation of a MaxVF upper-bound to other methods,
all driven by a newly introduced LoopVectorizationPlanner.

Differential Revision: https://reviews.llvm.org/D30653

llvm-svn: 297737
2017-03-14 13:07:04 +00:00
Jonas Paulsson
42e7a2d74b [TargetTransformInfo] getIntrinsicInstrCost() scalarization estimation improved
getIntrinsicInstrCost() used to only compute scalarization cost based on types.
This patch improves this so that the actual arguments are checked when they are
available, in order to handle only unique non-constant operands.

Tests updates:

Analysis/CostModel/X86/arith-fp.ll
Transforms/LoopVectorize/AArch64/interleaved_cost.ll
Transforms/LoopVectorize/ARM/interleaved_cost.ll

The improvement in getOperandsScalarizationOverhead() to differentiate on
constants made it necessary to update the interleaved_cost.ll tests even
though they do not relate to intrinsics.

Review: Hal Finkel
https://reviews.llvm.org/D29540

llvm-svn: 297705
2017-03-14 06:35:36 +00:00
Gil Rapaport
52cac734e2 [LV] Set memcheck metadata also for VF==1
This commit is a follow-up on r297580. It fixes the FIXME added temporarily
by that commit to keep the removal of Unroller's specialized version of
scalarizeInstruction() an NFC. See https://reviews.llvm.org/D30715 for details.

llvm-svn: 297610
2017-03-13 10:23:46 +00:00
Gil Rapaport
95732c0a6d [LV] A unified scalarizeInstruction() for Vectorizer and Unroller; NFC
Unroller's specialized scalarizeInstruction() is mostly duplicating Vectorizer's
variant. OTOH Vectorizer's scalarizeInstruction() already supports the special
case of VF==1 except for avoiding mask-bit extraction in that case. This patch
removes Unroller's specialized version in favor of a unified method.

The only functional difference between the two variants seems to be setting
memcheck metadata for loads and stores only in Vectorizer's variant, which is a
bug in Unroller. To keep this patch an NFC the unified method doesn't set
memcheck metadata for VF==1.

Differential Revision: https://reviews.llvm.org/D30715

llvm-svn: 297580
2017-03-12 12:31:38 +00:00
Ayal Zaks
0f64e83c30 Test commit.
llvm-svn: 297579
2017-03-12 09:48:06 +00:00
Michael Kuperstein
0a5d356cf1 [SLP] Revert everything that has to do with memory access sorting.
This reverts r293386, r294027, r294029 and r296411.

Turns out the SLP tree isn't actually a "tree" and we don't handle
accessing the same packet of loads in several different orders well,
causing miscompiles.

Revert until we can fix this properly.

llvm-svn: 297493
2017-03-10 18:59:07 +00:00
Daniel Berlin
294f6c0958 Add support for DenseMap/DenseSet count and find using const pointers
Summary:
Similar to SmallPtrSet, this makes find and count work with both const
referneces and const pointers.

Reviewers: dblaikie

Subscribers: llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30713

llvm-svn: 297424
2017-03-10 00:25:26 +00:00
Adam Nemet
d57520ae79 [SLP] Mark values in Dot that need to be extracted
llvm-svn: 297361
2017-03-09 05:48:03 +00:00
Adam Nemet
c956f416cc [SLP] Visualize SLP trees with -view-slp-tree
Analyzing larger trees is extremely difficult with the current debug output so
this adds GraphTraits and DOTGraphTraits on top of the VectorizableTree data
structure.  We can now display the SLP trees with Graphviz as in
https://reviews.llvm.org/F3132765.

I decorated the graph where a value needs to be gathered for one reason or
another.  These are the red nodes.

There are other improvement I am planning to make as I work through my case
here.  For example, I would also like to mark nodes that need to be extracted.

Differential Revision: https://reviews.llvm.org/D30731

llvm-svn: 297303
2017-03-08 18:47:50 +00:00
Matthew Simpson
9d666ee035 [LV] Select legal insert point when fixing first-order recurrences
Because IRBuilder performs constant-folding, it's not guaranteed that an
instruction in the original loop map to an instruction in the vector loop. It
could map to a constant vector instead. The handling of first-order recurrences
was incorrectly making this assumption when setting the IRBuilder's insert
point.

llvm-svn: 297302
2017-03-08 18:18:20 +00:00
Matthew Simpson
ca6ac576f1 [LV] Consider users that are memory accesses in uniforms expansion step
When expanding the set of uniform instructions beyond the seed instructions
(e.g., consecutive pointers), we mark a new instruction uniform if all its
loop-varying users are uniform. We should also allow users that are consecutive
or interleaved memory accesses. This fixes cases where we have an instruction
that is used as the pointer operand of a consecutive access but also used by a
non-memory instruction that later becomes uniform as part of the expansion.

llvm-svn: 297179
2017-03-07 18:47:30 +00:00
Michael Kuperstein
ecb8f70721 [SLP] Revert r296863 due to miscompiles.
Details and reproducer are on the email thread for r296863.

llvm-svn: 297103
2017-03-06 23:54:51 +00:00
Mohammad Shahid
d8acf02cf1 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.It also needs to recompute the proper Lane for
external use of vectorizable scalars based on shuffle mask.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Ide8773ce0ad3562f3cf4d1a0ad0f487e2f60ce5d
llvm-svn: 296863
2017-03-03 10:02:47 +00:00
Matthew Simpson
729924f526 [LV] Considier non-consecutive but vectorizable accesses for VF selection
When computing the smallest and largest types for selecting the maximum
vectorization factor, we currently ignore loads and stores of pointer types if
the memory access is non-consecutive. We do this because such accesses must be
scalarized regardless of vectorization factor, and thus shouldn't be considered
when determining the factor. This patch makes this check less aggressive by
also considering non-consecutive accesses that may be vectorized, such as
interleaved accesses. Because we don't know at the time of the check if an
accesses will certainly be vectorized (this is a cost model decision given a
particular VF), we consider all accesses that can potentially be vectorized.

Differential Revision: https://reviews.llvm.org/D30305

llvm-svn: 296747
2017-03-02 13:55:05 +00:00
Hans Wennborg
358597d3c9 Revert r296575 "[SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available"
It caused miscompiles, e.g. in Chromium (PR32109).

llvm-svn: 296654
2017-03-01 18:57:16 +00:00
Alexey Bataev
d9b0bf33dd [SLP] Preserve IR flags when vectorizing horizontal reductions.
Summary:
The SLP vectorizer should propagate IR-level optimization hints/flags
(nsw, nuw, exact, fast-math) when converting scalar horizontal
reductions instructions into vectors, just like for other vectorized
instructions.
It doe not include IR propagation for extra arguments, we need to handle
original scalar operations for extra args to propagate correct flags.

Reviewers: mkuper, mzolotukhin, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30418

llvm-svn: 296614
2017-03-01 12:43:39 +00:00
Alexey Bataev
28bee685c1 [SLP] Preserve IR flags for extra args.
Summary:
We should preserve IR flags for extra args. These IR flags should be
taken from original scalar operations, not from the reduction
operations.

Reviewers: mkuper, mzolotukhin, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30447

llvm-svn: 296613
2017-03-01 12:22:33 +00:00
Alexey Bataev
f077ffe566 [SLP] Fix for PR32038: extra add of PHI node when it is not required.
Summary:
If horizontal reduction tree starts from the binary operation that is
used in PHI node, but this PHI is not used in horizontal reduction, we
may end up with extra addition of this PHI node after vectorization.
Here is an example:
```
%phi = phi i32 [ %tmp, %end], ...
...
%tmp = add i32 %tmp1, %tmp2
end:
```
after vectorization we always have something like:

```
%phi = phi i32 [ %tmp, %end], ...
...
%red = extractelement <8 x 32> %vec.red, 0
%tmp = add i32 %red, %phi
end:
```
even if `%phi` is not used in reduction tree. Patch considers these PHI
nodes as extra arguments and considers them in the final result iff they
really used in reduction.

Reviewers: mkuper, hfinkel, mzolotukhin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30409

llvm-svn: 296606
2017-03-01 10:50:44 +00:00
Adam Nemet
58c6d3d189 [LV] These remark should have been missed remarks
The practice in LV is that we emit analysis remarks and then finally report
either a missed or applied remark on the final decision whether vectorization
is taking place.  On this code path, we were closing with an analysis remark.

llvm-svn: 296578
2017-03-01 04:31:15 +00:00
Mohammad Shahid
8ddc0dd2a4 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Id1e287f073fa4959713ba545fa4254db5da8b40d
llvm-svn: 296575
2017-03-01 03:51:54 +00:00
Adam Nemet
7c40766da5 Revert "(HEAD, origin/master, origin/HEAD, master) [LV] These should missed remarks"
This reverts commit r296544.

This got committed by accident.

llvm-svn: 296546
2017-02-28 23:54:27 +00:00