Commit Graph

188 Commits

Author SHA1 Message Date
Adam Nemet b6dc76ffe5 [LAA-memchecks 1/3] Split out NumComparisons checks. NFC
The check for the number of memchecks will be moved to the client of
this analysis.  Besides allowing for transform-specific thresholds, this
also lets Loop Distribution post-process the memchecks; Loop
Distribution only needs memchecks between pointers of different
partitions.

The motivation for this first patch is to untangle the CanDoRT check
from the NumComparison check before moving the NumComparison part.
CanDoRT means that we couldn't determine the bounds for the pointer.
Note that NumComparison is set independent of this flag.

llvm-svn: 231816
2015-03-10 18:54:19 +00:00
Adam Nemet 58913d65ad [LoopAccesses 3/3] Print the dependences with -analyze
The dependences are now expose through the new getInterestingDependences
API so we can use that with -analyze too and fix the FIXME.

This lets us remove the test that relied on -debug to check the
dependences.

llvm-svn: 231807
2015-03-10 17:40:43 +00:00
Adam Nemet 9c92657971 [LoopAccesses 2/3] Allow querying of interesting dependences
Gather an array of interesting dependences rather than just failing
after the first unsafe one and regarding the loop unsafe.  Loop
Distribution needs to be able to collect all dependences in order to
isolate the dependence cycles into their own partition.

Since the dependence checking algorithm is quadratic in terms of
accesses sharing the same underlying pointer, I am applying a cut-off
threshold (MaxInterestingDependence).  Exceeding that, the logic reverts
back to the original approach deeming the loop unsafe upon encountering
the first unsafe dependence.

The main idea of the patch is to split isDepedent from directly
answering the question whether the dep is safe for vectorization to
return a dependence type which then gets mapped to old boolean result
using Dependence::isSafeForVectorization.

Tested that this was compile-time neutral on SpecINT2006 LTO bitcode
inputs.  No assembly change on the testsuite including external.

llvm-svn: 231806
2015-03-10 17:40:37 +00:00
Adam Nemet dee666bc63 [LoopAccesses 1/3] Expose MemoryDepChecker to LAA users
LoopDistribution needs to query various results of the dependence
analysis.  This series will expose some more APIs and state of the
dependence checker.

This patch is a simple one to just expose the DepChecker instance.  The
set is compile-time neutral measured with LTO bitcode files of
SpecINT2006.  Also there is no assembly change on the testsuite.

llvm-svn: 231805
2015-03-10 17:40:34 +00:00
Mehdi Amini a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Mehdi Amini 46a43556db Make DataLayout Non-Optional in the Module
Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231270
2015-03-04 18:43:29 +00:00
Adam Nemet 9cc0c3999d [LV/LoopAccesses] Backward dependences are not safe just because the
accesses are via different types

Noticed this while generalizing the code for loop distribution.

I confirmed with Arnold that this was indeed a bug and managed to create
a testcase.

llvm-svn: 230647
2015-02-26 17:58:48 +00:00
Adam Nemet 1d862af764 [LoopAccesses] Add command-line option for RuntimeMemoryCheckThreshold
Also remove the somewhat misleading initializers from
VectorizationFactor and VectorizationInterleave.  They will get
initialized with the default ctor since no cl::init is provided.

llvm-svn: 230608
2015-02-26 04:39:09 +00:00
Adam Nemet 8bc61df9f2 [LoopAccesses] LAA::getInfo to use const reference for stride parameter
And other required const-correctness fixes to make this work.

llvm-svn: 230289
2015-02-24 00:41:59 +00:00
Adam Nemet 57ac766ee9 [LoopAccesses] Change LAA:getInfo to return a constant reference
As expected, this required a few more const-correctness fixes.

Based on Hal's feedback on D7684.

llvm-svn: 229899
2015-02-19 19:15:21 +00:00
Adam Nemet e91cc6ef93 [LoopAccesses] Add -analyze support
The LoopInfo in combination with depth_first is used to enumerate the
loops.

Right now -analyze is not yet complete.  It only prints the result of
the analysis, the report and the run-time checks.  Printing the unsafe
depedences will require a bit more reshuffling which I'd like to do in a
follow-on to this patchset.  Unsafe dependences are currently checked
via -debug-only=loop-accesses in the new test.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229898
2015-02-19 19:15:19 +00:00
Adam Nemet 2bd6e984ef [LoopAccesses] Split out LoopAccessReport from VectorizerReport
The only difference between these two is that VectorizerReport adds a
vectorizer-specific prefix to its messages.  When LAA is used in the
vectorizer context the prefix is added when we promote the
LoopAccessReport into a VectorizerReport via one of the constructors.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229897
2015-02-19 19:15:15 +00:00
Adam Nemet 3e87634fd8 [LoopAccesses] Add missing const to APIs in VectorizationReport
When I split out LoopAccessReport from this, I need to create some temps
so constness becomes necessary.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229896
2015-02-19 19:15:13 +00:00
Adam Nemet 929c38e8ff [LoopAccesses] Add canAnalyzeLoop
This allows the analysis to be attempted with any loop.  This feature
will be used with -analysis.  (LV only requests the analysis on loops
that have already satisfied these tests.)

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229895
2015-02-19 19:15:10 +00:00
Adam Nemet 339f42b396 [LoopAccesses] Change debug messages from LV to LAA
Also add pass name as an argument to VectorizationReport::emitAnalysis.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229894
2015-02-19 19:15:07 +00:00
Adam Nemet 3bfd93d789 [LoopAccesses] Create the analysis pass
This is a function pass that runs the analysis on demand.  The analysis
can be initiated by querying the loop access info via LAA::getInfo.  It
either returns the cached info or runs the analysis.

Symbolic stride information continues to reside outside of this analysis
pass. We may move it inside later but it's not a priority for me right
now.  The idea is that Loop Distribution won't support run-time stride
checking at least initially.

This means that when querying the analysis, symbolic stride information
can be provided optionally.  Whether stride information is used can
invalidate the cache entry and rerun the analysis.  Note that if the
loop does not have any symbolic stride, the entry should be preserved
across Loop Distribution and LV.

Since currently the only user of the pass is LV, I just check that the
symbolic stride information didn't change when using a cached result.

On the LV side, LoopVectorizationLegality requests the info object
corresponding to the loop from the analysis pass.  A large chunk of the
diff is due to LAI becoming a pointer from a reference.

A test will be added as part of the -analyze patch.

Also tested that with AVX, we generate identical assembly output for the
testsuite (including the external testsuite) before and after.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229893
2015-02-19 19:15:04 +00:00
Adam Nemet 436018c3ff [LoopAccesses] Cache the result of canVectorizeMemory
LAA will be an on-demand analysis pass, so we need to cache the result
of the analysis.  canVectorizeMemory is renamed to analyzeLoop which
computes the result.  canVectorizeMemory becomes the query function for
the cached result.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229892
2015-02-19 19:15:00 +00:00
Adam Nemet c922853b93 [LoopAccesses] Stash the report from the analysis rather than emitting it
The transformation passes will query this and then emit them as part of
their own report.  The currently only user LV is modified to do just
that.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229891
2015-02-19 19:14:56 +00:00
Adam Nemet f219c64723 [LoopAccesses] Make VectorizerParams global + fix for cyclic dep
As LAA is becoming a pass, we can no longer pass the params to its
constructor.  This changes the command line flags to have external
storage.  These can now be accessed both from LV and LAA.

VectorizerParams is moved out of LoopAccessInfo in order to shorten the
code to access it.

This commits also has the fix (D7731) to the break dependence cycle
between the analysis and vector libraries.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229890
2015-02-19 19:14:52 +00:00
Adam Nemet 04d4163e95 Revert "Reformat."
This reverts commit r229651.

I'd like to ultimately revert r229650 but this reformat stands in the
way.  I'll reformat the affected files once the the loop-access pass is
fully committed.

llvm-svn: 229889
2015-02-19 19:14:34 +00:00
NAKAMURA Takumi a250484c4c Reformat.
llvm-svn: 229651
2015-02-18 08:36:14 +00:00
NAKAMURA Takumi fa520c5f49 Revert r229622: "[LoopAccesses] Make VectorizerParams global" and others. r229622 brought cyclic dependencies between Analysis and Vector.
r229622: "[LoopAccesses] Make VectorizerParams global"
  r229623: "[LoopAccesses] Stash the report from the analysis rather than emitting it"
  r229624: "[LoopAccesses] Cache the result of canVectorizeMemory"
  r229626: "[LoopAccesses] Create the analysis pass"
  r229628: "[LoopAccesses] Change debug messages from LV to LAA"
  r229630: "[LoopAccesses] Add canAnalyzeLoop"
  r229631: "[LoopAccesses] Add missing const to APIs in VectorizationReport"
  r229632: "[LoopAccesses] Split out LoopAccessReport from VectorizerReport"
  r229633: "[LoopAccesses] Add -analyze support"
  r229634: "[LoopAccesses] Change LAA:getInfo to return a constant reference"
  r229638: "Analysis: fix buildbots"

llvm-svn: 229650
2015-02-18 08:34:47 +00:00
Saleem Abdulrasool 90b1d152b5 Analysis: fix buildbots
This should fix the compilation failure on the MSVC buildbots which find a
std::make_unique and llvm::make_unique via ADL, resulting in ambiguity.

llvm-svn: 229638
2015-02-18 05:09:50 +00:00
Adam Nemet 85fd9f8d09 [LoopAccesses] Change LAA:getInfo to return a constant reference
As expected, this required a few more const-correctness fixes.

Based on Hal's feedback on D7684.

llvm-svn: 229634
2015-02-18 03:44:33 +00:00
Adam Nemet 75bc2d111f [LoopAccesses] Add -analyze support
The LoopInfo in combination with depth_first is used to enumerate the
loops.

Right now -analyze is not yet complete.  It only prints the result of
the analysis, the report and the run-time checks.  Printing the unsafe
depedences will require a bit more reshuffling which I'd like to do in a
follow-on to this patchset.  Unsafe dependences are currently checked
via -debug-only=loop-accesses in the new test.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229633
2015-02-18 03:44:30 +00:00
Adam Nemet d7350dbb85 [LoopAccesses] Split out LoopAccessReport from VectorizerReport
The only difference between these two is that VectorizerReport adds a
vectorizer-specific prefix to its messages.  When LAA is used in the
vectorizer context the prefix is added when we promote the
LoopAccessReport into a VectorizerReport via one of the constructors.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229632
2015-02-18 03:44:25 +00:00
Adam Nemet 8b12afbeee [LoopAccesses] Add missing const to APIs in VectorizationReport
When I split out LoopAccessReport from this, I need to create some temps
so constness becomes necessary.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229631
2015-02-18 03:44:20 +00:00
Adam Nemet 450d417ecf [LoopAccesses] Add canAnalyzeLoop
This allows the analysis to be attempted with any loop.  This feature
will be used with -analysis.  (LV only requests the analysis on loops
that have already satisfied these tests.)

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229630
2015-02-18 03:44:08 +00:00
Adam Nemet a8945b7790 [LoopAccesses] Factor out RuntimePointerCheck::needsChecking
Will be used by the new RuntimePointerCheck::print.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229629
2015-02-18 03:43:58 +00:00
Adam Nemet d0db4c1395 [LoopAccesses] Change debug messages from LV to LAA
Also add pass name as an argument to VectorizationReport::emitAnalysis.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229628
2015-02-18 03:43:37 +00:00
Adam Nemet d6b7e29815 [LoopAccesses] Create the analysis pass
This is a function pass that runs the analysis on demand.  The analysis
can be initiated by querying the loop access info via LAA::getInfo.  It
either returns the cached info or runs the analysis.

Symbolic stride information continues to reside outside of this analysis
pass. We may move it inside later but it's not a priority for me right
now.  The idea is that Loop Distribution won't support run-time stride
checking at least initially.

This means that when querying the analysis, symbolic stride information
can be provided optionally.  Whether stride information is used can
invalidate the cache entry and rerun the analysis.  Note that if the
loop does not have any symbolic stride, the entry should be preserved
across Loop Distribution and LV.

Since currently the only user of the pass is LV, I just check that the
symbolic stride information didn't change when using a cached result.

On the LV side, LoopVectorizationLegality requests the info object
corresponding to the loop from the analysis pass.  A large chunk of the
diff is due to LAI becoming a pointer from a reference.

A test will be added as part of the -analyze patch.

Also tested that with AVX, we generate identical assembly output for the
testsuite (including the external testsuite) before and after.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229626
2015-02-18 03:43:24 +00:00
Adam Nemet 01abb2c355 [LoopAccesses] Make blockNeedsPredication static
blockNeedsPredication is in LoopAccess in order to share it with the
vectorizer.  It's a utility needed by LoopAccess not strictly provided
by it but it's a good place to share it.  This makes the function static
so that it no longer required to create an LoopAccessInfo instance in
order to access it from LV.

This was actually causing problems because it would have required
creating LAI much earlier that LV::canVectorizeMemory().

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229625
2015-02-18 03:43:19 +00:00
Adam Nemet 3cf32ad6db [LoopAccesses] Cache the result of canVectorizeMemory
LAA will be an on-demand analysis pass, so we need to cache the result
of the analysis.  canVectorizeMemory is renamed to analyzeLoop which
computes the result.  canVectorizeMemory becomes the query function for
the cached result.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229624
2015-02-18 03:42:57 +00:00
Adam Nemet 5474be2c80 [LoopAccesses] Stash the report from the analysis rather than emitting it
The transformation passes will query this and then emit them as part of
their own report.  The currently only user LV is modified to do just
that.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229623
2015-02-18 03:42:50 +00:00
Adam Nemet 4f3ede5a01 [LoopAccesses] Make VectorizerParams global
As LAA is becoming a pass, we can no longer pass the params to its
constructor.  This changes the command line flags to have external
storage.  These can now be accessed both from LV and LAA.

VectorizerParams is moved out of LoopAccessInfo in order to shorten the
code to access it.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229622
2015-02-18 03:42:43 +00:00
Adam Nemet 30f16e1696 [LoopAccesses] Rename LoopAccessAnalysis to LoopAccessInfo
LoopAccessAnalysis will be used as the name of the pass.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229621
2015-02-18 03:42:35 +00:00
Adam Nemet 7206d7a5d2 [LV] Move addRuntimeCheck to LoopAccessAnalysis
This will allow it to be shared with the new Loop Distribution pass.

getFirstInst is currently duplicated across LoopVectorize.cpp and
LoopAccessAnalysis.cpp.  This is a short-term work-around until we figure out
a better solution.

NFC.  (The code moved is adjusted a bit for the name of the Loop member and
that PtrRtCheck is now a reference rather than a pointer.)

llvm-svn: 228418
2015-02-06 18:31:04 +00:00
Adam Nemet 0456327cfb [LoopVectorize] Move LoopAccessAnalysis to its own module
Other than moving code and adding the boilerplate for the new files, the code
being moved is unchanged.

There are a few global functions that are shared with the rest of the
LoopVectorizer.  I moved these to the new module as well (emitLoopAnalysis,
stripIntegerCast, replaceSymbolicStrideSCEV) along with the Report class used
by emitLoopAnalysis.  There is probably room for further improvement in this
area.

I kept DEBUG_TYPE "loop-vectorize" because it's used as the PassName with
emitOptimizationRemarkAnalysis.  This will obviously have to change.

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

llvm-svn: 227756
2015-02-01 16:56:15 +00:00