Commit Graph

39 Commits

Author SHA1 Message Date
Adam Nemet
86dbc2b6d3 [LAA-memchecks 3/3] Introduce pointer partitions for memchecks
This is the final patch that actually introduces the new parameter of
partition mapping to RuntimePointerCheck::needsChecking.

Another API (LAI::getInstructionsForAccess) is also exposed that helps
to map pointers to instructions because ultimately we partition
instructions.

The WIP version of the Loop Distribution pass in D6930 has been adapted
to use all this.  See for example, how
InstrPartitionContainer::computePartitionSetForPointers sets up the
partitions using the above API and then calls to LAI::addRuntimeCheck
with the pointer partitions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231818 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 18:54:26 +00:00
Adam Nemet
c320ed14d2 [LAA-memchecks 2/3] Move number of memcheck threshold checking to LV
Now the analysis won't "fail" if the memchecks exceed the threshold.  It
is the transform pass' responsibility to perform the check.

This allows the transform pass to further analyze/eliminate the
memchecks.  E.g. in Loop distribution we only need to check pointers
that end up in different partitions.

Note that there is a slight change of functionality here.  The logic in
analyzeLoop is that if dependence checking fails due to non-constant
distance between the pointers, another attempt is made to prove safety
of the dependences purely using run-time checks.

Before this patch we could fail the loop due to exceeding the memcheck
threshold after the first step, now we only check the threshold in the
client after the full analysis.  There is no measurable compile-time
effect but I wanted to record this here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231817 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 18:54:23 +00:00
Adam Nemet
8e7d56f6f7 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231807 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 17:40:43 +00:00
Adam Nemet
7063c7e084 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231806 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 17:40:37 +00:00
Adam Nemet
0ddb48c2f8 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231805 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 17:40:34 +00:00
Mehdi Amini
529919ff31 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>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
Adam Nemet
5a51d864b9 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230608 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-26 04:39:09 +00:00
Eric Christopher
435571ada6 Fix a couple of depedent->dependent typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230584 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-26 00:00:33 +00:00
Adam Nemet
989a0200c2 [LoopAccesses] LAA::getInfo to use const reference for stride parameter
And other required const-correctness fixes to make this work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230289 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-24 00:41:59 +00:00
Adam Nemet
b7e0193c4d [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229899 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:21 +00:00
Adam Nemet
c182ce09e9 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229898 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:19 +00:00
Adam Nemet
4db669fb26 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229897 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:15 +00:00
Adam Nemet
7d39ae845d [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229896 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:13 +00:00
Adam Nemet
5c4c262b3c [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229895 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:10 +00:00
Adam Nemet
9fdb32eb84 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229894 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:07 +00:00
Adam Nemet
0ea25c2e64 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229893 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:04 +00:00
Adam Nemet
093a04b6d6 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229892 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:15:00 +00:00
Adam Nemet
7b507eb2a5 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229891 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:14:56 +00:00
Adam Nemet
4b86046b7c [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229890 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:14:52 +00:00
Adam Nemet
c76d187944 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229889 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-19 19:14:34 +00:00
NAKAMURA Takumi
582e77af02 Reformat.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229651 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 08:36:14 +00:00
NAKAMURA Takumi
383d8c7fdd 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"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229650 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 08:34:47 +00:00
Adam Nemet
5934863461 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229634 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:44:33 +00:00
Adam Nemet
f367b60abe [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229633 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:44:30 +00:00
Adam Nemet
c548c640bc [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229632 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:44:25 +00:00
Adam Nemet
69c9697fa7 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229631 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:44:20 +00:00
Adam Nemet
4166c7ff59 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229630 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:44:08 +00:00
Adam Nemet
0cbfb71d7b [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229629 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:43:58 +00:00
Adam Nemet
ce5c5c0301 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229628 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:43:37 +00:00
Adam Nemet
718b023033 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229626 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:43:24 +00:00
Adam Nemet
0d1e8dd84e [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229625 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:43:19 +00:00
Adam Nemet
14cc2e25c5 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229624 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:42:57 +00:00
Adam Nemet
8b0647f26b [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229623 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:42:50 +00:00
Adam Nemet
eefec589e8 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229622 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:42:43 +00:00
Adam Nemet
38a9ebb065 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229621 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:42:35 +00:00
Adam Nemet
d7aa78535c [LoopAccesses] Make raw_string_ostream local in VectorizationReport
Since VectorizationReport will be part of the result of the analysis it
will be stored in a container.  However, one of its members is a
raw_string_ostream which cannot be copy-constructed.

This makes the raw_string_ostream local to the << operator.

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229620 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-18 03:42:15 +00:00
Adam Nemet
b3189eac3f [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.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228418 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-06 18:31:04 +00:00
Adam Nemet
3fe93fe70a [LoopVectorize] Fix rebase glitch in r227751
LoopVectorizationLegality::{getNumLoads,getNumStores} should forward to
LoopAccessAnalysis now.

Thanks to Takumi for noticing this!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227992 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-03 17:59:53 +00:00
Adam Nemet
2000a7c9b2 [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227756 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-01 16:56:15 +00:00