Commit Graph

963 Commits

Author SHA1 Message Date
Teresa Johnson
9c27b59cec Change TargetLibraryInfo analysis passes to always require Function
Summary:
This is the first change to enable the TLI to be built per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.

This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.

Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.

There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.

Reviewers: chandlerc, hfinkel

Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66428

llvm-svn: 371284
2019-09-07 03:09:36 +00:00
Sjoerd Meijer
718f909ccd [LV] Tail-folding, runtime scev checks
Now that we allow tail-folding, not only when we optimise for size, make
sure we do not run in this assert.

Differential revision: https://reviews.llvm.org/D66932

llvm-svn: 370711
2019-09-03 08:53:02 +00:00
Sjoerd Meijer
0469b0e4ef [LV] Tail-folding with runtime memory checks
The loop vectorizer was running in an assert when it tried to fold the tail and
had to emit runtime memory disambiguation checks.

Differential revision: https://reviews.llvm.org/D66803

llvm-svn: 370707
2019-09-03 08:38:24 +00:00
Ayal Zaks
d15df0ede5 [LV] Fold tail by masking - handle reductions
Allow vectorizing loops that have reductions when tail is folded by masking.
A select is introduced in VPlan, choosing between the last value carried by the
loop-exit/live-out instruction of the reduction, and the penultimate value
carried by the reduction phi, according to the "i < n" mask of fold-tail.
This select replaces the last value as the live-out value of the loop.

Differential Revision: https://reviews.llvm.org/D66720

llvm-svn: 370173
2019-08-28 09:02:23 +00:00
Jonas Devlieghere
0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Dorit Nuzman
d57d73daed [LV] fold-tail predication should be respected even with assume_safety
assume_safety implies that loads under "if's" can be safely executed
speculatively (unguarded, unmasked). However this assumption holds only for the
original user "if's", not those introduced by the compiler, such as the
fold-tail "if" that guards us from loading beyond the original loop trip-count.
Currently the combination of fold-tail and assume-safety pragmas results in
ignoring the fold-tail predicate that guards the loads, generating unmasked
loads. This patch fixes this behavior.

Differential Revision: https://reviews.llvm.org/D66106

Reviewers: Ayal, hsaito, fhahn
llvm-svn: 368973
2019-08-15 07:12:14 +00:00
Dorit Nuzman
491ca2425d [LV] Fold-tail flag
This is the compiler-flag equivalent of the Predicate pragma
(https://reviews.llvm.org/D65197), to direct the vectorizer to fold the
remainder-loop into the main-loop using predication.

Differential Revision: https://reviews.llvm.org/D66108

Reviewers: Ayal, hsaito, fhahn, SjoerdMeije
llvm-svn: 368801
2019-08-14 05:22:20 +00:00
Craig Topper
005b22855e [LoopVectorize][X86] Clamp interleave factor if we have a known constant trip count that is less than VF*interleave
If we know the trip count, we should make sure the interleave factor won't cause the vectorized loop to exceed it.

Improves one of the cases from PR42674

Differential Revision: https://reviews.llvm.org/D65896

llvm-svn: 368215
2019-08-07 21:44:14 +00:00
Mitch Phillips
924359dc0f Revert "[X86] Add more extract subvector cost model tests for smaller element sizes and smaller than 128-bit vectors."
This reverts commit fc33e33776.

This commit depends on the rolled back commit rL367901, and thus needs
to be rolled back.

llvm-svn: 368109
2019-08-06 23:38:14 +00:00
Craig Topper
fc33e33776 [X86] Add more extract subvector cost model tests for smaller element sizes and smaller than 128-bit vectors.
With the switch to widening legalization, we need to a better
job of costing extractions of less than 128-bits.

llvm-svn: 368081
2019-08-06 20:12:41 +00:00
Hideki Saito
ec818d7fb3 [LV][NFC] Share the LV illegality reporting with LoopVectorize.
Reviewers: hsaito, fhahn, rengolin
 
Reviewed By: rengolin
 
Patch by psamolysov, thanks!
 
Differential Revision: https://reviews.llvm.org/D62997

llvm-svn: 367980
2019-08-06 06:08:48 +00:00
Sjoerd Meijer
e0dfce0723 Follow up of rL367592, fix the build
Some buildbots complained about:
error: default label in switch which covers all enumeration values

llvm-svn: 367603
2019-08-01 18:54:29 +00:00
Sjoerd Meijer
20b198ec5e [LV] Tail-Loop Folding
This allows folding of the scalar epilogue loop (the tail) into the main
vectorised loop body when the loop is annotated with a "vector predicate"
metadata hint. To fold the tail, instructions need to be predicated (masked),
enabling/disabling lanes for the remainder iterations.

Differential Revision: https://reviews.llvm.org/D65197

llvm-svn: 367592
2019-08-01 18:21:44 +00:00
Sjoerd Meijer
5c606cef79 [LV] Scalar Epilogue Lowering. NFC.
This refactors boolean 'OptForSize' that was passed around in a lot of places.
It controlled folding of the tail loop, the scalar epilogue, into the main loop
but code-size reasons may not be the only reason to do this. Thus, this is a
first step to generalise the concept of tail-loop folding, and hence OptForSize
has been renamed and is using an enum ScalarEpilogueStatus that holds the
status how the epilogue should be lowered.

This will be followed up by D65197, that picks up the predicate loop hint and
performs the tail-loop folding.

Differential Revision: https://reviews.llvm.org/D64916

llvm-svn: 366993
2019-07-25 08:06:02 +00:00
Florian Hahn
1d554b7441 [LoopVectorize] Pass unfiltered list of arguments to getIntrinsicInstCost.
We do not compute the scalarization overhead in getVectorIntrinsicCost
and TTI::getIntrinsicInstrCost requires the full arguments list.

llvm-svn: 366049
2019-07-15 08:48:47 +00:00
Florian Hahn
9428d95ce7 [LV] Exclude loop-invariant inputs from scalar cost computation.
Loop invariant operands do not need to be scalarized, as we are using
the values outside the loop. We should ignore them when computing the
scalarization overhead.

Fixes PR41294

Reviewers: hsaito, rengolin, dcaballe, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D59995

llvm-svn: 366030
2019-07-14 20:12:36 +00:00
Orlando Cazalet-Hyams
1251cac62a [DebugInfo@O2][LoopVectorize] pr39024: Vectorized code linenos step through loop even after completion
Summary:
Bug: https://bugs.llvm.org/show_bug.cgi?id=39024

The bug reports that a vectorized loop is stepped through 4 times and each step through the loop seemed to show a different path. I found two problems here:

A) An incorrect line number on a preheader block (for.body.preheader) instruction causes a step into the loop before it begins.
B) Instructions in the middle block have different line numbers which give the impression of another iteration.

In this patch I give all of the middle block instructions the line number of the scalar loop latch terminator branch. This seems to provide the smoothest debugging experience because the vectorized loops will always end on this line before dropping into the scalar loop. To solve problem A I have altered llvm::SplitBlockPredecessors to accommodate loop header blocks.

I have set up a separate review D61933 for a fix which is required for this patch.

Reviewers: samsonov, vsk, aprantl, probinson, anemet, hfinkel, jmorse

Reviewed By: hfinkel, jmorse

Subscribers: jmorse, javed.absar, eraman, kcc, bjope, jmellorcrummey, hfinkel, gbedwell, hiraditya, zzheng, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D60831

> llvm-svn: 363046

llvm-svn: 363786
2019-06-19 10:50:47 +00:00
Warren Ristow
6452bdd29b [LV] Suppress vectorization in some nontemporal cases
When considering a loop containing nontemporal stores or loads for
vectorization, suppress the vectorization if the corresponding
vectorized store or load with the aligment of the original scaler
memory op is not supported with the nontemporal hint on the target.

This adds two new functions:
  bool isLegalNTStore(Type *DataType, unsigned Alignment) const;
  bool isLegalNTLoad(Type *DataType, unsigned Alignment) const;

to TTI, leaving the target independent default implementation as
returning true, but with overriding implementations for X86 that
check the legality based on available Subtarget features.

This fixes https://llvm.org/PR40759

Differential Revision: https://reviews.llvm.org/D61764

llvm-svn: 363581
2019-06-17 17:20:08 +00:00
Whitney Tsang
15b7f5b72d PHINode: introduce setIncomingValueForBlock() function, and use it.
Summary:
There is PHINode::getBasicBlockIndex() and PHINode::setIncomingValue()
but no function to replace incoming value for a specified BasicBlock*
predecessor.
Clearly, there are a lot of places that could use that functionality.

Reviewer: craig.topper, lebedev.ri, Meinersbur, kbarton, fhahn
Reviewed By: Meinersbur, fhahn
Subscribers: fhahn, hiraditya, zzheng, jsji, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D63338

llvm-svn: 363566
2019-06-17 14:38:56 +00:00
Bjorn Pettersson
83773b77a5 [LV] Deny irregular types in interleavedAccessCanBeWidened
Summary:
Avoid that loop vectorizer creates loads/stores of vectors
with "irregular" types when interleaving. An example of
an irregular type is x86_fp80 that is 80 bits, but that
may have an allocation size that is 96 bits. So an array
of x86_fp80 is not bitcast compatible with a vector
of the same type.

Not sure if interleavedAccessCanBeWidened is the best
place for this check, but it solves the problem seen
in the added test case. And it is the same kind of check
that already exists in memoryInstructionCanBeWidened.

Reviewers: fhahn, Ayal, craig.topper

Reviewed By: fhahn

Subscribers: hiraditya, rkruppe, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63386

llvm-svn: 363547
2019-06-17 12:02:24 +00:00
Orlando Cazalet-Hyams
a947156396 Revert "[DebugInfo@O2][LoopVectorize] pr39024: Vectorized code linenos step through loop even after completion"
This reverts commit 1a0f7a2077.
See phabricator thread for D60831.

llvm-svn: 363132
2019-06-12 08:34:51 +00:00
Orlando Cazalet-Hyams
1a0f7a2077 [DebugInfo@O2][LoopVectorize] pr39024: Vectorized code linenos step through loop even after completion
Summary:
Bug: https://bugs.llvm.org/show_bug.cgi?id=39024

The bug reports that a vectorized loop is stepped through 4 times and each step through the loop seemed to show a different path. I found two problems here:

A) An incorrect line number on a preheader block (for.body.preheader) instruction causes a step into the loop before it begins.
B) Instructions in the middle block have different line numbers which give the impression of another iteration.

In this patch I give all of the middle block instructions the line number of the scalar loop latch terminator branch. This seems to provide the smoothest debugging experience because the vectorized loops will always end on this line before dropping into the scalar loop. To solve problem A I have altered llvm::SplitBlockPredecessors to accommodate loop header blocks.

I have set up a separate review D61933 for a fix which is required for this patch.

Reviewers: samsonov, vsk, aprantl, probinson, anemet, hfinkel, jmorse

Reviewed By: hfinkel, jmorse

Subscribers: jmorse, javed.absar, eraman, kcc, bjope, jmellorcrummey, hfinkel, gbedwell, hiraditya, zzheng, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D60831

llvm-svn: 363046
2019-06-11 10:37:20 +00:00
Florian Hahn
9bbdde2598 [LV] Remove the redundant using LoopVectorizationPlanner:VPlanPtr
VPlan.h already contains the declaration of VPlanPtr type alias:

using VPlanPtr = std::unique_ptr<VPlan>;

The LoopVectorizationPlanner class also contains the same declaration
of VPlanPtr and therefore LoopVectorize requires a long wording when
its methods return VPlanPtr:

    LoopVectorizationPlanner::VPlanPtr
    LoopVectorizationPlanner::buildVPlanWithVPRecipes(...)

but LoopVectorize.cpp includes VPlan.h (via LoopVectorizationPlanner.h)
and can use VPlanPtr from that header.

Patch by Pavel Samolysov.

Reviewers: hsaito, rengolin, fhahn

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D62576

llvm-svn: 362126
2019-05-30 18:46:13 +00:00
Craig Topper
778e445c58 [LoopVectorize] Add FNeg instruction support
Differential Revision: https://reviews.llvm.org/D62510

llvm-svn: 362124
2019-05-30 18:19:35 +00:00
Simon Pilgrim
3c05cad03e LoopVectorizationCostModel::selectInterleaveCount - assert we have a non-zero loop cost. NFCI.
The input LoopCost value can be zero, but if so it should be recalculated with the current VF. After that it should always be non-zero.

llvm-svn: 361387
2019-05-22 14:18:17 +00:00
Florian Hahn
9e778e6c73 [LV] Move getScalarizationOverhead and vector call cost computations to CM. (NFC)
This reduces the number of parameters we need to pass in and they seem a
natural fit in LoopVectorizationCostModel. Also simplifies things for
D59995.

As a follow up refactoring, we could only expose a expose a
shouldUseVectorIntrinsic() helper in LoopVectorizationCostModel, instead
of calling getVectorCallCost/getVectorIntrinsicCost in
InnerLoopVectorizer/VPRecipeBuilder.

Reviewers: Ayal, hsaito, dcaballe, rengolin

Reviewed By: rengolin

Differential Revision: https://reviews.llvm.org/D61638

llvm-svn: 360758
2019-05-15 10:05:49 +00:00
Alina Sbirlea
f31eba6494 [MemorySSA] Teach LoopSimplify to preserve MemorySSA.
Summary:
Preserve MemorySSA in LoopSimplify, in the old pass manager, if the analysis is available.
Do not preserve it in the new pass manager.
Update tests.

Subscribers: nemanjai, jlebar, javed.absar, Prazek, kbarton, zzheng, jsji, llvm-commits, george.burgess.iv, chandlerc

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60833

llvm-svn: 360270
2019-05-08 17:05:36 +00:00
Kostya Serebryany
b9c5768302 revert r360162 as it breaks most of the buildbots
llvm-svn: 360190
2019-05-07 20:57:11 +00:00
Orlando Cazalet-Hyams
78a6062c24 [DebugInfo@O2][LoopVectorize] pr39024: Vectorized code linenos step through loop even after completion
Summary:
Bug: https://bugs.llvm.org/show_bug.cgi?id=39024

The bug reports that a vectorized loop is stepped through 4 times and each step through the loop seemed to show a different path. I found two problems here:

A) An incorrect line number on a preheader block (for.body.preheader) instruction causes a step into the loop before it begins.
B) Instructions in the middle block have different line numbers which give the impression of another iteration.

In this patch I give all of the middle block instructions the line number of the scalar loop latch terminator branch. This seems to provide the smoothest debugging experience because the vectorized loops will always end on this line before dropping into the scalar loop. To solve problem A I have altered llvm::SplitBlockPredecessors to accommodate loop header blocks.

Reviewers: samsonov, vsk, aprantl, probinson, anemet, hfinkel

Reviewed By: hfinkel

Subscribers: bjope, jmellorcrummey, hfinkel, gbedwell, hiraditya, zzheng, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D60831

llvm-svn: 360162
2019-05-07 15:37:38 +00:00
Alina Sbirlea
733c8c40c8 Enable LoopVectorization by default.
Summary:
When refactoring vectorization flags, vectorization was disabled by default in the new pass manager.
This patch re-enables is for both managers, and changes the assumptions opt makes, based on the new defaults.
Comments in opt.cpp should clarify the intended use of all flags to enable/disable vectorization.

Reviewers: chandlerc, jgorbe

Subscribers: jlebar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61091

llvm-svn: 359167
2019-04-25 04:49:48 +00:00
Alina Sbirlea
0499a2f961 [NewPassManager] Adding pass tuning options: loop vectorize.
Summary:
Trying to add the plumbing necessary to add tuning options to the new pass manager.
Testing with the flags for loop vectorize.

Reviewers: chandlerc

Subscribers: sanjoy, mehdi_amini, jlebar, steven_wu, dexonsmith, dang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59723

llvm-svn: 358763
2019-04-19 16:11:59 +00:00
Hiroshi Yamauchi
09e539fcae [PGO] Profile guided code size optimization.
Summary:
Enable some of the existing size optimizations for cold code under PGO.

A ~5% code size saving in big internal app under PGO.

The way it gets BFI/PSI is discussed in the RFC thread

http://lists.llvm.org/pipermail/llvm-dev/2019-March/130894.html 

Note it doesn't currently touch loop passes.

Reviewers: davidxl, eraman

Reviewed By: eraman

Subscribers: mgorny, javed.absar, smeenai, mehdi_amini, eraman, zzheng, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59514

llvm-svn: 358422
2019-04-15 16:49:00 +00:00
Florian Hahn
db1a69c250 [VPLAN] Minor improvement to testing and debug messages.
1. Use computed VF for stress testing.
2. If the computed VF does not produce vector code (VF smaller than 2), force VF to be 4.
3. Test vectorization of i64 data on AArch64 to make sure we generate VF != 4 (on X86 that was already tested on AVX).

Patch by Francesco Petrogalli <francesco.petrogalli@arm.com>

Differential Revision: https://reviews.llvm.org/D59952

llvm-svn: 358056
2019-04-10 08:17:28 +00:00
Evandro Menezes
85bd3978ae [IR] Refactor attribute methods in Function class (NFC)
Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

llvm-svn: 357731
2019-04-04 22:40:06 +00:00
Vedant Kumar
c6bceec01a [DebugInfo] Fix pr41180 : Loop Vectorization Debugify Failure
Bug: https://bugs.llvm.org/show_bug.cgi?id=41180

In the bug test case the debug location was missing for the cmp instruction in
the "middle block" BB. This patch fixes the bug by copying the debug location
from the cmp of the scalar loop's terminator branch, if it exists.

The patch also fixes the debug location on the subsequent branch instruction.
It was previously using the location of the of the original loop's pre-header
block terminator. Both of these instructions will now map to the source line of
the conditional branch in the original loop.

A regression test has been added that covers these issues.

Patch by Orlando Cazalet-Hyams!

Differential Revision: https://reviews.llvm.org/D59944

llvm-svn: 357499
2019-04-02 17:28:34 +00:00
Benjamin Kramer
ba2ea93ad1 Make helper functions static. NFC.
llvm-svn: 357187
2019-03-28 17:18:42 +00:00
Florian Hahn
e21ed594d8 [VPlan] Determine Vector Width programmatically.
With this change, the VPlan native path is triggered with the directive:

   #pragma clang loop vectorize(enable)

There is no need to specify the vectorize_width(N) clause.

Patch by Francesco Petrogalli <francesco.petrogalli@arm.com>

Differential Revision: https://reviews.llvm.org/D57598

llvm-svn: 357156
2019-03-28 10:37:12 +00:00
Sanjoy Das
3f5ce18658 Reland "Relax constraints for reduction vectorization"
Change from original commit: move test (that uses an X86 triple) into the X86
subdirectory.

Original description:
Gating vectorizing reductions on *all* fastmath flags seems unnecessary;
`reassoc` should be sufficient.

Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal

Reviewed By: sdesmalen

Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57728

llvm-svn: 355889
2019-03-12 01:31:44 +00:00
Sanjoy Das
2136a5bc49 Revert "Relax constraints for reduction vectorization"
This reverts commit r355868.  Breaks hexagon.

llvm-svn: 355873
2019-03-11 22:37:31 +00:00
Sanjoy Das
93f8cc186a Relax constraints for reduction vectorization
Summary:
Gating vectorizing reductions on *all* fastmath flags seems unnecessary;
`reassoc` should be sufficient.

Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal

Reviewed By: sdesmalen

Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57728

llvm-svn: 355868
2019-03-11 21:36:41 +00:00
Alina Sbirlea
0a8bc14ad7 [MemorySSA & LoopPassManager] Add remaining book keeping [NFCI].
Add plumbing to get MemorySSA in the remaining loop passes.
Also update unit test to add the dependency.
[EnableMSSALoopDependency remains disabled].

llvm-svn: 353901
2019-02-12 23:48:02 +00:00
Florian Hahn
f557a94aa3 [LV] Remove unnecessary assignment to UserIC.
llvm-svn: 353469
2019-02-07 21:23:37 +00:00
Florian Hahn
ba5acbc4fe [LV] Prevent interleaving if computeMaxVF returned None.
As discussed in D57382, interleaving should be avoided if computeMaxVF
returns None, same as we currently do for vectorization.

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=6477

Reviewers: Ayal, dcaballe, hsaito, mkuper, rengolin

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D57837

llvm-svn: 353461
2019-02-07 20:49:10 +00:00
James Y Knight
7716075a17 [opaque pointer types] Pass value type to GetElementPtr creation.
This cleans up all GetElementPtr creation in LLVM to explicitly pass a
value type rather than deriving it from the pointer's element-type.

Differential Revision: https://reviews.llvm.org/D57173

llvm-svn: 352913
2019-02-01 20:44:47 +00:00
James Y Knight
14359ef1b6 [opaque pointer types] Pass value type to LoadInst creation.
This cleans up all LoadInst creation in LLVM to explicitly pass the
value type rather than deriving it from the pointer's element-type.

Differential Revision: https://reviews.llvm.org/D57172

llvm-svn: 352911
2019-02-01 20:44:24 +00:00
Mircea Trofin
ec02630278 [llvm] Clarify responsiblity of some of DILocation discriminator APIs
Summary:
Renamed setBaseDiscriminator to cloneWithBaseDiscriminator, to match
similar APIs. Also changed its behavior to copy over the other
discriminator components, instead of eliding them.

Renamed cloneWithDuplicationFactor to
cloneByMultiplyingDuplicationFactor, which more closely matches what
this API does.

Reviewers: dblaikie, wmi

Reviewed By: dblaikie

Subscribers: zzheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D56220

llvm-svn: 351996
2019-01-24 00:10:25 +00:00
Hideki Saito
4e4ecae028 [LV][VPlan] Change to implement VPlan based predication for
VPlan-native path

Context: Patch Series #2 for outer loop vectorization support in LV
using VPlan. (RFC:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119523.html).

Patch series #2 checks that inner loops are still trivially lock-step
among all vector elements. Non-loop branches are blindly assumed as
divergent.

Changes here implement VPlan based predication algorithm to compute
predicates for blocks that need predication. Predicates are computed
for the VPLoop region in reverse post order. A block's predicate is
computed as OR of the masks of all incoming edges. The mask for an
incoming edge is computed as AND of predecessor block's predicate and
either predecessor's Condition bit or NOT(Condition bit) depending on
whether the edge from predecessor block to the current block is true
or false edge.

Reviewers: fhahn, rengolin, hsaito, dcaballe

Reviewed By: fhahn

Patch by Satish Guggilla, thanks!

Differential Revision: https://reviews.llvm.org/D53349

llvm-svn: 351990
2019-01-23 22:43:12 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
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llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Mircea Trofin
b53eeb6f4c [llvm] API for encoding/decoding DWARF discriminators.
Summary:
Added a pair of APIs for encoding/decoding the 3 components of a DWARF discriminator described in http://lists.llvm.org/pipermail/llvm-dev/2016-October/106532.html: the base discriminator, the duplication factor (useful in profile-guided optimization) and the copy index (used to identify copies of code in cases like loop unrolling)

The encoding packs 3 unsigned values in 32 bits. This CL addresses 2 issues:
- communicates overflow back to the user
- supports encoding all 3 components together. Current APIs assume a sequencing of events. For example, creating a new discriminator based on an existing one by changing the base discriminator was not supported.

Reviewers: davidxl, danielcdh, wmi, dblaikie

Reviewed By: dblaikie

Subscribers: zzheng, dmgreen, aprantl, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D55681

llvm-svn: 349973
2018-12-21 22:48:50 +00:00
Michael Kruse
d4eb13c880 [LoopVectorize] Rename pass options. NFC.
Rename:
NoUnrolling to InterleaveOnlyWhenForced
and
AlwaysVectorize to !VectorizeOnlyWhenForced

Contrary to what the name 'AlwaysVectorize' suggests, it does not
unconditionally vectorize all loops, but applies a cost model to
determine whether vectorization is profitable to all loops. Hence,
passing false will disable the cost model, except when a loop is marked
with llvm.loop.vectorize.enable. The 'OnlyWhenForced' suffix (suggested
by @hfinkel in D55716) better matches this behavior.

Similarly, 'NoUnrolling' disables the profitability cost model for
interleaving (a term to distinguish it from unrolling by the
LoopUnrollPass); rename it for consistency.

Differential Revision: https://reviews.llvm.org/D55785

llvm-svn: 349513
2018-12-18 17:46:09 +00:00