Commit Graph

49 Commits

Author SHA1 Message Date
Eric Christopher 10563e16aa [Analysis/Transforms/Sanitizers] As part of using inclusive language
within the llvm project, migrate away from the use of blacklist and
whitelist.
2020-06-20 00:42:26 -07:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
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
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
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
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
David Blaikie 31b98d2e99 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Karl-Johan Karlsson 478232d52f [NaryReassociate] Detect deleted instr with WeakVH
Summary:
If NaryReassociate succeed it will, when replacing the old instruction
with the new instruction, also recursively delete trivially
dead instructions from the old instruction. However, if the input to the
NaryReassociate pass contain dead code it is not save to recursively
delete trivially deadinstructions as it might lead to deleting the newly
created instruction.

This patch will fix the problem by using WeakVH to detect this
rare case, when the newly created instruction is dead, and it will then
restart the basic block iteration from the beginning.

This fixes pr37539

Reviewers: tra, meheff, grosser, sanjoy

Reviewed By: sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47139

llvm-svn: 333155
2018-05-24 06:09:02 +00:00
David Blaikie 2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Evgeny Stupachenko 204ade4102 Add early exit on reassociation of 0 expression.
Summary:

Before the patch a try to reassociate ((v * 16) * 0) * 1 fall into infinite loop

Reviewers: pankajchawla

Differential Revision: http://reviews.llvm.org/D41467

From: Evgeny Stupachenko <evstupac@gmail.com>
                         <evgeny.v.stupachenko@intel.com>
llvm-svn: 326861
2018-03-07 02:17:08 +00:00
Eugene Zelenko 6cadde7f40 [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
Daniel Jasper 3344a21236 Revert r314923: "Recommit : Use the basic cost if a GEP is not used as addressing mode"
Significantly reduces performancei (~30%) of gipfeli
(https://github.com/google/gipfeli)

I have not yet managed to reproduce this regression with the open-source
version of the benchmark on github, but will work with others to get a
reproducer to you later today.

llvm-svn: 315680
2017-10-13 14:04:21 +00:00
Jun Bum Lim d40e03c2d8 Recommit : Use the basic cost if a GEP is not used as addressing mode
Recommitting r314517 with the fix for handling ConstantExpr.

Original commit message:
  Currently, getGEPCost() returns TCC_FREE whenever a GEP is a legal addressing
  mode in the target. However, since it doesn't check its actual users, it will
  return FREE even in cases where the GEP cannot be folded away as a part of
  actual addressing mode. For example, if an user of the GEP is a call
  instruction taking the GEP as a parameter, then the GEP may not be folded in
  isel.

llvm-svn: 314923
2017-10-04 18:33:52 +00:00
Alex Shlyapnikov e76aa3b0b2 Revert "Use the basic cost if a GEP is not used as addressing mode"
This reverts commit r314517.

This commit crashes sanitizer bots, for example:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/4167

Stack snippet:
...
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/Support/Casting.h:255:0
llvm::TargetTransformInfoImplCRTPBase<llvm::X86TTIImpl>::getGEPCost(llvm::GEPOperator const*, llvm::ArrayRef<llvm::Value const*>)
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h:742:0
llvm::TargetTransformInfoImplCRTPBase<llvm::X86TTIImpl>::getUserCost(llvm::User const*, llvm::ArrayRef<llvm::Value const*>)
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h:782:0
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/lib/Analysis/TargetTransformInfo.cpp:116:0
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/ADT/SmallVector.h:116:0
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/ADT/SmallVector.h:343:0
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/ADT/SmallVector.h:864:0
/mnt/b/sanitizer-buildbot1/sanitizer-x86_64-linux/build/llvm/include/llvm/Analysis/TargetTransformInfo.h:285:0
...

llvm-svn: 314560
2017-09-29 22:04:45 +00:00
Jun Bum Lim 0e16a59e83 Use the basic cost if a GEP is not used as addressing mode
Summary:
Currently, getGEPCost() returns TCC_FREE whenever a GEP is a legal addressing mode in the target.
However, since it doesn't check its actual users, it will return FREE even in cases
where the GEP cannot be folded away as a part of actual addressing mode.
For example, if an user of the GEP is a call instruction taking the GEP as a parameter,
then the GEP may not be folded in isel.

Reviewers: hfinkel, efriedma, mcrosier, jingyue, haicheng

Reviewed By: hfinkel

Subscribers: javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D38085

llvm-svn: 314517
2017-09-29 14:50:16 +00:00
Sanjoy Das e6bca0eecb Rename WeakVH to WeakTrackingVH; NFC
This relands r301424.

llvm-svn: 301812
2017-05-01 17:07:49 +00:00
Sanjoy Das 2cbeb00f38 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
Sanjoy Das 01de557738 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
Chandler Carruth 6acdca78a0 [PH] Replace uses of AssertingVH from members of analysis results with
a lazy-asserting PoisoningVH.

AssertVH is fundamentally incompatible with cache-invalidation of
analysis results. The invaliadtion happens after the AssertingVH has
already fired. Instead, use a PoisoningVH that will assert if the
dangling handle is ever used rather than merely be assigned or
destroyed.

This patch also removes all of the (numerous) doomed attempts to work
around this fundamental incompatibility. It is a pretty significant
simplification IMO.

The most interesting change is in the Inliner where we still do some
clearing because we don't want to rely on the coarse grained
invalidation strategy of the containing pass manager. However, I prefer
the approach that contains this logic to the cleanup phase of the
Inliner, and I think we could enhance the CGSCC analysis management
layer to make this even better in the future if desired.

The rest is straight cleanup.

I've also added a test for one of the harder cases to work around: when
a *module analysis* contains many AssertingVHes pointing at functions.

Differential Revision: https://reviews.llvm.org/D29006

llvm-svn: 292928
2017-01-24 12:55:57 +00:00
Chandler Carruth ca68a3ec47 [PM] Introduce an analysis set used to preserve all analyses over
a function's CFG when that CFG is unchanged.

This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.

I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.

Differential Revision: https://reviews.llvm.org/D28627

llvm-svn: 292054
2017-01-15 06:32:49 +00:00
Daniel Jasper aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Hal Finkel 3ca4a6bcf1 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Peter Collingbourne ab85225be4 IR: Change the gep_type_iterator API to avoid always exposing the "current" type.
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.

Differential Revision: https://reviews.llvm.org/D26594

llvm-svn: 288458
2016-12-02 02:24:42 +00:00
Peter Collingbourne 8dff03911c Analysis: Simplify the ScalarEvolution::getGEPExpr() interface. NFCI.
All existing callers were manually extracting information out of an existing
GEP instruction and passing it to getGEPExpr(). Simplify the interface by
changing it to take a GEPOperator instead.

llvm-svn: 286751
2016-11-13 06:59:50 +00:00
Daniel Berlin a36f46363f Convert some depth first traversals to depth_first
llvm-svn: 279331
2016-08-19 22:06:23 +00:00
Tim Shen b5e0f5ac95 [GraphTraits] Make nodes_iterator dereference to NodeType*/NodeRef
Currently nodes_iterator may dereference to a NodeType* or a NodeType&. Make them all dereference to NodeType*, which is NodeRef later.

Differential Revision: https://reviews.llvm.org/D23704
Differential Revision: https://reviews.llvm.org/D23705

llvm-svn: 279326
2016-08-19 21:20:13 +00:00
Sean Silva 0873e7d218 Add some comments linking back to PR28400.
Thanks to Mehdi for the suggestion!

llvm-svn: 277984
2016-08-08 07:03:49 +00:00
Sean Silva 7f21f4b264 [PM] More workaround for PR28400
llvm-svn: 277982
2016-08-08 05:38:06 +00:00
Wei Mi 1cf58f8996 [PM] Port NaryReassociate to the new PM
Differential Revision: https://reviews.llvm.org/D22648

llvm-svn: 276349
2016-07-21 22:28:52 +00:00
Jingyue Wu 15f3e82d42 [TTI] Expose TTI::getGEPCost and use it in SLSR and NaryReassociate.
NFC.

llvm-svn: 274940
2016-07-08 21:48:05 +00:00
Andrew Kaylor aa641a5171 Re-commit optimization bisect support (r267022) without new pass manager support.
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
2016-04-22 22:06:11 +00:00
Vedant Kumar 6013f45f92 Revert "Initial implementation of optimization bisect support."
This reverts commit r267022, due to an ASan failure:

  http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115
2016-04-22 06:51:37 +00:00
Andrew Kaylor f0f279291c Initial implementation of optimization bisect support.
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.

The bisection is enabled using a new command line option (-opt-bisect-limit).  Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit.  A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.

The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check.  Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute.  A new function call has been added for module and SCC passes that behaves in a similar way.

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267022
2016-04-21 17:58:54 +00:00
Eduard Burtescu 19eb03106d [opaque pointer types] [NFC] GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.
Summary:
GEPOperator: provide getResultElementType alongside getSourceElementType.
This is made possible by adding a result element type field to GetElementPtrConstantExpr, which GetElementPtrInst already has.

GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16275

llvm-svn: 258145
2016-01-19 17:28:00 +00:00
Jingyue Wu ba3ca76ed2 [NaryReassociate] allow candidate to have a different type
Summary:
If Candiadte may have a different type from GEP, we should bitcast or
pointer cast it to GEP's type so that the later RAUW doesn't complain.

Added a test in nary-gep.ll

Reviewers: tra, meheff

Subscribers: mcrosier, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D15618

llvm-svn: 256035
2015-12-18 21:36:30 +00:00
Duncan P. N. Exon Smith be4d8cba1c Scalar: Remove remaining ilist iterator implicit conversions
Remove remaining `ilist_iterator` implicit conversions from
LLVMScalarOpts.

This change exposed some scary behaviour in
lib/Transforms/Scalar/SCCP.cpp around line 1770.  This patch changes a
call from `Function::begin()` to `&Function::front()`, since the return
was immediately being passed into another function that takes a
`Function*`.  `Function::front()` started to assert, since the function
was empty.  Note that `Function::end()` does not point at a legal
`Function*` -- it points at an `ilist_half_node` -- so the other
function was getting garbage before.  (I added the missing check for
`Function::isDeclaration()`.)

Otherwise, no functionality change intended.

llvm-svn: 250211
2015-10-13 19:26:58 +00:00
Jingyue Wu df1a1b113b [NaryReassociate] SeenExprs records WeakVH
Summary:
The instructions SeenExprs records may be deleted during rewriting.
FindClosestMatchingDominator should ignore these deleted instructions.

Fixes PR24301.

Reviewers: grosser

Subscribers: grosser, llvm-commits

Differential Revision: http://reviews.llvm.org/D13315

llvm-svn: 248983
2015-10-01 03:51:44 +00:00
Marcello Maggioni 454faa84e2 [NaryReassociate] Add support for Mul instructions
This patch extends the current pass by handling
Mul instructions as well.

Patch by: Volkan Keles (vkeles@apple.com)

llvm-svn: 247705
2015-09-15 17:22:52 +00:00
Jingyue Wu 10fcea5d4b [ValueTracking] computeOverflowForSignedAdd and isKnownNonNegative
Summary:
Refactor, NFC

Extracts computeOverflowForSignedAdd and isKnownNonNegative from NaryReassociate to ValueTracking in case
others need it.

Reviewers: reames

Subscribers: majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D11313

llvm-svn: 245591
2015-08-20 18:27:04 +00:00
Chandler Carruth 2f1fd1658f [PM] Port ScalarEvolution to the new pass manager.
This change makes ScalarEvolution a stand-alone object and just produces
one from a pass as needed. Making this work well requires making the
object movable, using references instead of overwritten pointers in
a number of places, and other refactorings.

I've also wired it up to the new pass manager and added a RUN line to
a test to exercise it under the new pass manager. This includes basic
printing support much like with other analyses.

But there is a big and somewhat scary change here. Prior to this patch
ScalarEvolution was never *actually* invalidated!!! Re-running the pass
just re-wired up the various other analyses and didn't remove any of the
existing entries in the SCEV caches or clear out anything at all. This
might seem OK as everything in SCEV that can uses ValueHandles to track
updates to the values that serve as SCEV keys. However, this still means
that as we ran SCEV over each function in the module, we kept
accumulating more and more SCEVs into the cache. At the end, we would
have a SCEV cache with every value that we ever needed a SCEV for in the
entire module!!! Yowzers. The releaseMemory routine would dump all of
this, but that isn't realy called during normal runs of the pipeline as
far as I can see.

To make matters worse, there *is* actually a key that we don't update
with value handles -- there is a map keyed off of Loop*s. Because
LoopInfo *does* release its memory from run to run, it is entirely
possible to run SCEV over one function, then over another function, and
then lookup a Loop* from the second function but find an entry inserted
for the first function! Ouch.

To make matters still worse, there are plenty of updates that *don't*
trip a value handle. It seems incredibly unlikely that today GVN or
another pass that invalidates SCEV can update values in *just* such
a way that a subsequent run of SCEV will incorrectly find lookups in
a cache, but it is theoretically possible and would be a nightmare to
debug.

With this refactoring, I've fixed all this by actually destroying and
recreating the ScalarEvolution object from run to run. Technically, this
could increase the amount of malloc traffic we see, but then again it is
also technically correct. ;] I don't actually think we're suffering from
tons of malloc traffic from SCEV because if we were, the fact that we
never clear the memory would seem more likely to have come up as an
actual problem before now. So, I've made the simple fix here. If in fact
there are serious issues with too much allocation and deallocation,
I can work on a clever fix that preserves the allocations (while
clearing the data) between each run, but I'd prefer to do that kind of
optimization with a test case / benchmark that shows why we need such
cleverness (and that can test that we actually make it faster). It's
possible that this will make some things faster by making the SCEV
caches have higher locality (due to being significantly smaller) so
until there is a clear benchmark, I think the simple change is best.

Differential Revision: http://reviews.llvm.org/D12063

llvm-svn: 245193
2015-08-17 02:08:17 +00:00
Jingyue Wu 2e424da39b [NaryReassociate] remove redundant code
This check is already done by findClosestMatchingDominator.

llvm-svn: 243065
2015-07-23 23:13:37 +00:00
Jingyue Wu cf02ef315f [NaryReassociate] enhances nsw by leveraging @llvm.assume
Summary:
nsw are flaky and can often be removed by optimizations. This patch enhances
nsw by leveraging @llvm.assume in the IR. Specifically, NaryReassociate now
understands that

    assume(a + b >= 0) && assume(a >= 0) ==> a +nsw b

As a result, it can split more sext(a + b) into sext(a) + sext(b) for CSE.

Test Plan: nary-gep.ll

Reviewers: broune, meheff

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D10822

llvm-svn: 241139
2015-07-01 03:38:49 +00:00
Matt Arsenault fb88aca348 Make NaryReassociate pass the address space to isLegalAddressingMode
No test since the kinds of transforms this prevents seem to not really
be relevant for SI's different addressing modes.

llvm-svn: 239261
2015-06-07 20:17:42 +00:00
Jingyue Wu c2a014697a [NaryReassociate] Run EarlyCSE after NaryReassociate
Summary:
This patch made two improvements to NaryReassociate and the NVPTX pipeline

1. Run EarlyCSE/GVN after NaryReassociate to get rid of redundant common
expressions.

2. When adding an instruction to SeenExprs, maps both the SCEV before and after
reassociation to that instruction.

Test Plan: updated @reassociate_gep_nsw in nary-gep.ll

Reviewers: meheff, broune

Reviewed By: broune

Subscribers: dberlin, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9947

llvm-svn: 238396
2015-05-28 04:56:52 +00:00
Jingyue Wu 4fc97f6df8 [NaryReassoc] reassociate GEP for CSE
Summary:
x = &a[i];
y = &a[i + j];

=>

y = x + j;

along with some refactoring work such as extracting method
findClosestMatchingDominator.

Depends on D9786 which provides the ScalarEvolution::getGEPExpr interface.

Test Plan: nary-gep.ll

Reviewers: meheff, broune

Reviewed By: broune

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9802

llvm-svn: 237971
2015-05-21 23:17:30 +00:00
Jingyue Wu c74e33bffe [NaryReassociate] avoid running forever
Avoid running forever by checking we are not reassociating an expression into
the same form.

Tested with @avoid_infinite_loops in nary-add.ll

llvm-svn: 237269
2015-05-13 18:12:24 +00:00
Jingyue Wu 72fca6c89b Resurrect r235688
We should skip vector types which are not SCEVable.

test/CodeGen/NVPTX/sched2.ll passes

llvm-svn: 235695
2015-04-24 04:22:39 +00:00
Jingyue Wu 8579b81329 [NaryReassociate] run NaryReassociate iteratively
Summary:
An alternative is to use a worklist approach. However, that approach
would break the traversing order so that we couldn't lookup SeenExprs
efficiently. I don't see a clear winner here, so I picked the easier approach.

Along with two minor improvements:
1. preserves ScalarEvolution by forgetting instructions replaced
2. removes dead code locally avoiding the need of running DCE afterwards

Test Plan: add to slsr-add.ll a test that requires multiple iterations

Reviewers: broune, dberlin, atrick, meheff

Reviewed By: atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9058

llvm-svn: 235151
2015-04-17 00:25:10 +00:00
Jingyue Wu 771dfe91cf [NaryReassociate] speeds up candidate searching
Summary:
This fixes a left-over efficiency issue in D8950.

As Andrew and Daniel suggested, we can store the candidates in a stack
and pop the top element when it does not dominate the current
instruction. This reduces the worst-case time complexity to O(n).

Test Plan: a new test in nary-add.ll that exercises this optimization.

Reviewers: broune, dberlin, meheff, atrick

Reviewed By: atrick

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D9055

llvm-svn: 235129
2015-04-16 18:42:31 +00:00
Jingyue Wu 8cb6b2a292 Simplify n-ary adds by reassociation
Summary:
This transformation reassociates a n-ary add so that the add can partially reuse
existing instructions. For example, this pass can simplify

  void foo(int a, int b) {
    bar(a + b);
    bar((a + 2) + b);
  }

to

  void foo(int a, int b) {
    int t = a + b;
    bar(t);
    bar(t + 2);
  }

saving one add instruction.

Fixes PR22357 (https://llvm.org/bugs/show_bug.cgi?id=22357).

Test Plan: nary-add.ll

Reviewers: broune, dberlin, hfinkel, meheff, sanjoy, atrick

Reviewed By: sanjoy, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8950

llvm-svn: 234855
2015-04-14 04:59:22 +00:00