Commit Graph

128 Commits

Author SHA1 Message Date
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
Adrian Prantl 83d87520ed GlobalDCE: Teach isEmptyFunction() to ignore debug intrinsics.
This fixes PR39669.
https://bugs.llvm.org/show_bug.cgi?id=39669

llvm-svn: 347065
2018-11-16 17:47:21 +00:00
Xin Tong 9b7e45159f [GlobalDCE] AvailableExternal linkage is checked in isDiscardableIfUnused [NFC].
Summary:
AvailableExternal was not handled in isDiscardableIfUnused when isDiscardableIfUnused
was added in r158476. Till it was handled in r247044. This is a NFC.

Reviewers: pcc, tejohnson

Reviewed By: tejohnson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D52319

llvm-svn: 342684
2018-09-20 21:16:16 +00:00
Michael Zolotukhin 6af4f232b5 Remove redundant includes from lib/Transforms.
llvm-svn: 320628
2017-12-13 21:31:01 +00:00
Michael Zolotukhin c4fcc189d2 [GlobalDCE] Use DenseMap instead of unordered_multimap for GVDependencies.
Summary:
std::unordered_multimap happens to be very slow when the number of elements
grows large. On one of our internal applications we observed a 17x compile time
improvement from changing it to DenseMap.

Reviewers: mehdi_amini, serge-sans-paille, davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38916

llvm-svn: 316045
2017-10-17 23:47:06 +00:00
Mehdi Amini 888dee444b Global DCE performance improvement
Change the original algorithm so that it scales better when meeting
very large bitcode where every instruction does not implies a global.

The target query is "how to you get all the globals referenced by
another global"?

Before this patch, it was doing this by walking the body (or the
initializer) and collecting the references. What this patch is doing,
it precomputing the answer to this query for the whole module by
walking the use-list of every global instead.

Patch by: Serge Guelton <serge.guelton@telecom-bretagne.eu>

Differential Revision: https://reviews.llvm.org/D28549

llvm-svn: 293328
2017-01-27 19:48:57 +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 e8c66b2766 [PM] Replace the hard invalidate in JumpThreading for LVI with correct
invalidation of deleted functions in GlobalDCE.

This was always testing a bug really triggered in GlobalDCE. Right now
we have analyses with asserting value handles into IR. As long as those
remain, when *deleting* an IR unit, we cannot wait for the normal
invalidation scheme to kick in even though it was designed to work
correctly in the face of these kinds of deletions. Instead, the pass
needs to directly handle invalidating the analysis results pointing at
that IR unit.

I've tought the Inliner about this and this patch teaches GlobalDCE.
This will handle the asserting VH case in the existing test as well as
other issues of the same fundamental variety. I've moved the test into
the GlobalDCE directory and added a comment explaining what is going on.

Note that we cannot simply require LVI here because LVI is too lazy.

llvm-svn: 292773
2017-01-23 08:33:24 +00:00
Peter Collingbourne 4f3b2df9bb GlobalDCE: Restore a statement accidentally removed in r285048.
llvm-svn: 285052
2016-10-25 02:57:27 +00:00
Peter Collingbourne 7695cb6da8 GlobalDCE: Deduplicate code. NFCI.
llvm-svn: 285048
2016-10-25 01:58:26 +00:00
Peter Collingbourne 6d88fde3af IR: Introduce Module::global_objects().
This is a convenience iterator that allows clients to enumerate the
GlobalObjects within a Module.

Also start using it in a few places where it is obviously the right thing
to use.

Differential Revision: http://reviews.llvm.org/D21580

llvm-svn: 273470
2016-06-22 20:29:42 +00:00
Chandler Carruth 164a2aa6f4 [PM] Remove support for omitting the AnalysisManager argument to new
pass manager passes' `run` methods.

This removes a bunch of SFINAE goop from the pass manager and just
requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead
argument. This is a small price to pay for the simplicity of the system
as a whole, despite the noise that changing it causes at this stage.

This will also helpfull allow us to make the signature of the run
methods much more flexible for different kinds af passes to support
things like intelligently updating the pass's progression over IR units.

While this touches many, many, files, the changes are really boring.
Mostly made with the help of my trusty perl one liners.

Thanks to Sean and Hal for bouncing ideas for this with me in IRC.

llvm-svn: 272978
2016-06-17 00:11:01 +00:00
David Majnemer 95549497ec [GlobalDCE, Misc] Don't remove functions referenced by ifuncs
We forgot to consider the target of ifuncs when considering if a
function was alive or dead.

N.B. Also update a few auxiliary tools like bugpoint and
verify-uselistorder.

This fixes PR27593.

llvm-svn: 268468
2016-05-04 00:20:48 +00:00
Davide Italiano 66228c4cf1 [IPO/GlobalDCE] Port to the new pass manager.
Differential Revision:  http://reviews.llvm.org/D19782

llvm-svn: 268425
2016-05-03 19:39:15 +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
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Dmitry Polukhin a3d5b0b218 [IFUNC] Use GlobalIndirectSymbol when aliases and ifuncs have something similar
Second part extracted from http://reviews.llvm.org/D15525

Use GlobalIndirectSymbol in all cases when aliases and ifuncs have
something in common.

Differential Revision: http://reviews.llvm.org/D18754

llvm-svn: 265382
2016-04-05 08:47:51 +00:00
Vedant Kumar 3a63fb316c Re-reapply "[IR] Move optional data in llvm::Function into a hungoff uselist"
Make personality functions, prefix data, and prologue data hungoff
operands of Function.

This is based on the email thread "[RFC] Clean up the way we store
optional Function data" on llvm-dev.

Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback!

Includes a fix to scrub value subclass data in dropAllReferences. Does not
use binary literals.

Differential Revision: http://reviews.llvm.org/D13829

llvm-svn: 256095
2015-12-19 08:52:49 +00:00
Vedant Kumar 44dd9871e8 Revert "Reapply "[IR] Move optional data in llvm::Function into a hungoff uselist""
This reverts commit r256093.

This broke lld-x86_64-win7 because of -Werror,-Wc++1y-extensions.

llvm-svn: 256094
2015-12-19 08:48:43 +00:00
Vedant Kumar d481752e68 Reapply "[IR] Move optional data in llvm::Function into a hungoff uselist"
Make personality functions, prefix data, and prologue data hungoff
operands of Function.

This is based on the email thread "[RFC] Clean up the way we store
optional Function data" on llvm-dev.

Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback!

Includes a fix to scrub value subclass data in dropAllReferences.

Differential Revision: http://reviews.llvm.org/D13829

llvm-svn: 256093
2015-12-19 08:29:51 +00:00
Vedant Kumar e069c4b6d1 Revert "[IR] Move optional data in llvm::Function into a hungoff uselist"
This reverts commit r256090.

This broke llvm-clang-lld-x86_64-debian-fast.

llvm-svn: 256091
2015-12-19 07:30:44 +00:00
Vedant Kumar be7525d4fa [IR] Move optional data in llvm::Function into a hungoff uselist
Make personality functions, prefix data, and prologue data hungoff
operands of Function.

This is based on the email thread "[RFC] Clean up the way we store
optional Function data" on llvm-dev.

Thanks to sanjoyd, majnemer, rnk, loladiro, and dexonsmith for feedback!

Differential Revision: http://reviews.llvm.org/D13829

llvm-svn: 256090
2015-12-19 07:08:56 +00:00
Yaron Keren 3d49f6df94 Rangify for loops in GlobalDCE, NFC.
llvm-svn: 242619
2015-07-18 19:57:34 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
David Majnemer 7fddeccb8b Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

llvm-svn: 239940
2015-06-17 20:52:32 +00:00
Peter Collingbourne 0dbc7088da GlobalDCE: Improve performance for large modules containing comdats.
When we encounter a global with a comdat, rather than iterating over
every global in the module to find globals in the same comdat, store the
members in a multimap. This effectively lowers the complexity to O(N log N),
improving performance significantly for large modules such as might be
encountered during LTO.

It looks like we used to do something like this until r219191.

No functional change.

Differential Revision: http://reviews.llvm.org/D8431

llvm-svn: 232743
2015-03-19 18:23:29 +00:00
Peter Collingbourne 51d2de7b9e Prologue support
Patch by Ben Gamari!

This redefines the `prefix` attribute introduced previously and
introduces a `prologue` attribute.  There are a two primary usecases
that these attributes aim to serve,

  1. Function prologue sigils

  2. Function hot-patching: Enable the user to insert `nop` operations
     at the beginning of the function which can later be safely replaced
     with a call to some instrumentation facility

  3. Runtime metadata: Allow a compiler to insert data for use by the
     runtime during execution. GHC is one example of a compiler that
     needs this functionality for its tables-next-to-code functionality.

Previously `prefix` served cases (1) and (2) quite well by allowing the user
to introduce arbitrary data at the entrypoint but before the function
body. Case (3), however, was poorly handled by this approach as it
required that prefix data was valid executable code.

Here we redefine the notion of prefix data to instead be data which
occurs immediately before the function entrypoint (i.e. the symbol
address). Since prefix data now occurs before the function entrypoint,
there is no need for the data to be valid code.

The previous notion of prefix data now goes under the name "prologue
data" to emphasize its duality with the function epilogue.

The intention here is to handle cases (1) and (2) with prologue data and
case (3) with prefix data.

References
----------

This idea arose out of discussions[1] with Reid Kleckner in response to a
proposal to introduce the notion of symbol offsets to enable handling of
case (3).

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-May/073235.html

Test Plan: testsuite

Differential Revision: http://reviews.llvm.org/D6454

llvm-svn: 223189
2014-12-03 02:08:38 +00:00
David Blaikie 70573dcd9f Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

llvm-svn: 222334
2014-11-19 07:49:26 +00:00
David Majnemer e025321d36 GlobalDCE: Don't drop any COMDAT members
If we require a single member of a comdat, require all of the other
members as well.

This fixes PR20981.

llvm-svn: 219191
2014-10-07 07:07:19 +00:00
Bruno Cardoso Lopes e2a1fa35df Remove dangling initializers in GlobalDCE
GlobalDCE deletes global vars and updates their initializers to nullptr
while leaving underlying constants to be cleaned up later by its uses.
The clean up may never happen, fix this by forcing it every time it's
safe to destroy constants.

Final patch by Rafael Espindola
http://reviews.llvm.org/D4931

<rdar://problem/17523868>

llvm-svn: 216390
2014-08-25 17:51:14 +00:00
Pete Cooper 91e4ba2f88 Revert "GlobalDCE: Delete available_externally initializers if it allows removing the value the initializer is referring to."
This reverts commit 5b55a47e94e28fbb56d0cd5d72c3db9105c15b4c.

A test case was found to crash after this was applied.  I'll file a bug to track fixing this with the test case needed.

llvm-svn: 212550
2014-07-08 17:06:03 +00:00
Benjamin Kramer 3c5b126239 GlobalDCE: Delete available_externally initializers if it allows removing the value the initializer is referring to.
This is useful for functions that are not actually available externally but
referenced by a vtable of some kind. Clang emits functions like this for the MS
ABI.

PR20182.

llvm-svn: 212337
2014-07-04 12:36:05 +00:00
David Majnemer dad0a645a7 IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

llvm-svn: 211920
2014-06-27 18:19:56 +00:00
Craig Topper 66f09ad041 [C++11] Use 'nullptr'.
llvm-svn: 210442
2014-06-08 22:29:17 +00:00
Richard Smith c167d656e7 Re-commit r208025, reverted in r208030, with a fix for a conformance issue
which GCC detects and Clang does not!

llvm-svn: 208033
2014-05-06 01:44:26 +00:00
Richard Smith 09bf116939 Revert r208025, which made buildbots unhappy for unknown reasons.
llvm-svn: 208030
2014-05-06 01:26:00 +00:00
Richard Smith 6cf1d744d8 Add llvm::function_ref (and a couple of uses of it), representing a type-erased reference to a callable object.
llvm-svn: 208025
2014-05-06 01:01:29 +00:00
Nico Weber 4b2acde21a Teach GlobalDCE how to remove empty global_ctor entries.
This moves most of GlobalOpt's constructor optimization
code out of GlobalOpt into Transforms/Utils/CDtorUtils.{h,cpp}. The
public interface is a single function OptimizeGlobalCtorsList() that
takes a predicate returning which constructors to remove.

GlobalOpt calls this with a function that statically evaluates all
constructors, just like it did before. This part of the change is
behavior-preserving.

Also add a call to this from GlobalDCE with a filter that removes global
constructors that contain a "ret" instruction and nothing else – this
fixes PR19590.

llvm-svn: 207856
2014-05-02 18:35:25 +00:00
Craig Topper f40110f4d8 [C++] Use 'nullptr'. Transforms edition.
llvm-svn: 207196
2014-04-25 05:29:35 +00:00
Chandler Carruth 964daaaf19 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

llvm-svn: 206844
2014-04-22 02:55:47 +00:00
Craig Topper 3e4c697ca1 [C++11] Add 'override' keyword to virtual methods that override their base class.
llvm-svn: 202953
2014-03-05 09:10:37 +00:00
Peter Collingbourne 3fa50f9b05 Implement function prefix data as an IR feature.
Previous discussion:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-July/063909.html

Differential Revision: http://llvm-reviews.chandlerc.com/D1191

llvm-svn: 190773
2013-09-16 01:08:15 +00:00
Benjamin Kramer adc1727c39 GlobalDCE: Fix an oversight in my last commit that could lead to crashes.
There is a Constant with non-constant operands: blockaddress.

llvm-svn: 179460
2013-04-13 16:11:14 +00:00
Benjamin Kramer 89ca4bc6d4 Fix a scalability issue with complex ConstantExprs.
This is basically the same fix in three different places. We use a set to avoid
walking the whole tree of a big ConstantExprs multiple times.

For example: (select cmp, (add big_expr 1), (add big_expr 2))
We don't want to visit big_expr twice here, it may consist of thousands of
nodes.

The testcase exercises this by creating an insanely large ConstantExprs out of
a loop. It's questionable if the optimizer should ever create those, but this
can be triggered with real C code. Fixes PR15714.

llvm-svn: 179458
2013-04-13 12:53:18 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Rafael Espindola def1b09be2 Implement the isSafeToDiscardIfUnused predicate and use it in globalopt and
globaldce. Globaldce was already removing linkonce globals, but globalopt was
not.

llvm-svn: 158476
2012-06-14 22:48:13 +00:00