Commit Graph

3292 Commits

Author SHA1 Message Date
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
Teresa Johnson 5e1c0e7610 [LTO] Make detection of WPD remark enablement more robust
Summary:
Currently only the first function in the module is checked to
see if it has remarks enabled. If that first function is a declaration,
remarks will be incorrectly skipped. Change to look for the first
non-empty function.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D51556

llvm-svn: 342477
2018-09-18 13:42:24 +00:00
Xin Tong 8a505c64b0 [CVP] Handle instructions with no user. No need to create CVPLattice state. This handles terminator instructions and more.
Summary:
I tested this patch by compiling sqlite3.ll (clang -O3 -mllvm -disable-llvm-optzns sqlite3.c.)

 opt -called-value-propagation sqlite3.ll -time-passes -f -o out.ll

 I get 10+% speedup for the pass. I expect some of the gain come from skipping terminator instructions.

    === BEFORE THE PATCH ===
    ===-------------------------------------------------------------------------===
                          ... Pass execution timing report ...
    ===-------------------------------------------------------------------------===
      Total Execution Time: 0.5562 seconds (0.5582 wall clock)

       ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Name ---
       0.2485 ( 46.4%)   0.0120 ( 57.7%)   0.2605 ( 46.8%)   0.2615 ( 46.8%)  Bitcode Writer
       0.1607 ( 30.0%)   0.0079 ( 37.7%)   0.1685 ( 30.3%)   0.1693 ( 30.3%)  Called Value Propagation
       0.1262 ( 23.6%)   0.0009 (  4.5%)   0.1271 ( 22.9%)   0.1275 ( 22.8%)  Module Verifier
       0.5353 (100.0%)   0.0209 (100.0%)   0.5562 (100.0%)   0.5582 (100.0%)  Total

    === AFTER THE PATCH ===
    ===-------------------------------------------------------------------------===
                          ... Pass execution timing report ...
    ===-------------------------------------------------------------------------===
      Total Execution Time: 0.5338 seconds (0.5355 wall clock)

       ---User Time---   --System Time--   --User+System--   ---Wall Time---  --- Name ---
       0.2498 ( 48.6%)   0.0118 ( 59.3%)   0.2615 ( 49.0%)   0.2629 ( 49.1%)  Bitcode Writer
       0.1377 ( 26.8%)   0.0075 ( 37.8%)   0.1452 ( 27.2%)   0.1455 ( 27.2%)  Called Value Propagation
       0.1264 ( 24.6%)   0.0006 (  3.0%)   0.1270 ( 23.8%)   0.1271 ( 23.7%)  Module Verifier
       0.5139 (100.0%)   0.0199 (100.0%)   0.5338 (100.0%)   0.5355 (100.0%)  Total

Reviewers: davide, mssimpso

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49108

llvm-svn: 342398
2018-09-17 15:28:01 +00:00
Alexandros Lamprineas 8a1c374b2e [GVNHoist] Re-enable GVNHoist by default
Rebase rL341954 since https://bugs.llvm.org/show_bug.cgi?id=38912
has been fixed by rL342055.

Precommit testing performed:
* Overnight runs of csmith comparing the output between programs
  compiled with gvn-hoist enabled/disabled.
* Bootstrap builds of clang with UbSan/ASan configurations.

llvm-svn: 342387
2018-09-17 12:24:55 +00:00
Wei Mi 6a14325dff [SampleFDO] Add FunctionOffsetTable in compact binary format profile.
The patch saves a function offset table which maps function name index to the
offset of its function profile to the start of the binary profile. By using
the function offset table, for those function profiles which will not be used
when compiling a module, the profile reader does't have to read them. For
profile size around 10~20M, it saves ~10% compile time.

Differential Revision: https://reviews.llvm.org/D51863

llvm-svn: 342283
2018-09-14 20:52:59 +00:00
Sebastian Pop 0f30f08b02 HotColdSplit: fix invalid SSA due to outlining
The test used to fail with an invalid phi node: the two predecessors were outlined
and the SSA representation was left invalid. The patch adds the exit block to the
cold region.

llvm-svn: 342277
2018-09-14 20:36:19 +00:00
Sebastian Pop 3abcf69074 HotColdSplit: fix isSingleEntrySingleExit
remove duplicate entries from isSingleEntrySingleExit: the Entry block is
already added by the loop over the dominance frontier.

Remove the heuristic from isOutlineCandidate that a region is too small when it
only contains a basic block. With this change we now grow regions starting from
a block and we continue adding to the ValidColdRegion. Check the heuristic just
before code generation.

llvm-svn: 342276
2018-09-14 20:36:14 +00:00
Sebastian Pop 1217160bb3 HotColdSplit: add back propagation to extend cold regions
Also fix a problem in forward propagation:
  const TerminatorInst *TI = It->getTerminator();
was set outside the while loop that iterates over It.

llvm-svn: 342275
2018-09-14 20:36:10 +00:00
Alexandros Lamprineas fe0512d575 Revert "[GVNHoist] Re-enable GVNHoist by default"
This reverts rL341954.

The builder `sanitizer-x86_64-linux-bootstrap-ubsan` has been
failing with timeouts at stage2 clang/ubsan:

[3065/3073] Linking CXX executable bin/lld
command timed out: 1200 seconds without output running python
../sanitizer_buildbot/sanitizers/buildbot_selector.py,
attempting to kill

llvm-svn: 342001
2018-09-11 22:10:57 +00:00
Alexandros Lamprineas db18e972d7 [GVNHoist] Re-enable GVNHoist by default
Rebase rL340922 since https://bugs.llvm.org/show_bug.cgi?id=38807
has been fixed by rL341947.

llvm-svn: 341954
2018-09-11 15:55:45 +00:00
Johannes Doerfert ae3cfeb3ad [FuncAttrs] Remove "access range attributes" for read-none functions
The presence of readnone and an access range attribute (argmemonly,
inaccessiblememonly, inaccessiblemem_or_argmemonly) is considered an
error by the verifier. This seems strict but also not wrong. This
patch makes sure function attribute detection will remove all access
range attributes for readnone functions.

llvm-svn: 341927
2018-09-11 11:51:29 +00:00
Sebastian Pop a1f20fcc96 HotColdSplitting: check that target supports cold calling convention
Before tagging a function with coldcc make sure the target supports cold calling
convention. Without this patch HotColdSplitting pass fails on aarch64 with:

  fatal error: error in backend: Unsupported calling convention.

llvm-svn: 341838
2018-09-10 15:08:02 +00:00
Aditya Kumar 801394a3d7 Hot cold splitting pass
Find cold blocks based on profile information (or optionally with static analysis).
Forward propagate profile information to all cold-blocks.
Outline a cold region.
Set calling conv and prof hint for the callsite of the outlined function.

Worked in collaboration with: Sebastian Pop <s.pop@samsung.com>
Differential Revision: https://reviews.llvm.org/D50658

llvm-svn: 341669
2018-09-07 15:03:49 +00:00
Wei Mi 94d44c97bc [SampleFDO] Make sample profile loader unaware of compact format change.
The patch tries to make sample profile loader independent of profile format
change. It moves compact format related code into FunctionSamples and
SampleProfileReader classes, and sample profile loader only has to interact
with those two classes and will be unaware of profile format changes.

The cleanup also contain some fixes to further remove the difference between
compactbinary format and binary format. After the cleanup using different
formats originated from the same profile will generate the same binaries,
which we verified by compiling two large server benchmarks w/wo thinlto.

Differential Revision: https://reviews.llvm.org/D51643

llvm-svn: 341591
2018-09-06 22:03:37 +00:00
Hiroshi Yamauchi 9775a620b0 [PGO] Control Height Reduction
Summary:
Control height reduction merges conditional blocks of code and reduces the
number of conditional branches in the hot path based on profiles.

if (hot_cond1) { // Likely true.
  do_stg_hot1();
}
if (hot_cond2) { // Likely true.
  do_stg_hot2();
}

->

if (hot_cond1 && hot_cond2) { // Hot path.
  do_stg_hot1();
  do_stg_hot2();
} else { // Cold path.
  if (hot_cond1) {
    do_stg_hot1();
  }
  if (hot_cond2) {
    do_stg_hot2();
  }
}

This speeds up some internal benchmarks up to ~30%.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: xbolva00, dmgreen, mehdi_amini, llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D50591

llvm-svn: 341386
2018-09-04 17:19:13 +00:00
Chandler Carruth 664aa868f5 [x86/SLH] Add a real Clang flag and LLVM IR attribute for Speculative
Load Hardening.

Wires up the existing pass to work with a proper IR attribute rather
than just a hidden/internal flag. The internal flag continues to work
for now, but I'll likely remove it soon.

Most of the churn here is adding the IR attribute. I talked about this
Kristof Beyls and he seemed at least initially OK with this direction.
The idea of using a full attribute here is that we *do* expect at least
some forms of this for other architectures. There isn't anything
*inherently* x86-specific about this technique, just that we only have
an implementation for x86 at the moment.

While we could potentially expose this as a Clang-level attribute as
well, that seems like a good question to defer for the moment as it
isn't 100% clear whether that or some other programmer interface (or
both?) would be best. We'll defer the programmer interface side of this
for now, but at least get to the point where the feature can be enabled
without relying on implementation details.

This also allows us to do something that was really hard before: we can
enable *just* the indirect call retpolines when using SLH. For x86, we
don't have any other way to mitigate indirect calls. Other architectures
may take a different approach of course, and none of this is surfaced to
user-level flags.

Differential Revision: https://reviews.llvm.org/D51157

llvm-svn: 341363
2018-09-04 12:38:00 +00:00
Alexandros Lamprineas f6db5bcd38 Revert r340922 "[GVNHoist] Re-enable GVNHoist by default"
Another sanitizer buildbot failed this time at bootstrap when
compiling SemaTemplateInstantiate.cpp with this assertion:
`dominates(MD, U) && "Memory Def does not dominate it's uses"'.

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/15047

llvm-svn: 340925
2018-08-29 13:00:55 +00:00
Alexandros Lamprineas c03b9b8854 [GVNHoist] Re-enable GVNHoist by default
Rebase rL338240 since the excessive memory usage observed when using
GVNHoist with UBSan has been fixed by rL340818.

Differential Revision: https://reviews.llvm.org/D49858

llvm-svn: 340922
2018-08-29 11:58:34 +00:00
David Bolvansky c1b27b562b [Inliner] Attribute callsites with inline remarks
Summary:
Sometimes reading an output *.ll file it is not easy to understand why some callsites are not inlined. We can read output of inline remarks (option --pass-remarks-missed=inline) and try correlating its messages with the callsites.

An easier way proposed by this patch is to add to every callsite processed by Inliner an attribute with the latest message that describes the cause of not inlining this callsite. The attribute is called //inline-remark//. By default this feature is off. It can be switched on by the option //-inline-remark-attribute//.

For example in the provided test the result method //@test1// has two callsites //@bar// and inline remarks report different inlining missed reasons:
  remark: <unknown>:0:0: bar not inlined into test1 because too costly to inline (cost=-5, threshold=-6)
  remark: <unknown>:0:0: bar not inlined into test1 because it should never be inlined (cost=never): recursive

It is not clear which remark correspond to which callsite. With the inline remark attribute enabled we get the reasons attached to their callsites:
  define void @test1() {
    call void @bar(i1 true) #0
    call void @bar(i1 false) #2
    ret void
  }
  attributes #0 = { "inline-remark"="(cost=-5, threshold=-6)" }
  ..
  attributes #2 = { "inline-remark"="(cost=never): recursive" }

Patch by: yrouban (Yevgeny Rouban)

Reviewers: xbolva00, tejohnson, apilipenko

Reviewed By: xbolva00, tejohnson

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D50435

llvm-svn: 340834
2018-08-28 15:27:25 +00:00
George Burgess IV aa09a82b4b s/std::set/DenseSet/; NFC
We only use this set for `insert` and `count`, so a hashing container
seems better here.

llvm-svn: 340783
2018-08-27 22:10:59 +00:00
Chandler Carruth 9ae926b973 [IR] Replace `isa<TerminatorInst>` with `isTerminator()`.
This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.

All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.

llvm-svn: 340701
2018-08-26 09:51:22 +00:00
David Bolvansky 1ccbddca2c Revert [Inliner] Attribute callsites with inline remarks
llvm-svn: 340619
2018-08-24 16:39:41 +00:00
David Bolvansky 7c0537a3ac [Inliner] Attribute callsites with inline remarks
Summary:
Sometimes reading an output *.ll file it is not easy to understand why some callsites are not inlined. We can read output of inline remarks (option --pass-remarks-missed=inline) and try correlating its messages with the callsites.

An easier way proposed by this patch is to add to every callsite processed by Inliner an attribute with the latest message that describes the cause of not inlining this callsite. The attribute is called //inline-remark//. By default this feature is off. It can be switched on by the option //-inline-remark-attribute//.

For example in the provided test the result method //@test1// has two callsites //@bar// and inline remarks report different inlining missed reasons:
  remark: <unknown>:0:0: bar not inlined into test1 because too costly to inline (cost=-5, threshold=-6)
  remark: <unknown>:0:0: bar not inlined into test1 because it should never be inlined (cost=never): recursive

It is not clear which remark correspond to which callsite. With the inline remark attribute enabled we get the reasons attached to their callsites:
  define void @test1() {
    call void @bar(i1 true) #0
    call void @bar(i1 false) #2
    ret void
  }
  attributes #0 = { "inline-remark"="(cost=-5, threshold=-6)" }
  ..
  attributes #2 = { "inline-remark"="(cost=never): recursive" }

Patch by: yrouban (Yevgeny Rouban)

Reviewers: xbolva00, tejohnson, apilipenko

Reviewed By: xbolva00, tejohnson

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D50435

llvm-svn: 340618
2018-08-24 16:28:36 +00:00
Brian Homerding 3ecabd709f [FunctionAttrs] Infer WriteOnly Function Attribute
These changes expand the FunctionAttr logic in order to mark functions as
WriteOnly when appropriate. This is done through an additional bool variable
and extended logic.

Reviewers: hfinkel, jdoerfert

Differential Revision: https://reviews.llvm.org/D48387

llvm-svn: 340537
2018-08-23 15:05:22 +00:00
Florian Hahn 3052290dc0 Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
This version of the patch fixes cleaning up ssa_copy intrinsics, so it does not
crash for instructions in blocks that have been marked unreachable.

This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 340525
2018-08-23 11:04:00 +00:00
Teresa Johnson cb9a82fc7b [ThinLTO] Add option for printing import failure reasons
Summary:
Adds the option for the printing of summary information about functions
considered but rejected for importing during the thin link.

Reviewers: davidxl

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D50881

llvm-svn: 340047
2018-08-17 16:53:47 +00:00
Fedor Sergeev b55705f6e9 [Inliner] add inliner stats to new pm version of inliner
Increment existing NumInlined and NumDeleted stats in InlinerPass::run.

llvm-svn: 339682
2018-08-14 15:19:14 +00:00
Teresa Johnson b0a1d3bdf1 [ThinLTO] Fix printing of WPD remarks
Summary:
When WPD is performed in a ThinLTO backend, the function may be created
if it isn't already in that module. Module::getOrInsertFunction may
add a bitcast, in which case the returned Constant is not a Function and
doesn't have a name. Invoke stripPointerCasts() on the returned value
where we access its name.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D49959

llvm-svn: 339640
2018-08-14 03:00:16 +00:00
JF Bastien fe258d9776 Re-commit "[NFC] More ConstantMerge refactoring"
My previous change moved some code upwards which caused an assert in debug mode
because the global value didn't necessarily have an initializer. Don't do that.

llvm-svn: 339485
2018-08-10 22:41:09 +00:00
JF Bastien b99f131ffd Revert "[NFC] More ConstantMerge refactoring"
Sanitizers seem unhappy.

llvm-svn: 339480
2018-08-10 22:10:20 +00:00
JF Bastien 62fb8ea4e0 [NFC] More ConstantMerge refactoring
This makes my upcoming patch much easier to read.

llvm-svn: 339478
2018-08-10 21:58:00 +00:00
JF Bastien 42ca9ccb70 [NFC] ConstantMerge: factor out some functions
This makes the code easier to read and will make an upcoming patch I have easier to review because that patch needed this refactoring to reuse some of the functions.

llvm-svn: 339391
2018-08-09 21:56:09 +00:00
JF Bastien ebcaa31768 ConstantMerge: update MadeChange when change is made
It was always false, which is obviously wrong.

llvm-svn: 339390
2018-08-09 21:36:57 +00:00
Reid Kleckner 80c6ec11d9 [GlobalOpt] Don't apply fastcc if it would break inalloca invariants
The inalloca parameter has to be the only parameter passed in memory.
Changing the convention to fastcc can break that.

At some point we should teach global opt how to optimize ABI attributes
like inalloca and maybe byval. These attributes are mainly used to match
C ABIs. They are harder for LLVM to optimize and they don't always
generate the best code.

Fixes PR38487

llvm-svn: 339360
2018-08-09 17:29:26 +00:00
JF Bastien 3f270336e1 [NFC] ConstantMerge: don't insert when find should be used
Summary: DenseMap's operator[] performs an insertion if the entry isn't found. The second phase of ConstantMerge isn't trying to insert anything: it's just looking to see if the first phased performed an insertion. Use find instead, avoiding insertion of every single global initializer in the map of constants. This has the side-effect of making all entries in CMap non-null (because only global declarations would have null initializers, and that would be a bug).

Subscribers: dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D50476

llvm-svn: 339309
2018-08-09 04:17:48 +00:00
David Bolvansky 1e51e6896f [NFC] Fixed unused function warnings
llvm-svn: 339021
2018-08-06 15:09:15 +00:00
David Bolvansky 3d2653bd39 Revert unused function fix
llvm-svn: 339020
2018-08-06 15:05:51 +00:00
David Bolvansky 6bca938bf0 [NFC] Fixed unused function warning
llvm-svn: 339019
2018-08-06 14:42:07 +00:00
David Bolvansky 1a56ac790a [NFC] Fixed unused function warning
llvm-svn: 338986
2018-08-06 04:45:46 +00:00
David Bolvansky c0aa4b75a4 Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338969
2018-08-05 14:53:08 +00:00
Graham Yiu 58dbc00559 [Partial Inlining] Fix small bug in detecting if we did something
- It's possible for 'Changed' to return as false even if we did
  partial inline something.  Fixed to accumulate return values

llvm-svn: 338896
2018-08-03 14:42:53 +00:00
Johannes Doerfert bed4babc56 [NFC][FunctionAttrs] Remove duplication in old/new PM pipeline
This patch just extract code into a separate function to remove some
duplication between the old and new pass manager pipeline. Due to the
different CGSCC iterators used, not all code duplication was eliminated.

llvm-svn: 338585
2018-08-01 16:37:51 +00:00
David Bolvansky fbbb83c782 Revert "Enrich inline messages", tests fail
llvm-svn: 338496
2018-08-01 08:02:40 +00:00
David Bolvansky 7f36cd9d96 Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338494
2018-08-01 07:37:16 +00:00
David Bolvansky ab79414f7b Revert Enrich inline messages
llvm-svn: 338389
2018-07-31 14:47:22 +00:00
David Bolvansky b562dbabda Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338387
2018-07-31 14:25:24 +00:00
Vlad Tsyrklevich 1c7160e85f Revert "[GVNHoist] Re-enable GVNHoist by default"
This reverts commit r338240 because it was causing OOMs on the UBSan
buildbot when building clang/lib/Sema/SemaChecking.cpp

llvm-svn: 338297
2018-07-30 20:07:33 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Alexandros Lamprineas de3ca964c1 [GVNHoist] Re-enable GVNHoist by default
My initial motivation for this came from https://reviews.llvm.org/D48122,
where it was pointed out that my change didn't fit well in SimplifyCFG and
therefore using GVNHoist was a better way to go. GVNHoist has been disabled
for a while as there was a list of bugs related to it.

I have fixed the following bugs:

https://bugs.llvm.org/show_bug.cgi?id=37808 -> https://reviews.llvm.org/D48372 (rL337149)
https://bugs.llvm.org/show_bug.cgi?id=36787 -> https://reviews.llvm.org/D49555 (rL337674)
https://bugs.llvm.org/show_bug.cgi?id=37445 -> https://reviews.llvm.org/D49425 (rL337680)

The next two bugs no longer occur, and it's unclear which commit fixed them:

https://bugs.llvm.org/show_bug.cgi?id=36635
https://bugs.llvm.org/show_bug.cgi?id=37791

I investigated this one and proved to be unrelated to GVNHoist, but a genuine bug in NewGvn:

https://bugs.llvm.org/show_bug.cgi?id=37660

To convince myself GVNHoist is in a good state I made a successful bootstrap build of LLVM.
Merging this change now in order to make it to the LLVM 7.0.0 branch.

Differential Revision: https://reviews.llvm.org/D49858

llvm-svn: 338240
2018-07-30 10:50:18 +00:00
David Green fc4b0fe0a2 [GlobalOpt] Test array indices inside structs for out-of-bounds accesses
We now, from clang, can turn arrays of
  static short g_data[] = {16, 16, 16, 16, 16, 16, 16, 16, 0, 0, 0, 0, 0, 0, 0, 0};
into structs of the form
  @g_data = internal global <{ [8 x i16], [8 x i16] }> ...

GlobalOpt will incorrectly SROA it, not realising that the access to the first
element may overflow into the second. This fixes it by checking geps more
thoroughly.

I believe this makes the globalsra-partial.ll test case invalid as the %i value
could be out of bounds. I've re-purposed it as a negative test for this case.

Differential Revision: https://reviews.llvm.org/D49816

llvm-svn: 338192
2018-07-28 08:20:10 +00:00