Commit Graph

14830 Commits

Author SHA1 Message Date
JF Bastien 8331458deb NFC mergefunc: const correctness
Some of the comparators were const others weren't making it annoying to add new comparators which call existing ones.

llvm-svn: 266247
2016-04-13 21:12:21 +00:00
Betul Buyukkurt bf8554c279 [PGO] Remove redundant VP instrumentation
LLVM optimization passes may reduce a profiled target expression
to a constant. Removing runtime calls at such instrumentation points
would help speedup the runtime of the instrumented program.

llvm-svn: 266229
2016-04-13 18:52:19 +00:00
Mehdi Amini b5b289339b Revert "Make aliases explicit in the summary"
Inadvertently commited...

This reverts commit e618ec93786d99df2ddf280ad2d5e02f5516cecf.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266215
2016-04-13 17:20:07 +00:00
Mehdi Amini ce744a95fd Make aliases explicit in the summary
Summary:
To be able to work accurately on the reference graph when taking decision
about internalizing, promoting, renaming, etc. We need to have the alias
information explicit.

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18836

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266214
2016-04-13 17:18:42 +00:00
David L Kreitzer 752c1448fe Simplify strlen to a subtraction for certain cases.
Patch by Li Huang (li1.huang@intel.com)

Differential Revision: http://reviews.llvm.org/D18230

llvm-svn: 266200
2016-04-13 14:31:06 +00:00
David Majnemer 3ee5f34469 [InstCombine] We folded an fcmp to an i1 instead of a vector of i1
Remove an ad-hoc transform in InstCombine and replace it with more
general machinery (ValueTracking, InstructionSimplify and VectorUtils).

This fixes PR27332.

llvm-svn: 266175
2016-04-13 06:55:52 +00:00
Mehdi Amini 105938302a Minor cleanup in Internalize, hide helper class using anonymous namespace (NFC)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266173
2016-04-13 06:32:29 +00:00
Mehdi Amini 59269a874f Really return whether Internalize did change the Module or not.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266169
2016-04-13 05:25:16 +00:00
Mehdi Amini 3949b9e6dd Modernize Internalizer with for-range loop (NFC)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266168
2016-04-13 05:25:12 +00:00
Mehdi Amini 24d3414f06 Refactor the InternalizePass into a helper class, and expose it through a public free function (NFC)
There is really no reason to require to instanciate a pass manager to
internalize.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266167
2016-04-13 05:25:08 +00:00
Mehdi Amini 4078709957 Refactor Internalization pass to use as a callback instead of a StringSet (NFC)
This will save a bunch of copies / initialization of intermediate
datastructure, and (hopefully) simplify the code.

This also abstract the symbol preservation mechanism outside of the
Internalization pass into the client code, which is not forced
to keep a map of strings for instance (ThinLTO will prefere hashes).

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266163
2016-04-13 04:20:32 +00:00
Mehdi Amini ef7555fbb2 Fix FunctionImport export list computation: need to take a reference to a map entry to actually modify it
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266159
2016-04-13 01:52:32 +00:00
Mehdi Amini 818f67add5 Fix mismatch on returned type between header and implementation for createNameAnonFunctionPass()
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266151
2016-04-12 23:25:11 +00:00
Sanjay Patel 5e5056d939 [x86, InstCombine] fix masked load pass-through operand to be a zero vector
This bug was introduced with:
http://reviews.llvm.org/rL262269

AVX masked loads are specified to set vector lanes to zero when the high bit of the mask
element for that lane is zero:
"If the mask is 0, the corresponding data element is set to zero in the load form of these
instructions, and unmodified in the store form." --Intel manual

Differential Revision: http://reviews.llvm.org/D19017

llvm-svn: 266148
2016-04-12 23:16:23 +00:00
Mehdi Amini d5faa267c4 Add a pass to name anonymous/nameless function
Summary:
For correct handling of alias to nameless
function, we need to be able to refer them through a GUID in the summary.
Here we name them using a hash of the non-private global names in the module.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18883

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266132
2016-04-12 21:35:28 +00:00
JF Bastien f90029bb14 NFC: MergeFunctions return early
Same effect, easier to read.

llvm-svn: 266128
2016-04-12 21:23:05 +00:00
Teresa Johnson c86af3345c [ThinLTO] Only compute imports for current module in FunctionImport pass
Summary:
The function import pass was computing all the imports for all the
modules in the index, and only using the imports for the current module.
Change this to instead compute only for the given module. This means
that the exports list can't be populated, but they weren't being used
anyway.

Longer term, the linker can collect all the imports and export lists
and serialize them out for consumption by the distributed backend
processes which use this pass.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18945

llvm-svn: 266125
2016-04-12 21:13:11 +00:00
JF Bastien 1bb32ac480 NFC: MergeFunctions update more comments
They are wordy. Some words were wrong.

llvm-svn: 266124
2016-04-12 21:13:01 +00:00
George Burgess IV 278199f615 Add the allocsize attribute to LLVM.
`allocsize` is a function attribute that allows users to request that
LLVM treat arbitrary functions as allocation functions.

This patch makes LLVM accept the `allocsize` attribute, and makes
`@llvm.objectsize` recognize said attribute.

The review for this was split into two patches for ease of reviewing:
D18974 and D14933. As promised on the revisions, I'm landing both
patches as a single commit.

Differential Revision: http://reviews.llvm.org/D14933

llvm-svn: 266032
2016-04-12 01:05:35 +00:00
JF Bastien 4f43cfd2c2 MergeFunctions: test alloca better
r237193 fix handling of alloca size / align in MergeFunctions, but only tested one and didn't follow FunctionComparator::cmpOperations's usual comparison pattern. It also didn't update Instruction.cpp:haveSameSpecialState which I'll do separately.

llvm-svn: 266022
2016-04-12 00:03:26 +00:00
Mehdi Amini ae280e54a9 ThinLTO renaming: use module hash instead of position in the summary
This is more robust to changes in the link ordering.

Differential Revision: http://reviews.llvm.org/D18946

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266018
2016-04-11 23:26:46 +00:00
Hans Wennborg e9134897f4 Fix a couple of redundant conditional expressions (PR27283, PR28282)
llvm-svn: 265987
2016-04-11 20:35:01 +00:00
Matthew Simpson 53207a99f9 [LoopUtils, LV] Fix PR27246 (first-order recurrences)
This patch ensures that when we detect first-order recurrences, we reject a phi
node if its previous value is also a phi node. During vectorization the initial
and previous values of the recurrence are shuffled together to create the value
for the current iteration. However, phi nodes are not widened like other
instructions. This fixes PR27246.

Differential Revision: http://reviews.llvm.org/D18971

llvm-svn: 265983
2016-04-11 19:48:18 +00:00
Sanjay Patel b91bcd704a add FIXME comment; NFC
llvm-svn: 265970
2016-04-11 17:35:57 +00:00
Sanjay Patel 3a48e9823e add an assert for safety; NFC
llvm-svn: 265969
2016-04-11 17:27:44 +00:00
Sanjay Patel 4b9c682acf variable names start with a capital letter; NFC
llvm-svn: 265968
2016-04-11 17:25:23 +00:00
Sanjay Patel 371290790f [InstCombine] use canEvaluateShiftedShift() to handle the lshr case (NFCI)
We need just a couple of logic tweaks to consolidate the shl and lshr cases.

This is step 5 of refactoring to solve PR26760:
https://llvm.org/bugs/show_bug.cgi?id=26760

llvm-svn: 265965
2016-04-11 17:11:55 +00:00
Sanjay Patel 816ec8882a [InstCombine] don't try to shift an illegal amount (PR26760)
This is the straightforward fix for PR26760:
https://llvm.org/bugs/show_bug.cgi?id=26760

But we still need to make some changes to generalize this helper function
and then send the lshr case into here.

llvm-svn: 265960
2016-04-11 16:50:32 +00:00
Sanjay Patel bd8b779d16 [InstCombine] rename variables in shifted-shift helper function (NFCI)
This is step 3 of refactoring to solve PR26760:
https://llvm.org/bugs/show_bug.cgi?id=26760

llvm-svn: 265954
2016-04-11 16:11:07 +00:00
Sanjay Patel 6eaff5cec6 [InstCombine] add helper function for shift-shift optimization (NFCI)
This is step 2 of refactoring to solve PR26760:
https://llvm.org/bugs/show_bug.cgi?id=26760

llvm-svn: 265951
2016-04-11 15:43:41 +00:00
Sanjoy Das f9d88e650b This reverts commit r265913 and r265912
See PR27315

r265913: "[IndVars] Eliminate op.with.overflow when possible"

r265912: "[SCEV] See through op.with.overflow intrinsics"
llvm-svn: 265950
2016-04-11 15:26:18 +00:00
Teresa Johnson 2d5487cf44 [ThinLTO] Move summary computation from BitcodeWriter to new pass
Summary:
This is the first step in also serializing the index out to LLVM
assembly.

The per-module summary written to bitcode is moved out of the bitcode
writer and to a new analysis pass (ModuleSummaryIndexWrapperPass).
The pass itself uses a new builder class to compute index, and the
builder class is used directly in places where we don't have a pass
manager (e.g. llvm-as).

Because we are computing summaries outside of the bitcode writer, we no
longer can use value ids created by the bitcode writer's
ValueEnumerator. This required changing the reference graph edge type
to use a new ValueInfo class holding a union between a GUID (combined
index) and Value* (permodule index). The Value* are converted to the
appropriate value ID during bitcode writing.

Also, this enables removal of the BitWriter library's dependence on the
Analysis library that was previously required for the summary computation.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18763

llvm-svn: 265941
2016-04-11 13:58:45 +00:00
Sanjoy Das a07ad647ee [IndVars] Eliminate op.with.overflow when possible
Summary:
If we can prove that an op.with.overflow intrinsic does not overflow, we
can get rid of the intrinsic, and replace it with non-wrapping
arithmetic.

Reviewers: atrick, regehr

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18685

llvm-svn: 265913
2016-04-10 22:50:31 +00:00
Elena Demikhovsky 751ed0a06a Loop vectorization with uniform load
Vectorization cost of uniform load wasn't correctly calculated.
As a result, a simple loop that loads a uniform value wasn't vectorized.

Differential Revision: http://reviews.llvm.org/D18940

llvm-svn: 265901
2016-04-10 16:53:19 +00:00
Teresa Johnson 3255eec16c [ThinLTO] Remove unused parameter (NFC)
llvm-svn: 265900
2016-04-10 15:17:26 +00:00
Sanjoy Das dd77e1e6a5 Maintain calling convention when inling calls to llvm.deoptimize
The behavior here was buggy -- we'd forget the calling convention after
inlining a callsite calling llvm.deoptimize.

llvm-svn: 265867
2016-04-09 00:22:59 +00:00
Evgeny Stupachenko 8788048403 test commit
llvm-svn: 265840
2016-04-08 20:20:38 +00:00
Duncan P. N. Exon Smith bb2c3e199e ValueMapper: Extract llvm::RemapFunction from IRMover.cpp, NFC
Strip out the remapping parts of IRLinker::linkFunctionBody and put them
in ValueMapper.cpp under the name Mapper::remapFunction (with a
top-level entry-point llvm::RemapFunction).

This is a nice cleanup on its own since it puts the remapping code
together and shares a single Mapper context for the entire
IRLinker::linkFunctionBody Call.  Besides that, this will make it easier
to break the co-recursion between IRMover.cpp and ValueMapper.cpp in
follow ups.

llvm-svn: 265835
2016-04-08 19:26:32 +00:00
Duncan P. N. Exon Smith adcebdf2d1 ValueMapper: Always use Mapper::mapValue from remapInstruction, NFCI
Use Mapper::mapValue instead of llvm::MapValue from
Mapper::remapInstruction when mapping an incoming block for a PHINode
(follow-up to r265832).  This will implicitly pass along the
Materializer argument, but when this code was added in r133513 there was
no Materializer argument.  I suspect this call to MapValue was just
missed in r182776 since it's not observable (basic blocks can't be
materialized, and they don't reference other values).

llvm-svn: 265833
2016-04-08 19:17:13 +00:00
Duncan P. N. Exon Smith a574e7a7a4 ValueMapper: Roll RemapInstruction into Mapper, NFC
Add Mapper::remapInstruction, move the guts of llvm::RemapInstruction
into it, and use the same Mapper for most of the calls to MapValue and
MapMetadata.  There should be no functionality change here.

I left off the call to MapValue that wasn't passing in a Materializer
argument (for basic blocks of PHINodes).  It shouldn't change
functionality either, but I'm suspicious enough to commit separately.

llvm-svn: 265832
2016-04-08 19:09:34 +00:00
Duncan P. N. Exon Smith 69341e6abc ValueMapper: Don't memoize metadata when RF_NoModuleLevelChanges
Prevent the Metadata side-table in ValueMap from growing unnecessarily
when RF_NoModuleLevelChanges.  As a drive-by, make ValueMap::hasMD,
which apparently had no users until I used it here for testing, actually
compile.

llvm-svn: 265828
2016-04-08 18:49:36 +00:00
Duncan P. N. Exon Smith e05ff7c1a7 ValueMapper: Stop memoizing MDStrings
Stop adding MDString to the Metadata section of the ValueMap in
MapMetadata.  It blows up the size of the map for no benefit, since we
can always return quickly anyway.

There is a potential follow-up that I don't think I'll push on right
away, but maybe someone else is interested:  stop checking for a
pre-mapped MDString, and move the `isa<MDString>()` checks in
Mapper::mapSimpleMetadata and MDNodeMapper::getMappedOp in front of the
`VM.getMappedMD()` calls.  While this would preclude explicitly
remapping MDStrings it would probably be a little faster.

llvm-svn: 265827
2016-04-08 18:47:02 +00:00
David Majnemer 56737722e4 [InstCombine] Fix miscompile in FoldSPFofSPF
We had a select of a cast of a select but attempted to replace the outer
select with the inner select dispite their incompatible types.

Patch by Anton Korobeynikov!

This fixes PR27236.

llvm-svn: 265805
2016-04-08 16:51:49 +00:00
David Majnemer fcc5811797 [InstCombine] Add a peephole for redundant assumes
Two or more identical assumes are occasionally next to each other in a
basic block.
While our generic machinery will turn a redundant assume into a no-op,
it is not super cheap.
We can perform a simpler check to achieve the same result for this case.

llvm-svn: 265801
2016-04-08 16:37:12 +00:00
David Majnemer 60c6abc3cc [LoopVectorize] Register cloned assumptions
InstCombine cannot effectively remove redundant assumptions without them
registered in the assumption cache.  The vectorizer can create identical
assumptions but doesn't register them with the cache, resulting in
slower compile times because InstCombine tries to reason about a lot
more assumptions.

Fix this by registering the cloned assumptions.

llvm-svn: 265800
2016-04-08 16:37:10 +00:00
Silviu Baranga 6f444dfd55 Re-commit [SCEV] Introduce a guarded backedge taken count and use it in LAA and LV
This re-commits r265535 which was reverted in r265541 because it
broke the windows bots. The problem was that we had a PointerIntPair
which took a pointer to a struct allocated with new. The problem
was that new doesn't provide sufficient alignment guarantees.
This pattern was already present before r265535 and it just happened
to work. To fix this, we now separate the PointerToIntPair from the
ExitNotTakenInfo struct into a pointer and a bool.

Original commit message:

Summary:
When the backedge taken codition is computed from an icmp, SCEV can
deduce the backedge taken count only if one of the sides of the icmp
is an AddRecExpr. However, due to sign/zero extensions, we sometimes
end up with something that is not an AddRecExpr.

However, we can use SCEV predicates to produce a 'guarded' expression.
This change adds a method to SCEV to get this expression, and the
SCEV predicate associated with it.

In HowManyGreaterThans and HowManyLessThans we will now add a SCEV
predicate associated with the guarded backedge taken count when the
analyzed SCEV expression is not an AddRecExpr. Note that we only do
this as an alternative to returning a 'CouldNotCompute'.

We use new feature in Loop Access Analysis and LoopVectorize to analyze
and transform more loops.

Reviewers: anemet, mzolotukhin, hfinkel, sanjoy

Subscribers: flyingforyou, mcrosier, atrick, mssimpso, sanjoy, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D17201

llvm-svn: 265786
2016-04-08 14:29:09 +00:00
Duncan P. N. Exon Smith 4ec55f8ab6 Reapply "ValueMapper: Treat LocalAsMetadata more like function-local Values"
This reverts commit r265765, reapplying r265759 after changing a call from
LocalAsMetadata::get to ValueAsMetadata::get (and adding a unit test).  When a
local value is mapped to a constant (like "i32 %a" => "i32 7"), the new debug
intrinsic operand may no longer be pointing at a local.

    http://lab.llvm.org:8080/green/job/clang-stage1-configure-RA_build/19020/

The previous coommit message follows:

--

This is a partial re-commit -- maybe more of a re-implementation -- of
r265631 (reverted in r265637).

This makes RF_IgnoreMissingLocals behave (almost) consistently between
the Value and the Metadata hierarchy.  In particular:

  - MapValue returns nullptr or "metadata !{}" for missing locals in
    MetadataAsValue/LocalAsMetadata bridging paris, depending on
    the RF_IgnoreMissingLocals flag.

  - MapValue doesn't memoize LocalAsMetadata-related results.

  - MapMetadata no longer deals with LocalAsMetadata or
    RF_IgnoreMissingLocals at all.  (This wasn't in r265631 at all, but
    I realized during testing it would make the patch simpler with no
    loss of generality.)

r265631 went too far, making both functions universally ignore
RF_IgnoreMissingLocals.  This broke building (e.g.) compiler-rt.
Reassociate (and possibly other passes) don't currently maintain
dominates-use invariants for metadata operands, resulting in IR like
this:

    define void @foo(i32 %arg) {
      call void @llvm.some.intrinsic(metadata i32 %x)
      %x = add i32 1, i32 %arg
    }

If the inliner chooses to inline @foo into another function, then
RemapInstruction will call `MapValue(metadata i32 %x)` and assert that
the return is not nullptr.

I've filed PR27273 to add a Verifier check and fix the underlying
problem in the optimization passes.

As a workaround, return `!{}` instead of nullptr for unmapped
LocalAsMetadata when RF_IgnoreMissingLocals is unset.  Otherwise, match
the behaviour of r265631.

Original commit message:

    ValueMapper: Make LocalAsMetadata match function-local Values

    Start treating LocalAsMetadata similarly to function-local members of
    the Value hierarchy in MapValue and MapMetadata.

      - Don't memoize them.
      - Return nullptr if they are missing.

    This also cleans up ConstantAsMetadata to stop listening to the
    RF_IgnoreMissingLocals flag.

llvm-svn: 265768
2016-04-08 03:13:22 +00:00
Duncan P. N. Exon Smith 805873148a Revert "ValueMapper: Treat LocalAsMetadata more like function-local Values"
This reverts commit r265759, since even this limited version breaks some
bots:
  http://lab.llvm.org:8011/builders/clang-ppc64be-linux/builds/3311
  http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/17696

This also reverts r265761 "ValueMapper: Unduplicate
RF_NoModuleLevelChanges check, NFC", since I had trouble separating it
from r265759.

llvm-svn: 265765
2016-04-08 00:56:21 +00:00
Sanjoy Das 5ce3272833 Don't IPO over functions that can be de-refined
Summary:
Fixes PR26774.

If you're aware of the issue, feel free to skip the "Motivation"
section and jump directly to "This patch".

Motivation:

I define "refinement" as discarding behaviors from a program that the
optimizer has license to discard.  So transforming:

```
void f(unsigned x) {
  unsigned t = 5 / x;
  (void)t;
}
```

to

```
void f(unsigned x) { }
```

is refinement, since the behavior went from "if x == 0 then undefined
else nothing" to "nothing" (the optimizer has license to discard
undefined behavior).

Refinement is a fundamental aspect of many mid-level optimizations done
by LLVM.  For instance, transforming `x == (x + 1)` to `false` also
involves refinement since the expression's value went from "if x is
`undef` then { `true` or `false` } else { `false` }" to "`false`" (by
definition, the optimizer has license to fold `undef` to any non-`undef`
value).

Unfortunately, refinement implies that the optimizer cannot assume
that the implementation of a function it can see has all of the
behavior an unoptimized or a differently optimized version of the same
function can have.  This is a problem for functions with comdat
linkage, where a function can be replaced by an unoptimized or a
differently optimized version of the same source level function.

For instance, FunctionAttrs cannot assume a comdat function is
actually `readnone` even if it does not have any loads or stores in
it; since there may have been loads and stores in the "original
function" that were refined out in the currently visible variant, and
at the link step the linker may in fact choose an implementation with
a load or a store.  As an example, consider a function that does two
atomic loads from the same memory location, and writes to memory only
if the two values are not equal.  The optimizer is allowed to refine
this function by first CSE'ing the two loads, and the folding the
comparision to always report that the two values are equal.  Such a
refined variant will look like it is `readonly`.  However, the
unoptimized version of the function can still write to memory (since
the two loads //can// result in different values), and selecting the
unoptimized version at link time will retroactively invalidate
transforms we may have done under the assumption that the function
does not write to memory.

Note: this is not just a problem with atomics or with linking
differently optimized object files.  See PR26774 for more realistic
examples that involved neither.

This patch:

This change introduces a new set of linkage types, predicated as
`GlobalValue::mayBeDerefined` that returns true if the linkage type
allows a function to be replaced by a differently optimized variant at
link time.  It then changes a set of IPO passes to bail out if they see
such a function.

Reviewers: chandlerc, hfinkel, dexonsmith, joker.eph, rnk

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18634

llvm-svn: 265762
2016-04-08 00:48:30 +00:00
Duncan P. N. Exon Smith 0fa8aca0e6 ValueMapper: Unduplicate RF_NoModuleLevelChanges check, NFC
llvm-svn: 265761
2016-04-08 00:41:10 +00:00
Duncan P. N. Exon Smith 267185ec92 ValueMapper: Treat LocalAsMetadata more like function-local Values
This is a partial re-commit -- maybe more of a re-implementation -- of
r265631 (reverted in r265637).

This makes RF_IgnoreMissingLocals behave (almost) consistently between
the Value and the Metadata hierarchy.  In particular:

  - MapValue returns nullptr or "metadata !{}" for missing locals in
    MetadataAsValue/LocalAsMetadata bridging paris, depending on
    the RF_IgnoreMissingLocals flag.

  - MapValue doesn't memoize LocalAsMetadata-related results.

  - MapMetadata no longer deals with LocalAsMetadata or
    RF_IgnoreMissingLocals at all.  (This wasn't in r265631 at all, but
    I realized during testing it would make the patch simpler with no
    loss of generality.)

r265631 went too far, making both functions universally ignore
RF_IgnoreMissingLocals.  This broke building (e.g.) compiler-rt.
Reassociate (and possibly other passes) don't currently maintain
dominates-use invariants for metadata operands, resulting in IR like
this:

    define void @foo(i32 %arg) {
      call void @llvm.some.intrinsic(metadata i32 %x)
      %x = add i32 1, i32 %arg
    }

If the inliner chooses to inline @foo into another function, then
RemapInstruction will call `MapValue(metadata i32 %x)` and assert that
the return is not nullptr.

I've filed PR27273 to add a Verifier check and fix the underlying
problem in the optimization passes.

As a workaround, return `!{}` instead of nullptr for unmapped
LocalAsMetadata when RF_IgnoreMissingLocals is unset.  Otherwise, match
the behaviour of r265631.

Original commit message:

    ValueMapper: Make LocalAsMetadata match function-local Values

    Start treating LocalAsMetadata similarly to function-local members of
    the Value hierarchy in MapValue and MapMetadata.

      - Don't memoize them.
      - Return nullptr if they are missing.

    This also cleans up ConstantAsMetadata to stop listening to the
    RF_IgnoreMissingLocals flag.

llvm-svn: 265759
2016-04-08 00:33:44 +00:00
Ulrich Weigand fc23907673 [GVN] Address review comments for D18662
As suggested by Chandler in his review comments for D18662, this
follow-on patch renames some variables in GetLoadValueForLoad and
CoerceAvailableValueToLoadType to hopefully make it more obvious
which variables hold value sizes and which hold load/store sizes.

No functional change intended.

llvm-svn: 265687
2016-04-07 15:55:11 +00:00
Ulrich Weigand 6e6966460a [GVN] Fix handling of sub-byte types in big-endian mode
When GVN wants to re-interpret an already available value in a smaller
type, it needs to right-shift the value on big-endian systems to ensure
the correct bytes are accessed.  The shift value is the difference of
the sizes of the two types.

This is correct as long as both types occupy multiples of full bytes.
However, when one of them is a sub-byte type like i1, this no longer
holds true: we still need to shift, but only to access the correct
*byte*.  Accessing bits within the byte requires no shift in either
endianness; e.g. an i1 resides in the least-significant bit of its
containing byte on both big- and little-endian systems.

Therefore, the appropriate shift value to be used is the difference of
the *storage* sizes of the two types.  This is already handled correctly
in one place where such a shift takes place (GetStoreValueForLoad), but
is incorrect in two other places: GetLoadValueForLoad and
CoerceAvailableValueToLoadType.

This patch changes both places to use the storage size as well.

Differential Revision: http://reviews.llvm.org/D18662

llvm-svn: 265684
2016-04-07 15:45:02 +00:00
Benjamin Kramer 4fb78518f1 Make helper functions static. NFC.
llvm-svn: 265653
2016-04-07 10:10:09 +00:00
Duncan P. N. Exon Smith 45601e867d Revert "ValueMapper: Make LocalAsMetadata match function-local Values"
This reverts commit r265631, since it caused bot failures:
http://lab.llvm.org:8011/builders/clang-ppc64be-linux/builds/3256
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-42vma/builds/7272

Looks like something is depending on the old behaviour.  I'll try to
track it down and recommit.

llvm-svn: 265637
2016-04-07 02:10:50 +00:00
Duncan P. N. Exon Smith fdccad925c ValueMapper: Allow RF_IgnoreMissingLocals and RF_NullMapMissingGlobalValues
Remove the assertion that disallowed the combination, since
RF_IgnoreMissingLocals should have no effect on globals.  As it happens,
RF_NullMapMissingGlobalValues asserted in MapValue(Constant*,...), so I
also changed a cast to a cast_or_null to get my test passing.

llvm-svn: 265633
2016-04-07 01:22:45 +00:00
Duncan P. N. Exon Smith c1e4070708 ValueMapper: Make LocalAsMetadata match function-local Values
Start treating LocalAsMetadata similarly to function-local members of
the Value hierarchy in MapValue and MapMetadata.

  - Don't memoize them.
  - Return nullptr if they are missing.

This also cleans up ConstantAsMetadata to stop listening to the
RF_IgnoreMissingLocals flag.

llvm-svn: 265631
2016-04-07 01:08:39 +00:00
Duncan P. N. Exon Smith da68cbc4ad IR: RF_IgnoreMissingValues => RF_IgnoreMissingLocals, NFC
Clarify what this RemapFlag actually means.

  - Change the flag name to match its intended behaviour.
  - Clearly document that it's not supposed to affect globals.
  - Add a host of FIXMEs to indicate how to fix the behaviour to match
    the intent of the flag.

RF_IgnoreMissingLocals should only affect the behaviour of
RemapInstruction for function-local operands; namely, for operands of
type Argument, Instruction, and BasicBlock.  Currently, it is *only*
passed into RemapInstruction calls (and the transitive MapValue calls
that it makes).

When I split Metadata from Value I didn't understand the flag, and I
used it in a bunch of places for "global" metadata.

This commit doesn't have any functionality change, but prepares to
cleanup MapMetadata and MapValue.

llvm-svn: 265628
2016-04-07 00:26:43 +00:00
Michael Zolotukhin 56ad4048ae Follow-up for r265605: don't mutate vector we're iterating.
llvm-svn: 265625
2016-04-07 00:09:42 +00:00
Mike Aizatsky 70ea45306a [sancov] enabling coverage edge pruning by default.
Differential Revision: http://reviews.llvm.org/D18844

llvm-svn: 265615
2016-04-06 23:24:37 +00:00
Michael Zolotukhin 97567e141e [LoopUnroll] Fix the way we update DT after complete unrolling.
Updating dominators for exit-blocks of the unrolled loops is not enough,
as shown in PR27157. The proper way is to update dominators for all
dominance-children of original loop blocks.

llvm-svn: 265605
2016-04-06 21:47:12 +00:00
JF Bastien 800f87a871 NFC: make AtomicOrdering an enum class
Summary:
In the context of http://wg21.link/lwg2445 C++ uses the concept of
'stronger' ordering but doesn't define it properly. This should be fixed
in C++17 barring a small question that's still open.

The code currently plays fast and loose with the AtomicOrdering
enum. Using an enum class is one step towards tightening things. I later
also want to tighten related enums, such as clang's
AtomicOrderingKind (which should be shared with LLVM as a 'C++ ABI'
enum).

This change touches a few lines of code which can be improved later, I'd
like to keep it as NFC for now as it's already quite complex. I have
related changes for clang.

As a follow-up I'll add:
  bool operator<(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>(AtomicOrdering, AtomicOrdering) = delete;
  bool operator<=(AtomicOrdering, AtomicOrdering) = delete;
  bool operator>=(AtomicOrdering, AtomicOrdering) = delete;
This is separate so that clang and LLVM changes don't need to be in sync.

Reviewers: jyknight, reames

Subscribers: jyknight, llvm-commits

Differential Revision: http://reviews.llvm.org/D18775

llvm-svn: 265602
2016-04-06 21:19:33 +00:00
Fiona Glaser 045afc4f66 Loop Unroll: add options and tweak to make Partial unrolling more useful
1. Add FullUnrollMaxCount option that works like MaxCount, but also limits
   the unroll count for fully unrolled loops. So if a loop has an iteration
   count over this, it won't fully unroll.
2. Add CLI options for MaxCount and the new option, so they can be tested
   (plus a test).
3. Make partial unrolling obey MaxCount.

An example use-case (the out of tree one this is originally designed for) is
a target’s TTI can analyze a loop and decide on a max unroll count separate
from the size threshold, e.g. based on register pressure, then constrain
LoopUnroll to not exceed that, regardless of the size of the unrolled loop.

llvm-svn: 265562
2016-04-06 16:57:25 +00:00
Fiona Glaser 16332ba861 LoopUnroll: only allow non-modulo Partial unrolling when Runtime=true
Patch by Evgeny Stupachenko <evstupac@gmail.com>.

llvm-svn: 265558
2016-04-06 16:43:45 +00:00
Silviu Baranga a393baf1fd Revert r265535 until we know how we can fix the bots
llvm-svn: 265541
2016-04-06 14:06:32 +00:00
Chad Rosier 074ce836f0 Simplify logic. NFC.
llvm-svn: 265537
2016-04-06 13:27:13 +00:00
Silviu Baranga 72b4a4a330 [SCEV] Introduce a guarded backedge taken count and use it in LAA and LV
Summary:
When the backedge taken codition is computed from an icmp, SCEV can
deduce the backedge taken count only if one of the sides of the icmp
is an AddRecExpr. However, due to sign/zero extensions, we sometimes
end up with something that is not an AddRecExpr.

However, we can use SCEV predicates to produce a 'guarded' expression.
This change adds a method to SCEV to get this expression, and the
SCEV predicate associated with it.

In HowManyGreaterThans and HowManyLessThans we will now add a SCEV
predicate associated with the guarded backedge taken count when the
analyzed SCEV expression is not an AddRecExpr. Note that we only do
this as an alternative to returning a 'CouldNotCompute'.

We use new feature in Loop Access Analysis and LoopVectorize to analyze
and transform more loops.

Reviewers: anemet, mzolotukhin, hfinkel, sanjoy

Subscribers: flyingforyou, mcrosier, atrick, mssimpso, sanjoy, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D17201

llvm-svn: 265535
2016-04-06 13:18:26 +00:00
Richard Trieu f35d4b0928 Add parentheses to silence warning.
llvm-svn: 265516
2016-04-06 04:22:00 +00:00
Duncan P. N. Exon Smith 6f2e37429a ValueMapper: Fix delayed blockaddress handling after r265273
r265273 added Mapper::mapBlockAddress, which delays mapping a
blockaddress value until the function has a body.  The condition was
backwards, and should be checking Function::empty instead of
GlobalValue::isDeclaration.

llvm-svn: 265508
2016-04-06 02:25:12 +00:00
Sanjoy Das 99abb2728b [RS4GC] Add a comment
llvm-svn: 265503
2016-04-06 01:33:54 +00:00
Sanjoy Das 8d89a2b296 [RS4GC] NFC cleanup of the DeferredReplacement class
Instead of constructors use clearly named factory methods.

llvm-svn: 265486
2016-04-05 23:18:53 +00:00
Sanjoy Das 49e974b33b [RS4GC] Better codegen for deoptimize calls
Don't emit a gc.result for a statepoint lowered from
@llvm.experimental.deoptimize since the call into __llvm_deoptimize is
effectively noreturn.  Instead follow the corresponding gc.statepoint
with an "unreachable".

llvm-svn: 265485
2016-04-05 23:18:35 +00:00
Duncan P. N. Exon Smith 818e5f38d2 Try harder to appease MSVC after r265456
r265465 wasn't good enough.  I need to spell out all the moves.

llvm-svn: 265470
2016-04-05 21:25:33 +00:00
Duncan P. N. Exon Smith 1de3c7e790 IR: Introduce ConstantAggregate, NFC
Add a common parent class for ConstantArray, ConstantVector, and
ConstantStruct called ConstantAggregate.  These are the aggregate
subclasses of Constant that take operands.

This is mainly a cleanup, adding common `isa` target and removing
duplicated code.  However, it also simplifies caching which constants
point transitively at `GlobalValue` (a possible future direction).

llvm-svn: 265466
2016-04-05 21:10:45 +00:00
Duncan P. N. Exon Smith f880d35b80 Try to appease MSVC after r265456
I can't remember if adding `= default` will make MSVC happy, or if I
have to spell this out.  Let's try the cleaner version first.

llvm-svn: 265465
2016-04-05 21:07:01 +00:00
Duncan P. N. Exon Smith ea7df770ae ValueMapper: Rewrite Mapper::mapMetadata without recursion
This commit completely rewrites Mapper::mapMetadata (the implementation
of llvm::MapMetadata) using an iterative algorithm.  The guts of the new
algorithm are in MDNodeMapper::map, the entry function in a new class.

Previously, Mapper::mapMetadata performed a recursive exploration of the
graph with eager "just in case there's a reason" malloc traffic.

The new algorithm has these benefits:

  - New nodes and temporaries are not created eagerly.
  - Uniquing cycles are not duplicated (see new unit test).
  - No recursion.

Given a node to map, it does this:

 1. Use a worklist to perform a post-order traversal of the transitively
    referenced unmapped nodes.

 2. Track which nodes will change operands, and which will have new
    addresses in the mapped scheme.  Propagate the changes through the
    POT until fixed point, to pick up uniquing cycles that need to
    change.

 3. Map all the distinct nodes without touching their operands.  If
    RF_MoveDistinctMetadata, they get mapped to themselves; otherwise,
    they get mapped to clones.

 4. Map the uniqued nodes (bottom-up), lazily creating temporaries for
    forward references as needed.

 5. Remap the operands of the distinct nodes.

Mehdi helped me out by profiling this with -flto=thin.  On his workload
(importing/etc. for opt.cpp), MapMetadata sped up by 15%, contributed
about 50% less to persistent memory, and made about 100x fewer calls to
malloc.  The speedup is less than I'd hoped.  The profile mainly blames
DenseMap lookups; perhaps there's a way to reduce them (e.g., by
disallowing remapping of MDString).

It would be nice to break the strange remaining recursion on the Value
side: MapValue => materializeInitFor => RemapInstruction => MapValue.  I
think we could do this by having materializeInitFor return a worklist of
things to be remapped.

llvm-svn: 265456
2016-04-05 20:23:21 +00:00
David L Kreitzer 188de5ae69 Adds the ability to use an epilog remainder loop during loop unrolling and makes
this the default behavior.

Patch by Evgeny Stupachenko (evstupac@gmail.com).

Differential Revision: http://reviews.llvm.org/D18158

llvm-svn: 265388
2016-04-05 12:19:35 +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
Sanjay Patel e77c7de459 use range loop; NFCI
llvm-svn: 265360
2016-04-04 23:05:06 +00:00
Zia Ansari a82a58a4e5 Enable unroll for constant bound loops when TripCount is not modulo of unroll factor, reducing it to maximum power-of-2 that satisfies threshold limit.
Commit for Evgeny Stupachenko (evstupac@gmail.com)

Differential Revision: http://reviews.llvm.org/D18290

llvm-svn: 265337
2016-04-04 19:24:46 +00:00
Betul Buyukkurt 18131c4216 [PGO] Avoid instrumenting direct callee's at value sites.
Direct callees' that are cast to other function prototypes,
show up in the Call/Invoke instructions as ConstantExpr's.
Currently llvm::CallSite's getCalledFunction() fails
to return the callees in such expressions as direct calls.
Value profiling should avoid instrumenting such cases. Mostly NFC.

llvm-svn: 265330
2016-04-04 18:56:36 +00:00
Teresa Johnson 0beb858e97 [ThinLTO] Augment FunctionImport dump with value name to GUID map
Summary:
To aid in debugging, dump out the correlation between value names and
GUID for each source module when it is materialized. This will make it
easier to comprehend the earlier summary-based function importing debug
trace which only has access to and prints the GUIDs.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18556

llvm-svn: 265326
2016-04-04 18:52:23 +00:00
Duncan P. N. Exon Smith 8e65f8ddfd ValueMapper: Remove old FIXMEs; almost NFC
Remove a few old FIXMEs from the original commit of the Metadata/Value
split in r223802.  These are commented out assertions to the effect that
calls between mapValue and mapMetadata never return nullptr.

(The only behaviour change is that Mapper::mapSimpleMetadata memoizes
the nullptr return.)

When I originally rewrote the mapping code, I thought we could be
stricter in the new metadata hierarchy and never return nullptr when
RF_NullMapMissingGlobalValues was off.  It's still not entirely clear to
me why these assertions failed (a few months ago, I had a theory that I
forgot to write down, but that's helping no one).

Understood or not, I no longer see how these commented-out assertions
would be useful.  I'm relegating them to the annals of source control
before making significant changes to ValueMapper.cpp.

llvm-svn: 265282
2016-04-04 04:59:56 +00:00
Duncan P. N. Exon Smith 756e1c3db4 ValueMapper: Disallow metadata mapping recursion through mapValue
This adds an assertion to maintain the property from r265273.  When
Mapper::mapSimpleMetadata calls Mapper::mapValue, it should not find its
way back to mapMetadataImpl.  This guarantees that mapSimpleMetadata is
not involved in any recursion.

Since Mapper::mapValue calls out to arbitrary materializers, we need to
save a bit on the ValueMap to make this assertion effective.

There should be no functionality change here.  This co-recursion should
already have been impossible.

llvm-svn: 265276
2016-04-03 20:54:51 +00:00
Duncan P. N. Exon Smith a997856b3d Work around MSVC failure from r265273
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/19726

llvm-svn: 265275
2016-04-03 20:42:21 +00:00
Duncan P. N. Exon Smith c6065e3a25 ValueMapper: Avoid recursion in mapSimplifiedMetadata, NFC
The main change is to delay materializing GlobalValue initializers from
Mapper::mapValue until Mapper::~Mapper.  This effectively removes all
recursion from mapSimplifiedMetadata, as promised in r265270.
mapSimplifiedMetadata calls mapValue for ConstantAsMetadata nodes to
find the mapped constant, and now it shouldn't be possible for mapValue
to indirectly re-invoke mapMetadata.  I'll add an assertion to that
effect in a follow-up (separated so that the assertion can easily be
reverted independently, if it comes to that).

This a step toward a broader goal: converting Mapper::mapMetadataImpl
from a recursive to an iterative algorithm.

When a BlockAddress points at a BasicBlock inside an unmaterialized
function body, we need to delay it until the function body is
materialized in Mapper::~Mapper.  This commit creates a temporary
BasicBlock and returns a new BlockAddress, then RAUWs the BasicBlock
once it is known.  This situation should be extremely rare since a
BlockAddress is usually used from within the function it's referencing
(and BlockAddress itself is rare).

There should be no observable functionality change.

llvm-svn: 265273
2016-04-03 20:17:45 +00:00
Duncan P. N. Exon Smith ae8bd4bd11 ValueMapper: Split out mapSimpleMetadata, NFC
Split out a helper for mapping metadata without operands.  This is any
metadata that is not an MDNode, and any MDNode where the answer is known
without looking at operands.

Through some weird twists, this function is co-recursive:

    mapSimpleMetadata
    => MapValue
    => materializeInitFor
    => linkFunctionBody
    => RemapInstructions
    => MapMetadata
    => mapSimpleMetadata

I plan to break the recursion in a follow-up.

llvm-svn: 265270
2016-04-03 19:31:01 +00:00
Duncan P. N. Exon Smith 829dc87a68 ValueMapper: Introduce Mapper helper class, NFC
Remove a bunch of boilerplate from ValueMapper.cpp by using a new
file-local class called Mapper.

llvm-svn: 265268
2016-04-03 19:06:24 +00:00
Davide Italiano d4f5a059e0 [SimplifyLibCalls] Garbage collect dead code.
We already skip optimizations if the return value
of printf() is used, so CI->use_empty() is always
true.

Differential Revision:  http://reviews.llvm.org/D18656

llvm-svn: 265253
2016-04-03 01:46:52 +00:00
Duncan P. N. Exon Smith 4b520e5ef6 Linker: Remove IRMover::isMetadataUnneeded indirection; almost NFC
Instead of checking live during MapMetadata whether a subprogram is
needed, seed the ValueMap with `nullptr` up-front.

There is a small hypothetical functionality change.  Previously, calling
MapMetadataOp on a node whose "scope:" chain led to an unneeded
subprogram would return nullptr.  However, if that were ever called,
then the subprogram would be needed; a situation that the IRMover is
supposed to avoid a priori!

Besides cleaning up the code a little, this restores a nice property:
MapMetadataOp returns the same as MapMetadata.

llvm-svn: 265229
2016-04-02 17:12:00 +00:00
Duncan P. N. Exon Smith da4a56d1ab ValueMapper: Add support for seeding metadata with nullptr
Support seeding a ValueMap with nullptr for Metadata entries, a
situation I didn't consider in the Metadata/Value split.

I added a ValueMapper::getMappedMD accessor that returns an
Optional<Metadata*> with the mapped (possibly null) metadata.  IRMover
needs to use this to avoid modifying the map when it's checking for
unneeded subprograms.  I updated a call from bugpoint since I find the
new code clearer.

llvm-svn: 265228
2016-04-02 17:04:38 +00:00
Mehdi Amini 89038a1071 Fix "warning: variabl 'XX’ set but not used" in release build (variable used in assertion, NFC)
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265220
2016-04-02 05:34:19 +00:00
Mehdi Amini ad5741b075 Create a typedef GlobalValue::GUID for uint64_t and RAUW (NFC)
Summary: This should make the code more readable, especially all the map declarations.

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18721

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265215
2016-04-02 05:07:53 +00:00
Rong Xu 0eb3603626 [PGO] Use a helper function to find all indirect call-sites
Use a helper function to find all the direct-calls-sites in a function.
Also split the code into a separated file as this will be use by
indirect-call-promotion transformation.

Differential Revision: http://reviews.llvm.org/D18704

llvm-svn: 265199
2016-04-01 23:16:44 +00:00
Peter Collingbourne dd711b93e0 LowerBitSets: Move declarations to separate namespace.
Should fix modules build.

llvm-svn: 265176
2016-04-01 18:46:50 +00:00
Mike Aizatsky 01c0f8d8a3 [sancov] save entry block from pruning (it is always full dominator)
llvm-svn: 265168
2016-04-01 18:13:19 +00:00
David Majnemer fe3f9d1721 [InstCombine] Don't sink an instr after a catchswitch
A catchswitch is a terminator, instructions cannot be inserted after it.

llvm-svn: 265158
2016-04-01 17:28:17 +00:00
David Majnemer 6f1f85f0e1 [SLPVectorizer] Don't insert an extractelement before a catchswitch
A catchswitch cannot be preceded by another instruction in the same
basic block (other than a PHI node).

Instead, insert the extract element right after the materialization of
the vectorized value.  This isn't optimal but is a reasonable compromise
given the constraints of WinEH.

This fixes PR27163.

llvm-svn: 265157
2016-04-01 17:28:15 +00:00
Rong Xu 8e8fe859e0 [PGO] Refactor PGOFuncName meta data code to be used in clang
Refactor the code that gets and creates PGOFuncName meta data so that it can be
used in clang's value profile annotation.

Differential Revision: http://reviews.llvm.org/D18623

llvm-svn: 265149
2016-04-01 16:43:30 +00:00
Mehdi Amini d7ad221c16 Add a module Hash in the bitcode and the combined index, implementing a kind of "build-id"
This is intended to be used for ThinLTO incremental build.

Differential Revision: http://reviews.llvm.org/D18213

This is a recommit of r265095 after fixing the Windows issues.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 265111
2016-04-01 05:33:11 +00:00