Commit Graph

5497 Commits

Author SHA1 Message Date
David Majnemer
75ce6bba4e [PHITransAddr] Don't translate unreachable values
Unreachable values may use themselves in strange ways due to their
dominance property.  Attempting to translate through them can lead to
infinite recursion, crashing LLVM.  Instead, claim that we weren't able
to translate the value.

This fixes PR23096.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238702 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-01 00:15:08 +00:00
David Majnemer
5a13050628 [PHITransAddr] Use std::find instead of std::count
There is no need to visit all the elements if we are merely performing a
membership check.  NFCI.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238701 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-01 00:15:04 +00:00
Benjamin Kramer
9589ff8949 Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238602 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-29 19:43:39 +00:00
Jingyue Wu
ed0d841f59 [DependenceAnalysis] Extend unifySubscriptType for handling coupled subscript groups.
Summary:
In continuation to an earlier commit to DependenceAnalysis.cpp by jingyue (r222100), the type for all subscripts in a coupled group need to be the same since constraints from one subscript may be propagated to another during testing. During testing, new SCEVs may be created and the operands for these need to be the same.
This patch extends unifySubscriptType() to work on lists of subscript pairs, ensuring a common extended type for all of them.

Test Plan:
Added a test case to NonCanonicalizedSubscript.ll which causes dependence analysis to crash without this fix.

All regression tests pass.

Reviewers: spop, sebpop, jingyue

Reviewed By: jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9698

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238573 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-29 16:58:08 +00:00
Wei Mi
61897e8564 Enable exitValue rewrite only when the cost of expansion is low.
The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost.

Differential Revision: http://reviews.llvm.org/D9800


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238507 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 21:49:07 +00:00
Pete Cooper
40d9379cd5 Add BranchProbabilityInfo::releaseMemory to clear the Weights field.
BranchProbabilityInfo was leaking 3MB of memory when running 'opt -O2 verify-uselistorder.lto.bc'.  This was due to the Weights member not being cleared once the pass is no longer needed.

This adds the releaseMemory override to clear that field.  The other fields are cleared at the end of runOnFunction so can stay there.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238462 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-28 19:43:06 +00:00
Chandler Carruth
34afa06cf2 [inliner] Fix the early-exit of the inline cost analysis to correctly
model the dense vector instruction bonuses.

Previously, this code really didn't effectively compute the density of
inlined vector instructions and apply the intended inliner bonus. It
would try to compute it repeatedly while analyzing the function and
didn't handle the case where future vector instructions would tip the
scales back towards the bonus.

Instead, speculatively apply all possible bonuses to the threshold
initially. Once we *know* that a certain bonus can not be applied,
subtract it. This should delay early bailout enough to get much more
consistent results without actually causing us to analyze huge swaths of
code. I expect some (hopefully mild) compile time hit here, and some
swings in performance, but this was definitely the intended behavior of
these bonuses.

This also dramatically simplifies the computation of the bonuses to not
interact with each other in confusing ways. The previous code didn't do
a good job of this and the values for bonuses may be surprising but are
at least now clearly written in the code.

Finally, fix code to be in line with comments and use zero as the
bailout condition.

Patch by Easwaran Raman, with some comment tweaks by me to try and
further clarify what is going on with this code.

http://reviews.llvm.org/D8267

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238276 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-27 02:49:05 +00:00
David Majnemer
fe0d65bcc6 [InstSimplify] Handle some overflow intrinsics in InstSimplify
This change does a few things:
- Move some InstCombine transforms to InstSimplify
- Run SimplifyCall from within InstCombine::visitCallInst
- Teach InstSimplify to fold [us]mul_with_overflow(X, undef) to 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237995 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 03:56:46 +00:00
Hans Wennborg
253c092e56 Revert r236894 "[BasicAA] Fix zext & sext handling"
This seems to have caused PR23626: Clang miscompiles webkit's base64 decoder

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237984 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-22 01:27:37 +00:00
Artur Pilipenko
946d5f5631 Test commit. Fix typo in MemDerefPrinter.cpp comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237893 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-21 11:57:38 +00:00
James Molloy
d594ba0815 Reapply r237539 with a fix for the Chromium build.
Make sure if we're truncating a constant that would then be sign extended
that the sign extension of the truncated constant is the same as the
original constant.

> Canonicalize min/max expressions correctly.
>
> This patch introduces a canonical form for min/max idioms where one operand
> is extended or truncated. This often happens when the other operand is a
> constant. For example:
>
> %1 = icmp slt i32 %a, i32 0
> %2 = sext i32 %a to i64
> %3 = select i1 %1, i64 %2, i64 0
>
> Would now be canonicalized into:
>
> %1 = icmp slt i32 %a, i32 0
> %2 = select i1 %1, i32 %a, i32 0
> %3 = sext i32 %2 to i64
>
> This builds upon a patch posted by David Majenemer
> (https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
> passively stopped instcombine from ruining canonical patterns. This
> patch additionally actively makes instcombine canonicalize too.
>
> Canonicalization of expressions involving a change in type from int->fp
> or fp->int are not yet implemented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237821 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-20 18:41:25 +00:00
Pete Cooper
9584e07a9c Change Function::getIntrinsicID() to return an Intrinsic::ID. NFC.
Now that Intrinsic::ID is a typed enum, we can forward declare it and so return it from this method.

This updates all users which were either using an unsigned to store it, or had a now unnecessary cast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237810 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-20 17:16:39 +00:00
Sanjoy Das
4d88c3ebad Dereferenceable, dereferenceable_or_null metadata for loads
Summary:
Introduce dereferenceable, dereferenceable_or_null metadata for loads
with the same semantic as corresponding attributes.

This patch depends on http://reviews.llvm.org/D9253

Patch by Artur Pilipenko!

Reviewers: hfinkel, sanjoy, reames

Reviewed By: sanjoy, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9365

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237720 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-19 20:10:19 +00:00
Sanjoy Das
0799eb1140 Exploit dereferenceable_or_null attribute in LICM pass
Summary:
Allow hoisting of loads from values marked with dereferenceable_or_null
attribute. For values marked with the attribute perform
context-sensitive analysis to determine whether it's known-non-null or
not.

Patch by Artur Pilipenko!

Reviewers: hfinkel, sanjoy, reames

Reviewed By: reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9253

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237593 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-18 18:07:00 +00:00
Jingyue Wu
2703007b7b [ScalarEvolution] refactor: extract interface getGEPExpr
Summary:
This allows other passes (such as SLSR) to compute the SCEV expression for an
imaginary GEP.

Test Plan: no regression

Reviewers: atrick, sanjoy

Reviewed By: sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9786

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237589 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-18 17:03:25 +00:00
Adam Nemet
a4c8c9292b [LoopAccesses] If shouldRetryWithRuntimeCheck, reset InterestingDependences
When dependence analysis encounters a non-constant distance between
memory accesses it aborts the analysis and falls back to run-time checks
only.  In this case we weren't resetting the array of dependences.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237574 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-18 15:37:03 +00:00
Adam Nemet
2f2bbe4ced [LoopAccesses] Rearrange printed lines in -analyze
"Store to invariant address..." is moved as the last line.  This is not
the prime result of the analysis.  Plus it simplifies some of the tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237573 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-18 15:36:57 +00:00
Adam Nemet
59f6c04f94 [LoopAccesses] Debug improvement
Report pointers with unknown bounds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237572 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-18 15:36:52 +00:00
James Molloy
eb9033d963 Allow min/max detection to see through casts.
This teaches the min/max idiom detector in ValueTracking to see through
casts such as SExt/ZExt/Trunc. SCEV can already do this, so we're bringing
non-SCEV analyses up to the same level.

The returned LHS/RHS will not match the type of the original SelectInst
any more, so a CastOp is returned too to inform the caller how to
convert to the SelectInst's type.

No in-tree users yet; this will be used by InstCombine in a followup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237452 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 16:04:50 +00:00
James Molloy
39a7d6e91d [DependenceAnalysis] Fix for PR21585: collectUpperBound triggers asserts
collectUpperBound hits an assertion when the back edge count is wider then the desired type.

If that happens, truncate the backedge count.

Patch by Philip Pfaffe!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237439 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-15 12:17:22 +00:00
Jingyue Wu
19eda5312a [ValueTracking] refactor: extract method haveNoCommonBitsSet
Summary:
Extract method haveNoCommonBitsSet so that we don't have to duplicate this logic in
InstCombine and SeparateConstOffsetFromGEP.

This patch also makes SeparateConstOffsetFromGEP more precise by passing
DominatorTree to computeKnownBits.

Test Plan: value-tracking-domtree.ll that tests ValueTracking indeed leverages dominating conditions

Reviewers: broune, meheff, majnemer

Reviewed By: majnemer

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D9734

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237407 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 23:53:19 +00:00
Andrea Di Biagio
56a5661c60 [ConstantFolding] Fix wrong folding of intrinsic 'convert.from.fp16'.
Function 'ConstantFoldScalarCall' (in ConstantFolding.cpp) works under the
wrong assumption that a call to 'convert.from.fp16' returns a value of
type 'float'.
However, intrinsic 'convert.from.fp16' can be overloaded; for example, we
can call 'convert.from.fp16.f64' to convert from half to double; etc.

Before this patch, the following example would have triggered an assertion
failure in opt (with -constprop):

```
define double @foo() {
entry:
  %0 = call double @llvm.convert.from.fp16.f64(i16 0)
  ret double %0
}
```

This patch fixes the problem in ConstantFolding.cpp. When folding a call to
convert.from.fp16, we perform a different kind of conversion based on the call
return type.

Added test 'Transform/ConstProp/convert-from-fp16.ll'.

Differential Revision: http://reviews.llvm.org/D9771


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237377 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-14 18:01:48 +00:00
Pete Cooper
33bf03ed89 Add llvm::all_of which wraps std::all_of.
This version doesn't need begin/end but can instead just take a type which has begin/end methods.

Use this to replace an eligible foreach loop in LoopInfo found by David Blaikie in r237224.

Reviewed by David Blaikie.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237301 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 22:19:13 +00:00
Teresa Johnson
dcc57103b8 Test commit: Remove unnecessary spaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237259 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 15:04:14 +00:00
Pete Cooper
a0706f51ce Constify arguments in AliasSetTracker methods. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237225 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 01:12:12 +00:00
Pete Cooper
c6c9f35804 Change a loop in LoopInfo to foreach. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237224 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 01:12:09 +00:00
Pete Cooper
c83d5914c3 Constify arguments to methods in LoopInfo. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237223 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-13 01:12:06 +00:00
Pete Cooper
f23c6af13d Convert PHI getIncomingValue() to foreach over incoming_values(). NFC.
We already had a method to iterate over all the incoming values of a PHI.  This just changes all eligible code to use it.

Ineligible code included anything which cared about the index, or was also trying to get the i'th incoming BB.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237169 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-12 20:05:31 +00:00
James Molloy
2605531fe8 Rip min/max pattern matching out of InstCombine and into
ValueTracking.

This matching functionality is useful in more than just InstCombine, so
make it available in ValueTracking.

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236998 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-11 14:42:20 +00:00
Sanjoy Das
5de9960136 [BasicAA] Fix zext & sext handling
Summary:

There are several unhandled edge cases in BasicAA's GetLinearExpression
method. This changes fixes outstanding issues, including zext / sext of
a constant with the sign bit set, and the refusal to decompose zexts or
sexts of wrapping arithmetic.

Test Plan: Unit tests added in //q.ext.ll//.

Patch by Nick White.

Reviewers: hfinkel, sanjoy

Reviewed By: hfinkel, sanjoy

Subscribers: sanjoy, llvm-commits, hfinkel

Differential Revision: http://reviews.llvm.org/D6682

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236894 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-08 18:58:55 +00:00
Diego Novillo
aa46024ea3 Fix information loss in branch probability computation.
Summary:
This addresses PR 22718. When branch weights are too large, they were
being clamped to the range [1, MaxWeightForBB]. But this clamping is
only applied to edges that go outside the range, so it distorts the
relative branch probabilities.

This patch changes the weight calculation to scale every branch so the
relative probabilities are preserved. The scaling is done differently
now. First, all the branch weights are added up, and if the sum exceeds
32 bits, it computes an integer scale to bring all the weights within
the range.

The patch fixes an existing test that had slightly wrong branch
probabilities due to the previous clamping. It now gets branch weights
scaled accordingly.

Reviewers: dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9442

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236750 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 17:22:06 +00:00
Michael Zolotukhin
d7b5144d53 Populate list of vectorizable functions for Accelerate library.
Summary:
This patch adds majority of supported by Accelerate library functions to the
list of vectorizable functions.

The full list of available vector functions could be found here:
https://developer.apple.com/library/mac/documentation/Performance/Conceptual/vecLib/index.html

Test Plan: Unit tests are added.

Reviewers: hfinkel, aschwaighofer, nadav

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9543

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236747 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 17:11:51 +00:00
Vince Harron
a94bd7a780 Added support for building against Android API-9 SDK
Created an abstraction for log2, llvm::Log2 in Support/MathExtras.h

Hid Android problems inside of it

Differential Revision: http://reviews.llvm.org/D9467



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236680 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-07 00:05:26 +00:00
Diego Novillo
26e46f2283 Allow 0-weight branches in BranchProbabilityInfo.
Summary:
When computing branch weights in BPI, we used to disallow branches with
weight 0. This is a minor nuisance, because a branch with weight 0 is
different to "don't have information". In the context of
instrumentation, it may mean "never executed", in the context of
sampling, it means "never or seldom executed".

In allowing 0 weight branches, I ran into issues with the switch
expansion code in selection DAG. It is currently hardwired to not handle
branches with weight 0. To maintain the current behaviour, I changed it
to use 1 when it finds 0, but perhaps the algorithm needs changes to
tolerate branches with weight zero.

Reviewers: hansw

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9533

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236617 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 17:55:11 +00:00
Wei Mi
cac51be31f [X86] Disable loop unrolling in loop vectorization pass when VF is 1.
The patch disabled unrolling in loop vectorization pass when VF==1 on x86 architecture,
by setting MaxInterleaveFactor to 1. Unrolling in loop vectorization pass may introduce
the cost of overflow check, memory boundary check and extra prologue/epilogue code when
regular unroller will unroll the loop another time. Disable it when VF==1 remove the
unnecessary cost on x86. The same can be done for other platforms after verifying
interleaving/memory bound checking to be not perf critical on those platforms.

Differential Revision: http://reviews.llvm.org/D9515


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236613 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 17:12:25 +00:00
Sanjoy Das
1df2d64d55 [Statepoint] Clean up Statepoint.h: accessor names.
Use getFoo() as accessors consistently and some other naming changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236564 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-06 02:36:26 +00:00
Daniel Berlin
7a5c0e599c Update BasicAliasAnalysis to understand that nothing aliases with undef values.
It got this in some cases (if one of them was an identified object), but not in all cases.

This caused stores to undef to block load-forwarding in some cases, etc.

Added test to Transforms/GVN to verify optimization occurs as expected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236511 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-05 18:10:49 +00:00
Richard Trieu
509e9d9471 Fix -Wpessimizing-move warnings by removing std::move calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236278 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-30 23:07:00 +00:00
Reid Kleckner
85b9ebb7e8 [WinEH] Start EH preparation for 32-bit x86, it uses no arguments
32-bit x86 MSVC-style exceptions are functionaly similar to 64-bit, but
they take no arguments. Instead, they implicitly use the value of EBP
passed in by the caller as a pointer to the parent's frame. In LLVM, we
can represent this as llvm.frameaddress(1), and feed that into all of
our calls to llvm.framerecover.

The next steps are:
- Add an alloca to the fs:00 linked list of handlers
- Add something like llvm.sjlj.lsda or generalize it to store in the
  alloca
- Move state number calculation to WinEHPrepare, arrange for
  FunctionLoweringInfo to call it
- Use the state numbers to insert explicit loads and stores in the IR

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236172 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 22:49:54 +00:00
Duncan P. N. Exon Smith
e56023a059 IR: Give 'DI' prefix to debug info metadata
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`.  The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.

Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one.  It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs.  YMMV of
course.

Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py.  I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three.  It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).

Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236120 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-29 16:38:44 +00:00
Daniel Berlin
b1e1aa04ed Make getModRefInfo(Instruction *) not crash on certain types of instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236023 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-28 19:19:14 +00:00
Diego Novillo
dafe3a524a Fix typo in comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235723 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-24 15:46:41 +00:00
Adam Nemet
50b9e7f7d4 [getUnderlyingOjbects] Analyze loop PHIs further to remove false positives
Specifically, if a pointer accesses different underlying objects in each
iteration, don't look through the phi node defining the pointer.

The motivating case is the underlyling-objects-2.ll testcase.  Consider
the loop nest:

  int **A;
  for (i)
    for (j)
       A[i][j] = A[i-1][j] * B[j]

This loop is transformed by Load-PRE to stash away A[i] for the next
iteration of the outer loop:

  Curr = A[0];          // Prev_0
  for (i: 1..N) {
    Prev = Curr;        // Prev = PHI (Prev_0, Curr)
    Curr = A[i];
    for (j: 0..N)
       Curr[j] = Prev[j] * B[j]
  }

Since A[i] and A[i-1] are likely to be independent pointers,
getUnderlyingObjects should not assume that Curr and Prev share the same
underlying object in the inner loop.

If it did we would try to dependence-analyze Curr and Prev and the
analysis of the corresponding SCEVs would fail with non-constant
distance.

To fix this, the getUnderlyingObjects API is extended with an optional
LoopInfo parameter.  This is effectively what controls whether we want
the above behavior or the original.  Currently, I only changed to use
this approach for LoopAccessAnalysis.

The other testcase is to guard the opposite case where we do want to
look through the loop PHI.  If we step through an array by incrementing
a pointer, the underlying object is the incoming value of the phi as the
loop is entered.

Fixes rdar://problem/19566729

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235634 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-23 20:09:20 +00:00
Philip Reames
1aa9710c60 Move Value.isDereferenceablePointer to ValueTracking [NFC]
Move isDereferenceablePointer function to Analysis. This function recursively tracks dereferencability over a chain of values like other functions in ValueTracking.

This refactoring is motivated by further changes to support dereferenceable_or_null attribute (http://reviews.llvm.org/D8650). isDereferenceablePointer will be extended to perform context-sensitive analysis and IR is not a good place to have such functionality.

Patch by: Artur Pilipenko <apilipenko@azulsystems.com>
Differential Revision: reviews.llvm.org/D9075




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235611 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-23 17:36:48 +00:00
Brendon Cahoon
8b94db17a4 Fix a type mismatch assert in SCEV division
An assert was triggered when attempting to create a new SCEV
with operands of different types in the visitAddRecExpr. In this
test case, the operand types of the numerator and denominator
are different. The SCEV division code should generate a
conservative answer when this happens.

Differential Revision: http://reviews.llvm.org/D9021


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235511 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-22 15:06:40 +00:00
Daniel Berlin
13ba3ca69f Revamp PredIteratorCache interface to be cleaner.
Summary:
This lets us use range based for loops.

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9169

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235416 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 21:11:50 +00:00
Daniel Berlin
29dbbd73de Move IDF Calculation to a separate file, expose an interface to it.
Summary:
MemorySSA uses this algorithm as well, and this enables us to reuse the code in both places.

There are no actual algorithm or datastructure changes in here, just code movement.

Reviewers: qcolombet, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9118

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235406 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 19:13:02 +00:00
Duncan P. N. Exon Smith
7f892716df DebugInfo: Drop rest of DIDescriptor subclasses
Delete the remaining subclasses of (the already deleted) `DIDescriptor`.
Part of PR23080.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235404 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 18:44:06 +00:00
Brendon Cahoon
d9b36e1007 Recognize n/1 in the SCEV divide function
n/1 generates a quotient equal to n and a remainder of 0.
If this case is not recognized, then the SCEV divide() function
can return a remainder that is greater than or equal to the
denominator, which means the delinearized subscripts for the
test case will be incorrect.

Differential Revision: http://reviews.llvm.org/D9003


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235311 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-20 16:03:28 +00:00
Adam Nemet
ee5f9c6278 [LoopAccesses] Improve debug output
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235238 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-17 22:43:10 +00:00