Commit Graph

5480 Commits

Author SHA1 Message Date
Diego Novillo 8c49a57266 Add documentation for new backedge mass propagation in irregular loops.
Tweak test cases and rename headerIndexFor -> getHeaderIndex.

llvm-svn: 239915
2015-06-17 16:28:22 +00:00
Chandler Carruth d1a130c202 [PM/AA] Suffix lots of member variables that directly use enumeration
names for counts with the word 'Count' to make them less ambiguous.

This will be an actual error if we use unscoped enums for any of these,
and generally this seems much clearer to read.

Also, use clang-format to normalize the formatting of this code which
seems to have been needlessly odd.

No functionality changed here.

llvm-svn: 239887
2015-06-17 07:21:41 +00:00
Chandler Carruth ecbd16829a [PM/AA] Remove the UnknownSize static member from AliasAnalysis.
This is now living in MemoryLocation, which is what it pertains to. It
is also an enum there rather than a static data member which is left
never defined.

llvm-svn: 239886
2015-06-17 07:21:38 +00:00
Chandler Carruth ac80dc7532 [PM/AA] Remove the Location typedef from the AliasAnalysis class now
that it is its own entity in the form of MemoryLocation, and update all
the callers.

This is an entirely mechanical change. References to "Location" within
AA subclases become "MemoryLocation", and elsewhere
"AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps
out-of-tree folks update.

llvm-svn: 239885
2015-06-17 07:18:54 +00:00
Chandler Carruth c41404a090 [PM/AA] Split the location computation out of getArgLocation so the
virtual interface on AliasAnalysis only deals with ModRef information.

This interface was both computing memory locations by using TLI and
other tricks to estimate the size of memory referenced by an operand,
and computing ModRef information through similar investigations. This
change narrows the scope of the virtual interface on AliasAnalysis
slightly.

Note that all of this code could live in BasicAA, and be done with
a single investigation of the argument, if it weren't for the fact that
the generic code in AliasAnalysis::getModRefBehavior for a callsite
calls into the virtual aspect of (now) getArgModRefInfo. But this
patch's arrangement seems a not terrible way to go for now.

The other interesting wrinkle is how we could reasonably extend LLVM
with support for custom memory location sizes and mod/ref behavior for
library routines. After discussions with Hal on the review, the
conclusion is that this would be best done by fleshing out the much
desired support for extensions to TLI, and support these types of
queries in that interface where we would likely be doing other library
API recognition and analysis.

Differential Revision: http://reviews.llvm.org/D10259

llvm-svn: 239884
2015-06-17 07:12:40 +00:00
Diego Novillo 9a779623d9 Fix PR 23525 - Separate header mass propagation in irregular loops.
Summary:
When propagating mass through irregular loops, the mass flowing through
each loop header may not be equal. This was causing wrong frequencies
to be computed for irregular loop headers.

Fixed by keeping track of masses flowing through each of the headers in
an irregular loop. To do this, we now keep track of per-header backedge
weights. After the loop mass is distributed through the loop, the
backedge weights are used to re-distribute the loop mass to the loop
headers.

Since each backedge will have a mass proportional to the different
branch weights, the loop headers will end up with a more approximate
weight distribution (as opposed to the current distribution that assumes
that every loop header is the same).

Reviewers: dexonsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10348

llvm-svn: 239843
2015-06-16 19:10:58 +00:00
Benjamin Kramer 1ee59cba5d [InstSimplify] Allow folding of fdiv X, X with just NaNs ignored
Any combination of +-inf/+-inf is NaN so it's already ignored with
nnan and we can skip checking for ninf. Also rephrase logic in comments
a bit.

llvm-svn: 239821
2015-06-16 14:57:29 +00:00
Philip Reames 66ab0f045a Move logic from JumpThreading into LazyValue info to simplify caller.
This change is hopefully NFC. The only tricky part is that I changed the context instruction being used to the branch rather than the comparison. I believe both to be correct, but the branch is strictly more powerful. With the moved code, using the branch instruction is required for the basic block comparison test to return the same result. The previous code was able to directly access both the branch and the comparison where the revised code is not.

Differential Revision: http://reviews.llvm.org/D9652

llvm-svn: 239797
2015-06-16 00:49:59 +00:00
Jingyue Wu 12b0c2835e [ValueTracking] do not overwrite analysis results already computed
Summary:
ValueTracking used to overwrite the analysis results computed from
assumes and dominating conditions. This patch fixes this issue.

Test Plan: test/Analysis/ValueTracking/assume.ll

Reviewers: hfinkel, majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10283

llvm-svn: 239718
2015-06-15 05:46:29 +00:00
Benjamin Kramer 228680ded8 [InstSimplify] fsub nnan x, x -> 0.0 is valid without ninf
Both inf - inf and (-inf) - (-inf) are NaN, so it's already covered by
nnan.

llvm-svn: 239702
2015-06-14 21:01:20 +00:00
Benjamin Kramer 4f0524614e [InstSimplify] Add self-fdiv identities for -ffinite-math-only.
When NaNs and Infs are ignored we can fold
 X /  X -> 1.0
-X /  X -> -1.0
 X / -X -> -1.0

llvm-svn: 239701
2015-06-14 18:53:58 +00:00
Pete Cooper 3664253c52 Don't create instructions from ConstantExpr's in CFLAliasAnalysis.
The CFLAA code currently calls ConstantExpr::getAsInstruction which creates an instruction from a constant expr.

We then pass that instruction to the InstVisitor to analyze it.

Its not necessary to create these instructions as we can just cast from Constant to Operator in the visitor.  This is how other InstVisitor’s such as SelectionDAGBuilder handle ConstantExpr.

llvm-svn: 239616
2015-06-12 16:13:54 +00:00
Yaron Keren 26ceb0845b Rangify for loops, NFC.
llvm-svn: 239596
2015-06-12 05:15:27 +00:00
Alexey Samsonov 89645dfa4d [GVN] Set proper debug locations for some instructions created by GVN.
Determining proper debug locations for instructions created in
PHITransAddr is tricky. We use a simple approach here and simply copy
debug locations from instructions computing load address to
"corresponding" instructions re-creating the address computation
in predecessor basic blocks.

This may not always be correct, given all the rearrangement and
simplification going on, and debug locations may jump around a lot,
as the basic blocks we copy locations between may be very far from
each other.

Still, this would work good in most simple cases (e.g. when chain
of address computing instruction is short, or our mapping turns out
to be 1-to-1), and we desire to have *some* reasonable debug locations
associated with newly inserted instructions.

See http://reviews.llvm.org/D10351 review thread for more details.

Test Plan: regression test suite

Reviewers: spatel, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10351

llvm-svn: 239479
2015-06-10 17:37:38 +00:00
Benjamin Kramer c1c3c84bb4 Replace loop with std::equal. NFC intended.
llvm-svn: 239430
2015-06-09 20:41:21 +00:00
Artur Pilipenko 7fad7e57e8 Minor refactoring of GEP handling in isDereferenceablePointer
For GEP instructions isDereferenceablePointer checks that all indices are constant and within bounds. Replace this index calculation logic to a call to accumulateConstantOffset. Separated from the http://reviews.llvm.org/D9791

Reviewed By: sanjoy

Differential Revision: http://reviews.llvm.org/D9874

llvm-svn: 239299
2015-06-08 11:58:13 +00:00
Silviu Baranga 98a137196a [LAA] Fix estimation of number of memchecks
Summary:
We need to add a runtime memcheck for pair of accesses (x,y) where at least one of x and y
are writes.
 
Assuming we have w writes and r reads, currently this number is  estimated as being
w* (w+r-1). This estimation will count (write,write) pairs twice and will overestimate
the number of checks required.

This change adds a getNumberOfChecks method to RuntimePointerCheck, which
will count the number of runtime checks needed (similar in implementation to
needsAnyChecking) and uses it to produce the correct number of runtime checks.

Test Plan:
llvm test suite
spec2k
spec2k6

Performance results: no changes observed (not surprising since the formula for 1 writer is basically the same, which would covers most cases - at least with the current check limit).

Reviewers: anemet

Reviewed By: anemet

Subscribers: mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D10217

llvm-svn: 239295
2015-06-08 10:27:06 +00:00
Hao Liu 32c0539691 [LoopVectorize] Teach Loop Vectorizor about interleaved memory accesses.
Interleaved memory accesses are grouped and vectorized into vector load/store and shufflevector.
E.g. for (i = 0; i < N; i+=2) {
       a = A[i];         // load of even element
       b = A[i+1];       // load of odd element
       ...               // operations on a, b, c, d
       A[i] = c;         // store of even element
       A[i+1] = d;       // store of odd element
     }

  The loads of even and odd elements are identified as an interleave load group, which will be transfered into vectorized IRs like:
     %wide.vec = load <8 x i32>, <8 x i32>* %ptr
     %vec.even = shufflevector <8 x i32> %wide.vec, <8 x i32> undef, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
     %vec.odd = shufflevector <8 x i32> %wide.vec, <8 x i32> undef, <4 x i32> <i32 1, i32 3, i32 5, i32 7>

  The stores of even and odd elements are identified as an interleave store group, which will be transfered into vectorized IRs like:
     %interleaved.vec = shufflevector <4 x i32> %vec.even, %vec.odd, <8 x i32> <i32 0, i32 4, i32 1, i32 5, i32 2, i32 6, i32 3, i32 7> 
     store <8 x i32> %interleaved.vec, <8 x i32>* %ptr

This optimization is currently disabled by defaut. To try it by adding '-enable-interleaved-mem-accesses=true'. 

llvm-svn: 239291
2015-06-08 06:39:56 +00:00
Hao Liu 751004a67d [LoopAccessAnalysis] Teach LAA to check the memory dependence between strided accesses.
Differential Revision: http://reviews.llvm.org/D9368

llvm-svn: 239285
2015-06-08 04:48:37 +00:00
Matt Arsenault e83379e8e4 Add isLegalAddressingMode address space argument to TTI
Update to match the TLI version, and remove the TLI version's
default argument.

llvm-svn: 239260
2015-06-07 20:12:03 +00:00
David Majnemer 3f0fb98d01 [InstCombine, InstSimplify] Move xforms from Combine to Simplify
There were several SelectInst combines that always returned an existing
instruction instead of modifying an old one or creating a new one.
These are prime candidates for moving to InstSimplify.

llvm-svn: 239229
2015-06-06 22:40:21 +00:00
Chandler Carruth 70c61c1a8a [PM/AA] Start refactoring AliasAnalysis to remove the analysis group and
port it to the new pass manager.

All this does is extract the inner "location" class used by AA into its
own full fledged type. This seems *much* cleaner as MemoryDependence and
soon MemorySSA also use this heavily, and it doesn't make much sense
being inside the AA infrastructure.

This will also make it much easier to break apart the AA infrastructure
into something that stands on its own rather than using the analysis
group design.

There are a few places where this makes APIs not make sense -- they were
taking an AliasAnalysis pointer just to build locations. I'll try to
clean those up in follow-up commits.

Differential Revision: http://reviews.llvm.org/D10228

llvm-svn: 239003
2015-06-04 02:03:15 +00:00
David Majnemer 7666be70e4 [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.

llvm-svn: 238702
2015-06-01 00:15:08 +00:00
David Majnemer fc41f63d77 [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.

llvm-svn: 238701
2015-06-01 00:15:04 +00:00
Benjamin Kramer f5e2fc474d 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.

llvm-svn: 238602
2015-05-29 19:43:39 +00:00
Jingyue Wu a84feb1727 [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

llvm-svn: 238573
2015-05-29 16:58:08 +00:00
Wei Mi e2538b5639 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

llvm-svn: 238507
2015-05-28 21:49:07 +00:00
Pete Cooper b9d2e34a4a 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.

llvm-svn: 238462
2015-05-28 19:43:06 +00:00
Chandler Carruth a004f22a2d [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

llvm-svn: 238276
2015-05-27 02:49:05 +00:00
David Majnemer 1503258157 [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.

llvm-svn: 237995
2015-05-22 03:56:46 +00:00
Hans Wennborg 2ecb8dc39c Revert r236894 "[BasicAA] Fix zext & sext handling"
This seems to have caused PR23626: Clang miscompiles webkit's base64 decoder

llvm-svn: 237984
2015-05-22 01:27:37 +00:00
Artur Pilipenko 0f90c86668 Test commit. Fix typo in MemDerefPrinter.cpp comment.
llvm-svn: 237893
2015-05-21 11:57:38 +00:00
James Molloy 2b21a7cf36 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.

llvm-svn: 237821
2015-05-20 18:41:25 +00:00
Pete Cooper 9e1d335697 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.

llvm-svn: 237810
2015-05-20 17:16:39 +00:00
Sanjoy Das f999547d11 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

llvm-svn: 237720
2015-05-19 20:10:19 +00:00
Sanjoy Das f8a0db50b2 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

llvm-svn: 237593
2015-05-18 18:07:00 +00:00
Jingyue Wu 2982d4d795 [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

llvm-svn: 237589
2015-05-18 17:03:25 +00:00
Adam Nemet df3dc5b9ca [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.

llvm-svn: 237574
2015-05-18 15:37:03 +00:00
Adam Nemet c3384320f2 [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.

llvm-svn: 237573
2015-05-18 15:36:57 +00:00
Adam Nemet f10ca27884 [LoopAccesses] Debug improvement
Report pointers with unknown bounds.

llvm-svn: 237572
2015-05-18 15:36:52 +00:00
James Molloy 270ef8c28b 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.

llvm-svn: 237452
2015-05-15 16:04:50 +00:00
James Molloy c0661aeaf8 [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!

llvm-svn: 237439
2015-05-15 12:17:22 +00:00
Jingyue Wu ca32190379 [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

llvm-svn: 237407
2015-05-14 23:53:19 +00:00
Andrea Di Biagio 2905999c22 [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

llvm-svn: 237377
2015-05-14 18:01:48 +00:00
Pete Cooper a264dc0933 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.

llvm-svn: 237301
2015-05-13 22:19:13 +00:00
Teresa Johnson bbcf75e59e Test commit: Remove unnecessary spaces.
llvm-svn: 237259
2015-05-13 15:04:14 +00:00
Pete Cooper 4bf388d9ad Constify arguments in AliasSetTracker methods. NFC
llvm-svn: 237225
2015-05-13 01:12:12 +00:00
Pete Cooper a889c12ecc Change a loop in LoopInfo to foreach. NFC
llvm-svn: 237224
2015-05-13 01:12:09 +00:00
Pete Cooper 016daa662f Constify arguments to methods in LoopInfo. NFC
llvm-svn: 237223
2015-05-13 01:12:06 +00:00
Pete Cooper 833f34d837 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.

llvm-svn: 237169
2015-05-12 20:05:31 +00:00