Commit Graph

7119 Commits

Author SHA1 Message Date
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
David Green da21170c49 [ConstantFolding] Fix to prevent constant folding having to repeatedly scan operands. NFCI
After the loop unroll threshold was increased in r295538, very
large constant expressions can be created. This prevents them
from having to be recursively scanned, leading to a compile
time blow-up.

Differential Revision: https://reviews.llvm.org/D30689

llvm-svn: 298356
2017-03-21 10:17:39 +00:00
Eli Friedman b1578d3612 [SCEV] Fix trip multiple calculation
If loop bound containing calculations like min(a,b), the Scalar
Evolution API getSmallConstantTripMultiple returns 4294967295 "-1"
as the trip multiple. The problem is that, SCEV use -1 * umax to
represent umin. The multiple constant -1 was returned, and the logic
of guarding against huge trip counts was skipped. Because -1 has 32
active bits.

The fix attempt to factor more general cases. First try to get the
greatest power of two divisor of trip count expression. In case
overflow happens, the trip count expression is still divisible by the
greatest power of two divisor returned. Returns 1 if not divisible by 2.

Patch by Huihui Zhang <huihuiz@codeaurora.org>

Differential Revision: https://reviews.llvm.org/D30840

llvm-svn: 298301
2017-03-20 20:25:46 +00:00
Simon Pilgrim 00b34996b4 Use MutableArrayRef for APFloat::convertToInteger
As discussed on D31074, use MutableArrayRef for destination integer buffers to help assert before stack overflows happen.

llvm-svn: 298253
2017-03-20 14:40:12 +00:00
Xin Tong aef0fcb191 Extract FindAvailablePtrLoadStore out of FindAvailableLoadedValue. NFCI
Summary:
Extract FindAvailablePtrLoadStore out of FindAvailableLoadedValue.
Prepare for upcoming change which will do phi-translation for load on
phi pointer in jump threading SimplifyPartiallyRedundantLoad.

This is in preparation for https://reviews.llvm.org/D30543

Reviewers: efriedma, sanjoy, davide, dberlin

Reviewed By: davide

Subscribers: junbuml, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D30524

llvm-svn: 298216
2017-03-19 15:27:52 +00:00
Brian Gesiak 1640e68728 [Analysis] bitreverse(undef) returns undef
Summary:
The reverse of an artbitrary bitpattern is also an arbitrary
bitpattern.

Reviewers: trentxintong, arsenm, majnemer

Reviewed By: majnemer

Subscribers: majnemer, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D31118

llvm-svn: 298201
2017-03-19 04:40:42 +00:00
Craig Topper 7cfd4a9d7a [ValueTracking] Remove deadish code from computeKnownBitsAddSub.
The code assigned to KnownZero, but later code unconditionally assigned over it. I'm pretty sure the later code can handle the same cases and more equally well.

llvm-svn: 298190
2017-03-18 18:21:46 +00:00
Craig Topper 3eb0d80de0 [ValueTracking] Add APInt::setSignBit and use it to replace ORing with getSignBit which will malloc if the bit width is larger than 64.
llvm-svn: 298180
2017-03-18 04:01:29 +00:00
Eli Friedman f7b060bd3e [SCEV] Use const Loop *L instead of Loop *L. NFC
Use const pointer in the trip count and trip multiple calculations.

Patch by Huihui Zhang <huihuiz@codeaurora.org>

llvm-svn: 298161
2017-03-17 22:19:52 +00:00
Michael Zolotukhin 99de88d1f3 [SCEV] Compute affine range in another way to avoid bitwidth extending.
Summary:
This approach has two major advantages over the existing one:
1. We don't need to extend bitwidth in our computations. Extending
bitwidth is a big issue for compile time as we often end up working with
APInts wider than 64bit, which is a slow case for APInt.
2. When we zero extend a wrapped range, we lose some information (we
replace the range with [0, 1 << src bit width)). Thus, avoiding such
extensions better preserves information.

Correctness testing:
I ran 'ninja check' with assertions that the new implementation of
getRangeForAffineAR gives the same results as the old one (this
functionality is not present in this patch). There were several failures
- I inspected them manually and found out that they all are caused by
the fact that we're returning more accurate results now (see bullet (2)
above).
Without such assertions 'ninja check' works just fine, as well as
SPEC2006.

Compile time testing:
CTMark/Os:
 - mafft/pairlocalalign	-16.98%
 - tramp3d-v4/tramp3d-v4	-12.72%
 - lencod/lencod	-11.51%
 - Bullet/bullet	-4.36%
 - ClamAV/clamscan	-3.66%
 - 7zip/7zip-benchmark	-3.19%
 - sqlite3/sqlite3	-2.95%
 - SPASS/SPASS	-2.74%
 - Average	-5.81%

Performance testing:
The changes are expected to be neutral for runtime performance.

Reviewers: sanjoy, atrick, pete

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30477

llvm-svn: 297992
2017-03-16 21:07:38 +00:00
Oliver Stannard 062041113f [ValueTracking] Out of range shifts might be undef
If it is possible for the RHS of a shift operation to be greater than or equal
to the bit-width, then the result might be undef, and we can't report any known
bits.

In some cases, this was allowing a transformation in instcombine which widened
an undef value from i1 to i32, increasing the range of values that a function
could return.

Differential revision: https://reviews.llvm.org/D30781

llvm-svn: 297724
2017-03-14 10:13:17 +00:00
Jonas Paulsson a48ea231c0 [TargetTransformInfo] getIntrinsicInstrCost() scalarization estimation improved
getIntrinsicInstrCost() used to only compute scalarization cost based on types.
This patch improves this so that the actual arguments are checked when they are
available, in order to handle only unique non-constant operands.

Tests updates:

Analysis/CostModel/X86/arith-fp.ll
Transforms/LoopVectorize/AArch64/interleaved_cost.ll
Transforms/LoopVectorize/ARM/interleaved_cost.ll

The improvement in getOperandsScalarizationOverhead() to differentiate on
constants made it necessary to update the interleaved_cost.ll tests even
though they do not relate to intrinsics.

Review: Hal Finkel
https://reviews.llvm.org/D29540

llvm-svn: 297705
2017-03-14 06:35:36 +00:00
Anna Thomas a10e3e4c34 [LVI] Add Datalayout to the class LazyValueInfo since all its Impls require it. NFC
llvm-svn: 297583
2017-03-12 14:06:41 +00:00
Sanjoy Das 3f1e8e0102 Use a WeakVH for UnknownInstructions in AliasSetTracker
Summary:
This change solves the same problem as D30726, except that this only
throws out the bathwater.

AST was not correctly tracking and deleting UnknownInstructions via
handles.  The existing code only tracks "pointers" in its
`ASTCallbackVH`, so an UnknownInstruction (that isn't also def'ing a
pointer used by another memory instruction) never gets a
`ASTCallbackVH`.

There are two other ways to solve this problem:

 - Use the `PointerRec` scheme for both known and unknown instructions.
 - Use a `CallbackVH` that erases the offending Instruction from the
   UnknownInstruction list.

Both of the above changes seemed to be significantly (and unnecessarily
IMO) more complex than this.

Reviewers: chandlerc, dberlin, hfinkel, reames

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D30849

llvm-svn: 297539
2017-03-11 01:15:48 +00:00
Davide Italiano 574e59786e [ProfileSummaryInfo] Remove unneeded braces. NFCI.
llvm-svn: 297506
2017-03-10 20:50:51 +00:00
Dehao Chen c2048155a0 Refactor the PSI to extract getCallSiteCount and remove checks for profile type.
Summary: There is no need to check profile count as only CallInst will have metadata attached.

Reviewers: eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30799

llvm-svn: 297500
2017-03-10 19:45:16 +00:00
Michael Kuperstein 5fb39a7966 [SLP] Revert everything that has to do with memory access sorting.
This reverts r293386, r294027, r294029 and r296411.

Turns out the SLP tree isn't actually a "tree" and we don't handle
accessing the same packet of loads in several different orders well,
causing miscompiles.

Revert until we can fix this properly.

llvm-svn: 297493
2017-03-10 18:59:07 +00:00
Yaron Keren 1de4792c55 Implement getPassName() for IR printing passes.
llvm-svn: 297442
2017-03-10 07:09:20 +00:00
Dehao Chen 22645eea7a Do not use branch metadata to check if a basic block is hot.
Summary: We should not use that to check basic block hotness as optimization may mess it up.

Reviewers: eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30800

llvm-svn: 297437
2017-03-10 01:44:37 +00:00
Sanjay Patel 962a8431ea [InstSimplify] allow folds for bool vector div/rem
llvm-svn: 297411
2017-03-09 21:56:03 +00:00
Sanjay Patel 2b1f6f4b92 [InstSimplify] vector div/rem with any zero element in divisor is undef
This was suggested as a DAG simplification in the review for rL297026 :
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20170306/435253.html
...but let's start with IR since we have actual docs for IR (LangRef).

Differential Revision:
https://reviews.llvm.org/D30665

llvm-svn: 297390
2017-03-09 16:20:52 +00:00
Teresa Johnson d820447212 Perform symbol binding for .symver versioned symbols
Summary:
In a .symver assembler directive like:
.symver name, name2@@nodename
"name2@@nodename" should get the same symbol binding as "name".

While the ELF object writer is updating the symbol binding for .symver
aliases before emitting the object file, not doing so when the module
inline assembly is handled by the RecordStreamer is causing the wrong
behavior in *LTO mode.

E.g. when "name" is global, "name2@@nodename" must also be marked as
global. Otherwise, the symbol is skipped when iterating over the LTO
InputFile symbols (InputFile::Symbol::shouldSkip). So, for example,
when performing any *LTO via the gold-plugin, the versioned symbol
definition is not recorded by the plugin and passed back to the
linker. If the object was in an archive, and there were no other symbols
needed from that object, the object would not be included in the final
link and references to the versioned symbol are undefined.

The llvm-lto2 tests added will give an error about an unused symbol
resolution without the fix.

Reviewers: rafael, pcc

Reviewed By: pcc

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D30485

llvm-svn: 297332
2017-03-09 00:19:49 +00:00
Amjad Aboud 5448e989a5 [SLP] Fixed non-deterministic behavior in Loop Vectorizer.
Differential Revision: https://reviews.llvm.org/D30638

llvm-svn: 297257
2017-03-08 05:09:10 +00:00
Sebastian Pop 4a4d245b19 Handle UnreachableInst in isGuaranteedToTransferExecutionToSuccessor
A block with an UnreachableInst does not transfer execution to a successor.
The problem was exposed by GVN-hoist. This patch fixes bug 32153.

Patch by Aditya Kumar.

Differential Revision: https://reviews.llvm.org/D30667

llvm-svn: 297254
2017-03-08 01:54:50 +00:00
Michael Kuperstein 768d013a03 [SLP] Revert r296863 due to miscompiles.
Details and reproducer are on the email thread for r296863.

llvm-svn: 297103
2017-03-06 23:54:51 +00:00
Sanjay Patel 0cb2ee9287 [InstSimplify] refactor related div/rem folds; NFCI
llvm-svn: 297052
2017-03-06 19:08:35 +00:00
Sanjay Patel 79a9ecbe80 [InstSimplify] remove misleading comments; NFC
Div/rem-of-0 does not cause faults/undef (not the same as div/rem-by-0).

llvm-svn: 297029
2017-03-06 16:49:35 +00:00
Sanjoy Das 1bd479dd5c [SCEV] Decrease the recursion threshold for CompareValueComplexity
Fixes PR32142.

r287232 accidentally increased the recursion threshold for
CompareValueComplexity from 2 to 32.  This change reverses that change
by introducing a separate flag for CompareValueComplexity's threshold.

llvm-svn: 296992
2017-03-05 23:49:17 +00:00
Mohammad Shahid bdac9f30c0 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.It also needs to recompute the proper Lane for
external use of vectorizable scalars based on shuffle mask.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Ide8773ce0ad3562f3cf4d1a0ad0f487e2f60ce5d
llvm-svn: 296863
2017-03-03 10:02:47 +00:00
Hans Wennborg cc4ff78c9d Revert r296575 "[SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available"
It caused miscompiles, e.g. in Chromium (PR32109).

llvm-svn: 296654
2017-03-01 18:57:16 +00:00
Igor Laevsky 37cba43604 [BasicAA] Take attributes into account when requesting modref info for a call site
Differential Revision: https://reviews.llvm.org/D29989

llvm-svn: 296617
2017-03-01 13:19:51 +00:00
Mohammad Shahid 175ffa8c35 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Id1e287f073fa4959713ba545fa4254db5da8b40d
llvm-svn: 296575
2017-03-01 03:51:54 +00:00
Francis Visoiu Mistrih 262ad16a3a [LCG] Fix EXPENSIVE_CHECKS typo. NFC
Differential Revision: https://reviews.llvm.org/D30434

llvm-svn: 296500
2017-02-28 18:34:55 +00:00
Dehao Chen a60cdd3881 Add function importing info from samplepgo profile to the module summary.
Summary: For SamplePGO, the profile may contain cross-module inline stacks. As we need to make sure the profile annotation happens when all the hot inline stacks are expanded, we need to pass this info to the module importer so that it can import proper functions if necessary. This patch implemented this feature by emitting cross-module targets as part of function entry metadata. In the module-summary phase, the metadata is used to build call edges that points to functions need to be imported.

Reviewers: mehdi_amini, tejohnson

Reviewed By: tejohnson

Subscribers: davidxl, llvm-commits

Differential Revision: https://reviews.llvm.org/D30053

llvm-svn: 296498
2017-02-28 18:09:44 +00:00
Michael Kuperstein c07cca85fb [SLP] Load sorting should not try to sort things that aren't loads.
We may get a VL where the first element is a load, but the others
aren't. Trying to sort such VLs can only lead to sorrow.

llvm-svn: 296411
2017-02-27 23:18:11 +00:00
Sanjoy Das 39a684d117 [ValueTracking] Don't do an unchecked shift in ComputeNumSignBits
Summary:
Previously we used to return a bogus result, 0, for IR like `ashr %val,
-1`.

I've also added an assert checking that `ComputeNumSignBits` at least
returns 1.  That assert found an already checked in test case where we
were returning a bad result for `ashr %val, -1`.

Fixes PR32045.

Reviewers: spatel, majnemer

Reviewed By: spatel, majnemer

Subscribers: efriedma, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D30311

llvm-svn: 296273
2017-02-25 20:30:45 +00:00
Easwaran Raman a8b9cdc9e2 [InlineCost] Move the code in isGEPOffsetConstant to a lambda.
Differential revision: https://reviews.llvm.org/D30112

llvm-svn: 296208
2017-02-25 00:10:22 +00:00
Xin Tong 68ea9aa23a Fix Indentation. NFCI
llvm-svn: 296169
2017-02-24 20:59:26 +00:00
Adam Nemet 2531df3d49 [ORE] Remove ORE.emit{{.+}} functions
Last use was killed in my previous patch. The preferred way is now to
construct the remark, pipe things to it and pass it to ORE.emit.

llvm-svn: 296019
2017-02-23 21:32:53 +00:00
Adam Nemet 41b019a39c [LAA] Remove unused LoopAccessReport
The need for this removed when I converted everything to use the opt-remark
classes directly with the streaming interface.

llvm-svn: 296017
2017-02-23 21:17:36 +00:00
Davide Italiano e122d6885a [ModuleSummaryAnalysis] Don't crash when referencing unnamed globals.
Instead, just be conservative as these are unfrequent enough. Thanks
to Peter Collingbourne for the discussion about this on IRC.

llvm-svn: 295861
2017-02-22 18:53:38 +00:00
Justin Bogner 8281c81413 OptDiag: Add const to some interfaces that don't modify anything. NFC
This needed a const_cast for the dominator tree recalculation in
OptimizationRemarkEmitter, but we do that all over the place already
and it's safe.

llvm-svn: 295812
2017-02-22 07:38:17 +00:00
Sanjoy Das 5cd6c5cacf [ValueTracking] Make poison propagation more aggressive
Summary:
Motivation: fix PR31181 without regression (the actual fix is still in
progress).  However, the actual content of PR31181 is not relevant
here.

This change makes poison propagation more aggressive in the following
cases:

 1. poision * Val == poison, for any Val.  In particular, this changes
    existing intentional and documented behavior in these two cases:
     a. Val is 0
     b. Val is 2^k * N
 2. poison << Val == poison, for any Val
 3. getelementptr is poison if any input is poison

I think all of these are justified (and are axiomatically true in the
new poison / undef model):

1a: we need poison * 0 to be poison to allow transforms like these:

  A * (B + C) ==> A * B + A * C

If poison * 0 were 0 then the above transform could not be allowed
since e.g. we could have A = poison, B = 1, C = -1, making the LHS

  poison * (1 + -1) = poison * 0 = 0

and the RHS

  poison * 1 + poison * -1 = poison + poison = poison

1b: we need e.g. poison * 4 to be poison since we want to allow

  A * 4 ==> A + A + A + A

If poison * 4 were a value with all of their bits poison except the
last four; then we'd not be able to do this transform since then if A
were poison the LHS would only be "partially" poison while the RHS
would be "full" poison.

2: Same reasoning as (1b), we'd like have the following kinds
transforms be legal:

  A << 1 ==> A + A

Reviewers: majnemer, efriedma

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D30185

llvm-svn: 295809
2017-02-22 06:52:32 +00:00
Sanjoy Das 7b0b408973 [ValueTracking] clang-format a section I'm about to touch; NFC
(Whitespace only change)

llvm-svn: 295690
2017-02-21 02:42:42 +00:00
Sanjay Patel fe67255961 [InstSimplify] add nsw/nuw (xor X, signbit), signbit --> X
The change to InstCombine in:
https://reviews.llvm.org/D29729
...exposes this missing fold in InstSimplify, so adding this
first to avoid a regression.

llvm-svn: 295573
2017-02-18 21:59:09 +00:00
Easwaran Raman 617f63640b Refactor instruction simplification code in visitors. NFC.
Several visitors check if operands to the instruction are constants,
either as it is or after looking up SimplifiedValues, check if the
result is a constant and update the SimplifiedValues map. This
refactoring splits it into a common function that does the checking of
whether the operands are constants and updating of the SimplifiedValues
table, and an instruction specific part that is implemented by each
instruction visitor as a lambda and passed to the common function.

Differential revision: https://reviews.llvm.org/D30104

llvm-svn: 295552
2017-02-18 17:22:52 +00:00
Justin Bogner d890f95bf6 OptDiag: Decouple backend diagnostics from debug info metadata
This creates and uses a DiagnosticLocation type rather than using
DebugLoc for this purpose in the backend diagnostics. This is NFC for
now, but will allow us to create locations for diagnostics without
having to create new metadata nodes when we don't have a DILocation.

llvm-svn: 295519
2017-02-18 00:42:23 +00:00
Matthew Simpson a899f86054 [LAA] Remove unused code (NFC)
llvm-svn: 295493
2017-02-17 20:46:52 +00:00
Peter Collingbourne 9421c2dc54 AssumptionCache: Disable the verifier by default, move it behind a hidden cl::opt and verify from releaseMemory().
This is a short term solution to the problem that many passes currently fail
to update the assumption cache. In the long term the verifier should not
be controllable with a flag. We should either fix all passes to correctly
update the assumption cache and enable the verifier unconditionally or
somehow arrange for the assumption list to be updated automatically by passes.

Differential Revision: https://reviews.llvm.org/D30003

llvm-svn: 295236
2017-02-15 21:10:09 +00:00
Adam Nemet 4c98023724 [LazyBFI] Fix typos
llvm-svn: 295073
2017-02-14 17:21:12 +00:00
Igor Laevsky c11c1ed909 [SCEV] Cache results during GetMinTrailingZeros query
Differential Revision: https://reviews.llvm.org/D29759

llvm-svn: 295060
2017-02-14 15:53:12 +00:00
Sanjay Patel 97e4b98749 [ValueTracking] use nonnull argument attribute to eliminate null checks
Enhancing value tracking's analysis of null-ness was suggested in D27855, so here's a first attempt at that.

This is part of solving:
https://llvm.org/bugs/show_bug.cgi?id=28430

Differential Revision: https://reviews.llvm.org/D28204

llvm-svn: 294897
2017-02-12 15:35:34 +00:00
Dorit Nuzman eac89d736c [LV/LoopAccess] Check statically if an unknown dependence distance can be
proven larger than the loop-count

This fixes PR31098: Try to resolve statically data-dependences whose
compile-time-unknown distance can be proven larger than the loop-count, 
instead of resorting to runtime dependence checking (which are not always 
possible).

For vectorization it is sufficient to prove that the dependence distance 
is >= VF; But in some cases we can prune unknown dependence distances early,
and even before selecting the VF, and without a runtime test, by comparing 
the distance against the loop iteration count. Since the vectorized code 
will be executed only if LoopCount >= VF, proving distance >= LoopCount 
also guarantees that distance >= VF. This check is also equivalent to the 
Strong SIV Test.

Reviewers: mkuper, anemet, sanjoy

Differential Revision: https://reviews.llvm.org/D28044

llvm-svn: 294892
2017-02-12 09:32:53 +00:00
Peter Collingbourne be9ffaacfa IR: Function summary extensions for whole-program devirtualization pass.
The summary information includes all uses of llvm.type.test and
llvm.type.checked.load intrinsics that can be used to devirtualize calls,
including any constant arguments for virtual constant propagation.

Differential Revision: https://reviews.llvm.org/D29734

llvm-svn: 294795
2017-02-10 22:29:38 +00:00
Chandler Carruth 1f8fcfeac5 [PM/LCG] Teach LCG to support spurious reference edges.
Somewhat amazingly, this only requires teaching it to clean them up when
deleting a dead function from the graph. And we already have exactly the
necessary data structures to do that in the parent RefSCCs.

This allows ArgPromote to work in a much simpler way be merely letting
reference edges linger in the graph after the causing IR is deleted. We
will clean up these edges when we run any function pass over the IR, but
don't remove them eagerly.

This avoids all of the quadratic update issues both in the current pass
manager and in my previous attempt with the new pass manager.

Differential Revision: https://reviews.llvm.org/D29579

llvm-svn: 294663
2017-02-09 23:30:14 +00:00
Chandler Carruth aaad9f84be [PM/LCG] Teach the LazyCallGraph how to replace a function without
disturbing the graph or having to update edges.

This is motivated by porting argument promotion to the new pass manager.
Because of how LLVM IR Function objects work, in order to change their
signature a new object needs to be created. This is efficient and
straight forward in the IR but previously was very hard to implement in
LCG. We could easily replace the function a node in the graph
represents. The challenging part is how to handle updating the edges in
the graph.

LCG previously used an edge to a raw function to represent a node that
had not yet been scanned for calls and references. This was the core
of its laziness. However, that model causes this kind of update to be
very hard:
1) The keys to lookup an edge need to be `Function*`s that would all
   need to be updated when we update the node.
2) There will be some unknown number of edges that haven't transitioned
   from `Function*` edges to `Node*` edges.

All of this complexity isn't necessary. Instead, we can always build
a node around any function, always pointing edges at it and always using
it as the key to lookup an edge. To maintain the laziness, we need to
sink the *edges* of a node into a secondary object and explicitly model
transitioning a node from empty to populated by scanning the function.
This design seems much cleaner in a number of ways, but importantly
there is now exactly *one* place where the `Function*` has to be
updated!

Some other cleanups that fall out of this include having something to
model the *entry* edges more accurately. Rather than hand rolling parts
of the node in the graph itself, we have an explicit `EdgeSequence`
object that gives us exactly the functionality needed. We also have
a consistent place to define the edge iterators and can use them for
both the entry edges and the internal edges of the graph.

The API used to model the separation between a node and its edges is
intentionally very thin as most clients are expected to deal with nodes
that have populated edges. We model this exactly as an optional does
with an additional method to populate the edges when that is
a reasonable thing for a client to do. This is based on API design
suggestions from Richard Smith and David Blaikie, credit goes to them
for helping pick how to model this without it being either too explicit
or too implicit.

The patch is somewhat noisy due to shifting around iterator types and
new syntax for walking the edges of a node, but most of the
functionality change is in the `Edge`, `EdgeSequence`, and `Node` types.

Differential Revision: https://reviews.llvm.org/D29577

llvm-svn: 294653
2017-02-09 23:24:13 +00:00
Daniel Berlin 73ad5cb9b1 Drop graph_ prefix
llvm-svn: 294621
2017-02-09 20:37:46 +00:00
Daniel Berlin 58a6e57394 GraphTraits: Add range versions of graph traits functions (graph_nodes, graph_children, inverse_graph_nodes, inverse_graph_children).
Summary:
Convert all obvious node_begin/node_end and child_begin/child_end
pairs to range based for.

Sending for review in case someone has a good idea how to make
graph_children able to be inferred. It looks like it would require
changing GraphTraits to be two argument or something. I presume
inference does not happen because it would have to check every
GraphTraits in the world to see if the noderef types matched.

Note: This change was 3-staged with clang as well, which uses
Dominators/etc from LLVM.

Reviewers: chandlerc, tstellarAMD, dblaikie, rsmith

Subscribers: arsenm, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D29767

llvm-svn: 294620
2017-02-09 20:37:24 +00:00
Vitaly Buka 9987d98370 LVI: Fix use-of-uninitialized-value after r294463
BlockValueStack can be reallocated making reference e invalid.

llvm-svn: 294572
2017-02-09 09:28:05 +00:00
Daniel Berlin 9c92a469b4 LVI: Add a per-value worklist limit to LazyValueInfo.
Summary:
LVI is now depth first, which is optimal for iteration strategy in
terms of work per call.  However, the way the results get cached means
it can still go very badly N^2 or worse right now.  The overdefined
cache is per-block, because LVI wants to try to get different results
for the same name in different blocks (IE solve the problem
PredicateInfo solves).  This means even if we discover a value is
overdefined after going very deep, it doesn't cache this information,
causing it to end up trying to rediscover it again and again.  The
same is true for values along the way.  In practice, overdefined
anywhere should mean overdefined everywhere (this is how, for example,
SCCP works).

Until we get around to reworking the overdefined cache, we need to
limit the worklist size we process.  Note that permanently reverting
the DFS strategy exploration seems the wrong strategy (temporarily
seems fine if we really want).  BFS is clearly the wrong approach, it
just gets luckier on some testcases.  It's also very hard to design
an effective throttle for BFS. For DFS, the throttle is directly related
to the depth of the CFG.  So really deep CFGs will get cutoff, smaller
ones will not. As the CFG simplifies, you get better results.
In BFS, the limit is it's related to the fan-out times average block size,
which is harder to reason about or make good choices for.

Bug being filed about the overdefined cache, but it will require major
surgery to fix it (plumbing predicateinfo through CVP or LVI).

Note: I did not make this number configurable because i'm not sure
anyone really needs to tweak this knob.  We run CVP 3 times. On the
testcases i have the slow ones happen in the middle, where CVP is
doing cleanup work other things are effective at.  Over the course of
3 runs, we don't see to have any real loss of performance.

I haven't gotten a minimized testcase yet, but just imagine in your
head a testcase where, going *up* the CFG, you have branches, one of
which leads 50000 blocks deep, and the other, to something where the
answer is overdefined immediately.  BFS would discover the overdefined
faster than DFS, but do more work to do so.  In practice, the right
answer is "once DFS discovers overdefined for a value, stop trying to
get more info about that value" (and so, DFS would normally cache the
overdefined results for every value it passed through in those 50k
blocks, and never do that work again. But it don't, because of the
naming problem)

Reviewers: chandlerc, djasper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29715

llvm-svn: 294463
2017-02-08 15:22:52 +00:00
Chandler Carruth 346542b769 Revert r293017 and fix the actual underlying issue.
The patch committed in r293017, as discussed on the list, doesn't really
make sense but was causing an actual issue to go away.

The issue turns out to be that in one place the extra template arguments
were dropped from the OuterAnalysisManagerProxy. This in turn caused the
types used in one set of places to access the key to be completely
different from the types used in another set of places for both Loop and
CGSCC cases where there are extra arguments.

I have literally no idea how anything seemed to work with this bug in
place. It blows my mind. But it did except for mingw64 in a DLL build.

I've added a really handy static assert that helps ensure we don't break
this in the future. It immediately diagnoses the issue with a compile
failure and a very clear error message. Much better that staring at
backtraces on a build bot. =]

llvm-svn: 294267
2017-02-07 01:50:48 +00:00
Philip Reames c80bd0486d [LVI] Switch from BFS to DFS exploration order
This patch changes the order in which LVI explores previously unexplored paths.

Previously, the code used an BFS strategy where each unexplored input was added to the search queue before any of them were explored. This has the effect of causing all inputs to be explored before returning to re-evaluate the merge point (non-local or phi node). This has the unfortunate property of doing redundant work if one of the inputs to the merge is found to be overdefined (i.e. unanalysable). If any input is overdefined, the result of the merge will be too; regardless of the values of other inputs.

The new code uses a DFS strategy where we re-evaluate the merge after evaluating each input. If we discover an overdefined input, we immediately return without exploring other inputs.

We have reports of large (4-10x) improvements of compile time with this patch and some reports of more precise analysis results as well.  See the review discussion for details.  The original motivating case was pr10584.

Differential Revision: https://reviews.llvm.org/D28190

llvm-svn: 294264
2017-02-07 00:25:24 +00:00
Chandler Carruth a80cfb3063 [PM/LCG] Fix the no-asserts build after r294227. Sorry for the noise.
llvm-svn: 294235
2017-02-06 20:59:07 +00:00
Chandler Carruth 2e0fe3e65b [PM/LCG] Remove the lazy RefSCC formation from the LazyCallGraph during
iteration.

The lazy formation of RefSCCs isn't really the most important part of
the laziness here -- that has to do with walking the functions
themselves -- and isn't essential to maintain. Originally, there were
incremental update algorithms that relied on updates happening
predominantly near the most recent RefSCC formed, but those have been
replaced with ones that have much tighter general case bounds at this
point. We do still perform asserts that only scale well due to this
incrementality, but those are easy to place behind EXPENSIVE_CHECKS.

Removing this simplifies the entire analysis by having a single up-front
step that builds all of the RefSCCs in a direct Tarjan walk. We can even
easily replace this with other or better algorithms at will and with
much less confusion now that there is no iterator-based incremental
logic involved. This removes a lot of complexity from LCG.

Another advantage of moving in this direction is that it simplifies
testing the system substantially as we no longer have to worry about
observing and mutating the graph half-way through the RefSCC formation.

We still need a somewhat special iterator for RefSCCs because we want
the iterator to remain stable in the face of graph updates. However,
this now merely involves relative indexing to the current RefSCC's
position in the sequence which isn't too hard.

Differential Revision: https://reviews.llvm.org/D29381

llvm-svn: 294227
2017-02-06 19:38:06 +00:00
Sanjay Patel 54656ca7db [ValueTracking] emit a remark when we detect a conflicting assumption (PR31809)
This is a follow-up to D29395 where we try to be good citizens and let the user know that
we've probably gone off the rails.

This should allow us to resolve:
https://llvm.org/bugs/show_bug.cgi?id=31809

Differential Revision: https://reviews.llvm.org/D29404

llvm-svn: 294208
2017-02-06 18:26:06 +00:00
Daniil Fukalov 6378bdb2dd [SCEV] limit recursion depth and operands number in getAddExpr
for a quite big function with source like

%add = add nsw i32 %mul, %conv
%mul1 = mul nsw i32 %add, %conv
%add2 = add nsw i32 %mul1, %add
%mul3 = mul nsw i32 %add2, %add
; repeat couple of thousands times
that can be produced by loop unroll, getAddExpr() tries to recursively construct SCEV and runs almost infinite time.

Added recursion depth restriction (with new parameter to set it)

Reviewers: sanjoy

Subscribers: hfinkel, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D28158

llvm-svn: 294181
2017-02-06 12:38:06 +00:00
Michael Kuperstein 2a735b71b6 [SLP] Make sortMemAccesses explicitly return an error. NFC.
llvm-svn: 294029
2017-02-03 19:32:50 +00:00
Michael Kuperstein 723999d4aa [SLP] Use SCEV to sort memory accesses.
This generalizes memory access sorting to use differences between SCEVs,
instead of relying on constant offsets. That allows us to properly do
SLP vectorization of non-sequentially ordered loads within loops bodies.

Differential Revision: https://reviews.llvm.org/D29425

llvm-svn: 294027
2017-02-03 19:09:45 +00:00
Mehdi Amini 1380edf4ef Revert "[ThinLTO] Add an auto-hide feature"
This reverts commit r293970.

After more discussion, this belongs to the linker side and
there is no added value to do it at this level.

llvm-svn: 293993
2017-02-03 07:41:43 +00:00
Mehdi Amini b0a8ff71e5 [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

This is a recommit of r293912 after fixing build failures,
and a recommit of r293918 after fixing LLD tests.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293970
2017-02-03 00:32:38 +00:00
Mehdi Amini 21c89dc920 Revert "[ThinLTO] Add an auto-hide feature"
This reverts commit r293918, one lld test does not pass.

llvm-svn: 293961
2017-02-02 23:20:36 +00:00
Xinliang David Li 58fcc9bdce [PGO] internal option cleanups
1. Added comments for options
2. Added missing option cl::desc field
3. Uniified function filter option for graph viewing.
   Now PGO count/raw-counts share the same
   filter option: -view-bfi-func-name=.

llvm-svn: 293938
2017-02-02 21:29:17 +00:00
Xinliang David Li 1eb4ec6a2e [PGO] make graph view internal options available for all builds
Differential Revision: https://reviews.llvm.org/D29259

llvm-svn: 293921
2017-02-02 19:18:56 +00:00
Mehdi Amini 97624fb1ec [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

This is a recommit of r293912 after fixing build failures.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293918
2017-02-02 18:31:35 +00:00
Mehdi Amini 827600deaf Revert "[ThinLTO] Add an auto-hide feature"
This reverts r293912, bots are broken.

llvm-svn: 293914
2017-02-02 18:24:37 +00:00
Mehdi Amini dc5a7444f0 [ThinLTO] Add an auto-hide feature
When a symbol is not exported outside of the
DSO, it is can be hidden. Usually we try to internalize
as much as possible, but it is not always possible, for
instance a symbol can be referenced outside of the LTO
unit, or there can be cross-module reference in ThinLTO.

Differential Revision: https://reviews.llvm.org/D28978

llvm-svn: 293912
2017-02-02 18:13:46 +00:00
Jun Bum Lim 180bc5a021 [JumpThread] Enhance finding partial redundant loads by continuing scanning single predecessor
Summary: While scanning predecessors to find an available loaded value, if the predecessor has a single predecessor, we can continue scanning through the single predecessor.

Reviewers: mcrosier, rengolin, reames, davidxl, haicheng

Reviewed By: rengolin

Subscribers: zzheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D29200

llvm-svn: 293896
2017-02-02 15:12:34 +00:00
Adam Nemet 0bf1b863b9 [LV] Also port failure remarks to new OptimizationRemarkEmitter API
llvm-svn: 293866
2017-02-02 05:41:51 +00:00
Sanjay Patel 52e4e6594e [ValueTracking] remove a FIXME for something we don't want to do; NFC
The comment was added with:
https://reviews.llvm.org/rL293773
...but there would be a cost to implement this and possibly no payoff.

llvm-svn: 293823
2017-02-01 22:27:34 +00:00
Matthew Simpson ba5cf9dfee [LV] Move interleaved access helper functions to VectorUtils (NFC)
This patch moves some helper functions related to interleaved access
vectorization out of LoopVectorize.cpp and into VectorUtils.cpp. We would like
to use these functions in a follow-on patch that improves interleaved load and
store lowering in (ARM/AArch64)ISelLowering.cpp. One of the functions was
already duplicated there and has been removed.

Differential Revision: https://reviews.llvm.org/D29398

llvm-svn: 293788
2017-02-01 17:45:46 +00:00
Sanjay Patel 25f6d710d9 [ValueTracking] avoid crashing from bad assumptions (PR31809)
A program may contain llvm.assume info that disagrees with other analysis. 
This may be caused by UB in the program, so we must not crash because of that.

As noted in the code comments:
https://llvm.org/bugs/show_bug.cgi?id=31809
...we can do better, but this at least avoids the assert/crash in the bug report.

Differential Revision: https://reviews.llvm.org/D29395

llvm-svn: 293773
2017-02-01 15:41:32 +00:00
Eli Friedman 10d1ff64fe [SCEV] Simplify/generalize howFarToZero solving.
Make SolveLinEquationWithOverflow take the start as a SCEV, so we can
solve more cases. With that implemented, get rid of the special case
for powers of two.

The additional functionality probably isn't particularly useful,
but it might help a little for certain cases involving pointer
arithmetic.

Differential Revision: https://reviews.llvm.org/D28884

llvm-svn: 293576
2017-01-31 00:42:42 +00:00
Matt Arsenault 42b6478344 NVPTX: Refactor NVPTXInferAddressSpaces to check TTI
Add a new TTI hook for getting the generic address space value.

llvm-svn: 293563
2017-01-30 23:02:12 +00:00
Sanjay Patel 14a4b8185f [ValueTracking] clean up lookThroughCast; NFCI
1. Use auto with dyn_cast.
2. Don't use else after return.
3. Convert chain of 'else if' to switch.
4. Improve variable names.

llvm-svn: 293432
2017-01-29 16:34:57 +00:00
Mohammad Shahid 3121334d32 [SLP] Vectorize loads of consecutive memory accesses, accessed in non-consecutive (jumbled) way.
The jumbled scalar loads will be sorted while building the tree and these accesses will be marked to generate shufflevector after the vectorized load with proper mask.

Reviewers: hfinkel, mssimpso, mkuper

Differential Revision: https://reviews.llvm.org/D26905

Change-Id: I9c0c8e6f91a00076a7ee1465440a3f6ae092f7ad
llvm-svn: 293386
2017-01-28 17:59:44 +00:00
Matthias Braun 8c209aa877 Cleanup dump() functions.
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html

For reference:
- Public headers should just declare the dump() method but not use
  LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  LLVM_DUMP_METHOD void MyClass::dump() {
    // print stuff to dbgs()...
  }
  #endif

llvm-svn: 293359
2017-01-28 02:02:38 +00:00
Peter Collingbourne 5ad775f2e8 Analysis: Add appropriate const qualification to functions in TypeMetadataUtils.cpp. NFC.
llvm-svn: 293341
2017-01-27 22:55:30 +00:00
Mehdi Amini 1726fc698c Fix BasicAA incorrect assumption on GEP
This is fixing pr31761: BasicAA is deducing NoAlias
on the result of the GEP if the base pointer is itself NoAlias.

This is possible only if the NoAlias on the base pointer is
deduced with a non-sized query: this should guarantee that
the pointers are belonging to different memory allocation
and that the GEP can't legally jump from one to another.

Differential Revision: https://reviews.llvm.org/D29216

llvm-svn: 293293
2017-01-27 16:12:22 +00:00
Justin Lebar 322c127bee [ValueTracking] Add comment that CannotBeOrderedLessThanZero does the wrong thing for powi.
Summary:
CannotBeOrderedLessThanZero(powi(x, exp)) returns true if
CannotBeOrderedLessThanZero(x).  But powi(-0, exp) is negative if exp is
odd, so we actually want to return SignBitMustBeZero(x).

Except that also isn't right, because we want to return true if x is
NaN, even if x has a negative sign bit.

What we really need in order to fix this is a consistent approach in
this function to handling the sign bit of NaNs.  Without this it's very
difficult to say what the correct behavior here is.

Reviewers: hfinkel, efriedma, sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28927

llvm-svn: 293243
2017-01-27 00:58:34 +00:00
Daniil Fukalov b09dac59fc [SCEV] Introduce add operation inlining limit
Inlining in getAddExpr() can cause abnormal computational time in some cases.
New parameter -scev-addops-inline-threshold is intruduced with default value 500.

Reviewers: sanjoy

Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D28812

llvm-svn: 293176
2017-01-26 13:33:17 +00:00
Chandler Carruth 41421df02b [PM] Use PoisoningVH correctly when merely deleting entries in a map
with it.

This code was dereferencing the PoisoningVH which isn't allowed once it
is poisoned. But the code itself really doesn't need to access the
pointer, it is just doing the safe stuff of clearing out data structures
keyed on the pointer value.

Change the code to use iterators to erase directly from a DenseMap. This
is also substantially more efficient as it avoids lots of hashing and
lookups to do the erasure. DenseMap supports iterating behind the
iteration which is fairly easy to implement.

Sadly, I don't have a test case here. I'm not even close and I don't
know that I ever will be. The issue is that several of the tricky
aspects of fixing this only show up when you cause the stack's
SmallVector to be in *EXACTLY* the right location. I only ever got
a reproduction for those with Clang, and only with *exactly* the right
command line flags. Any adjustment, even to seemingly unrelated flags,
would make partial and half-way solutions magically start to "work". In
good news, all of this was caught with the LLVM test suite. Also, there
is no *specific* code here that is untested, just that the old pattern
of code won't immediately fail on any test case I've managed to
contrive.

llvm-svn: 293160
2017-01-26 08:31:54 +00:00
Jonas Paulsson 8e2f948ef0 [TargetTransformInfo] Refactor and improve getScalarizationOverhead()
Refactoring to remove duplications of this method.

New method getOperandsScalarizationOverhead() that looks at the present unique
operands and add extract costs for them. Old behaviour was to just add extract
costs for one operand of the type always, which still happens in
getArithmeticInstrCost() if no operands are provided by the caller.

This is a good start of improving on this, but there are more places
that can be improved by using getOperandsScalarizationOverhead().

Review: Hal Finkel
https://reviews.llvm.org/D29017

llvm-svn: 293155
2017-01-26 07:03:25 +00:00
Adam Nemet 916923e689 [llc] Add -pass-remarks-output
This is the opt/llc counterpart of -fsave-optimization-record to output
optimization remarks in a YAML file.

llvm-svn: 293121
2017-01-26 00:39:51 +00:00
Justin Lebar 7e3184c412 [ValueTracking] Implement SignBitMustBeZero correctly for sqrt.
Summary:
Previously we assumed that the result of sqrt(x) always had 0 as its
sign bit.  But sqrt(-0) == -0.

Reviewers: hfinkel, efriedma, sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28928

llvm-svn: 293115
2017-01-26 00:10:26 +00:00
Adam Nemet a964066705 New OptimizationRemarkEmitter pass for MIR
This allows MIR passes to emit optimization remarks with the same level
of functionality that is available to IR passes.

It also hooks up the greedy register allocator to report spills.  This
allows for interesting use cases like increasing interleaving on a loop
until spilling of registers is observed.

I still need to experiment whether reporting every spill scales but this
demonstrates for now that the functionality works from llc
using -pass-remarks*=<pass>.

Differential Revision: https://reviews.llvm.org/D29004

llvm-svn: 293110
2017-01-25 23:20:33 +00:00
Adam Nemet 484f93db30 [OptDiag] Split code region out of DiagnosticInfoOptimizationBase
Code region is the only part of this class that is IR-specific.  Code
region is moved down in the inheritance tree to a new derived class,
called DiagnosticInfoIROptimization.

All the existing remarks are derived from this new class now.

This allows the new MIR pass-remark classes to be derived from
DiagnosticInfoOptimizationBase.

Also because we keep the name DiagnosticInfoOptimizationBase, the clang
parts don't need any adjustment.

Differential Revision: https://reviews.llvm.org/D29003

llvm-svn: 293109
2017-01-25 23:20:25 +00:00
whitequark 16f1e5f1ca Mark @llvm.powi.* as safe to speculatively execute.
Floating point intrinsics in LLVM are generally not speculatively
executed, since most of them are defined to behave the same as libm
functions, which set errno.

However, the @llvm.powi.* intrinsics do not correspond to any libm
function, and lacks any defined error handling semantics in LangRef.
It most certainly does not alter errno.

llvm-svn: 293041
2017-01-25 09:32:30 +00:00
NAKAMURA Takumi 28dc4d5122 Rewind instantiations of OuterAnalysisManagerProxy in r289317, r291651, and r291662.
I found root class should be instantiated for variadic tempate to instantiate static member explicitly.

This will fix failures in mingw DLL build.

llvm-svn: 293017
2017-01-25 04:26:29 +00:00
Sanjay Patel 562272536a [InstSimplify] try to eliminate icmp Pred (add nsw X, C1), C2
I was surprised to see that we're missing icmp folds based on 'add nsw' in InstCombine, 
but we should handle the InstSimplify cases first because that could make the InstCombine
code simpler.

Here are Alive-based proofs for the logic:

Name: add_neg_constant
Pre: C1 < 0 && (C2 > ((1<<(width(C1)-1)) + C1))
%a = add nsw i7 %x, C1
%b = icmp sgt %a, C2
  =>
%b = false

Name: add_pos_constant
Pre: C1 > 0 && (C2 < ((1<<(width(C1)-1)) + C1 - 1))
%a = add nsw i6 %x, C1
%b = icmp slt %a, C2
  =>
%b = false

Name: nuw
Pre: C1 u>= C2
%a = add nuw i11 %x, C1
%b = icmp ult %a, C2
  =>
%b = false

Differential Revision: https://reviews.llvm.org/D29053

llvm-svn: 292952
2017-01-24 17:03:24 +00:00
Chandler Carruth 6acdca78a0 [PH] Replace uses of AssertingVH from members of analysis results with
a lazy-asserting PoisoningVH.

AssertVH is fundamentally incompatible with cache-invalidation of
analysis results. The invaliadtion happens after the AssertingVH has
already fired. Instead, use a PoisoningVH that will assert if the
dangling handle is ever used rather than merely be assigned or
destroyed.

This patch also removes all of the (numerous) doomed attempts to work
around this fundamental incompatibility. It is a pretty significant
simplification IMO.

The most interesting change is in the Inliner where we still do some
clearing because we don't want to rely on the coarse grained
invalidation strategy of the containing pass manager. However, I prefer
the approach that contains this logic to the cleanup phase of the
Inliner, and I think we could enhance the CGSCC analysis management
layer to make this even better in the future if desired.

The rest is straight cleanup.

I've also added a test for one of the harder cases to work around: when
a *module analysis* contains many AssertingVHes pointing at functions.

Differential Revision: https://reviews.llvm.org/D29006

llvm-svn: 292928
2017-01-24 12:55:57 +00:00