Commit Graph

6578 Commits

Author SHA1 Message Date
Benjamin Kramer 3bc1edf95b Use arrays or initializer lists to feed ArrayRefs instead of SmallVector where possible.
No functionality change intended.

llvm-svn: 274431
2016-07-02 11:41:39 +00:00
Xinliang David Li 94734eef33 [PM] refactor LoopAccessInfo code part-2
Differential Revision: http://reviews.llvm.org/D21636

llvm-svn: 274334
2016-07-01 05:59:55 +00:00
Adam Nemet f45594c912 [LAA] Fix alphabetical sorting of headers. NFC
llvm-svn: 274302
2016-07-01 00:09:02 +00:00
Matt Arsenault 727e279ac4 SLPVectorizer: Move propagateMetadata to VectorUtils
This will be re-used by the LoadStoreVectorizer.

Fix handling of range metadata and testcase by Justin Lebar.

llvm-svn: 274281
2016-06-30 21:17:59 +00:00
Sanjoy Das 0da2d14766 [SCEV] Compute max be count from shift operator only if all else fails
In particular, check to see if we can compute a precise trip count by
exhaustively simulating the loop first.

llvm-svn: 274199
2016-06-30 02:47:28 +00:00
George Burgess IV d86e38e1db [CFLAA] Add support for ModRef queries.
This patch makes CFLAA answer some ModRef queries. Because we don't
distinguish between reading/writing when making StratifiedSets, we're
unable to offer any of the readonly-related answers.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21858

llvm-svn: 274197
2016-06-30 02:11:26 +00:00
Elena Demikhovsky 5e21c94f25 Reverted patch 273864
llvm-svn: 274115
2016-06-29 10:01:06 +00:00
Craig Topper df7454f94b Revert "[ValueTracking] Teach computeKnownBits for PHI nodes to compute sign bit for a recurrence with a NSW addition."
This is breaking an optimizaton remark test in clang. I've identified a couple fixes for that, but want to understand it better before I commit to anything.

llvm-svn: 274102
2016-06-29 04:57:00 +00:00
Craig Topper 2cc199baff [ValueTracking] Teach computeKnownBits for PHI nodes to compute sign bit for a recurrence with a NSW addition.
If a operation for a recurrence is an addition with no signed wrap and both input sign bits are 0, then the result sign bit must also be 0. Similar for the negative case.

I found this deficiency while playing around with a loop in the x86 backend that contained a signed division that could be optimized into an unsigned division if we could prove both inputs were positive. One of them being the loop induction variable. With this patch we can perform the conversion for this case. One of the test cases here is a contrived variation of the loop I was looking at.

Differential revision: http://reviews.llvm.org/D21493

llvm-svn: 274098
2016-06-29 03:46:47 +00:00
Chad Rosier 02e831cf2f Typos. NFC.
llvm-svn: 274038
2016-06-28 17:19:10 +00:00
Xinliang David Li 3e176c77ab [BFI/MBFI]: cfg graph view with color scheme
This patch enhances dot graph viewer to show hot regions
with hot bbs/edges displayed in red. The ratio of the bb
freq to the max freq of the function needs to be no less
than the value specified by view-hot-freq-percent option.
The default value is 10 (i.e. 10%).

llvm-svn: 273996
2016-06-28 06:58:21 +00:00
Xinliang David Li 8dd5ce97f9 [BFI]: enhance BFI graph dump
MBFI supports profile count dumping and function
name based filtering. Add these two feature to
BFI as well. The filtering option is shared between
BFI and MBFI: -view-bfi-func-name=..

llvm-svn: 273992
2016-06-28 04:07:03 +00:00
Xinliang David Li 55415f2565 [BFI]: graph viewer code refactoring
BFI and MBFI's dot traits class share most of the
code and all future enhancement. This patch extracts
common implementation into base class BFIDOTGraphTraitsBase.

This patch also enables BFI graph to show branch probability
on edges as MBFI does before.

llvm-svn: 273990
2016-06-28 03:41:29 +00:00
Chandler Carruth dca834089a [PM] Improve the debugging and logging facilities of the CGSCC bits of
the new pass manager.

This adds operator<< overloads for the various bits of the
LazyCallGraph, dump methods for use from the debugger, and debug logging
using them to the CGSCC pass manager.

Having this was essential for debugging the call graph update patch, and
I've extracted what I could from that patch here to minimize the delta.

llvm-svn: 273961
2016-06-27 23:26:08 +00:00
George Burgess IV f10c7fc286 [CFLAA] Make MSVC happy. NFC.
Apparently, MSVC complains if there's an implicit conversion from
`unsigned` to `unsigned long long`, if the `unsigned` is the result of
a bit shift.

llvm-svn: 273955
2016-06-27 22:50:01 +00:00
Easwaran Raman 22eb80a114 Fix size computation of array allocation in inline cost analysis
Differential revision: http://reviews.llvm.org/D21690

llvm-svn: 273952
2016-06-27 22:31:53 +00:00
George Burgess IV 11ff52bffc [CFLAA] Use unsigned numbers for bit-shifts.
This uses `1U` instead of `1ULL` because StratifiedAttrs is a 32-bit
bitset.

Thanks to Hans-Bernhard Broker for bringing this up.

llvm-svn: 273902
2016-06-27 18:35:00 +00:00
Elena Demikhovsky 4c58b2761a Fixed consecutive memory access detection in Loop Vectorizer.
It did not handle correctly cases without GEP.

The following loop wasn't vectorized:

for (int i=0; i<len; i++)

  *to++ = *from++;

I use getPtrStride() to find Stride for memory access and return 0 is the Stride is not 1 or -1.

Re-commit rL273257 - revision: http://reviews.llvm.org/D20789

llvm-svn: 273864
2016-06-27 11:19:23 +00:00
Igor Breger 7357849dca [ConstantFolding] Fix bitcast vector of i1.
Differential Revision: http://reviews.llvm.org/D21735

llvm-svn: 273845
2016-06-27 06:42:54 +00:00
Benjamin Kramer aa2091505f Apply clang-tidy's modernize-loop-convert to lib/Analysis.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273816
2016-06-26 17:27:42 +00:00
David Majnemer bb53d23ef8 [InstSimplify] Replace calls to null with undef
Calling null is undefined behavior, we can simplify the resulting value
to undef.

llvm-svn: 273777
2016-06-25 07:37:30 +00:00
Peter Collingbourne 0312f614b1 IR: Introduce llvm.type.checked.load intrinsic.
This intrinsic safely loads a function pointer from a virtual table pointer
using type metadata. This intrinsic is used to implement control flow integrity
in conjunction with virtual call optimization. The virtual call optimization
pass will optimize away llvm.type.checked.load intrinsics associated with
devirtualized calls, thereby removing the type check in cases where it is
not needed to enforce the control flow integrity constraint.

This patch also introduces the capability to copy type metadata between
global variables, and teaches the virtual call optimization pass to do so.

Differential Revision: http://reviews.llvm.org/D21121

llvm-svn: 273756
2016-06-25 00:23:04 +00:00
Eli Friedman 5a52856cc8 Fix documentation for FindAvailableLoadedValue.
llvm-svn: 273734
2016-06-24 21:32:15 +00:00
Peter Collingbourne 7efd750607 IR: New representation for CFI and virtual call optimization pass metadata.
The bitset metadata currently used in LLVM has a few problems:

1. It has the wrong name. The name "bitset" refers to an implementation
   detail of one use of the metadata (i.e. its original use case, CFI).
   This makes it harder to understand, as the name makes no sense in the
   context of virtual call optimization.

2. It is represented using a global named metadata node, rather than
   being directly associated with a global. This makes it harder to
   manipulate the metadata when rebuilding global variables, summarise it
   as part of ThinLTO and drop unused metadata when associated globals are
   dropped. For this reason, CFI does not currently work correctly when
   both CFI and vcall opt are enabled, as vcall opt needs to rebuild vtable
   globals, and fails to associate metadata with the rebuilt globals. As I
   understand it, the same problem could also affect ASan, which rebuilds
   globals with a red zone.

This patch solves both of those problems in the following way:

1. Rename the metadata to "type metadata". This new name reflects how
   the metadata is currently being used (i.e. to represent type information
   for CFI and vtable opt). The new name is reflected in the name for the
   associated intrinsic (llvm.type.test) and pass (LowerTypeTests).

2. Attach metadata directly to the globals that it pertains to, rather
   than using the "llvm.bitsets" global metadata node as we are doing now.
   This is done using the newly introduced capability to attach
   metadata to global variables (r271348 and r271358).

See also: http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html

Differential Revision: http://reviews.llvm.org/D21053

llvm-svn: 273729
2016-06-24 21:21:32 +00:00
Reid Kleckner fbd5eef691 Revert "InstCombine rule to fold trunc when value available"
This reverts commit r273608.

Broke building code with sanitizers, where apparently these kinds of
loads, casts, and truncations are common:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/24502
http://crbug.com/623099

llvm-svn: 273703
2016-06-24 18:42:58 +00:00
George Burgess IV d9c39fcbca Attempt to fix MSVC breakage caused by r273636.
Apparently earlier versions of MSVC don't have constexpr bitset ctors.

llvm-svn: 273637
2016-06-24 01:41:29 +00:00
George Burgess IV a3d62be733 [CFLAA] Propagate StratifiedAttrs in interproc. analysis.
This patch also has a refactor that kills StratifiedAttr, and leaves us
with StratifiedAttrs, because having both was mildly redundant.

This patch makes us correctly handle stratified attributes when doing
interprocedural analysis. It also adds another attribute, AttrCaller,
which acts like AttrUnknown. We can filter out AttrCaller values when
during interprocedural analysis, since the caller should have
information about what arguments it's passing to its callee.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21645

llvm-svn: 273636
2016-06-24 01:00:03 +00:00
George Burgess IV d14d05affe Attempt #2 to unbreak bots broken by r273596.
Some of the bots running GCC 4.7 seem to be having trouble with lambdas
that explicitly capture `this`. Relevant-looking bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53137

llvm-svn: 273613
2016-06-23 20:59:13 +00:00
Anna Thomas 31a0b2088f InstCombine rule to fold trunc when value available
Summary:
This instcombine rule folds away trunc operations that have value available from a prior load or store.
This kind of code can be generated as a result of GVN widening the load or from source code as well.

Reviewers: reames, majnemer, sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21246

llvm-svn: 273608
2016-06-23 20:22:22 +00:00
George Burgess IV fe1397b977 Attempt to fix breakage caused by r273596.
llvm-svn: 273601
2016-06-23 19:16:04 +00:00
George Burgess IV 1f99da54c2 [CFLAA] Use better interprocedural function summaries.
Previously, we just unified any arguments that seemed to be related to
each other. With this patch, we now respect dereference levels, etc.
which should make us substantially more accurate. Proper handling of
StratifiedAttrs will be done in a later patch.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21536

llvm-svn: 273596
2016-06-23 18:55:23 +00:00
Sanjay Patel e053621071 [ValueTracking] simplify logic in ComputeNumSignBits (NFCI)
This was noted in http://reviews.llvm.org/D21610 . The previous code
predated the use of APInt ( http://reviews.llvm.org/rL47654 ), so it
had to account for the fixed width of uint64_t.

Now that we're using the variable width APInt, we can remove some
complexity.

llvm-svn: 273584
2016-06-23 17:41:59 +00:00
Michael Zolotukhin 2d3592d481 [LoopUnrollAnalyzer] Fix a bug in UnrolledInstAnalyzer::visitLoad.
When simplifying a load we need to make sure that the type of the
simplified value matches the type of the instruction we're processing.
In theory, we can handle casts here as we deal with constant data, but
since it's not implemented at the moment, we at least need to bail out.

This fixes PR28262.

llvm-svn: 273562
2016-06-23 14:31:31 +00:00
Xinliang David Li ce030acb4e [PM]: LoopAccessInfo simple refactoring
To make definition of mov ctors easier.
Differential Revision: http://reviews.llvm.org/D21563

llvm-svn: 273506
2016-06-22 23:20:59 +00:00
Sanjay Patel a06d989552 [ValueTracking] improve ComputeNumSignBits for vector constants
This is similar to the computeKnownBits improvement in rL268479. 
There's probably more we can do for vector logic instructions, but 
this should let us see non-splat constant masking ops that can
become vector selects instead of and/andn/or sequences.

Differential Revision: http://reviews.llvm.org/D21610

llvm-svn: 273459
2016-06-22 19:20:59 +00:00
Xinliang David Li b12b353a41 [BFI]: NFC refactoring
move getBlockProfileCount implementation to the
base class so that MBFI can share too.

llvm-svn: 273442
2016-06-22 17:12:12 +00:00
Elena Demikhovsky a266cf0518 reverted the prev commit due to assertion failure
llvm-svn: 273258
2016-06-21 12:10:11 +00:00
Elena Demikhovsky 9823c995bc Fixed consecutive memory access detection in Loop Vectorizer.
It did not handle correctly cases without GEP.

The following loop wasn't vectorized:

for (int i=0; i<len; i++)
  *to++ = *from++;

I use getPtrStride() to find Stride for memory access and return 0 is the Stride is not 1 or -1.

Differential revision: http://reviews.llvm.org/D20789

llvm-svn: 273257
2016-06-21 11:32:01 +00:00
David Majnemer e61e4bfd87 Replace silly uses of 'signed' with 'int'
llvm-svn: 273244
2016-06-21 05:10:24 +00:00
Davide Italiano 9cc0bca23c [TargetLibraryInfo] Reduce code duplication.
llvm-svn: 273241
2016-06-21 04:32:21 +00:00
George Burgess IV 9fdbfe17a8 [CFLAA] Be more aggressive with interprocedural analysis.
This patch makes us perform interprocedural analysis on functions that
don't have internal linkage. It also removes a test that should've been
deleted in an earlier commit (since other tests now cover everything
that the newly-removed test covers).

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21513

llvm-svn: 273229
2016-06-21 01:42:47 +00:00
George Burgess IV a99cd049d0 Attempt to make MSVC buildbots happy.
Broken by r273219.

llvm-svn: 273220
2016-06-20 23:20:49 +00:00
George Burgess IV 87b2e41416 [CFLAA] Add interprocedural function summaries.
This patch adds function summaries, so that we don't need to recompute
various properties about function parameters/return values at each
callsite of a function. It also adds many interprocedural tests for
CFLAA.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21475#inline-182390

llvm-svn: 273219
2016-06-20 23:10:56 +00:00
Sanjay Patel 9ad8fb68f7 [InstSimplify] analyze (optionally casted) icmps to eliminate obviously false logic (PR27869)
By moving this transform to InstSimplify from InstCombine, we sidestep the problem/question
raised by PR27869:
https://llvm.org/bugs/show_bug.cgi?id=27869
...where InstCombine turns an icmp+zext into a shift causing us to miss the fold.

Credit to David Majnemer for a draft patch of the changes to InstructionSimplify.cpp.

Differential Revision: http://reviews.llvm.org/D21512

llvm-svn: 273200
2016-06-20 20:59:59 +00:00
Patrik Hagglund 96f13afcbc Avoid output indeterminism between GCC and Clang builds.
Remove dependency of the evalution order of function arguments, which
is unspecified.

Patch by David Stenberg.

llvm-svn: 273145
2016-06-20 10:19:04 +00:00
Eli Friedman f3b71581dd Fix dynamically linked debug builds.
On the surface, this might not look like it does anything... but
actually it brings in the declaration "extern template class
AnalysisManager<Loop>;", which suppresses the instantiation of the
constructor, which avoids the funny interaction between "extern
template" and -fvisibility-inlines-hidden.

llvm-svn: 273133
2016-06-20 02:48:11 +00:00
Sanjay Patel f8ee0e0218 fix formatting, typo; NFC
llvm-svn: 273118
2016-06-19 17:20:27 +00:00
Sean Silva 7cb30664fc Add a super basic LazyCallGraph DOT printer.
Access it through -passes=print-lcg-dot

Let me know any suggestions for changing the rendering; I'm not
particularly attached to what is implemented here.

llvm-svn: 273082
2016-06-18 09:17:32 +00:00
Sanjoy Das e8fd9561cb [SCEV] Fix incorrect trip count computation
The way we elide max expressions when computing trip counts is incorrect
-- it breaks cases like this:

```
static int wrapping_add(int a, int b) {
  return (int)((unsigned)a + (unsigned)b);
}

void test() {
  volatile int end_buf = 2147483548; // INT_MIN - 100
  int end = end_buf;

  unsigned counter = 0;
  for (int start = wrapping_add(end,  200); start < end; start++)
    counter++;

  print(counter);
}
```

Note: the `NoWrap` variable that was being tested has little to do with
the values flowing into the max expression; it is a property of the
induction variable.

test/Transforms/LoopUnroll/nsw-tripcount.ll was added to solely test
functionality I'm reverting in this change, so I've deleted the test
fully.

llvm-svn: 273079
2016-06-18 04:38:31 +00:00
Adam Nemet a9f09c6245 [LAA] Enable symbolic stride speculation for all LAA clients
This is a functional change for LLE and LDist.  The other clients (LV,
LVerLICM) already had this explicitly enabled.

The temporary boolean parameter to LAA is removed that allowed turning
off speculation of symbolic strides.  This makes LAA's caching interface
LAA::getInfo only take the loop as the parameter.  This makes the
interface more friendly to the new Pass Manager.

The flag -enable-mem-access-versioning is moved from LV to a LAA which
now allows turning off speculation globally.

llvm-svn: 273064
2016-06-17 22:35:41 +00:00
Benjamin Kramer 4dea8f542b Avoid duplicated map lookups. No functionality change intended.
llvm-svn: 273030
2016-06-17 18:59:41 +00:00
Benjamin Kramer 1d67ac5639 [PPC] Strength-reduce SmallVectors into arrays.
No functionality change intended.

llvm-svn: 272999
2016-06-17 13:15:10 +00:00
Chandler Carruth 164a2aa6f4 [PM] Remove support for omitting the AnalysisManager argument to new
pass manager passes' `run` methods.

This removes a bunch of SFINAE goop from the pass manager and just
requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead
argument. This is a small price to pay for the simplicity of the system
as a whole, despite the noise that changing it causes at this stage.

This will also helpfull allow us to make the signature of the run
methods much more flexible for different kinds af passes to support
things like intelligently updating the pass's progression over IR units.

While this touches many, many, files, the changes are really boring.
Mostly made with the help of my trusty perl one liners.

Thanks to Sean and Hal for bouncing ideas for this with me in IRC.

llvm-svn: 272978
2016-06-17 00:11:01 +00:00
Adam Nemet c953bb9953 [LV] Move management of symbolic strides to LAA. NFCI
This is still NFCI, so the list of clients that allow symbolic stride
speculation does not change (yes: LV and LoopVersioningLICM, no: LLE,
LDist).  However since the symbolic strides are now managed by LAA
rather than passed by client a new bool parameter is used to enable
symbolic stride speculation.

The existing test Transforms/LoopVectorize/version-mem-access.ll checks
that stride speculation is performed for LV.

The previously added test Transforms/LoopLoadElim/symbolic-stride.ll
ensures that no speculation is performed for LLE.

The next patch will change the functionality and turn on symbolic stride
speculation in all of LAA's clients and remove the bool parameter.

llvm-svn: 272970
2016-06-16 22:57:55 +00:00
Matt Arsenault 8dad57cc49 TTI: Add hook for memory width to vectorize
llvm-svn: 272964
2016-06-16 21:43:12 +00:00
Igor Laevsky 87f0d0e185 Revert r272891 "[JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo"
It was causing failures in Profile-i386 and Profile-x86_64 tests.

llvm-svn: 272912
2016-06-16 16:25:53 +00:00
Igor Laevsky c9179fd2c2 [JumpThreading] Prevent dangling pointer problems in BranchProbabilityInfo
We should update results of the BranchProbabilityInfo after removing block in JumpThreading. Otherwise 
we will get dangling pointer inside BranchProbabilityInfo cache.

Differential Revision: http://reviews.llvm.org/D20957

llvm-svn: 272891
2016-06-16 13:28:25 +00:00
Adam Nemet 139ffba398 [LAA] Rename Strides to SymblicStrides in analyzeLoop. NFC
This is to facilitate to move of SymblicStrides from LV to LAA.

llvm-svn: 272879
2016-06-16 08:27:03 +00:00
Adam Nemet bdbc5227ce [LAA] Default getInfo to not speculate symbolic strides. NFC
Soon we won't be passing Strides to getInfo and then we'll have fewer
call sites to update.

llvm-svn: 272878
2016-06-16 08:26:56 +00:00
Eli Friedman bd254a6f45 [InstCombine] Don't widen metadata on store-to-load forwarding
The original check for load CSE or store-to-load forwarding is wrong
when the forwarded stored value happened to be a load.

Ref https://github.com/JuliaLang/julia/issues/16894

Differential Revision: http://reviews.llvm.org/D21271

Patch by Yichao Yu!

llvm-svn: 272868
2016-06-16 02:33:42 +00:00
George Burgess IV 259d90194e [CFLAA] Ignore non-pointers, move Attrs to graph nodes.
This patch makes CFLAA ignore non-pointer values, since we can now
sanely do that with the escaping/unknown attributes. Additionally,
StratifiedAttrs make more sense to sit on nodes than edges (since
they're properties of values, and ultimately end up on the nodes of
StratifiedSets). So, this patch puts said attributes on nodes.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21387

llvm-svn: 272833
2016-06-15 20:43:41 +00:00
David Majnemer b62692e2e0 [TargetLibraryInfo] Teach isValidProtoForLibFunc about tan
We would fail to validate the type of the tan function which would cause
downstream users of isValidProtoForLibFunc to assert.

This fixes PR28143.

llvm-svn: 272802
2016-06-15 16:47:23 +00:00
Sanjoy Das b277a425c4 [SCEV] Use dyn_cast<T> instead of dyn_cast<const T>; NFC
The const is unnecessary.

llvm-svn: 272759
2016-06-15 06:53:55 +00:00
Sanjoy Das aba989f454 [SCEV] Use cast<> instead of dyn_cast; NFC
llvm-svn: 272758
2016-06-15 06:53:51 +00:00
Sanjoy Das 0e392d5dd7 [SCEV] clang-format some sections
llvm-svn: 272753
2016-06-15 04:37:50 +00:00
Sanjoy Das 5a3d893b48 [SCEV] Change the interface for SolveQuadraticEquation; NFC
Use Optional<T> to denote the absence of a solution, not
SCEVCouldNotCompute.  This makes the usage of SolveQuadraticEquation
somewhat simpler.

llvm-svn: 272752
2016-06-15 04:37:47 +00:00
Peter Collingbourne 96efdd6107 IR: Introduce local_unnamed_addr attribute.
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.

This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
  the normal rule that the global must have a unique address can be broken without
  being observable by the program by performing comparisons against the global's
  address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
  its own copy of the global if it requires one, and the copy in each linkage unit
  must be the same)
- It is a constant or a function (which means that the program cannot observe that
  the unique-address rule has been broken by writing to the global)

Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.

See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.html
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.

Part of the fix for PR27553.

Differential Revision: http://reviews.llvm.org/D20348

llvm-svn: 272709
2016-06-14 21:01:22 +00:00
Sanjoy Das d7e8206b58 [ValueTracking] Calls to @llvm.assume always return
This change teaches llvm::isGuaranteedToTransferExecutionToSuccessor
that calls to @llvm.assume always terminate.  Most other relevant
intrinsics should be covered by the "CS.onlyReadsMemory() ||
CS.onlyAccessesArgMemory()" bit but we were missing @llvm.assumes
because we state that it clobbers memory.

Added an LICM test case, but this change is not specific to LICM.

llvm-svn: 272703
2016-06-14 20:23:16 +00:00
George Burgess IV 24eb0daf7c [CFLAA] Tag arguments as escaped instead of unknown.
This patch also includes some refactoring.

Prior to this patch, we tagged all CFLAA attributes as unknown. This is
suboptimal, since it meant that any Value used as an argument would be
considered to alias any other Value that existed.

Now that we have the machinery to tag sets below the set for an
arbitrary value with attributes, it's okay to be less conservative with
arguments. (Specifically, we still tag the set under an argument with
unknown).

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21262

llvm-svn: 272690
2016-06-14 18:12:28 +00:00
George Burgess IV e17756e0fe [CFLAA] Refactor graph-building code. NFC.
This patch refactors CFLAA's graph building code. This makes keeping
track of common state (TargetLibraryInfo, ...) easier.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21261

llvm-svn: 272688
2016-06-14 18:02:27 +00:00
Nicolai Haehnle 377975f2f7 AMDGPU: mark {exp,log}10{,f,l} library functions as unavailable
Summary:
The SimplifyLibCalls part of InstCombine generates calls to those otherwise.

I wonder if at some point we shouldn't just call disableAllFunctions() and
then enable functions on a whitelist basis...

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96495

Reviewers: arsenm, tstellarAMD

Subscribers: llvm-commits, kzhuravl

Differential Revision: http://reviews.llvm.org/D21282

llvm-svn: 272664
2016-06-14 13:14:53 +00:00
Sean Silva 687019facb [PM] Port LVI to the new PM.
This is a bit gnarly since LVI is maintaining its own cache.
I think this port could be somewhat cleaner, but I'd rather not spend
too much time on it while we still have the old pass hanging around and
limiting how much we can clean things up.
Once the old pass is gone it will be easier (less time spent) to clean
it up anyway.

This is the last dependency needed for porting JumpThreading which I'll
do in a follow-up commit (there's no printer pass for LVI or anything to
test it, so porting a pass that depends on it seems best).

I've been mostly following:
r269370 / D18834 which ported Dependence Analysis
r268601 / D19839 which ported BPI

llvm-svn: 272593
2016-06-13 22:01:25 +00:00
Sanjoy Das d0bdf3e02b Fix AAResults::callCapturesBefore for operand bundles
Summary:
AAResults::callCapturesBefore would previously ignore operand
bundles. It was possible for a later instruction to miss its memory
dependency on a call site that would only access the pointer through a
bundle.

Patch by Oscar Blumberg!

Reviewers: sanjoy

Differential Revision: http://reviews.llvm.org/D21286

llvm-svn: 272580
2016-06-13 19:55:04 +00:00
George Burgess IV 99646871a7 Attempt to make windows buildbots happy.
Broken by r272578. I didn't realize that the default move ctor
complaints would happen for non-template classes. :)

llvm-svn: 272579
2016-06-13 19:38:49 +00:00
George Burgess IV dc96febc37 [CFLAA] Refactor to remove redundant maps. NFC.
Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21233

llvm-svn: 272578
2016-06-13 19:21:18 +00:00
Eli Friedman f1da33e4d3 [LICM] Make isGuaranteedToExecute more accurate.
Summary:
Make isGuaranteedToExecute use the
isGuaranteedToTransferExecutionToSuccessor helper, and make that helper
a bit more accurate.

There's a potential performance impact here from assuming that arbitrary
calls might not return. This probably has little impact on loads and
stores to a pointer because most things alias analysis can reason about
are dereferenceable anyway. The other impacts, like less aggressive
hoisting of sdiv by a variable and less aggressive hoisting around
volatile memory operations, are unlikely to matter for real code.

This also impacts SCEV, which uses the same helper.  It's a minor
improvement there because we can tell that, for example, memcpy always
returns normally. Strictly speaking, it's also introducing
a bug, but it's not any worse than everywhere else we assume readonly
functions terminate.

Fixes http://llvm.org/PR27857.

Reviewers: hfinkel, reames, chandlerc, sanjoy

Subscribers: broune, llvm-commits

Differential Revision: http://reviews.llvm.org/D21167

llvm-svn: 272489
2016-06-11 21:48:25 +00:00
Mehdi Amini bbacddfe92 Interprocedural Register Allocation (IPRA) Analysis
Add an option to enable the analysis of MachineFunction register
usage to extract the list of clobbered registers.

When enabled, the CodeGen order is changed to be bottom up on the Call
Graph.

The analysis is split in two parts, RegUsageInfoCollector is the
MachineFunction Pass that runs post-RA and collect the list of
clobbered registers to produce a register mask.

An immutable pass, RegisterUsageInfo, stores the RegMask produced by
RegUsageInfoCollector, and keep them available. A future tranformation
pass will use this information to update every call-sites after
instruction selection.

Patch by Vivek Pandya <vivekvpandya@gmail.com>

Differential Revision: http://reviews.llvm.org/D20769

llvm-svn: 272403
2016-06-10 16:19:46 +00:00
Richard Trieu fae70b6f2b Add null checks before using a pointer.
llvm-svn: 272359
2016-06-10 01:42:05 +00:00
George Burgess IV 652ec4f595 [CFLAA] Handle global/arg attrs more sanely.
Prior to this patch, we used argument/global stratified attributes in
order to note that a value could have come from either dereferencing a
global/arg, or from the assignment from a global/arg.

Now, AttrUnknown is placed on sets when we see a dereference, instead of
the global/arg attributes. This allows us to be more aggressive in the
future when we see global/arg attributes without AttrUnknown.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21110

llvm-svn: 272335
2016-06-09 23:15:04 +00:00
Easwaran Raman 71069cf67d Use ProfileSummaryInfo in inline cost analysis.
Instead of directly using MaxFunctionCount and function entry count to determine callee hotness, use the isHotFunction/isColdFunction methods provided by ProfileSummaryInfo.

Differential revision: http://reviews.llvm.org/D21045

llvm-svn: 272321
2016-06-09 22:23:21 +00:00
Xinliang David Li ecde1c7f3d Revert r272194 No need for it if loop Analysis Manager is used
llvm-svn: 272243
2016-06-09 03:22:39 +00:00
Sanjoy Das 1eade91513 Minor clean up in loopHasNoAbnormalExits; NFC
llvm-svn: 272238
2016-06-09 01:14:03 +00:00
Sanjoy Das c7f69b921f Be wary of abnormal exits from loop when exploiting UB
We can safely rely on a NoWrap add recurrence causing UB down the road
only if we know the loop does not have a exit expressed in a way that is
opaque to ScalarEvolution (e.g. by a function call that conditionally
calls exit(0)).

I believe with this change PR28012 is fixed.

Note: I had to change some llvm-lit tests in LoopReroll, since it looks
like they were depending on this incorrect behavior.

llvm-svn: 272237
2016-06-09 01:13:59 +00:00
Sanjoy Das 97cd7d5d44 Factor out a loopHasNoAbnormalExits; NFC
llvm-svn: 272236
2016-06-09 01:13:54 +00:00
Xinliang David Li 572135f717 [PM] Refector LoopAccessInfo analysis code
This is the preparation patch to port the analysis to new PM

Differential Revision: http://reviews.llvm.org/D20560

llvm-svn: 272194
2016-06-08 20:15:37 +00:00
Benjamin Kramer c321e53402 Apply most suggestions of clang-tidy's performance-unnecessary-value-param
Avoids unnecessary copies. All changes audited & pass tests with asan.
No functional change intended.

llvm-svn: 272190
2016-06-08 19:09:22 +00:00
George Burgess IV fd4e2f7cb2 Attempt #2 to appease the buildbots.
MSVC calls the copy ctor on StratifiedSets for some reason. So,
undelete it.

llvm-svn: 272184
2016-06-08 17:56:35 +00:00
Sanjoy Das 2401c98475 [SCEV] Break out of loop if there is no more work to do
This is NFC as far as externally visible behavior is concerned, but will
keep us from spinning in the worklist traversal algorithm unnecessarily.

llvm-svn: 272182
2016-06-08 17:48:46 +00:00
Sanjoy Das 8598412e24 [SCEV] Track no-abnormal-exits instead of no-throw calls
Absence of may-unwind calls is not enough to guarantee that a
UB-generating use of an add-rec poison in the loop latch will actually
cause UB.  We also need to guard against calls that terminate the thread
or infinite loop themselves.

This partially addresses PR28012.

llvm-svn: 272181
2016-06-08 17:48:42 +00:00
Sanjoy Das 9a65cd214d Teach isGuarantdToTransferExecToSuccessor about debug info intrinsics
Calls to `@llvm.dbg.*` can be assumed to terminate.

llvm-svn: 272180
2016-06-08 17:48:36 +00:00
Sanjoy Das a19edc4d15 Fix a bug in SCEV's poison value propagation
The worklist algorithm introduced in rL271151 didn't check to see if the
direct users of the post-inc add recurrence propagates poison.  This
change fixes the problem and makes the code structure more obvious.

Note for release managers: correctness wise, this bug wasn't a
regression introduced by rL271151 -- the behavior of SCEV around
post-inc add recurrences was strictly improved (in terms of correctness)
in rL271151.

llvm-svn: 272179
2016-06-08 17:48:31 +00:00
George Burgess IV 785f391131 Try to appease buildbots.
r272064 apparently made them angry. This undoes some changes made in
r272064 (defaulting move ctors) to make them happy again.

llvm-svn: 272173
2016-06-08 17:27:14 +00:00
Benjamin Kramer 46e38f3678 Avoid copies of std::strings and APInt/APFloats where we only read from it
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.

llvm-svn: 272126
2016-06-08 10:01:20 +00:00
George Burgess IV 60af226b86 [CFLAA] Kill dead code/fix comments in StratifiedSets.
Also use default/delete instead of hand-written ctors.

Thanks to Jia Chen for bringing this stuff up.

llvm-svn: 272064
2016-06-07 21:41:18 +00:00
George Burgess IV a1f9a2daeb [CFLAA] Add AttrEscaped, remove bit twiddling functions.
This patch does a few things:

- Unifies AttrAll and AttrUnknown (since they were used for more or less
  the same purpose anyway).

- Introduces AttrEscaped, an attribute that notes that a value escapes
  our analysis for a given set, but not that an unknown value flows into
  said set.

- Removes functions that take bit indices, since we also had functions
  that took bitsets, and the use of both (with similar names) was
  unclear and bug-prone.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D21000

llvm-svn: 272040
2016-06-07 18:35:37 +00:00
Andrey Turetskiy 9f02c58670 [LAA] Improve non-wrapping pointer detection by handling loop-invariant case.
This fixes PR26314. This patch adds new helper “isNoWrap” with detection of
loop-invariant pointer case.

Patch by Roman Shirokiy.

Ref: https://llvm.org/bugs/show_bug.cgi?id=26314

Differential Revision: http://reviews.llvm.org/D17268

llvm-svn: 272014
2016-06-07 14:55:27 +00:00
Michael Zolotukhin 19edbadfc5 [LoopUnrollAnalyzer] Fix a crash in analyzeLoopUnrollCost.
In some cases, when simplifying with SCEV, we might consider pointer values as
just usual integer values.  Thus, we might get a different type from what we
had originally in the map of simplified values, and hence we need to check
types before operating on the values.

This fixes PR28015.

llvm-svn: 271931
2016-06-06 19:21:40 +00:00
Matthew Simpson e3e3b994ae [LAA] Use load and store vectors (NFC)
Contributed-by: Aditya Kumar <hiraditya@msn.com>
Differential Revision: http://reviews.llvm.org/D20953

llvm-svn: 271895
2016-06-06 14:15:41 +00:00
Simon Pilgrim ba319ded5e [Analysis] Enabled BITREVERSE as a vectorizable intrinsic
Allows XOP to vectorize BITREVERSE - other targets will follow as their costmodels improve.

llvm-svn: 271803
2016-06-04 20:21:07 +00:00
Easwaran Raman 019e0bf592 Reapply r271728 after adding move cobstructor for ProfileSummaryInfo
llvm-svn: 271745
2016-06-03 22:54:26 +00:00
Easwaran Raman 94edaaaefb Revert r271728 as it breaks Windows build
llvm-svn: 271738
2016-06-03 21:14:26 +00:00
Easwaran Raman d142050f3a Analysis pass to access profile summary info
Differential Revision: http://reviews.llvm.org/D20648

llvm-svn: 271728
2016-06-03 20:37:19 +00:00
Sanjay Patel dba8b4c04d transform obscured FP sign bit ops into a fabs/fneg using TLI hook
This is effectively a revert of:
http://reviews.llvm.org/rL249702 - [InstCombine] transform masking off of an FP sign bit into a fabs() intrinsic call (PR24886)
and:
http://reviews.llvm.org/rL249701 - [ValueTracking] teach computeKnownBits that a fabs() clears sign bits
and a reimplementation as a DAG combine for targets that have IEEE754-compliant fabs/fneg instructions.

This is intended to resolve the objections raised on the dev list:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098154.html
and:
https://llvm.org/bugs/show_bug.cgi?id=24886#c4

In the interest of patch minimalism, I've only partly enabled AArch64. PowerPC, MIPS, x86 and others can enable later.

Differential Revision: http://reviews.llvm.org/D19391

llvm-svn: 271573
2016-06-02 20:01:37 +00:00
Sanjoy Das 48cad71243 Inline isDereferenceableFromAttribute; NFC
Now that `Value::getPointerDereferenceableBytes` looks beyond just
attributes, the name `isDereferenceableFromAttribute` is misleading.
Just inline the function, since it is small and only used once.

llvm-svn: 271456
2016-06-02 00:52:53 +00:00
Sanjoy Das 00953cbe1d Remove Value::isPointerDereferenceable; NFCI
... and merge into `Value::getPointerDereferenceableBytes`. This was
suggested by Artur Pilipenko in D20764 -- since we no longer allow loads
of unsized types, there is no need anymore to have this special logic.

llvm-svn: 271455
2016-06-02 00:52:48 +00:00
Geoff Berry 0c09517867 [SCEV] Keep SCEVExpander insert points consistent.
Summary:
Make sure that the SCEVExpander Builder insert point and any
saved/restored insert points are kept consistent (i.e. their Instruction
and BasicBlock match) when moving instructions in SCEVExpander.

This fixes an issue triggered by
http://reviews.llvm.org/D18001 [LSR] Create fewer redundant instructions.

Test case will be added in reapply commit of above change:
http://reviews.llvm.org/D18480 Reapply [LSR] Create fewer redundant instructions.

Reviewers: sanjoy

Subscribers: mzolotukhin, sanjoy, qcolombet, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20703

llvm-svn: 271424
2016-06-01 20:03:09 +00:00
Daniel Berlin 73694bb92b Revert "Claim NoAlias if two GEPs index different fields of the same struct"
This reverts commit 2d5d6493f43eb68493a3852b8c226ac9fafdc7eb.

llvm-svn: 271422
2016-06-01 18:55:32 +00:00
George Burgess IV 18b83fe6cf [CFLAA] Recognize builtin allocation functions.
This patch extends CFLAA to recognize allocation functions such as
malloc, free, etc, so we can treat them more aggressively.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D20776

llvm-svn: 271421
2016-06-01 18:39:54 +00:00
Daniel Berlin e846c9dc52 Claim NoAlias if two GEPs index different fields of the same struct
Patch by Taewook Oh

Summary: Patch for Bug 27478. Make BasicAliasAnalysis claims NoAlias if two GEPs index different fields of the same structure.

Reviewers: hfinkel, dberlin

Subscribers: dberlin, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20665

llvm-svn: 271415
2016-06-01 18:12:01 +00:00
Sanjoy Das 10df497a1f Reduce dependence on pointee types when deducing dereferenceability
Summary:
Change some of the internal interfaces in Loads.cpp to keep track of the
number of bytes we're trying to prove dereferenceable using an explicit
`Size` parameter.

Before this, the `Size` parameter was implicitly inferred from the
pointee type of the pointer whose dereferenceability we were trying to
prove, causing us to be conservative around bitcasts. This was
unfortunate since bitcast instructions are no-ops and should never
break optimizations.  With an explicit `Size` parameter, we're more
precise (as shown in the test cases), and the code is simpler.

We should eventually move towards a `DerefQuery` struct that groups
together a base pointer, an offset, a size and an alignment; but this
patch is a first step.

Reviewers: apilipenko, dblaikie, hfinkel, reames

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20764

llvm-svn: 271406
2016-06-01 16:47:45 +00:00
George Burgess IV a880146925 [CFLAA] Don't link GEP pointers to GEP indices.
Code like the following is considered broken, and doesn't need to be
supported by our AA magicks:

void getFoo(int *P) {
  int *PAlias = (int *)((char *)NULL + (uintptr_t)P);
}

This patch makes CFLAA drop support for code like this.

Patch by Jia Chen.

Differential Revision: http://reviews.llvm.org/D20775

llvm-svn: 271322
2016-05-31 19:55:05 +00:00
Saleem Abdulrasool d2f705ddf9 X86: permit using SjLj EH on x86 targets as an option
This adds support to the backed to actually support SjLj EH as an exception
model.  This is *NOT* the default model, and requires explicitly opting into it
from the frontend.  GCC supports this model and for MinGW can still be enabled
via the `--using-sjlj-exceptions` options.

Addresses PR27749!

llvm-svn: 271244
2016-05-31 01:48:07 +00:00
Sanjoy Das f857081c8c [SCEV] Consolidate comments; NFC
Consolidate documentation by removing comments from the .cpp file where
the comments in the .cpp file were copy-pasted from the header.

llvm-svn: 271157
2016-05-29 00:38:22 +00:00
Sanjoy Das 108fcf2e2c [SCEV] Rename functions to LLVM style; NFC
llvm-svn: 271156
2016-05-29 00:38:00 +00:00
Sanjoy Das f49ca52b9d [SCEV] See through op.with.overflow intrinsics (re-apply)
Summary:
This change teaches SCEV to see reduce `(extractvalue
0 (op.with.overflow X Y))` into `op X Y` (with a no-wrap tag if
possible).

This was first checked in at r265912 but reverted in r265950 because it
exposed some issues around how SCEV handled post-inc add recurrences.
Those issues have now been fixed.

Reviewers: atrick, regehr

Subscribers: mcrosier, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D18684

llvm-svn: 271152
2016-05-29 00:34:42 +00:00
Sanjoy Das 7e4a64167d [SCEV] Don't always add no-wrap flags to post-inc add recs
Fixes PR27315.

The post-inc version of an add recurrence needs to "follow the same
rules" as a normal add or subtract expression.  Otherwise we miscompile
programs like

```
int main() {
  int a = 0;
  unsigned a_u = 0;
  volatile long last_value;
  do {
    a_u += 3;
    last_value = (long) ((int) a_u);
    if (will_add_overflow(a, 3)) {
      // Leave, and don't actually do the increment, so no UB.
      printf("last_value = %ld\n", last_value);
      exit(0);
    }
    a += 3;
  } while (a != 46);
  return 0;
}
```

This patch changes SCEV to put no-wrap flags on post-inc add recurrences
only when the poison from a potential overflow will go ahead to cause
undefined behavior.

To avoid regressing performance too much, I've assumed infinite loops
without side effects is undefined behavior to prove poison<->UB
equivalence in more cases.  This isn't ideal, but is not new to LLVM as
a whole, and far better than the situation I'm trying to fix.

llvm-svn: 271151
2016-05-29 00:32:17 +00:00
Sanjoy Das 70c2bbd29c [ValueTracking] ICmp instructions propagate poison
This is a stripped down version of D19211, leaving out the questionable
"branching in poison is UB" bit.

llvm-svn: 271150
2016-05-29 00:31:18 +00:00
Michael Zolotukhin d69cd1e086 [LoopUnrollAnalyzer] Add a comment to visitCastInst.
llvm-svn: 271086
2016-05-28 01:40:14 +00:00
Benjamin Kramer 82de7d323d Apply clang-tidy's misc-move-constructor-init throughout LLVM.
No functionality change intended, maybe a tiny performance improvement.

llvm-svn: 270997
2016-05-27 14:27:24 +00:00
Michael Zolotukhin 15e745133e [LoopUnrollAnalyzer] Bail out instead of dying with assert when facing huge index.
This fixes PR27902.

llvm-svn: 270946
2016-05-27 00:55:16 +00:00
Michael Kuperstein ae21491819 [BasicAA] Extend inbound GEP negative offset logic to GlobalVariables
r270777 improved the precision of alloca vs. inbounbds GEP alias queries: if
we have (a) an inbounds GEP and (b) a pointer based on an alloca, and the
beginning of the object the GEP points to would have a negative offset with
respect to the alloca, then the GEP can not alias pointer (b).

This makes the same logic fire when (b) is based on a GlobalVariable instead
of an alloca.

Differential Revision: http://reviews.llvm.org/D20652

llvm-svn: 270893
2016-05-26 19:30:49 +00:00
David Majnemer 7f32420ed5 [CaptureTracking] Volatile operations capture their memory location
The memory location that corresponds to a volatile operation is very
special.  They are observed by the machine in ways which we cannot
reason about.

Differential Revision: http://reviews.llvm.org/D20555

llvm-svn: 270879
2016-05-26 17:36:22 +00:00
Peter Collingbourne b9aa1f4a03 MemorySSA: Revert r269678 and r268068; replace with special casing in MemorySSA.
It turns out that too many passes are relying on alias analysis results
for control dependencies. Until we fix that by introducing a more accurate
modelling of control dependencies, special case assume in MemorySSA instead.

Also introduce tests to ensure we don't regress the FunctionAttrs or LICM
passes.

Differential Revision: http://reviews.llvm.org/D20658

llvm-svn: 270823
2016-05-26 04:58:46 +00:00
Davide Italiano bd543d0a0b [LazyValueInfo] Simplify `return after else`. NFCI.
llvm-svn: 270779
2016-05-25 22:29:34 +00:00
Michael Kuperstein 82069c44ca [BasicAA] Improve precision of alloca vs. inbounds GEP alias queries
If a we have (a) a GEP and (b) a pointer based on an alloca, and the
beginning of the object the GEP points would have a negative offset with
repsect to the alloca, then the GEP can not alias pointer (b).

For example, consider code like:

struct { int f0, int f1, ...} foo;
...
foo alloca;
foo *random = bar(alloca);
int *f0 = &alloca.f0
int *f1 = &random->f1;

Which is lowered, approximately, to:
%alloca = alloca %struct.foo
%random = call %struct.foo* @random(%struct.foo* %alloca)
%f0 = getelementptr inbounds %struct, %struct.foo* %alloca, i32 0, i32 0
%f1 = getelementptr inbounds %struct, %struct.foo* %random, i32 0, i32 1

Assume %f1 and %f0 alias. Then %f1 would point into the object allocated
by %alloca. Since the %f1 GEP is inbounds, that means %random must also
point into the same object. But since %f0 points to the beginning of %alloca,
the highest %f1 can be is (%alloca + 3). This means %random can not be higher
than (%alloca - 1), and so is not inbounds, a contradiction.

Differential Revision: http://reviews.llvm.org/D20495

llvm-svn: 270777
2016-05-25 22:23:08 +00:00
Hal Finkel 2f6886844e Look for a loop's starting location in the llvm.loop metadata
Getting accurate locations for loops is important, because those locations are
used by the frontend to generate optimization remarks. Currently, optimization
remarks for loops often appear on the wrong line, often the first line of the
loop body instead of the loop itself. This is confusing because that line might
itself be another loop, or might be somewhere else completely if the body was
inlined function call. This happens because of the way we find the loop's
starting location. First, we look for a preheader, and if we find one, and its
terminator has a debug location, then we use that. Otherwise, we look for a
location on an instruction in the loop header.

The fallback heuristic is not bad, but will almost always find the beginning of
the body, and not the loop statement itself. The preheader location search
often fails because there's often not a preheader, and even when there is a
preheader, depending on how it was formed, it sometimes carries the location of
some preceeding code.

I don't see any good theoretical way to fix this problem. On the other hand,
this seems like a straightforward solution: Put the debug location in the
loop's llvm.loop metadata. A companion Clang patch will cause Clang to insert
llvm.loop metadata with appropriate locations when generating debugging
information. With these changes, our loop remarks have much more accurate
locations.

Differential Revision: http://reviews.llvm.org/D19738

llvm-svn: 270771
2016-05-25 21:42:37 +00:00
Ahmed Bougacha 201b97f550 [TLI] Also cover Linux 64 libfunc (stat64, ...) prototype checking.
My script missed those in r270750.

llvm-svn: 270763
2016-05-25 21:16:33 +00:00
Ahmed Bougacha 1fe3f1ca50 [TLI] Fix NumParams==0 prototype checking typo.
There was a typo in r267758. It caused invalid accesses when
given something like "void @free(...)", as NumParams == 0, and
we then try to look at the 0th parameter.

Turns out, most of these were untested; add both attribute
and missing-prototype checks for all libc libfuncs.

Differential Revision: http://reviews.llvm.org/D20543

llvm-svn: 270750
2016-05-25 20:22:45 +00:00
Oleg Ranevskyy eb4eccae5c [SCEV] No-wrap flags are not propagated when folding "{S,+,X}+T ==> {S+T,+,X}"
Summary:
**Description**

This makes `WidenIV::widenIVUse` (IndVarSimplify.cpp) fail to widen narrow IV uses in some cases. The latter affects IndVarSimplify which may not eliminate narrow IV's when there actually exists such a possibility, thereby producing ineffective code.

When `WidenIV::widenIVUse` gets a NarrowUse such as `{(-2 + %inc.lcssa),+,1}<nsw><%for.body3>`, it first tries to get a wide recurrence for it via the `getWideRecurrence` call.
`getWideRecurrence` returns recurrence like this: `{(sext i32 (-2 + %inc.lcssa) to i64),+,1}<nsw><%for.body3>`.

Then a wide use operation is generated by `cloneIVUser`. The generated wide use is evaluated to `{(-2 + (sext i32 %inc.lcssa to i64))<nsw>,+,1}<nsw><%for.body3>`, which is different from the `getWideRecurrence` result. `cloneIVUser` sees the difference and returns nullptr.

This patch also fixes the broken LLVM tests by adding missing <nsw> entries introduced by the correction.

**Minimal reproducer:**
```
int foo(int a, int b, int c);
int baz();

void bar()
{
   int arr[20];
   int i = 0;

   for (i = 0; i < 4; ++i)
     arr[i] = baz();

   for (; i < 20; ++i)
     arr[i] = foo(arr[i - 4], arr[i - 3], arr[i - 2]);
}
```

**Clang command line:**
```
clang++ -mllvm -debug -S -emit-llvm -O3 --target=aarch64-linux-elf test.cpp -o test.ir
```

**Expected result:**
The ` -mllvm -debug` log shows that all the IV's for the second `for` loop have been eliminated.

Reviewers: sanjoy

Subscribers: atrick, asl, aemerson, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D20058

llvm-svn: 270695
2016-05-25 13:01:33 +00:00
Michael Zolotukhin 7216dd4668 [LoopUnrollAnalyzer] Fix a crash in UnrolledInstAnalyzer::visitCastInst.
This fixes PR27847. Now for real.

llvm-svn: 270629
2016-05-24 22:59:58 +00:00
Sanjay Patel 23019d1006 [ValueTracking, InstSimplify] extend isKnownNonZero() to handle vector constants
Similar in spirit to D20497 :
If all elements of a constant vector are known non-zero, then we can say that the
whole vector is known non-zero.

It seems like we could extend this to FP scalar/vector too, but isKnownNonZero()
says it only works for integers and pointers for now.

Differential Revision: http://reviews.llvm.org/D20544

llvm-svn: 270562
2016-05-24 14:18:49 +00:00
Michael Zolotukhin 3898b2b587 [LoopUnrollAnalyzer] Fix a crash in UnrolledInstAnalyzer::visitCastInst.
This fixes PR27847.

llvm-svn: 270517
2016-05-24 00:51:01 +00:00
Sanjay Patel e8dc090a2b fix formatting; NFC
llvm-svn: 270465
2016-05-23 17:57:54 +00:00
Sanjay Patel 8ec7e7c216 use 'auto' with 'dyn_cast'; fix formatting; NFC
llvm-svn: 270370
2016-05-22 16:07:20 +00:00
Sanjay Patel e2e89ef936 [ValueTracking, InstCombine] extend isKnownToBeAPowerOfTwo() to handle vector splat constants
We could try harder to handle non-splat vector constants too, 
but that seems much rarer to me.

Note that the div test isn't resolved because there's a check
for isIntegerTy() guarding that transform.

Differential Revision: http://reviews.llvm.org/D20497

llvm-svn: 270369
2016-05-22 15:41:53 +00:00
Michael Kuperstein c6de57e47a Revert r270268 due to unused variable warnings.
llvm-svn: 270272
2016-05-20 20:55:51 +00:00
Michael Kuperstein f45e5b58b8 [BasicAA] Turn DecomposeGEPExpression runtime checks into asserts.
When it has a DataLayout, DecomposeGEPExpression() should return the same object
as GetUnderlyingObject(). Per the FIXME, it currently always has a DL, so the
runtime check is redundant and can become an assert.

llvm-svn: 270268
2016-05-20 20:26:50 +00:00
Easwaran Raman bb578ef0dd Allow -inline-threshold to override default threshold.
Before r257832, the threshold used by SimpleInliner was explicitly specified or generated from opt levels and passed to the base class Inliner's constructor. There, it was first overridden by explicitly specified -inline-threshold. The refactoring in r257832 did not preserve this behavior for all opt levels. This change brings back the original behavior.

Differential Revision: http://reviews.llvm.org/D20452

llvm-svn: 270153
2016-05-19 23:02:09 +00:00
Matthew Simpson 6feebe9847 [LAA] Check independence of strided accesses before forward case
This patch changes the order in which we attempt to prove the independence of
strided accesses. We previously did this after we knew the dependence distance
was positive. With this change, we check for independence before handling the
negative distance case. The patch prevents LAA from reporting forward
dependences for independent strided accesses.

This change was requested in the review of D19984.

llvm-svn: 270072
2016-05-19 15:37:19 +00:00
Sanjoy Das f5d40d5350 [SCEV] Be more aggressive in proving NUW
... for AddRec's in loops for which SCEV is unable to compute a max
tripcount.  This is the NUW variant of r269211 and fixes PR27691.

(Note: PR27691 is not a correct or stability bug, it was created to
track a pending task).

llvm-svn: 269790
2016-05-17 17:51:14 +00:00
Geoff Berry 9b4ff336ce [BasicAA] Update comments based on feedback from hfinkel. NFCI.
Original change Hal's comments were based on:
http://reviews.llvm.org/D19730

llvm-svn: 269678
2016-05-16 18:51:54 +00:00
Matthew Simpson 37ec5f914e [LAA] Rename forwarding conflict detection option (NFC)
This patch renames the option enabling the store-to-load forwarding conflict
detection optimization. This change was requested in the review of D20241.

llvm-svn: 269668
2016-05-16 17:00:56 +00:00
Adam Nemet 884d313b7f [LAA] Comment couldPreventStoreLoadForward. NFC
Also s/Cycles/Iters/ in NumCyclesForStoreLoadThroughMemory to make it
clear that this is not about clock cycles but loop cycles/iterations.

llvm-svn: 269667
2016-05-16 16:57:47 +00:00
Adam Nemet 9b5852aeb2 [LAA] clang-format the function couldPreventStoreLoadForward. NFC
llvm-svn: 269666
2016-05-16 16:57:42 +00:00
Matthew Simpson a250dc9f11 [LAA] Add option to disable conflict detection (NFC)
llvm-svn: 269654
2016-05-16 14:14:49 +00:00
Adam Nemet c62e554e9a [LAA] Include MaxSafeDepDistBytes in the analysis print-out
llvm-svn: 269508
2016-05-13 22:49:13 +00:00
Adam Nemet 4ad38b63d5 [LAA] Prepare the code to print more things in the summary. NFC
llvm-svn: 269507
2016-05-13 22:49:09 +00:00
Michael Zolotukhin 963a6d9c69 Revert "Revert "[Unroll] Implement a conservative and monotonically increasing cost tracking system during the full unroll heuristic analysis that avoids counting any instruction cost until that instruction becomes "live" through a side-effect or use outside the...""
This reverts commit r269395.

Try to reapply with a fix from chapuni.

llvm-svn: 269486
2016-05-13 21:23:25 +00:00
Silviu Baranga 24dbd2e760 [scan-build] fix warnings emiited on LLVM Analysis code base
Fix "Logic error" warnings of the type "Called C++ object pointer is
null" reported by Clang Static Analyzer on the following files:

lib/Analysis/ScalarEvolution.cpp,
lib/Analysis/LoopInfo.cpp.

Patch by Apelete Seketeli!

llvm-svn: 269424
2016-05-13 14:54:50 +00:00
Michael Zolotukhin 9be3b8b9bb Revert "[Unroll] Implement a conservative and monotonically increasing cost tracking system during the full unroll heuristic analysis that avoids counting any instruction cost until that instruction becomes "live" through a side-effect or use outside the..."
This reverts commit r269388.

It caused some bots to fail, I'm reverting it until I investigate the
issue.

llvm-svn: 269395
2016-05-13 06:32:25 +00:00
Michael Zolotukhin b7b8052982 [Unroll] Implement a conservative and monotonically increasing cost tracking system during the full unroll heuristic analysis that avoids counting any instruction cost until that instruction becomes "live" through a side-effect or use outside the...
Summary:
...loop after the last iteration.

This is really hard to do correctly. The core problem is that we need to
model liveness through the induction PHIs from iteration to iteration in
order to get the correct results, and we need to correctly de-duplicate
the common subgraphs of instructions feeding some subset of the
induction PHIs. All of this can be driven either from a side effect at
some iteration or from the loop values used after the loop finishes.

This patch implements this by storing the forward-propagating analysis
of each instruction in a cache to recall whether it was free and whether
it has become live and thus counted toward the total unroll cost. Then,
at each sink for a value in the loop, we recursively walk back through
every value that feeds the sink, including looping back through the
iterations as needed, until we have marked the entire input graph as
live. Because we cache this, we never visit instructions more than twice
-- once when we analyze them and put them into the cache, and once when
we count their cost towards the unrolled loop. Also, because the cache
is only two bits and because we are dealing with relatively small
iteration counts, we can store all of this very densely in memory to
avoid this from becoming an excessively slow analysis.

The code here is still pretty gross. I would appreciate suggestions
about better ways to factor or split this up, I've stared too long at
the algorithmic side to really have a good sense of what the design
should probably look at.

Also, it might seem like we should do all of this bottom-up, but I think
that is a red herring. Specifically, the simplification power is *much*
greater working top-down. We can forward propagate very effectively,
even across strange and interesting recurrances around the backedge.
Because we use data to propagate, this doesn't cause a state space
explosion. Doing this level of constant folding, etc, would be very
expensive to do bottom-up because it wouldn't be until the last moment
that you could collapse everything. The current solution is essentially
a top-down simplification with a bottom-up cost accounting which seems
to get the best of both worlds. It makes the simplification incremental
and powerful while leaving everything dead until we *know* it is needed.

Finally, a core property of this approach is its *monotonicity*. At all
times, the current UnrolledCost is a conservatively low estimate. This
ensures that we will never early-exit from the analysis due to exceeding
a threshold when if we had continued, the cost would have gone back
below the threshold. These kinds of bugs can cause incredibly hard to
track down random changes to behavior.

We could use a techinque similar (but much simpler) within the inliner
as well to avoid considering speculated code in the inline cost.

Reviewers: chandlerc

Subscribers: sanjoy, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D11758

llvm-svn: 269388
2016-05-13 01:42:39 +00:00
Michael Zolotukhin a59a308e8d [LoopUnrollAnalyzer] Don't treat gep-instructions with simplified offset as simplified.
Summary:
Currently we consider such instructions as simplified, which is incorrect,
because if their user isn't simplified, we can't actually simplify them too.
This biases our estimates of profitability: for instance the analyzer expects
much more gains from unrolling memcpy loops than there actually are.

Reviewers: hfinkel, chandlerc

Subscribers: mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D17365

llvm-svn: 269387
2016-05-13 01:42:34 +00:00
Chandler Carruth 49c22190d0 [PM] Port of the DepndenceAnalysis to the new PM.
Ported DA to the new PM by splitting the former DependenceAnalysis Pass
into a DependenceInfo result type and DependenceAnalysisWrapperPass type
and adding a new PM-style DependenceAnalysis analysis pass returning the
DependenceInfo.

Patch by Philip Pfaffe, most of the review by Justin.

Differential Revision: http://reviews.llvm.org/D18834

llvm-svn: 269370
2016-05-12 22:19:39 +00:00
Adam Nemet 2c34ab51a4 [LAA] Use std::min. NFC
llvm-svn: 269356
2016-05-12 21:41:53 +00:00
Sanjoy Das 4e8c80382f [SCEVExpander] Fix a failed cast<> assertion
SCEVExpander::replaceCongruentIVs assumes the backedge value of an
SCEV-analysable PHI to always be an instruction, when this is not
necessarily true.  For now address this by bailing out of the
optimization if the backedge value of the PHI is a non-Instruction.

llvm-svn: 269213
2016-05-11 17:41:41 +00:00
Sanjoy Das abb7b93eb9 [SCEVExpander] Don't break SSA in replaceCongruentIVs
`SCEVExpander::replaceCongruentIVs` bypasses `hoistIVInc` if both the
original and the isomorphic increments are PHI nodes.  Doing this can
break SSA if the isomorphic increment is not dominated by the original
increment.  Get rid of the bypass, and let `hoistIVInc` do the right
thing.

Fixes PR27232 (compile time crash/hang).

llvm-svn: 269212
2016-05-11 17:41:34 +00:00
Sanjoy Das 787c2460c2 [SCEV] Be more aggressive around proving no-wrap
... for AddRec's in loops for which SCEV is unable to compute a max
tripcount.  This is not a problem for "normal" loops[0] that don't have
guards or assumes, but helps in cases where we have guards or assumes in
the loop that can be used to constrain incoming values over the backedge.

This partially fixes PR27691 (we still don't handle the NUW case).

[0]: for "normal" loops, in the cases where we'd be able to prove
no-wrap via isKnownPredicate, we'd also be able to compute a max
tripcount.

llvm-svn: 269211
2016-05-11 17:41:26 +00:00
Vedant Kumar ee20294af5 [BasicAA] Compare GEP indices based on value (Fix PR27418)
Equivalent GEP indices with different types are treated as different
indices altogether, leading to an incorrect AA result. Fix the issue
by comparing indices based on their values.

Thanks to Mikael Holmén for reporting the issue!

Differential Revision: http://reviews.llvm.org/D19935

llvm-svn: 269197
2016-05-11 15:45:43 +00:00
Artur Pilipenko 7a26326442 NFC. Introduce Value::isPointerDereferenceable
Extract a part of isDereferenceableAndAlignedPointer functionality to Value:
    
Reviewed By: hfinkel, sanjoy
    
Differential Revision: http://reviews.llvm.org/D17611

llvm-svn: 269190
2016-05-11 14:43:28 +00:00
Easwaran Raman 9b792923d0 Revert r269131
llvm-svn: 269138
2016-05-10 23:26:04 +00:00
Easwaran Raman 7eccf4ee0e Reapply r266477 and r266488
llvm-svn: 269131
2016-05-10 22:03:23 +00:00
Sanjay Patel 6786bc5390 [InstSimplify] use computeKnownBits on shift amount operands
Do simplifications common to all shift instructions based on the amount shifted:
1. If the shift amount is known larger than the bitwidth, the result is undefined.
2. If the valid bits of the shift amount are all known to be 0, it's a shift by zero, so the shift operand is the result.

Note that we could generalize the shift-by-zero transform into a shift-by-constant if all of the valid bits in the shift
amount are known, but that would have to be done in InstCombine rather than here because it would mean we need to create
a new shift instruction.

Differential Revision: http://reviews.llvm.org/D19874

llvm-svn: 269114
2016-05-10 20:46:54 +00:00
Peter Collingbourne ccdc225c27 Re-apply r269081 and r269082 with a fix for MSVC.
llvm-svn: 269094
2016-05-10 18:07:21 +00:00
Peter Collingbourne 4d41cb6cc6 Revert r269081 and r269082 while I try to find the right incantation to fix MSVC build.
llvm-svn: 269091
2016-05-10 17:54:43 +00:00
Peter Collingbourne 0df2b085bc WholeProgramDevirt: Move logic for finding devirtualizable call sites to Analysis.
The plan is to eventually make this logic simpler, however I expect it to
be a little tricky for the foreseeable future (at least until we're rid of
pointee types), so move it here so that it can be reused to build a summary
index for devirtualization.

Differential Revision: http://reviews.llvm.org/D20005

llvm-svn: 269081
2016-05-10 17:34:21 +00:00
Silviu Baranga adf4b739ea [LAA] Use re-written SCEV expressions when computing distances
This removes a redundant stride versioning step (we already
do it in getPtrStride, so it has no effect) and uses PSE to
get the SCEV expressions for the source and destination
(this might have changed when getPtrStride was called).

I discovered this through code inspection, and couldn't
produce a regression test for it.

llvm-svn: 269052
2016-05-10 12:28:49 +00:00
James Molloy aa1d638800 Revert "[VectorUtils] Query number of sign bits to allow more truncations"
This was a fairly simple patch but on closer inspection was seriously flawed and caused PR27690.

This reverts commit r268921.

llvm-svn: 269051
2016-05-10 12:27:23 +00:00
Denis Zobnin 15d1e64b2b [LAA] Rename "isStridedPtr" with "getPtrStride". NFC.
Changing misleading function name was approved in http://reviews.llvm.org/D17268.
Patch by Roman Shirokiy.

llvm-svn: 269021
2016-05-10 05:55:16 +00:00
Sanjoy Das 12c91dc4c8 [ValueTracking] Use guards to prove non-nullness of a value
Reviewers: apilipenko, majnemer, reames

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20044

llvm-svn: 269008
2016-05-10 02:35:44 +00:00
Sanjoy Das d47f42435a [BasicAA] Guard intrinsics don't write to memory
Summary:
The idea is very close to what we do for assume intrinsics: we mark the
guard intrinsics as writing to arbitrary memory to maintain control
dependence, but under the covers we teach AA that they do not mod any
particular memory location.

Reviewers: chandlerc, hfinkel, gbiv, reames

Subscribers: george.burgess.iv, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19575

llvm-svn: 269007
2016-05-10 02:35:41 +00:00
Sanjoy Das 0b6518d24e [SCEVExpander] Clang format expressions; NFC
The boolean expressions are somewhat hard to read otherwise.

llvm-svn: 268998
2016-05-10 00:32:31 +00:00
Sanjoy Das 2512d0c837 [SCEV] Use guards to prove predicates
We can use calls to @llvm.experimental.guard to prove predicates,
relying on the fact that in all locations domianted by a call to
@llvm.experimental.guard the predicate it is guarding is known to be
true.

llvm-svn: 268997
2016-05-10 00:31:49 +00:00
Adam Nemet 0a77dfad95 [LV] Hint at the new loop distribution pragma in optimization remark
When we encounter unsafe memory dependencies, loop distribution could
help.

Even though, the diagnostics is in LAA, it's only currently emitted in
the vectorizer.

llvm-svn: 268987
2016-05-09 23:03:44 +00:00
Sanjay Patel 0f153424a9 [Inliner] don't assume that a Constant alloca size is a ConstantInt (PR27277)
Differential Revision: http://reviews.llvm.org/D20077

llvm-svn: 268980
2016-05-09 21:51:53 +00:00
Matt Arsenault 1af53a91c0 DivergenceAnalysis: Fix crash with no return blocks
The post dominator tree does not have a root node in this case.

llvm-svn: 268933
2016-05-09 16:57:08 +00:00
Sanjay Patel 0fb9880bf5 fix spelling; NFC
llvm-svn: 268929
2016-05-09 16:07:45 +00:00
James Molloy 5c20e27b7f [VectorUtils] Query number of sign bits to allow more truncations
When deciding if a vector calculation can be done in a smaller bitwidth, use sign bit information from ValueTracking to add more information and allow more truncations.

llvm-svn: 268921
2016-05-09 14:32:30 +00:00
David Majnemer eac58d8f68 [X86] Promote several single precision FP libcalls on Windows
A number of libcalls don't exist in any particular lib but are, instead,
defined in math.h as inline functions (even in C mode!).  Don't rely on
their existence when lowering @llvm.{cos,sin,floor,..}.f32, promote them
instead.

N.B. We had logic to handle FREM but were missing out on a number of
others.  This change generalizes the FREM handling.

llvm-svn: 268875
2016-05-08 08:15:50 +00:00
Sanjoy Das 987aaa1374 [ValueTracking] Hoist some computation out of a loop; NFC
There is no need to match the comparison instruction repeatedly.

llvm-svn: 268836
2016-05-07 02:08:24 +00:00
Sanjoy Das 5056e19fce Clean up comment; NFC
llvm-svn: 268835
2016-05-07 02:08:22 +00:00
Sanjoy Das 6082c1a39c Delete trailing whitespace; NFC
llvm-svn: 268834
2016-05-07 02:08:15 +00:00
Mehdi Amini 3b132e34b0 ThinLTO: fix assertion and refactor check for hidden use from inline ASM in a helper function
This test was crashing, and currently it breaks bootstrapping clang with debuginfo

Differential Revision: http://reviews.llvm.org/D20008

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 268715
2016-05-06 08:25:33 +00:00
Adam Nemet 724ab22378 [LAA] Fix confusing debug message
This message used to be correct, when all we cared about was whether the
dependence was safe (i.e. NoDep) or unsafe.  With the current more
precise characterization, this is a forward dep.

llvm-svn: 268695
2016-05-05 23:41:28 +00:00
Xinliang David Li 28a932742c [PM] port Branch Frequency Analaysis pass to new PM
llvm-svn: 268687
2016-05-05 21:13:27 +00:00
Chad Rosier 226a734f1a [ValueTracking] Early exit when further analysis won't be fruitful.
This should have NFC in the context of codegen, but may have positive
implications on compile-time.

llvm-svn: 268651
2016-05-05 17:41:19 +00:00
Chad Rosier 25cfb7dbd6 [ValueTracking] Improve isImpliedCondition for matching LHS and Imm RHSs.
llvm-svn: 268636
2016-05-05 15:39:18 +00:00
Xinliang David Li 6e5dd41481 [PM] Port Branch Probability Analysis pass to the new pass manager.
Differential Revision: http://reviews.llvm.org/D19839

llvm-svn: 268601
2016-05-05 02:59:57 +00:00
David Majnemer 3918cdd2a1 [ConstantFolding, ValueTracking] Fold constants involving bitcasts of ConstantVector
We assumed that ConstantVectors would be rather uninteresting from the
perspective of analysis.  However, this is not the case due to a quirk
of how LLVM handles vectors of i1.  Vectors of i1 are not
ConstantDataVectors like vectors of i8, i16, i32 or i64 because i1's
SizeInBits differs from it's StoreSizeInBytes.  This leads to it being
categorized as a ConstantVector instead of a ConstantDataVector.

Instead, treat ConstantVector more uniformly.

This fixes PR27591.

llvm-svn: 268479
2016-05-04 06:13:33 +00:00
Justin Bogner e839c3e6ab PM: Check that loop passes preserve a basic set of analyses
A loop pass that didn't preserve this entire set of passes wouldn't
play well with other loop passes, since these are generally a basic
requirement to do any interesting transformations to a loop.

Adds a helper to get the set of analyses a loop pass should preserve,
and checks that any loop pass we run satisfies the requirement.

llvm-svn: 268444
2016-05-03 21:35:08 +00:00
Sanjoy Das 013a4ac4aa [SCEV] Tweak the output format and content of -analyze
In the "LoopDispositions:" section:

 - Instead of printing out a list, print out a "dictionary" to make it
   obvious by inspection which disposition is for which loop.  This is
   just a cosmetic change.

 - Print dispositions for parent _and_ sibling loops.  I will use this
   to write a test case.

llvm-svn: 268405
2016-05-03 17:49:57 +00:00
Anna Thomas 43d7e1cbff Fold compares irrespective of whether allocation can be elided
Summary
When a non-escaping pointer is compared to a global value, the
comparison can be folded even if the corresponding malloc/allocation
call cannot be elided.
We need to make sure the global value is not null, since comparisons to
null cannot be folded.

In future, we should also handle cases when the the comparison
instruction dominates the pointer escape.

Reviewers: sanjoy
Subscribers s.egerton, llvm-commits

Differential Revision: http://reviews.llvm.org/D19549

llvm-svn: 268390
2016-05-03 14:58:21 +00:00
David Majnemer 3d90bb79c4 [LoopUnroll] Unroll loops which have exit blocks to EH pads
We were overly cautious in our analysis of loops which have invokes
which unwind to EH pads.  The loop unroll transform is safe because it
only clones blocks in the loop body, it does not try to split critical
edges involving EH pads.  Instead, move the necessary safety check to
LoopUnswitch.

N.B. The safety check for loop unswitch is covered by an existing test
which fails without it.

llvm-svn: 268357
2016-05-03 03:57:40 +00:00
John Regehr e1c481dccf [LVI] Add an API to LazyValueInfo so that it can export ConstantRanges
that it computes. Currently this is used for testing and precision
tuning, but it might be used by optimizations later.

Differential Revision: http://reviews.llvm.org/D19179

llvm-svn: 268291
2016-05-02 19:58:00 +00:00
George Burgess IV 6edb891c8e [CFLAA] Fix a use-of-invalid-pointer bug.
As shown in the diff, we used to add to CFLAA's cache by doing
`Cache[Fn] = buildSetsFrom(Fn)`. `buildSetsFrom(Fn)` may cause `Cache`
to reallocate its underlying storage, if this happens and `Cache[Fn]`
was evaluated prior to `buildSetsFrom(Fn)`, then we'll store the result
to a bad address.

Patch by Jia Chen.

llvm-svn: 268269
2016-05-02 18:09:19 +00:00
Simon Pilgrim 33ae13d3c3 Fixed MSVC 'not all control paths return a value' warning
llvm-svn: 268198
2016-05-01 15:52:31 +00:00
Sanjoy Das f2f00fb11a [SCEV] When printing via -analysis, dump loop disposition
There are currently some bugs in tree around SCEV caching an incorrect
loop disposition.  Printing out loop dispositions will let us write
whitebox tests as those are fixed.

The dispositions are printed as a list in "inside out" order,
i.e. innermost loop first.

llvm-svn: 268177
2016-05-01 04:51:05 +00:00
David Majnemer 826e9831a7 [ValueTracking] Make the code in lookThroughCast
No functionality change is intended.

llvm-svn: 268108
2016-04-29 21:22:04 +00:00
Chad Rosier cd62bf5821 [InstCombine] Determine the result of a select based on a dominating condition.
Differential Revision: http://reviews.llvm.org/D19550

llvm-svn: 268104
2016-04-29 21:12:31 +00:00
David Majnemer d2a074b1f4 [ValueTracking] matchSelectPattern needs to be more careful around FP
matchSelectPattern attempts to see through casts which mask min/max
patterns from being more obvious.  Under certain circumstances, it would
misidentify a sequence of instructions as a min/max because it assumed
that folding casts would preserve the result.  This is not the case for
floating point <-> integer casts.

This fixes PR27575.

llvm-svn: 268086
2016-04-29 18:40:34 +00:00
Geoff Berry b92cd5293e [BasicAA] Treat llvm.assume as not accessing memory in getModRefBehavior(Function)
Reviewers: dberlin, chandlerc, hfinkel, reames, sanjoy

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19730

llvm-svn: 268068
2016-04-29 17:18:28 +00:00