Commit Graph

6192 Commits

Author SHA1 Message Date
Chris Bieneman e49730d4ba Remove autoconf support
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html

"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi

Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark

Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D16471

llvm-svn: 258861
2016-01-26 21:29:08 +00:00
Haicheng Wu f1c00a22be [LIR] Add support for structs and hand unrolled loops
This is a recommit of r258620 which causes PR26293.

The original message:

Now LIR can turn following codes into memset:

typedef struct foo {
  int a;
  int b;
} foo_t;

void bar(foo_t *f, unsigned n) {
  for (unsigned i = 0; i < n; ++i) {
    f[i].a = 0;
    f[i].b = 0;
  }
}

void test(foo_t *f, unsigned n) {
  for (unsigned i = 0; i < n; i += 2) {
    f[i] = 0;
    f[i+1] = 0;
  }
}

llvm-svn: 258777
2016-01-26 02:27:47 +00:00
Quentin Colombet a392810bea Speculatively revert r258620 as it is the likely culprid of PR26293.
llvm-svn: 258703
2016-01-25 19:12:49 +00:00
James Molloy 121de0bcfa [DemandedBits] Fix computation of demanded bits for ICmps
The computation of ICmp demanded bits is independent of the individual operand being evaluated. We simply return a mask consisting of the minimum leading zeroes of both operands.

We were incorrectly passing "I" to ComputeKnownBits - this should be "UserI->getOperand(0)". In cases where we were evaluating the 1th operand, we were taking the minimum leading zeroes of it and itself.

This should fix PR26266.

llvm-svn: 258690
2016-01-25 14:49:36 +00:00
Manuel Jacob 0af37b21c8 Remove duplicate documentation in ConstantFolding.cpp. NFC.
The documentation for these functions is already present in the header file.

llvm-svn: 258649
2016-01-23 22:49:54 +00:00
Haicheng Wu dd5e9d2159 [LIR] Add support for structs and hand unrolled loops
Now LIR can turn following codes into memset:

typedef struct foo {
  int a;
  int b;
} foo_t;

void bar(foo_t *f, unsigned n) {
  for (unsigned i = 0; i < n; ++i) {
    f[i].a = 0;
    f[i].b = 0;
  }
}

void test(foo_t *f, unsigned n) {
  for (unsigned i = 0; i < n; i += 2) {
    f[i] = 0;
    f[i+1] = 0;
  }
}

llvm-svn: 258620
2016-01-23 06:52:41 +00:00
Eduard Burtescu 68e7f49f8e [opaque pointer types] [NFC] DataLayout::getIndexedOffset: take source element type instead of pointer type and rename to getIndexedOffsetInType.
Summary:

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16282

llvm-svn: 258478
2016-01-22 03:08:27 +00:00
Eduard Burtescu e2a6917849 [opaque pointer types] [NFC] FindAvailableLoadedValue: take LoadInst instead of just the pointer.
Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16422

llvm-svn: 258477
2016-01-22 01:51:51 +00:00
Eduard Burtescu 1423921a24 [opaque pointer types] [NFC] Add an explicit type argument to ConstantFoldLoadFromConstPtr.
Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16418

llvm-svn: 258472
2016-01-22 01:17:26 +00:00
Eduard Burtescu 2f4758b1cc [opaque pointer types] [NFC] Take advantage of get{Source,Result}ElementType when folding GEPs.
Summary:

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16302

llvm-svn: 258456
2016-01-21 23:42:06 +00:00
David Majnemer 3af5bf30e3 [InstCombine] Simplify (x >> y) <= x
This commit extends the patterns recognised by InstSimplify to also handle (x >> y) <= x in the same way as (x /u y) <= x.

The missing optimisation was found investigating why LLVM did not optimise away bound checks in a binary search: https://github.com/rust-lang/rust/pull/30917

Patch by Andrea Canciani!

Differential Revision: http://reviews.llvm.org/D16402

llvm-svn: 258422
2016-01-21 18:55:54 +00:00
Adam Nemet af761104ba [TTI] Add getCacheLineSize
Summary:
And use it in PPCLoopDataPrefetch.cpp.

@hfinkel, please let me know if your preference would be to preserve the
ppc-loop-prefetch-cache-line option in order to be able to override the
value of TTI::getCacheLineSize for PPC.

Reviewers: hfinkel

Subscribers: hulx2000, mcrosier, mssimpso, hfinkel, llvm-commits

Differential Revision: http://reviews.llvm.org/D16306

llvm-svn: 258419
2016-01-21 18:28:36 +00:00
Manuel Jacob f3ee254bc2 Undo r258163 "Move part of an if condition into an assertion. NFC."
This undoes the change made in r258163.  The assertion fails if `Ptr` is of a
vector type.  The previous code doesn't look completely correct either, so I'll
investigate this more.

llvm-svn: 258411
2016-01-21 17:36:14 +00:00
Manuel Jacob e902459c4b Change ConstantFoldInstOperands to take Instruction instead of opcode and type. NFC.
Summary:
The previous form, taking opcode and type, is moved to an internal
helper and the new form, taking an instruction, is a wrapper around this
helper.

Although this is a slight cleanup on its own, the main motivation is to
refactor the constant folding API to ease migration to opaque pointers.
This will be follow-up work.

Reviewers: eddyb

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D16383

llvm-svn: 258391
2016-01-21 06:33:22 +00:00
Manuel Jacob 925d029461 Introduce ConstantFoldCastOperand function and migrate some callers of ConstantFoldInstOperands to use it. NFC.
Summary:
Although this is a slight cleanup on its own, the main motivation is to
refactor the constant folding API to ease migration to opaque pointers.
This will be follow-up work.

Reviewers: eddyb

Subscribers: zzheng, dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D16380

llvm-svn: 258390
2016-01-21 06:31:08 +00:00
Manuel Jacob a61ca37b6d Introduce ConstantFoldBinaryOpOperands function and migrate some callers of ConstantFoldInstOperands to use it. NFC.
Summary:
Although this is a slight cleanup on its own, the main motivation is to
refactor the constant folding API to ease migration to opaque pointers.
This will be follow-up work.

Reviewers: eddyb

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D16378

llvm-svn: 258389
2016-01-21 06:26:35 +00:00
Sanjay Patel f44bd38092 fix typo; NFC
llvm-svn: 258332
2016-01-20 18:59:48 +00:00
Sanjoy Das 29a4b5dc0d [SCEV] Fix PR26207
In some cases, the max backedge taken count can be more conservative
than the exact backedge taken count (for instance, because
ScalarEvolution::getRange is not control-flow sensitive whereas
computeExitLimitFromICmp can be).  In these cases,
computeExitLimitFromCond (specifically the bit that deals with `and` and
`or` instructions) can create an ExitLimit instance with a
`SCEVCouldNotCompute` max backedge count expression, but a computable
exact backedge count expression.  This violates an implicit SCEV
assumption: a computable exact BE count should imply a computable max BE
count.

This change

 - Makes the above implicit invariant explicit by adding an assert to
   ExitLimit's constructor

 - Changes `computeExitLimitFromCond` to be more robust around
   conservative max backedge counts

llvm-svn: 258184
2016-01-19 20:53:51 +00:00
Sanjoy Das 0ff078736f [SCEV] Use range-for; NFC
llvm-svn: 258183
2016-01-19 20:53:46 +00:00
Manuel Jacob 3f49f654a2 Move part of an if condition into an assertion. NFC.
llvm-svn: 258163
2016-01-19 19:04:49 +00:00
Eduard Burtescu 19eb03106d [opaque pointer types] [NFC] GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.
Summary:
GEPOperator: provide getResultElementType alongside getSourceElementType.
This is made possible by adding a result element type field to GetElementPtrConstantExpr, which GetElementPtrInst already has.

GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16275

llvm-svn: 258145
2016-01-19 17:28:00 +00:00
Dan Gohman 0553299586 [WebAssembly] Re-enable loop idiom recognition for memcpy et al.
llvm-svn: 258125
2016-01-19 14:49:23 +00:00
Adam Nemet d8968f0945 [LAA] Include function name in debug output
llvm-svn: 258088
2016-01-18 21:16:33 +00:00
Eduard Burtescu 90c4449128 [opaque pointer types] Alloca: use getAllocatedType() instead of getType()->getPointerElementType().
Reviewers: mjacob

Subscribers: llvm-commits, dblaikie

Differential Revision: http://reviews.llvm.org/D16272

llvm-svn: 258028
2016-01-18 00:10:01 +00:00
Sanjay Patel 6435c6ede0 fix variable names; NFC
llvm-svn: 258027
2016-01-17 23:18:05 +00:00
Sanjay Patel 9613b29927 fix typos; NFC
llvm-svn: 258026
2016-01-17 23:13:48 +00:00
Manuel Jacob 20c6d5bcb8 [opaque pointer types] [breaking-change] [NFC] SimplifyGEPInst: take the source element type of the GEP as an argument.
Patch by Eduard Burtescu.

Reviewers: dblaikie, mjacob

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16281

llvm-svn: 258024
2016-01-17 22:46:43 +00:00
Manuel Jacob da2c9baa07 [NFC] Remove one dead PointerType::getElementType() call.
Reviewers: dblaikie, mjacob

Subscribers: llvm-commits, dblaikie

Patch by Eduard Burtescu.

Differential Revision: http://reviews.llvm.org/D16274

llvm-svn: 258022
2016-01-17 22:28:28 +00:00
Artur Pilipenko f84dc06e5b Push isDereferenceableAndAlignedPointer down into isSafeToLoadUnconditionally
Reviewed By: reames

Differential Revision: http://reviews.llvm.org/D16226

llvm-svn: 258010
2016-01-17 12:35:29 +00:00
Manuel Jacob 5f6eaac611 GlobalValue: use getValueType() instead of getType()->getPointerElementType().
Reviewers: mjacob

Subscribers: jholewinski, arsenm, dsanders, dblaikie

Patch by Eduard Burtescu.

Differential Revision: http://reviews.llvm.org/D16260

llvm-svn: 257999
2016-01-16 20:30:46 +00:00
Igor Laevsky 28eeb3f66c [BasicAliasAnalysis] Take into account operand bundles in the getModRefInfo function
Differential Revision: http://reviews.llvm.org/D16225

llvm-svn: 257991
2016-01-16 12:15:53 +00:00
Matthias Braun feb81bc682 ValueTracking: Put DataLayout reference into the Query structure, NFC.
It looks nicer and improves the compiletime of a typical
clang -O3 -emit-llvm run by ~0.6% for me.

Differential Revision: http://reviews.llvm.org/D16205

llvm-svn: 257944
2016-01-15 22:22:04 +00:00
Joseph Tremoulet 44b3f961e1 [WinEH] Rename CatchReturnInst::getParentPad, NFC
Summary:
Rename to getCatchSwitchParentPad, to make it more clear which ancestor
the "parent" in question is.  Add a comment pointing out the key feature
that the returned pad indicates which funclet contains the successor
block.

Reviewers: rnk, andrew.w.kaylor, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16222

llvm-svn: 257933
2016-01-15 21:16:19 +00:00
Artur Pilipenko 6dd6969cee Change isSafeToLoadUnconditionally arguments order. Separated from http://reviews.llvm.org/D10920.
llvm-svn: 257894
2016-01-15 15:27:46 +00:00
Sanjay Patel 960e5349af rangify; NFCI
llvm-svn: 257845
2016-01-15 00:08:10 +00:00
Sanjay Patel 784b5e3ff0 remove duplicate documentation comments (already in the header file) ; NFC
llvm-svn: 257835
2016-01-14 23:23:04 +00:00
Easwaran Raman f4bb2f0dc3 Refactor threshold computation for inline cost analysis
Differential Revision: http://reviews.llvm.org/D15401

llvm-svn: 257832
2016-01-14 23:16:29 +00:00
Rui Ueyama da00f2fdf4 Update to use new name alignTo().
llvm-svn: 257804
2016-01-14 21:06:47 +00:00
James Molloy c5eded5c1e Revert "[ValueTracking] Understand more select patterns in ComputeKnownBits"
This reverts commit r257769. Backing this out because of stage2 failures.

llvm-svn: 257773
2016-01-14 15:49:32 +00:00
James Molloy a9497f53c9 [ValueTracking] Understand more select patterns in ComputeKnownBits
Some patterns of select+compare allow us to know exactly the value of the uppermost bits in the select result. For example:

  %b = icmp ugt i32 %a, 5
  %c = select i1 %b, i32 2, i32 %a

Here we know that %c is bounded by 5, and therefore KnownZero = ~APInt(5).getActiveBits() = ~7.

There are several such patterns, and this patch attempts to understand a reasonable subset of them - namely when the base values are the same (as above), and when they are related by a simple (add nsw), for example (add nsw %a, 4) and %a.

llvm-svn: 257769
2016-01-14 15:23:19 +00:00
Vaivaswatha Nagaraj 68befd7094 [GlobalsAA] Relax condition in checking globals as args to functions
Summary:
Since globals may escape as function arguments (even when they have been 
found to be non-escaping, because of optimizations such as memcpyoptimizer
that replaces stores with memcpy), all arguments to a function are checked
during query to make sure they are identifiable. At that time, also ensure
we return a conservative result only if the arguments don't alias to our global.

Reviewers: hfinkel, jmolloy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16140

llvm-svn: 257750
2016-01-14 08:46:45 +00:00
Sanjay Patel d7f613dd76 fix formatting; NFC
llvm-svn: 257688
2016-01-13 22:17:13 +00:00
Sanjay Patel d99299e4bc don't duplicate comments that are in the header file; NFC
llvm-svn: 257676
2016-01-13 21:38:23 +00:00
Sanjay Patel da08082a57 rangify; NFCI
llvm-svn: 257646
2016-01-13 18:37:28 +00:00
Sanjay Patel c5d29aa7c4 don't repeat names in comments ; NFC
llvm-svn: 257643
2016-01-13 17:43:35 +00:00
Sanjay Patel f23416852f fix typo
llvm-svn: 257626
2016-01-13 17:23:52 +00:00
Sanjay Patel c775fa43d0 fix typo
llvm-svn: 257613
2016-01-13 16:34:10 +00:00
Fiona Glaser db7824f0c1 CannotBeOrderedLessThanZero: add some missing cases
llvm-svn: 257542
2016-01-12 23:37:30 +00:00
Sanjay Patel 34ea70a5c9 getParent()->getParent() == getFunction() and clang-format ; NFC
llvm-svn: 257399
2016-01-11 22:24:35 +00:00
Sanjay Patel 472cc78ccb don't repeat function names in comments; NFC
llvm-svn: 257396
2016-01-11 22:14:42 +00:00
Justin Bogner e9fb228d59 LoopInfo: Simplify ownership of Loop objects
It's strange that LoopInfo mostly owns the Loop objects, but that it
defers deleting them to the loop pass manager. Instead, change the
oddly named "updateUnloop" to "markAsRemoved" and have it queue the
Loop object for deletion. We can't delete the Loop immediately when we
remove it, since we need its pointer identity still, so we'll mark the
object as "invalid" so that clients can see what's going on.

llvm-svn: 257191
2016-01-08 19:08:53 +00:00
Kyle Butt a02ce98bd4 [Vectorization] Actually return from error case in isStridedPtr
The early return seems to be missed. This causes a radical and wrong loop
optimization on powerpc. It isn't reproducible on x86_64, because
"UseInterleaved" is false.

Patch by Tim Shen.

llvm-svn: 257134
2016-01-08 01:55:13 +00:00
James Molloy 9971a6841c [GlobalsAA] Partially back out r248576
See PR25822 for a more full summary, but we were conflating the concepts of "capture" and "escape". We were proving nocapture and using that proof to infer noescape, which is not true. Escaped-ness is a function-local property - as soon as a value is used in a call argument it escapes. Capturedness is a related but distinct property. It implies a *temporally limited* escape. Consider:

  static int a;
  int b;
  int g(int * nocapture arg);
  int f() {
    a = 2;  // Even though a escapes to g, it is not captured so can be treated as non-escaping here.
    g(&a);  // But here it must be treated as escaping.
    g(&b);  // Now that g(&a) has returned we know it was not captured so we can treat it as non-escaping again.
  }

The original commit did not sufficiently understand this nuance and so caused PR25822 and PR26046.

r248576 included both a performance improvement (which has been backed out) and a related conformance fix (which has been kept along with its testcase).

llvm-svn: 257058
2016-01-07 13:33:28 +00:00
Weiming Zhao 0f1762caf9 Recommit r256952 "Filtering IR printing for print-after-all/print-before-all"
Fix lit test fail due to outputting an extra line.

Differential Revision: http://reviews.llvm.org/D15776

llvm-svn: 256987
2016-01-06 22:55:03 +00:00
Weiming Zhao b243c95c6a Revert r256952 due to lit test fails.
llvm-svn: 256954
2016-01-06 18:31:44 +00:00
Weiming Zhao eac0636805 Filtering IR printing for print-after-all/print-before-all
Summary:
This patch implements "-print-funcs" option to support function filtering for IR printing like -print-after-all, -print-before etc.
Examples:
  -print-after-all -print-funcs=foo,bar

Reviewers: mcrosier, joker.eph

Subscribers: tejohnson, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D15776

llvm-svn: 256952
2016-01-06 18:20:25 +00:00
Philip Reames fe46cadcf9 [BasicAA] Extract WriteOnly predicate on parameters [NFC]
Since writeonly is the only missing attribute and special case left for the memset/memcpy family of intrinsics, rearrange the code to make that much more clear.

llvm-svn: 256949
2016-01-06 18:10:35 +00:00
Amaury Sechet 457cc4db9e Revert "GlobalsAA: Take advantage of ArgMemOnly, InaccessibleMemOnly and InaccessibleMemOrArgMemOnly attributes"
Summary:
This reverts commit 5a9e526f29cf8510ab5c3d566fbdcf47ac24e1e9.

As per discussion in D15665

This also add a test case so that regression introduced by that diff are not reintroduced.

Reviewers: vaivaswatha, jmolloy, hfinkel, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15919

llvm-svn: 256932
2016-01-06 13:23:52 +00:00
Philip Reames ae050a5703 [BasicAA] Remove special casing of memset_pattern16 in favor of generic attribute inference
Most of the properties of memset_pattern16 can be now covered by the generic attributes and inferred by InferFunctionAttrs.  The only exceptions are:
- We don't yet have a writeonly attribute for the first argument.
- We don't have an attribute for modeling the access size facts encoded in MemoryLocation.cpp.  

Differential Revision: http://reviews.llvm.org/D15879

llvm-svn: 256911
2016-01-06 04:53:16 +00:00
Philip Reames cdf46d1b52 [BasicAA] Delete dead code related to memset/memcpy/memmove intrinsics [NFCI]
We only need to describe the writeonly property of one of the arguments. All of the rest of the semantics are nicely described by existing attributes in Intrinsics.td.

Differential Revision: http://reviews.llvm.org/D15880

llvm-svn: 256910
2016-01-06 04:43:03 +00:00
Manuel Jacob 83eefa6d20 [Statepoints] Refactor GCRelocateOperands into an intrinsic wrapper. NFC.
Summary:
This commit renames GCRelocateOperands to GCRelocateInst and makes it an
intrinsic wrapper, similar to e.g. MemCpyInst.  Also, all users of
GCRelocateOperands were changed to use the new intrinsic wrapper instead.

Reviewers: sanjoy, reames

Subscribers: reames, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D15762

llvm-svn: 256811
2016-01-05 04:03:00 +00:00
Philip Reames a694a0b141 [MDA] Don't be quite as conservative for noalias functions
If we encounter a noalias call that alias analysis can't analyse, we can fall down into the generic call handling rather than giving up entirely. I noticed this while reading through the code for another purpose.

I can't seem to write a test case which changes; that sorta makes sense given any test case would have to be an inconsistency in AA. Suggestions welcome.

Differential Revision: http://reviews.llvm.org/D15825

llvm-svn: 256802
2016-01-05 00:49:14 +00:00
Philip Reames 2466719e44 [MemoryBuiltins] Remove isOperatorNewLike by consolidating non-null inference handling
This patch removes the isOperatorNewLike predicate since it was only being used to establish a non-null return value and we have attributes specifically for that purpose with generic handling. To keep approximate the same behaviour for existing frontends, I added the various operator new like (i.e. instances of operator new) to InferFunctionAttrs. It's not really clear to me why this isn't handled in Clang, but I didn't want to break existing code and any subtle assumptions it might have.

Once this patch is in, I'm going to start separating the isAllocLike family of predicates. These appear to be being used for a mixture of things which should be more clearly separated and documented. Today, they're being used to indicate (at least) aliasing facts, CSE-ability, and default values from an allocation site.

Differential Revision: http://reviews.llvm.org/D15820

llvm-svn: 256787
2016-01-04 22:49:23 +00:00
Nick Lewycky 947ca8ac52 Fix comment in typo. NFC
llvm-svn: 256761
2016-01-04 16:44:44 +00:00
Chandler Carruth 7664127f8c Fix a horrible infloop in value tracking in the face of dead code.
Amazingly, we just never triggered this without:
1) Moving code around for MetadataTracking so that a certain *different*
   amount of inlining occurs in the per-TU compile step.
2) Then you LTO opt or clang with a bootstrap, and get inlining, loop
   opts, and GVN line up everything *just* right.

I don't really know how we didn't hit this before. We really need to be
fuzz testing stuff, it shouldn't be hard to trigger. I'm working on
crafting a reduced nice test case, and will submit that when I have it,
but I want to get LTO build bots going again.

llvm-svn: 256735
2016-01-04 07:23:12 +00:00
Craig Topper e30b8ca149 Use std::is_sorted and std::none_of instead of manual loops. NFC
llvm-svn: 256719
2016-01-03 19:43:40 +00:00
Sanjay Patel 41160c2094 [ValueTracking] fix bug computing isKnownToBeAPowerOfTwo() with arithmetic shift right (PR25900)
This is a fix for:
https://llvm.org/bugs/show_bug.cgi?id=25900

If we think that an arithmetic right shift of a power of two is always a power of two, 
an sdiv gets wrongly converted to udiv.

Differential Revision: http://reviews.llvm.org/D15827

llvm-svn: 256655
2015-12-30 22:40:52 +00:00
Philip Reames 87a8677e3d [MemoryBuiltins] Delete dead code [NFC]
llvm-svn: 256565
2015-12-29 17:04:43 +00:00
Easwaran Raman b9f7120e7a Refactor inline costs analysis by removing the InlineCostAnalysis class
InlineCostAnalysis is an analysis pass without any need for it to be one.
Once it stops being an analysis pass, it doesn't maintain any useful state
and the member functions inside can be made free functions. NFC.

Differential Revision: http://reviews.llvm.org/D15701

llvm-svn: 256521
2015-12-28 20:28:19 +00:00
Elena Demikhovsky 5494698828 Implemented cost model for masked gather and scatter operations
The cost is calculated for all X86 targets. When gather/scatter instruction
is not supported we calculate the cost of scalar sequence.

Differential revision: http://reviews.llvm.org/D15677

llvm-svn: 256519
2015-12-28 20:10:59 +00:00
Chandler Carruth 9153911551 [lcg] Fix a few more formatting goofs found by clang-format. NFC.
llvm-svn: 256480
2015-12-28 01:54:20 +00:00
Chandler Carruth 85dbea99ee Add a missing const qualifier on the context instruction. This somehow
has always been missing. =/

llvm-svn: 256371
2015-12-24 09:08:08 +00:00
JF Bastien 61ad8b3907 Fix SCEV r256338.
llvm-svn: 256344
2015-12-23 18:18:53 +00:00
Sanjoy Das 2fbfb25ad6 [SCEV] Fix getLoopBackedgeTakenCounts
The way `getLoopBackedgeTakenCounts` is written right now isn't
correct. It will try to compute and store the BE counts of a Loop
 #{child loop} number of times (which may be zero).

llvm-svn: 256338
2015-12-23 17:48:14 +00:00
David Majnemer 2bc2538470 [OperandBundles] Have GlobalsModRef play nice with operand bundles
A call site's use of a Value might not correspond to an argument
operand but to a bundle operand.

llvm-svn: 256329
2015-12-23 09:58:46 +00:00
Akira Hatanaka 1cb242eb13 Provide a way to specify inliner's attribute compatibility and merging.
This reapplies r256277 with two changes:

- In emitFnAttrCompatCheck, change FuncName's type to std::string to fix
  a use-after-free bug.
- Remove an unnecessary install-local target in lib/IR/Makefile. 

Original commit message for r252949:

Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 256304
2015-12-22 23:57:37 +00:00
Cong Hou 6a2c71af0b [BPI] Fix two potential divide-by-zero operations that are introduced in r256263.
llvm-svn: 256303
2015-12-22 23:45:55 +00:00
Akira Hatanaka 9c05cc5670 Revert r256277 and r256279.
Some of the bots failed again.

llvm-svn: 256280
2015-12-22 20:29:09 +00:00
Akira Hatanaka a61deb249b Provide a way to specify inliner's attribute compatibility and merging.
This reapplies r252990 and r252949. I've added member function getKind
to the Attr classes which returns the enum or string of the attribute.

Original commit message for r252949:

Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 256277
2015-12-22 20:00:05 +00:00
Cong Hou e93b8e1539 [BPI] Replace weights by probabilities in BPI.
This patch removes all weight-related interfaces from BPI and replace
them by probability versions. With this patch, we won't use edge weight
anymore in either IR or MC passes. Edge probabilitiy is a better
representation in terms of CFG update and validation.


Differential revision: http://reviews.llvm.org/D15519 

llvm-svn: 256263
2015-12-22 18:56:14 +00:00
Jun Bum Lim a23e5f7516 Enhance BranchProbabilityInfo::calcUnreachableHeuristics for InvokeInst
This is recommit of r256028 with minor fixes in unittests:
  CodeGen/Mips/eh.ll
  CodeGen/Mips/insn-zero-size-bb.ll

Original commit message:

When identifying blocks post-dominated by an unreachable-terminated block
in BranchProbabilityInfo, consider only the edge to the normal destination
block if the terminator is InvokeInst and let calcInvokeHeuristics() decide
edge weights for the InvokeInst.

llvm-svn: 256202
2015-12-21 22:00:51 +00:00
Michael Zolotukhin 0c97988e54 [ValueTracking] Properly handle non-sized types in isAligned function.
Reviewers: apilipenko, reames, sanjoy, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15597

llvm-svn: 256192
2015-12-21 20:38:18 +00:00
Jingyue Wu 3f422280f5 [DivergenceAnalysis] fix a bug in computing influence regions
Fixes PR25864

llvm-svn: 256036
2015-12-18 21:44:26 +00:00
Rafael Espindola 708a91a103 Revert "Enhance BranchProbabilityInfo::calcUnreachableHeuristics for InvokeInst"
This reverts commit r256028.

It broke:

    LLVM :: CodeGen/Mips/eh.ll
    LLVM :: CodeGen/Mips/insn-zero-size-bb.ll

llvm-svn: 256032
2015-12-18 21:23:32 +00:00
Jun Bum Lim 51a247065e Enhance BranchProbabilityInfo::calcUnreachableHeuristics for InvokeInst
When identifying blocks post-dominated by an unreachable-terminated block
in BranchProbabilityInfo, consider only the edge to the normal destination
block if the terminator is InvokeInst and let calcInvokeHeuristics() decide
edge weights for the InvokeInst.

llvm-svn: 256028
2015-12-18 20:53:47 +00:00
Andrew Kaylor 123048d26a [WinEH] Update LCSSA to handle catchswitch with handlers inside and outside a loop
Differential Revision: http://reviews.llvm.org/D15630

llvm-svn: 256005
2015-12-18 18:12:35 +00:00
Vaivaswatha Nagaraj ed237938da GlobalsAA: Take advantage of ArgMemOnly, InaccessibleMemOnly and InaccessibleMemOrArgMemOnly attributes
Summary:
1. Modify AnalyzeCallGraph() to retain function info for external functions
if the function has [InaccessibleMemOr]ArgMemOnly flags.
2. When analyzing the use of a global is function parameter at a call site,
mark the callee also as modifying the global appropriately.
3. Add additional test cases.

Depends on D15499

Reviewers: hfinkel, jmolloy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15605

llvm-svn: 255994
2015-12-18 11:02:52 +00:00
Sanjoy Das 0de2feceb1 [SCEV] Add and use SCEVConstant::getAPInt; NFCI
llvm-svn: 255921
2015-12-17 20:28:46 +00:00
Andy Gibbs 33a0eb740e Revert r254592 (virtual dtor in SCEVPredicate).
Clang has better diagnostics in this case.  It is not necessary therefore
to change the destructor to avoid what is effectively an invalid warning
in gcc.  Instead, better handle the warning flags given to the compiler.

llvm-svn: 255905
2015-12-17 16:43:53 +00:00
Justin Bogner 883a3ea67f LPM: Make callers of LPM.deleteLoopFromQueue update LoopInfo directly. NFC
As of r255720, the loop pass manager will DTRT when passes update the
loop info for removed loops, so they no longer need to reach into
LPPassManager APIs to do this kind of transformation. This change very
nearly removes the need for the LPPassManager to even be passed into
loop passes - the only remaining pass that uses the LPM argument is
LoopUnswitch.

llvm-svn: 255797
2015-12-16 18:40:20 +00:00
Justin Bogner e0fde5c6d0 Fix typo in r255720
llvm-svn: 255724
2015-12-16 00:17:34 +00:00
Justin Bogner 6e9810c8ef LPM: Simplify how passes mark loops for deletion. NFC
When a pass removes a loop it currently has to reach up into the
LPPassManager's internals to update the state of the iteration over
loops. This reverse dependency results in a pretty awkward interplay
of the LPPassManager and its Passes.

Here, we change this to instead keep track of when a loop has become
"unlooped" in the Loop objects themselves, then the LPPassManager can
check this and manipulate its own state directly. This opens the door
to allow most of the loop passes to work without a backreference to
the LPPassManager.

I've kept passes calling the LPPassManager::deleteLoopFromQueue API
now so I could put an assert in to prove that this is NFC, but a later
pass will update passes just to preserve the LoopInfo directly and
stop referencing the LPPassManager completely.

llvm-svn: 255720
2015-12-16 00:01:02 +00:00
Nicolai Hahnle 78fd4f087b AMDGPU: mark ldexp LibCalls as unavailable
Summary:
The LibCallSimplifier will turn llvm.exp2.* intrinsics into ldexp* libcalls
which do not make sense with the AMDGPU backend.

In the long run, we'll want an llvm.ldexp.* intrinsic to properly make use of
this optimization, but this works around the problem for now.

See also: http://reviews.llvm.org/D14327 (suggested llvm.ldexp.* implementation)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92709

Reviewers: arsenm, tstellarAMD

Differential Revision: http://reviews.llvm.org/D14990

llvm-svn: 255658
2015-12-15 17:24:15 +00:00
David Majnemer bbfc7219ef [IR] Remove terminatepad
It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function.  This is not sufficient to
implement fully generic filters but MSVC doesn't support them which
makes terminatepad a little over-designed.

Depends on D15478.

Differential Revision: http://reviews.llvm.org/D15479

llvm-svn: 255522
2015-12-14 18:34:23 +00:00
David Majnemer f28c52f8f7 Try to appease a buildbot
The builder complains thusly:
error C2027: use of undefined type 'llvm::raw_ostream'

Try to make it happy by including raw_ostream.h

llvm-svn: 255425
2015-12-12 05:53:20 +00:00
David Majnemer 8a1c45d6e8 [IR] Reformulate LLVM's EH funclet IR
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
  but they are difficult to explain to others, even to seasoned LLVM
  experts.
- catchendpad and cleanupendpad are optimization barriers.  They cannot
  be split and force all potentially throwing call-sites to be invokes.
  This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
  It is unsplittable, starts a funclet, and has control flow to other
  funclets.
- The nesting relationship between funclets is currently a property of
  control flow edges.  Because of this, we are forced to carefully
  analyze the flow graph to see if there might potentially exist illegal
  nesting among funclets.  While we have logic to clone funclets when
  they are illegally nested, it would be nicer if we had a
  representation which forbade them upfront.

Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
  flow, just a bunch of simple operands;  catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
  the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
  the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad.  Their presence can be inferred
  implicitly using coloring information.

N.B.  The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for.  An expert should take a
look to make sure the results are reasonable.

Reviewers: rnk, JosephTremoulet, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D15139

llvm-svn: 255422
2015-12-12 05:38:55 +00:00
Akira Hatanaka 2992beec00 [LazyValueInfo] Stop inserting overdefined values into ValueCache to
reduce memory usage.

Previously, LazyValueInfoCache inserted overdefined lattice values into
both ValueCache and OverDefinedCache. This wasn't necessary and was
causing LazyValueInfo to use an excessive amount of memory in some cases.

This patch changes LazyValueInfoCache to insert overdefined values only
into OverDefinedCache. The memory usage decreases by 70 to 75% when one
of the files in llvm is compiled.

rdar://problem/11388615

Differential revision: http://reviews.llvm.org/D15391

llvm-svn: 255320
2015-12-11 00:49:47 +00:00
Silviu Baranga 9cd9a7e310 Re-commit r255115, with the PredicatedScalarEvolution class moved to
ScalarEvolution.h, in order to avoid cyclic dependencies between the Transform
and Analysis modules:

[LV][LAA] Add a layer over SCEV to apply run-time checked knowledge on SCEV expressions

Summary:
This change creates a layer over ScalarEvolution for LAA and LV, and centralizes the
usage of SCEV predicates. The SCEVPredicatedLayer takes the statically deduced knowledge
by ScalarEvolution and applies the knowledge from the SCEV predicates. The end goal is
that both LAA and LV should use this interface everywhere.

This also solves a problem involving the result of SCEV expression rewritting when
the predicate changes. Suppose we have the expression (sext {a,+,b}) and two predicates
  P1: {a,+,b} has nsw
  P2: b = 1.

Applying P1 and then P2 gives us {a,+,1}, while applying P2 and the P1 gives us
sext({a,+,1}) (the AddRec expression was changed by P2 so P1 no longer applies).
The SCEVPredicatedLayer maintains the order of transformations by feeding back
the results of previous transformations into new transformations, and therefore
avoiding this issue.

The SCEVPredicatedLayer maintains a cache to remember the results of previous
SCEV rewritting results. This also has the benefit of reducing the overall number
of expression rewrites.

Reviewers: mzolotukhin, anemet

Subscribers: jmolloy, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D14296

llvm-svn: 255122
2015-12-09 16:06:28 +00:00
Silviu Baranga ad1ccb357b Revert r255115 until we figure out how to fix the bot failures.
llvm-svn: 255117
2015-12-09 15:25:28 +00:00
Silviu Baranga 41eb682501 [LV][LAA] Add a layer over SCEV to apply run-time checked knowledge on SCEV expressions
Summary:
This change creates a layer over ScalarEvolution for LAA and LV, and centralizes the
usage of SCEV predicates. The SCEVPredicatedLayer takes the statically deduced knowledge
by ScalarEvolution and applies the knowledge from the SCEV predicates. The end goal is
that both LAA and LV should use this interface everywhere.

This also solves a problem involving the result of SCEV expression rewritting when
the predicate changes. Suppose we have the expression (sext {a,+,b}) and two predicates
  P1: {a,+,b} has nsw
  P2: b = 1.

Applying P1 and then P2 gives us {a,+,1}, while applying P2 and the P1 gives us
sext({a,+,1}) (the AddRec expression was changed by P2 so P1 no longer applies).
The SCEVPredicatedLayer maintains the order of transformations by feeding back
the results of previous transformations into new transformations, and therefore
avoiding this issue.

The SCEVPredicatedLayer maintains a cache to remember the results of previous
SCEV rewritting results. This also has the benefit of reducing the overall number
of expression rewrites.

Reviewers: mzolotukhin, anemet

Subscribers: jmolloy, sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D14296

llvm-svn: 255115
2015-12-09 15:03:52 +00:00
Sanjoy Das d87e4354a7 [SCEV] Use for-each; NFC
llvm-svn: 255069
2015-12-08 22:53:36 +00:00
Sanjoy Das 7d75267db7 [SCEV] Move some struct declarations inside functions; NFC
Reduces the scope over which the struct is visible, making its usages
obvious.  I did not move structs in cases where this wasn't a clear
win (the struct is too large, or is grouped in some other interesting
way).

llvm-svn: 255003
2015-12-08 04:32:54 +00:00
Sanjoy Das 7881abd076 [SCEV] Fix indentation; NFC
llvm-svn: 255002
2015-12-08 04:32:51 +00:00
Sanjoy Das 683bf070ef [IndVars] Have getInsertPointForUses preserve LCSSA
Summary:
Also add a stricter post-condition for IndVarSimplify.

Fixes PR25578.  Test case by Michael Zolotukhin.

Reviewers: hfinkel, atrick, mzolotukhin

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15059

llvm-svn: 254977
2015-12-08 00:13:21 +00:00
Sanjoy Das b771eb6d69 [SCEVExpander] Have hoistIVInc preserve LCSSA
Summary:
(Note: the problematic invocation of hoistIVInc that caused PR24804 came
from IndVarSimplify, not from SCEVExpander itself)

Fixes PR24804.  Test case by David Majnemer.

Reviewers: hfinkel, majnemer, atrick, mzolotukhin

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15058

llvm-svn: 254976
2015-12-08 00:13:17 +00:00
Easwaran Raman 6d90d9f102 Use updated threshold for indirect call bonus
When considering foo->bar inlining, if there is an indirect call in foo which gets resolved to a direct call (say baz), then we try to inline baz into bar with a threshold T and subtract max(T - Cost(bar->baz), 0) from Cost(foo->bar). This patch uses max(Threshold(bar->baz) - Cost(bar->baz)) instead, where Thresheld(bar->baz) could be different from T due to bonuses or subtractions. Threshold(bar->baz) - Cost(bar->baz) better represents the desirability of inlining baz into bar.

Differential Revision: http://reviews.llvm.org/D14309

llvm-svn: 254945
2015-12-07 21:21:20 +00:00
Sanjay Patel e4b9f507cf fix 'the the '; NFC
llvm-svn: 254928
2015-12-07 19:21:39 +00:00
David Majnemer f6665f65b7 [Analysis] Become aware of MSVC's new/delete functions
The compiler can take advantage of the allocation/deallocation
function's properties.  We knew how to do this for Itanium but had no
support for MSVC-style functions.

llvm-svn: 254656
2015-12-03 22:45:19 +00:00
Easwaran Raman 3676da4b4a Test commit.
Remove blank spaces at the end of comments

llvm-svn: 254630
2015-12-03 19:03:20 +00:00
Andy Gibbs 81b1a27e53 Fix class SCEVPredicate has virtual functions and accessible non-virtual destructor.
It is not enough to simply make the destructor virtual since there is a g++ 4.7
issue (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53613) that throws the
error "looser throw specifier for ... overridding ~SCEVPredicate() noexcept".

llvm-svn: 254592
2015-12-03 08:20:20 +00:00
David Majnemer 6f4583c511 Forgot to add this file with r254562.
llvm-svn: 254565
2015-12-02 23:09:05 +00:00
David Majnemer 70497c696a Move EH-specific helper functions to a more appropriate place
No functionality change is intended.

llvm-svn: 254562
2015-12-02 23:06:39 +00:00
Elena Demikhovsky 47fa271a9b Fixed a failure in getSpaltValue()
llvm-svn: 254409
2015-12-01 12:30:40 +00:00
Elena Demikhovsky 0781d7b2b4 Fixed a failure in cost calculation for vector GEP
Cost calculation for vector GEP failed with due to invalid cast to GEP index operand.
The bug is fixed, added a test.

http://reviews.llvm.org/D14976

llvm-svn: 254408
2015-12-01 12:08:36 +00:00
Sanjoy Das 347d272c5c Introduce a range version of std::find, and use in SCEV
Reviewers: dblaikie, pcc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15064

llvm-svn: 254391
2015-12-01 07:49:27 +00:00
Sanjoy Das ff3b8b4c33 Introduce a range version of std::any_of, and use it in SCEV
Reviewers: dblaikie, pcc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15063

llvm-svn: 254390
2015-12-01 07:49:23 +00:00
Cong Hou d97c100dc4 Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.
(This is the second attempt to submit this patch. The first caused two assertion
 failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687)

The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254377
2015-12-01 05:29:22 +00:00
Hans Wennborg 1dbaf67537 Revert r254348: "Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces."
and the follow-up r254356: "Fix a bug in MachineBlockPlacement that may cause assertion failure during BranchProbability construction."

Asserts were firing in Chromium builds. See PR25687.

llvm-svn: 254366
2015-12-01 03:49:42 +00:00
Cong Hou fa1917c673 Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.
The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254348
2015-12-01 00:02:51 +00:00
Sanjoy Das 9b0015f77d [SCEV] Use lambda instead of std::bind; NFC
The lambda is more readable.

llvm-svn: 254276
2015-11-29 23:40:57 +00:00
Sanjoy Das 3b827c7028 [SCEV] Use range version of all_of; NFC
llvm-svn: 254275
2015-11-29 23:40:53 +00:00
Craig Topper b4b66d06df Remove unnecessary intermediate lambda. NFC
llvm-svn: 254243
2015-11-29 04:37:14 +00:00
Charlie Turner 54336a5a4e [LoopVectorize] Use MapVector rather than DenseMap for MinBWs.
The order in which instructions are truncated in truncateToMinimalBitwidths
effects code generation. Switch to a map with a determinisic order, since the
iteration order over a DenseMap is not defined.

This code is not hot, so the difference in container performance isn't
interesting.

Many thanks to David Blaikie for making me aware of MapVector!

Fixes PR25490.

Differential Revision: http://reviews.llvm.org/D14981

llvm-svn: 254179
2015-11-26 20:39:51 +00:00
Davide Italiano 6f93df8105 [Analysis/CallGraph] Switch dump() definitions over to LLVM_DUMP_METHOD.
llvm-svn: 253842
2015-11-23 02:58:42 +00:00
Sanjoy Das 0194743fad [SCEV] Use C++11'isms
llvm-svn: 253837
2015-11-22 21:20:13 +00:00
Sanjoy Das b37c4c414b [SCEVExpander] Use C++isms; NFC
llvm-svn: 253801
2015-11-21 23:20:10 +00:00
Rong Xu a1f61fe841 Add some constantness to GetSuccessorNumber().
llvm-svn: 253733
2015-11-20 23:02:06 +00:00
Peter Collingbourne c85f4ced4d ScalarEvolution: do not set nuw when creating exprs of form <expr> + <all-ones>.
The nuw constraint will not be satisfied unless <expr> == 0.

This bug has been around since r102234 (in 2010!), but was uncovered by
r251052, which introduced more aggressive optimization of nuw scev expressions.

Differential Revision: http://reviews.llvm.org/D14850

llvm-svn: 253627
2015-11-20 01:26:13 +00:00
Pete Cooper 67cf9a723b Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253543
2015-11-19 05:56:52 +00:00
Pete Cooper 72bc23ef02 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

llvm-svn: 253511
2015-11-18 22:17:24 +00:00
Igor Laevsky 7310c68e85 Revert "Revert "Strip metadata when speculatively hoisting instructions (r252604)"
Failing clang test is now fixed by the r253458.

llvm-svn: 253459
2015-11-18 14:50:18 +00:00
Rafael Espindola 55512f9b25 Default SetVector to use a DenseSet.
We use to have an odd difference among MapVector and SetVector. The map
used a DenseMop, but the set used a SmallSet, which in turn uses a
std::set.

I have changed SetVector to use a DenseSet. If you were depending on the
old behaviour you can pass an explicit set type or use SmallSetVector.
The common cases for needing to do it are:

* Optimizing for small sets.
* Sets for types not supported by DenseSet.

llvm-svn: 253439
2015-11-18 06:52:18 +00:00
George Burgess IV 2ae15e0609 Specify explicit storage type for AllocType. NFC.
llvm-svn: 253366
2015-11-17 19:48:06 +00:00
David Majnemer 6727c015dc [AliasAnalysis] CatchPad and CatchRet can modify escaped memory
CatchPad and CatchRet behave a lot like function calls: they can
potentially modify any memory which has been escaped.

llvm-svn: 253323
2015-11-17 08:15:14 +00:00
David Majnemer 0345b0fa9e Fix a typo in BasicAliasAnalysis
llvm-svn: 253322
2015-11-17 08:15:08 +00:00
Benjamin Kramer 83709b1c1e Move helper classes into anonymous namespaces. NFC.
llvm-svn: 253189
2015-11-16 09:01:28 +00:00
Akira Hatanaka 5af7ace4ee Revert r252990.
Some of the buildbots are still failing.

llvm-svn: 252999
2015-11-13 01:44:32 +00:00
Akira Hatanaka c7dfb76fe7 Provide a way to specify inliner's attribute compatibility and merging.
This reapplies r252949. I've changed the type of FuncName to be
std::string instead of StringRef in emitFnAttrCompatCheck.

Original commit message for r252949:

Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 252990
2015-11-13 01:23:11 +00:00
Akira Hatanaka f3aa82f666 Revert r252949.
It broke some of the bots including clang-x64-ninja-win7.

llvm-svn: 252951
2015-11-12 21:19:18 +00:00
Akira Hatanaka 61b81a563a Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 252949
2015-11-12 20:59:43 +00:00
Sanjoy Das 53da2fe729 Revert r243347 "Add TargetTransformInfo::isZExtFree."
r243347 was intended to support a change to LSR (r243348).  That change
to LSR has since had to be reverted (r243939) because it was buggy, and
now the code added in r243347 is untested and unexercised.  Given that,
I think it is appropriate to revert r243347 for now, with the intent of
adding it back in later if I get around to checking in a fixed version
of r243348.

llvm-svn: 252948
2015-11-12 20:51:52 +00:00
Sanjoy Das dc26df4abe [ValueTracking] Remove untested / unreachable code, NFC
Right now isTruePredicate is only ever called with Pred == ICMP_SLE or
ICMP_ULE, and the ICMP_SLT and ICMP_ULT cases are dead.  This change
removes the untested dead code so that the function is not misleading.

llvm-svn: 252676
2015-11-11 00:16:41 +00:00
Sanjoy Das 925681053d [ValueTracking] Teach isImpliedCondition a new bitwise trick
Summary:
This change teaches isImpliedCondition to prove things like

  (A | 15) < L  ==>  (A | 14) < L

if the low 4 bits of A are known to be zero.

Depends on D14391

Reviewers: majnemer, reames, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14392

llvm-svn: 252673
2015-11-10 23:56:20 +00:00
Sanjoy Das af1400f84b [ValueTracking] Use m_APInt instead of m_ConstantInt, NFC
This change would add functionality if isImpliedCondition worked on
vector types; but since it bail out on vector predicates this change is
an NFC.

llvm-svn: 252672
2015-11-10 23:56:15 +00:00
Philip Reames 2d858747df [ValueTracking] Recognize that and(x, add (x, -1)) clears the low bit
This is a cleaned up version of a patch by John Regehr with permission. Originally found via the souper tool.

If we add an odd number to x, then bitwise-and the result with x, we know that the low bit of the result must be zero. Either it was zero in x originally, or the add cleared it in the temporary value. As a result, one of the two values anded together must have the bit cleared.

Differential Revision: http://reviews.llvm.org/D14315

llvm-svn: 252629
2015-11-10 18:46:14 +00:00
Renato Golin 0e77d72b0a Revert "Strip metadata when speculatively hoisting instructions"
This reverts commit r252604, as it broke all ARM and AArch64 buildbots, as
well as some x86, et al.

llvm-svn: 252623
2015-11-10 18:01:16 +00:00
Igor Laevsky 01c3692a10 Strip metadata when speculatively hoisting instructions
This is fix for PR24059.

When we are hoisting instruction above some condition it may turn out
that metadata on this instruction was control dependant on the condition.
This metadata becomes invalid and we need to drop it.

This patch should cover most obvious places of speculative execution (which
I have found by greping isSafeToSpeculativelyExecute). I think there are more
cases but at least this change covers the severe ones.

Differential Revision: http://reviews.llvm.org/D14398

llvm-svn: 252604
2015-11-10 14:10:31 +00:00
Hans Wennborg 21ce8ecb09 Inliner: Do zero-cost inlines even if above a negative threshold (PR24851)
Differential Revision: http://reviews.llvm.org/D14499

llvm-svn: 252595
2015-11-10 09:47:48 +00:00
Davide Italiano bfd3082e85 [TargetLibraryInfo] Add support for fls, flsl, flsll.
This is a prerequisite for further optimisations of these functions,
which will be commited as a separate patch.

Differential Revision:	http://reviews.llvm.org/D14219

llvm-svn: 252535
2015-11-09 23:23:20 +00:00
James Molloy 45f67d52d0 [LoopVectorize] Address post-commit feedback on r250032
Implemented as many of Michael's suggestions as were possible:
  * clang-format the added code while it is still fresh.
  * tried to change Value* to Instruction* in many places in computeMinimumValueSizes - unfortunately there are several places where Constants need to be handled so this wasn't possible.
  * Reduce the pass list on loop-vectorization-factors.ll.
  * Fix a bug where we were querying MinBWs for I->getOperand(0) but using MinBWs[I].

llvm-svn: 252469
2015-11-09 14:32:05 +00:00
Duncan P. N. Exon Smith 83c4b68720 ADT: Remove last implicit ilist iterator conversions, NFC
Some implicit ilist iterator conversions have crept back into Analysis,
Transforms, Hexagon, and llvm-stress.  This removes them.

I'll commit a patch immediately after this to disallow them (in a
separate patch so that it's easy to revert if necessary).

llvm-svn: 252371
2015-11-07 00:01:16 +00:00
Sanjoy Das 55ea67cea7 [ValueTracking] Add parameters to isImpliedCondition; NFC
Summary:
This change makes the `isImpliedCondition` interface similar to the rest
of the functions in ValueTracking (in that it takes a DataLayout,
AssumptionCache etc.).  This is an NFC, intended to make a later diff
less noisy.

Depends on D14369

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14391

llvm-svn: 252333
2015-11-06 19:01:08 +00:00
Sanjoy Das c01b4d2b28 [ValueTracking] De-pessimize isImpliedCondition around unsigned compares
Summary:
Currently `isImpliedCondition` will optimize "I +_nuw C < L ==> I < L"
only if C is positive.  This is an unnecessary restriction -- the
implication holds even if `C` is negative.

Reviewers: reames, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14369

llvm-svn: 252332
2015-11-06 19:01:03 +00:00
Sanjoy Das 9349dcc74a [ValueTracking] Add a framework for encoding implication rules
Summary:
This change adds a framework for adding more smarts to
`isImpliedCondition` around inequalities.  Informally,
`isImpliedCondition` will now try to prove "A < B ==> C < D" by proving
"C <= A && B <= D", since then it follows "C <= A < B <= D".

While this change is in principle NFC, I could not think of a way to not
handle cases like "i +_nsw 1 < L ==> i < L +_nsw 1" (that ValueTracking
did not handle before) while keeping the change understandable.  I've
added tests for these cases.

Reviewers: reames, majnemer, hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14368

llvm-svn: 252331
2015-11-06 19:00:57 +00:00
Sanjoy Das c1a2977fb2 Re-apply r251050 with a for PR25421
The bug: I missed adding break statements in the switch / case.

Original commit message:

[SCEV] Teach SCEV some axioms about non-wrapping arithmetic

Summary:
 - A s<  (A + C)<nsw> if C >  0
 - A s<= (A + C)<nsw> if C >= 0
 - (A + C)<nsw> s<  A if C <  0
 - (A + C)<nsw> s<= A if C <= 0

Right now `C` needs to be a constant, but we can later generalize it to
be a non-constant if needed.

Reviewers: atrick, hfinkel, reames, nlewycky

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D13686

llvm-svn: 252236
2015-11-05 23:45:38 +00:00
Richard Trieu f8978e1a74 Revert r251050 to fix miscompile when running Clang -O1
See bug for details: https://llvm.org/bugs/show_bug.cgi?id=25421
Some comparisons were incorrectly replaced with a constant value.

llvm-svn: 252231
2015-11-05 23:20:36 +00:00
Alexander Kornienko 484e48e3a3 Refactor: Simplify boolean conditional return statements in llvm/lib/Analysis
Patch by Richard Thomson!

Differential revision: http://reviews.llvm.org/D9967

llvm-svn: 252209
2015-11-05 21:07:12 +00:00
Mehdi Amini afd135197b Fix LoopAccessAnalysis when potentially nullptr check are involved
Summary:
GetUnderlyingObjects() can return "null" among its list of objects,
we don't want to deduce that two pointers can point to the same
memory in this case, so filter it out.

Reviewers: anemet

Subscribers: dexonsmith, llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 252149
2015-11-05 05:49:43 +00:00
Sanjoy Das ea34382dfa [CaptureTracking] Support operand bundles conservatively
Summary:
Earlier CaptureTracking would assume all "interesting" operands to a
call or invoke were its arguments.  With operand bundles this is no
longer true.

Note: an earlier change got `doesNotCapture` working correctly with
operand bundles.

This change uses DSE to test the changes to CaptureTracking.  DSE is a
vehicle for testing only, and is not directly involved in this change.

Reviewers: reames, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14306

llvm-svn: 252095
2015-11-04 23:21:06 +00:00
Justin Bogner c2b98f03db PM: Rephrase PrintLoopPass as a wrapper around a new-style pass. NFC
Splits PrintLoopPass into a new-style pass and a PrintLoopPassWrapper,
much like we already do for PrintFunctionPass and PrintModulePass.

llvm-svn: 252085
2015-11-04 22:24:08 +00:00
Philip Reames aeefae0cc5 [LVI] Update a comment to clarify what's actually happening and why
llvm-svn: 252033
2015-11-04 01:47:04 +00:00
Adam Nemet 397f5829c7 [LAA] LLE 5/6: Add predicate functions Dependence::isForward/isBackward, NFC
Summary: Will be used by the LoopLoadElimination pass.

Reviewers: hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13258

llvm-svn: 252016
2015-11-03 23:50:03 +00:00
Adam Nemet a2df750fb3 [LAA] LLE 3/6: Rename InterestingDependence to Dependences, NFC
Summary:
We now collect all types of dependences including lexically forward
deps not just "interesting" ones.

Reviewers: hfinkel

Subscribers: rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D13256

llvm-svn: 251985
2015-11-03 21:39:52 +00:00
Adam Nemet d7037c56d3 [LAA] LLE 2/6: Fix a NoDep case that should be a Forward dependence
Summary:
When the dependence distance in zero then we have a loop-independent
dependence from the earlier to the later access.

No current client of LAA uses forward dependences so other than
potentially hitting the MaxDependences threshold earlier, this change
shouldn't affect anything right now.

This and the previous patch were tested together for compile-time
regression.  None found in LNT/SPEC.

Reviewers: hfinkel

Subscribers: rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D13255

llvm-svn: 251973
2015-11-03 20:13:43 +00:00
Adam Nemet b45516e875 [LAA] LLE 1/6: Expose Forward dependences
Summary:
Before this change, we didn't use to collect forward dependences since
none of the current clients (LV, LDist) required them.

The motivation to also collect forward dependences is a new pass
LoopLoadElimination (LLE) which discovers store-to-load forwarding
opportunities across the loop's backedge.  The pass uses both lexically
forward or backward loop-carried dependences to detect these
opportunities.

The new pass also analyzes loop-independent (forward) dependences since
they can conflict with the loop-carried dependences in terms of how the
data flows through memory.

The newly added test only covers loop-carried forward dependences
because loop-independent ones are currently categorized as NoDep.  The
next patch will fix this.

The two patches were tested together for compile-time regression.  None
found in LNT/SPEC.

Note that with this change LAA provides all dependences rather than just
"interesting" ones.  A subsequent NFC patch will remove the now trivial
isInterestingDependence and rename the APIs.

Reviewers: hfinkel

Subscribers: jmolloy, rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D13254

llvm-svn: 251972
2015-11-03 20:13:23 +00:00
Silviu Baranga 308a7c7ed4 Fix PR25372 - teach replaceCongruentPHIs to handle cases where SE evaluates a PHI to a SCEVConstant
Summary:
Since now Scalar Evolution can create non-add rec expressions for PHI
nodes, it can also create SCEVConstant expressions. This will confuse
replaceCongruentPHIs, which previously relied on the fact that SCEV
could not produce constants in this case.

We will now replace the node with a constant in these cases - or avoid
processing the Phi in case of a type mismatch.

Reviewers: sanjoy

Subscribers: llvm-commits, majnemer

Differential Revision: http://reviews.llvm.org/D14230

llvm-svn: 251938
2015-11-03 16:27:04 +00:00
Tim Northover 89a6eefe6f TvOS: add missing support for some libcalls.
llvm-svn: 251811
2015-11-02 18:00:00 +00:00
Silviu Baranga e3c0534b11 [SCEV][LV] Add SCEV Predicates and use them to re-implement stride versioning
Summary:
SCEV Predicates represent conditions that typically cannot be derived from
static analysis, but can be used to reduce SCEV expressions to forms which are
usable for different optimizers.

ScalarEvolution now has the rewriteUsingPredicate method which can simplify a
SCEV expression using a SCEVPredicateSet. The normal workflow of a pass using
SCEVPredicates would be to hold a SCEVPredicateSet and every time assumptions
need to be made a new SCEV Predicate would be created and added to the set.
Each time after calling getSCEV, the user will call the rewriteUsingPredicate
method.

We add two types of predicates
SCEVPredicateSet - implements a set of predicates
SCEVEqualPredicate - tests for equality between two SCEV expressions

We use the SCEVEqualPredicate to re-implement stride versioning. Every time we
version a stride, we will add a SCEVEqualPredicate to the context.
Instead of adding specific stride checks, LoopVectorize now adds a more
generic SCEV check.

We only need to add support for this in the LoopVectorizer since this is the
only pass that will do stride versioning.

Reviewers: mzolotukhin, anemet, hfinkel, sanjoy

Subscribers: sanjoy, hfinkel, rengolin, jmolloy, llvm-commits

Differential Revision: http://reviews.llvm.org/D13595

llvm-svn: 251800
2015-11-02 14:41:02 +00:00
Sanjoy Das 52bfa0faa4 [SCEV] Fix PR25369
Have `getConstantEvolutionLoopExitValue` work correctly with multiple
entry loops.

As far as I can tell, `getConstantEvolutionLoopExitValue` never did the
right thing for multiple entry loops; and before r249712 it would
silently return an incorrect answer.  r249712 changed SCEV to fail an
assert on a multiple entry loop, and this change fixes the underlying
issue.

llvm-svn: 251770
2015-11-02 02:06:01 +00:00
Davide Italiano 83b3481601 [LibraryInfo] Point to FreeBSD HEAD repo and not to a dolphin branch.
The latter might go away (anytime soon).

llvm-svn: 251765
2015-11-01 17:00:13 +00:00
Sanjoy Das 337d4786e1 [SCEV] Don't create SCEV expressions that break LCSSA
Prevent `createNodeFromSelectLikePHI` from creating SCEV expressions
that break LCSSA.

A better fix for the same issue is to teach SCEVExpander to not break
LCSSA by inserting PHI nodes at appropriate places.  That's planned for
the future.

Fixes PR25360.

llvm-svn: 251756
2015-10-31 23:21:40 +00:00
Sanjoy Das f25d25a156 [SCEV] Use auto and range for; NFC
llvm-svn: 251755
2015-10-31 23:21:32 +00:00
Silviu Baranga f91c80720d [SCEV] Generalize the SCEV algorithm for creating expressions for PHI nodes
Summary:
When forming expressions for phi nodes having an incoming value from
outside the loop A and a value coming from the previous iteration B
we were forming an AddRec if:
  - B was an AddRec
  - the value A was equal to the value for B at iteration -1 (or equal
    to the value of B shifted by one iteration, at iteration 0)

In this case, we were computing the expression to be the expression of
B, shifted by one iteration.

This changes generalizes the logic above by removing the restriction that
B needs to be an AddRec. For this we introduce two expression rewriters
that allow us to
  - shift an expression by one iteration
  - get the value of an expression at iteration 0

This allows us to get SCEV expressions for PHI nodes when these expressions
are not AddRecExprs.

Reviewers: sanjoy

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D14175

llvm-svn: 251700
2015-10-30 15:02:28 +00:00
Philip Reames 70efccd7dd Fix an unused variable warning which broke the clang-cmake-mips builder
llvm-svn: 251614
2015-10-29 04:21:49 +00:00
Philip Reames eb3e9dad7f [LVI/CVP] Teach LVI about range metadata
Somewhat shockingly for an analysis pass which is computing constant ranges, LVI did not understand the ranges provided by range metadata.

As part of this change, I included a change to CVP primarily because doing so made it much easier to write small self contained test cases. CVP was previously only handling the non-local operand case, but given that LVI can sometimes figure out information about instructions standalone, I don't see any reason to restrict this.  There could possibly be a compile time impact from this, but I suspect it should be minimal.  If anyone has an example which substaintially regresses, please let me know.  I could restrict the block local handling to ICmps feeding Terminator instructions if needed.  

Note that this patch continues a somewhat bad practice in LVI. In many cases, we know facts about values, and separate context sensitive facts about values. LVI makes no effort to distinguish and will frequently cache the same value fact repeatedly for different contexts. I would like to change this, but that's a large enough change that I want it to go in separately with clear documentation of what's changing. Other examples of this include the non-null handling, and arguments.

As a meta comment: the entire motivation of this change was being able to write smaller (aka reasonable sized) test cases for a future patch teaching LVI about select instructions.

Differential Revision: http://reviews.llvm.org/D13543

llvm-svn: 251606
2015-10-29 03:57:17 +00:00
Philip Reames dbbd77921d [InstSimplify] sgt on i1s also encodes implication
Follow on to http://reviews.llvm.org/D13074, implementing something pointed out by Sanjoy. His truth table from his comment on that bug summarizes things well:
LHS | RHS | LHS >=s RHS | LHS implies RHS
0 | 0 | 1 (0 >= 0) | 1
0 | 1 | 1 (0 >= -1) | 1
1 | 0 | 0 (-1 >= 0) | 0
1 | 1 | 1 (-1 >= -1) | 1

The key point is that an "i1 1" is the value "-1", not "1".

Differential Revision: http://reviews.llvm.org/D13756

llvm-svn: 251597
2015-10-29 03:19:10 +00:00
Tim Northover 8b40366b54 ARM: teach backend about WatchOS and TvOS libcalls.
The most substantial changes are again for watchOS: libcalls are hard-float if
needed and sincos has a different calling convention.

llvm-svn: 251571
2015-10-28 22:51:16 +00:00
Hal Finkel 1140e1704b Revert "r251451 - [AliasSetTracker] Use mod/ref information for UnknownInstr"
It looks like this broke the stage 2 builder:
  http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto/6989/

Original commit message:

AliasSetTracker does not need to convert the access mode to ModRefAccess if the
new visited UnknownInst has only 'REF' modrefinfo to existing pointers in the
sets.

Patch by Andrew Zhogin!

llvm-svn: 251562
2015-10-28 22:13:41 +00:00
Sanjoy Das c88f5d3c2c [SCEV] Compute max backedge count for loops with "shift ivs"
This teaches SCEV to compute //max// backedge taken counts for loops
like

    for (int i = k; i != 0; i >>>= 1)
      whatever();

SCEV yet cannot represent the exact backedge count for these loops, and
this patch does not change that.  This is really geared towards teaching
SCEV that loops like the above are *not* infinite.

llvm-svn: 251558
2015-10-28 21:27:14 +00:00
Igor Laevsky 559d170021 [AliasAnalysis] Take into account readnone attribute for the function arguments
Differential Revision: http://reviews.llvm.org/D13992

llvm-svn: 251535
2015-10-28 17:54:48 +00:00
JF Bastien ddaa1c7eb1 WebAssembly: disable some loop-idiom recognition
memset/memcpy aren't fully supported yet. We should invert this test
once they are supported.

llvm-svn: 251534
2015-10-28 17:50:23 +00:00
Igor Laevsky 36e84c0fc7 [AliasAnalysis] Take into account readonly attribute for the function arguments
In getArgModRefInfo we consider all arguments as having MRI_ModRef.
However for arguments marked with readonly attribute we can return 
more precise answer - MRI_Ref.

Differential Revision: http://reviews.llvm.org/D13992

llvm-svn: 251525
2015-10-28 16:42:00 +00:00
Benjamin Kramer 039b10423a Put global classes into the appropriate namespace.
Most of the cases belong into an anonymous namespace. No
functionality change intended.

llvm-svn: 251515
2015-10-28 13:54:36 +00:00
James Molloy c67dec690f [GlobalsAA] An indirect global that is initialized is not fair game
When checking if an indirect global (a global with pointer type) is only assigned by allocation functions, first check if the global is itself initialized. If it is, it's not only assigned by allocation functions.

This fixes PR25309. Thanks to David Majnemer for reducing the test case!

llvm-svn: 251508
2015-10-28 10:41:29 +00:00
Sanjoy Das 3ef1e689c9 [ValueTracking] Expose `implies` via ValueTracking, NFC
Summary: This will allow a later patch to `JumpThreading` use this functionality.

Reviewers: reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13971

llvm-svn: 251488
2015-10-28 03:20:19 +00:00
Sanjoy Das 1d1929aace [ValueTracking] Use !range metadata more aggressively in KnownBits
Summary:
Teach `computeKnownBitsFromRangeMetadata` to use `!range` metadata more
aggressively.

Reviewers: majnemer, nlewycky, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14100

llvm-svn: 251487
2015-10-28 03:20:15 +00:00
Hal Finkel b1bb739166 [AliasSetTracker] Use mod/ref information for UnknownInstr
AliasSetTracker does not need to convert the access mode to ModRefAccess if the
new visited UnknownInst has only 'REF' modrefinfo to existing pointers in the
sets.

Patch by Andrew Zhogin!

llvm-svn: 251451
2015-10-27 20:37:04 +00:00
David Majnemer 235acde953 [ScalarEvolutionExpander] PHI on a catchpad can be used on both edges
A PHI on a catchpad might be used by both edges out of the catchpad,
feeding back into a loop.  In this case, just use the insertion point.
Anything more clever would require new basic blocks or PHI placement.

llvm-svn: 251442
2015-10-27 19:48:28 +00:00
David Majnemer dd9a815746 [ScalarEvolutionExpander] Properly insert no-op casts + EH Pads
We want to insert no-op casts as close as possible to the def.  This is
tricky when the cast is of a PHI node and the BasicBlocks between the
def and the use cannot hold any instructions.  Iteratively walk EH pads
until we hit a non-EH pad.

This fixes PR25326.

llvm-svn: 251393
2015-10-27 07:36:42 +00:00
Sanjoy Das 63d2b77961 [ValueTracking] Don't special case wrapped ConstantRanges; NFCI
Use `getUnsignedMax` directly instead of special casing a wrapped
ConstantRange.

The previous code would have been "buggy" (and this would have been a
semantic change) if LLVM allowed !range metadata to denote full
ranges. E.g. in

  %val = load i1, i1* %ptr, !range !{i1 1, i1 1} ;; == full set

ValueTracking would conclude that the high bit (IOW the only bit) in
%val was zero.

Since !range metadata does not allow empty or full ranges, this change
is just a minor stylistic improvement.

llvm-svn: 251380
2015-10-27 01:36:06 +00:00
Sanjoy Das 49edd3b3a8 [SCEV] Refactor out ScalarEvolution::getDataLayout; NFC
llvm-svn: 251375
2015-10-27 00:52:09 +00:00
Keno Fischer 277bfaefaf Initialize BasicAAWrapperPass in it's constructor
Summary: This idiom is used elsewhere in LLVM, but was overlooked here.

Reviewers: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13628

llvm-svn: 251348
2015-10-26 21:22:58 +00:00
Cong Hou fff8ccf579 Check the case that the numerator and denominator are both zeros when getting edge probabilities in BPI and return 100% in this case.
This issue is triggered in PGO mode when bootstrapping LLVM. It seems that it is not guaranteed that edge weights are always greater than zero which are read from profile data.

llvm-svn: 251317
2015-10-26 18:00:17 +00:00
James Molloy 493e57de01 [ValueTracking] Extend r251146 to catch a fairly common case
Even though we may not know the value of the shifter operand, it's possible we know the shifter operand is non-zero. This can allow us to infer more known bits - for example:

  %1 = load %p !range {1, 5}
  %2 = shl %q, %1

We don't know %1, but we do know that it is nonzero so %2[0] is known zero, and importantly %2 is known non-zero.

Calling isKnownNonZero is nontrivially expensive so use an Optional to run it lazily and cache its result.

llvm-svn: 251294
2015-10-26 14:10:46 +00:00
Davide Italiano f04d89bdb4 [ScalarEvolution] Throw away dead code.
llvm-svn: 251256
2015-10-25 20:00:49 +00:00
Davide Italiano 2071f4cc5a [ScalarEvolution] Get rid of NDEBUG in header (correctly this time).
llvm-svn: 251255
2015-10-25 19:55:24 +00:00
Davide Italiano 0c34243ac1 [ScalarEvolution] Get rid of NDEBUG in header.
llvm-svn: 251249
2015-10-25 19:13:36 +00:00
Elena Demikhovsky 092858588a Scalarizer for masked.gather and masked.scatter intrinsics.
When the target does not support these intrinsics they should be converted to a chain of scalar load or store operations.
If the mask is not constant, the scalarizer will build a chain of conditional basic blocks.
I added isLegalMaskedGather() isLegalMaskedScatter() APIs.

Differential Revision: http://reviews.llvm.org/D13722

llvm-svn: 251237
2015-10-25 15:37:55 +00:00
Benjamin Kramer 5611561e99 Use all_of to simplify control flow. NFC.
llvm-svn: 251202
2015-10-24 19:30:37 +00:00
Benjamin Kramer 74b6d3b967 Use find_if to simplify control flow. NFC.
llvm-svn: 251200
2015-10-24 19:03:15 +00:00
Benjamin Kramer 557b601b08 [BasicAliasAnalysis] Simplify expression, no functional change.
(-1) - x + 1 is the same as -x.

llvm-svn: 251185
2015-10-24 11:38:01 +00:00
Sanjoy Das a7e13782f1 Extract out getConstantRangeFromMetadata; NFC
The loop idiom creating a ConstantRange is repeated twice in the
codebase, time to give it a name and a home.

The loop is also repeated in `rangeMetadataExcludesValue`, but using
`getConstantRangeFromMetadata` there would not be an NFC -- the range
returned by `getConstantRangeFromMetadata` may contain a value that none
of the subranges did.

llvm-svn: 251180
2015-10-24 05:37:35 +00:00
Sanjoy Das bb5ffc50b7 Fix whitespace issues in two places; NFC
llvm-svn: 251179
2015-10-24 05:37:28 +00:00
Hal Finkel f2199b2178 Handle non-constant shifts in computeKnownBits, and use computeKnownBits for constant folding in InstCombine/Simplify
First, the motivation: LLVM currently does not realize that:

  ((2072 >> (L == 0)) >> 7) & 1 == 0

where L is some arbitrary value. Whether you right-shift 2072 by 7 or by 8, the
lowest-order bit is always zero. There are obviously several ways to go about
fixing this, but the generic solution pursued in this patch is to teach
computeKnownBits something about shifts by a non-constant amount. Previously,
we would give up completely on these. Instead, in cases where we know something
about the low-order bits of the shift-amount operand, we can combine (and
together) the associated restrictions for all shift amounts consistent with
that knowledge. As a further generalization, I refactored all of the logic for
all three kinds of shifts to have this capability. This works well in the above
case, for example, because the dynamic shift amount can only be 0 or 1, and
thus we can say a lot about the known bits of the result.

This brings us to the second part of this change: Even when we know all of the
bits of a value via computeKnownBits, nothing used to constant-fold the result.
This introduces the necessary code into InstCombine and InstSimplify. I've
added it into both because:

  1. InstCombine won't automatically pick up the associated logic in
     InstSimplify (InstCombine uses InstSimplify, but not via the API that
     passes in the original instruction).

  2. Putting the logic in InstCombine allows the resulting simplifications to become
     part of the iterative worklist

  3. Putting the logic in InstSimplify allows the resulting simplifications to be
     used by everywhere else that calls SimplifyInstruction (inlining, unrolling,
     and many others).

And this requires a small change to our definition of an ephemeral value so
that we don't break the rest case from r246696 (where the icmp feeding the
@llvm.assume, is also feeding a br). Under the old definition, the icmp would
not be considered ephemeral (because it is used by the br), but this causes the
assume to remove itself (in addition to simplifying the branch structure), and
it seems more-useful to prevent that from happening.

llvm-svn: 251146
2015-10-23 20:37:08 +00:00
Sanjoy Das 52f7b08b4a [SCEV] Fix stylistic issue in MatchBinaryAddToConst; NFCI
Instead of checking `(FlagsPresent & ExpectedFlags) != 0`, check
`(FlagsPresent & ExpectedFlags) == ExpectedFlags`.  Right now they're
equivalent since `ExpectedFlags` can only be either `FlagNUW` or
`FlagNSW`, but if we ever pass in `ExpectedFlags` as `FlagNUW | FlagNSW`
then checking `(FlagsPresent & ExpectedFlags) != 0` would be wrong.

llvm-svn: 251142
2015-10-23 20:09:57 +00:00
James Molloy 05a896a8d1 [BasicAA] Bugfix for r251016
If the loaded type sizes don't match the element type of the sequential type, all bets are off and the addresses may, indeed, overlap.

Surprisingly, this just got caught in one test, on one builder, out of the 30+ builders testing this change. Congratulations go to http://lab.llvm.org:8011/builders/clang-aarch64-lnt/builds/5205.

llvm-svn: 251112
2015-10-23 14:17:03 +00:00
Sanjoy Das 42801100e1 [SCEV] Get rid of an unnecessary lambda; NFC
llvm-svn: 251099
2015-10-23 06:57:21 +00:00
Sanjoy Das 0714e3e245 [SCEV] Fix a latent bug in `getPreStartForExtend`
I could not come up a way to test this -- I think this bug is latent
today, and will not actually result in a miscompile.

In `getPreStartForExtend`, SCEV constructs `PreStart` as a sum of all of
`SA`'s operands except `Op`.  It also uses `SA`'s no-wrap flags, and
this is problematic because removing an element from an add expression
can make it signed-wrap.  E.g. if `SA` was `(127 + 1 + -1)`, then it
could safely be `<nsw>` (since `sext(127) + sext(1) + sext(-1)` ==
`sext(127 + 1 + -1)`), but `(127 + 1)` (== `PreStart` if `Op` is `-1`)
is not `<nsw>`.

Transferring `<nuw>` from `SA` to `PreStart` is safe, as far as I can
tell.

llvm-svn: 251097
2015-10-23 06:33:47 +00:00
Justin Bogner f98df7a0d1 LoopPass: Remove redoLoop, it isn't used. NFC
In r251064 I removed a logically unreachable call to `redoLoop`, and
now there aren't any callers of this API at all. Remove the needless
complexity.

llvm-svn: 251067
2015-10-22 21:31:34 +00:00
Justin Bogner 35e46cdd04 LoopPass: Simplify the API for adding a new loop. NFC
The insertLoop() API is only used to add new loops, and has confusing
ownership semantics. Simplify it by replacing it with addLoop().

llvm-svn: 251064
2015-10-22 21:21:32 +00:00
Sanjoy Das eeca9f6fd4 [SCEV] Commute zero extends through <nuw> additions
llvm-svn: 251052
2015-10-22 19:57:38 +00:00
Sanjoy Das 6e78b17b43 [SCEV] Opportunistically interpret unsigned constraints as signed
Summary:
An unsigned comparision is equivalent to is corresponding signed version
if both the operands being compared are positive.  Teach SCEV to use
this fact when profitable.

Reviewers: atrick, hfinkel, reames, nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13687

llvm-svn: 251051
2015-10-22 19:57:34 +00:00
Sanjoy Das 1123148d40 [SCEV] Teach SCEV some axioms about non-wrapping arithmetic
Summary:
 - A s<  (A + C)<nsw> if C >  0
 - A s<= (A + C)<nsw> if C >= 0
 - (A + C)<nsw> s<  A if C <  0
 - (A + C)<nsw> s<= A if C <= 0

Right now `C` needs to be a constant, but we can later generalize it to
be a non-constant if needed.

Reviewers: atrick, hfinkel, reames, nlewycky

Subscribers: sanjoy, llvm-commits

Differential Revision: http://reviews.llvm.org/D13686

llvm-svn: 251050
2015-10-22 19:57:29 +00:00
Sanjoy Das a060e602fd [SCEV] Commute sign extends through nsw additions
Summary: Depends on D13613.

Reviewers: atrick, hfinkel, reames, nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13685

llvm-svn: 251049
2015-10-22 19:57:25 +00:00
Sanjoy Das 8f27415c05 [SCEV] Mark AddExprs as nsw or nuw if legal
Summary:
This uses `ScalarEvolution::getRange` and not potentially control
dependent `nsw` and `nuw` bits on the arithmetic instruction.

Reviewers: atrick, hfinkel, nlewycky

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D13613

llvm-svn: 251048
2015-10-22 19:57:19 +00:00
James Molloy 5b2a732fac [GlobalsAA] Loosen an overly conservative bailout
Instead of bailing out when we see loads, analyze them. If we can prove that the loaded-from address must escape, then we can conclude that a load from that address must escape too and therefore cannot alias a non-addr-taken global.

When checking if a Value can alias a non-addr-taken global, if the Value is a LoadInst of a non-global, recurse instead of bailing.

If we can follow a trail of loads up to some base that is captured, we know by inference that all the loads we followed are also captured.

llvm-svn: 251017
2015-10-22 13:44:26 +00:00
James Molloy 5a4d8cd519 [BasicAA] Non-equal indices in a GEP of a SequentialType don't overlap
If the final indices of two GEPs can be proven to not be equal, and
the GEP is of a SequentialType (not a StructType), then the two GEPs
do not alias.

llvm-svn: 251016
2015-10-22 13:28:18 +00:00
James Molloy 1d88d6f289 [ValueTracking] Add a new predicate: isKnownNonEqual()
isKnownNonEqual(A, B) returns true if it can be determined that A != B.

At the moment it only knows two facts, that a non-wrapping add of nonzero to a value cannot be that value:

A + B != A [where B != 0, addition is nsw or nuw]

and that contradictory known bits imply two values are not equal.

This patch also hooks this up to InstSimplify; InstSimplify had a peephole for the first fact but not the second so this teaches InstSimplify a new trick too (alas no measured performance impact!)

llvm-svn: 251012
2015-10-22 13:18:42 +00:00
Chandler Carruth 2be10754a9 [AA] Enhance the new AliasAnalysis infrastructure with an optional
"external" AA wrapper pass.

This is a generic hook that can be used to thread custom code into the
primary AAResultsWrapperPass for the legacy pass manager in order to
allow it to merge external AA results into the AA results it is
building. It does this by threading in a raw callback and so it is
*very* powerful and should serve almost any use case I have come up with
for extending the set of alias analyses used. The only thing not well
supported here is using a *different order* of alias analyses. That form
of extension *is* supportable with the new pass manager, and I can make
the callback structure here more elaborate to support it in the legacy
pass manager if this is a critical use case that people are already
depending on, but the only use cases I have heard of thus far should be
reasonably satisfied by this simpler extension mechanism.

It is hard to test this using normal facilities (the built-in AAs don't
use this for obvious reasons) so I've written a fairly extensive set of
custom passes in the alias analysis unit test that should be an
excellent test case because it models the out-of-tree users: it adds
a totally custom AA to the system. This should also serve as
a reasonably good example and guide for out-of-tree users to follow in
order to rig up their existing alias analyses.

No support in opt for commandline control is provided here however. I'm
really unhappy with the kind of contortions that would be required to
support that. It would fully re-introduce the analysis group
self-recursion kind of patterns. =/

I've heard from out-of-tree users that this will unblock their use cases
with extending AAs on top of the new infrastructure and let us retain
the new analysis-group-free-world.

Differential Revision: http://reviews.llvm.org/D13418

llvm-svn: 250894
2015-10-21 12:15:19 +00:00
James Molloy 17379c4ea1 [GlobalsAA] Fix a really horrible iterator invalidation bug
We were keeping a reference to an object in a DenseMap then mutating it. At the end of the function we were attempting to clone that reference into other keys in the DenseMap, but DenseMap may well decide to resize its hashtable which would invalidate the reference!

It took an extremely complex testcase to catch this - many thanks to Zhendong Su for catching it in PR25225.

This fixes PR25225.

llvm-svn: 250692
2015-10-19 08:54:59 +00:00
Elena Demikhovsky 20662e39f1 Removed parameter "Consecutive" from isLegalMaskedLoad() / isLegalMaskedStore().
Originally I planned to use the same interface for masked gather/scatter and set isConsecutive to "false" in this case.

Now I'm implementing masked gather/scatter and see that the interface is inconvenient. I want to add interfaces isLegalMaskedGather() / isLegalMaskedScatter() instead of using the "Consecutive" parameter in the existing interfaces.

Differential Revision: http://reviews.llvm.org/D13850

llvm-svn: 250686
2015-10-19 07:43:38 +00:00
Sanjoy Das d295f2c7ca [SCEV] Fix whitespace issues and remove extra braces; NFC
llvm-svn: 250636
2015-10-18 00:29:27 +00:00
Sanjoy Das f07d2a7143 [SCEV] Use std::all_of and std::any_of; NFC
llvm-svn: 250635
2015-10-18 00:29:23 +00:00
Sanjoy Das 6391459069 [SCEV] Use auto where it helps remove line breaks; NFC
llvm-svn: 250634
2015-10-18 00:29:20 +00:00
Sanjoy Das d9f6d33a7f [SCEV] Use range for loops; NFC
llvm-svn: 250633
2015-10-18 00:29:16 +00:00
Manman Ren 72d44b1b09 Recommit r250345, it was reverted in r250366 to investigate a bot failure.
Our internal bot is still red after r250366.

llvm-svn: 250415
2015-10-15 14:59:40 +00:00
Aaron Ballman 58f413c518 Silencing a -Wtype-limits warning; an unsigned value will always be >= 0; NFC.
llvm-svn: 250404
2015-10-15 13:55:43 +00:00
Manman Ren f5499fd9d5 Temporarily revert r250345 to sort out bot failure.
With r250345 and r250343, we start to observe the following failure
when bootstrap clang with lto and pgo:
PHI node entries do not match predecessors!
  %.sroa.029.3.i = phi %"class.llvm::SDNode.13298"* [ null, %30953 ], [ null, %31017 ], [ null, %30998 ], [ null, %_ZN4llvm8dyn_castINS_14ConstantSDNodeENS_7SDValueEEENS_10cast_rettyIT_T0_E8ret_typeERS5_.exit.i.1804 ], [ null, %30975 ], [ null, %30991 ], [ null, %_ZNK4llvm3EVT13getScalarTypeEv.exit.i.1812 ], [ %..sroa.029.0.i, %_ZN4llvm11SmallVectorIiLj8EED1Ev.exit.i.1826 ], !dbg !451895
label %30998
label %_ZNK4llvm3EVTeqES0_.exit19.thread.i
LLVM ERROR: Broken function found, compilation aborted!

I will re-commit this if the bot does not recover.

llvm-svn: 250366
2015-10-15 04:58:24 +00:00
Cong Hou b74d3b3b86 Update the branch weight metadata in JumpThreading pass.
Currently in JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB).

This is the third attempt to submit this patch, while the first two led to failures in some FDO tests. After investigation, it is the edge weight normalization that caused those failures. In this patch the edge weight normalization is fixed so that there is no zero weight in the output and the sum of all weights can fit in 32-bit integer. Several unit tests are added.

Differential revision: http://reviews.llvm.org/D10979

llvm-svn: 250345
2015-10-14 23:14:17 +00:00
Philip Reames ddcf6b35a2 Tighten known bits for ctpop based on zero input bits
This is a cleaned up patch from the one written by John Regehr based on the findings of the Souper superoptimizer.

The basic idea here is that input bits that are known zero reduce the maximum count that the intrinsic could return. We know that the number of bits required to represent a particular count is at most log2(N)+1.

Differential Revision: http://reviews.llvm.org/D13253

llvm-svn: 250338
2015-10-14 22:42:12 +00:00
Manman Ren 2c8e16d507 Revert r250204 and r250240 due to bot failure. We failed to build PGO-ed clang.
llvm-svn: 250264
2015-10-14 03:04:03 +00:00
Kostya Serebryany 5cb86d5a40 [asan] Disabling speculative loads under asan. Patch by Mike Aizatsky
llvm-svn: 250259
2015-10-14 00:21:05 +00:00
Sanjoy Das 16e7ff171b [SCEV] Use `SCEV::isAllOnesValue` directly; NFC.
Instead of `dyn_cast` ing to `SCEVConstant` and checking the contained
`ConstantInteger.

llvm-svn: 250251
2015-10-13 23:28:31 +00:00
Cong Hou 7ab123a5cf Update the branch weight metadata in JumpThreading pass.
Currently in JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB).

Differential revision: http://reviews.llvm.org/D10979

llvm-svn: 250204
2015-10-13 18:43:10 +00:00
James Molloy 860507f838 [GlobalsAA] Don't assume anything about functions that may be overridden
Weak linkage and friends allow a symbol to be overriden outside the
code generator's model, so GlobalsAA shouldn't assume that anything it
can compute about such a symbol is valid.

llvm-svn: 250156
2015-10-13 10:43:33 +00:00
Manman Ren 9f824dab1d Revert 250089 due to bot failure. It failed when building clang itself with PGO.
llvm-svn: 250145
2015-10-13 03:38:02 +00:00
Sanjoy Das 1ed6910338 [SCEV] Put some utilites in the ScalarEvolution class
In a later commit, `SplitBinaryAdd` will be used outside `IsConstDiff`,
so lift that out.  And lift out `IsConstDiff` as
`computeConstantDifference` to keep things clean and to avoid playing
C++ access specifier games.

NFC.

llvm-svn: 250143
2015-10-13 02:53:27 +00:00
Cong Hou 3320bcd815 Update the branch weight metadata in JumpThreading pass.
In JumpThreading pass, the branch weight metadata is not updated after CFG modification. Consider the jump threading on PredBB, BB, and SuccBB. After jump threading, the weight on BB->SuccBB should be adjusted as some of it is contributed by the edge PredBB->BB, which doesn't exist anymore. This patch tries to update the edge weight in metadata on BB->SuccBB by scaling it by 1 - Freq(PredBB->BB) / Freq(BB->SuccBB). 

Differential revision: http://reviews.llvm.org/D10979

llvm-svn: 250089
2015-10-12 19:44:08 +00:00
James Molloy 55d633bd60 [LoopVectorize] Shrink integer operations into the smallest type possible
C semantics force sub-int-sized values (e.g. i8, i16) to be promoted to int
type (e.g. i32) whenever arithmetic is performed on them.

For targets with native i8 or i16 operations, usually InstCombine can shrink
the arithmetic type down again. However InstCombine refuses to create illegal
types, so for targets without i8 or i16 registers, the lengthening and
shrinking remains.

Most SIMD ISAs (e.g. NEON) however support vectors of i8 or i16 even when
their scalar equivalents do not, so during vectorization it is important to
remove these lengthens and truncates when deciding the profitability of
vectorization.

The algorithm this uses starts at truncs and icmps, trawling their use-def
chains until they terminate or instructions outside the loop are found (or
unsafe instructions like inttoptr casts are found). If the use-def chains
starting from different root instructions (truncs/icmps) meet, they are
unioned. The demanded bits of each node in the graph are ORed together to form
an overall mask of the demanded bits in the entire graph. The minimum bitwidth
that graph can be truncated to is the bitwidth minus the number of leading
zeroes in the overall mask.

The intention is that this algorithm should "first do no harm", so it will
never insert extra cast instructions. This is why the use-def graphs are
unioned, so that subgraphs with different minimum bitwidths do not need casts
inserted between them.

This algorithm works hard to reduce compile time impact. DemandedBits are only
queried if there are extends of illegal types and if a truncate to an illegal
type is seen. In the general case, this results in a simple linear scan of the
instructions in the loop.

No non-noise compile time impact was seen on a clang bootstrap build.

llvm-svn: 250032
2015-10-12 12:34:45 +00:00
Tobias Grosser 374bce0c22 SCEV: Allow simple AddRec * Parameter products in delinearization
This patch also allows the -delinearize pass to delinearize expressions that do
not have an outermost SCEVAddRec expression. The SCEV::delinearize
infrastructure allowed this since r240952, but the -delinearize pass was not
updated yet.

llvm-svn: 250018
2015-10-12 08:02:00 +00:00
Duncan P. N. Exon Smith 5a82c916b0 Analysis: Remove implicit ilist iterator conversions
Remove implicit ilist iterator conversions from LLVMAnalysis.

I came across something really scary in `llvm::isKnownNotFullPoison()`
which relied on `Instruction::getNextNode()` being completely broken
(not surprising, but scary nevertheless).  This function is documented
(and coded to) return `nullptr` when it gets to the sentinel, but with
an `ilist_half_node` as a sentinel, the sentinel check looks into some
other memory and we don't recognize we've hit the end.

Rooting out these scary cases is the reason I'm removing the implicit
conversions before doing anything else with `ilist`; I'm not at all
surprised that clients rely on badness.

I found another scary case -- this time, not relying on badness, just
bad (but I guess getting lucky so far) -- in
`ObjectSizeOffsetEvaluator::compute_()`.  Here, we save out the
insertion point, do some things, and then restore it.  Previously, we
let the iterator auto-convert to `Instruction*`, and then set it back
using the `Instruction*` version:

    Instruction *PrevInsertPoint = Builder.GetInsertPoint();

    /* Logic that may change insert point */

    if (PrevInsertPoint)
      Builder.SetInsertPoint(PrevInsertPoint);

The check for `PrevInsertPoint` doesn't protect correctly against bad
accesses.  If the insertion point has been set to the end of a basic
block (i.e., `SetInsertPoint(SomeBB)`), then `GetInsertPoint()` returns
an iterator pointing at the list sentinel.  The version of
`SetInsertPoint()` that's getting called will then call
`PrevInsertPoint->getParent()`, which explodes horribly.  The only
reason this hasn't blown up is that it's fairly unlikely the builder is
adding to the end of the block; usually, we're adding instructions
somewhere before the terminator.

llvm-svn: 249925
2015-10-10 00:53:03 +00:00
Reid Kleckner 14e773500e [WinEH] Delete the old landingpad implementation of Windows EH
The new implementation works at least as well as the old implementation
did.

Also delete the associated preparation tests. They don't exercise
interesting corner cases of the new implementation. All the codegen
tests of the EH tables have already been ported.

llvm-svn: 249918
2015-10-09 23:34:53 +00:00
Artur Pilipenko ffd132878a ValueTracking: use getAlignment in isAligned
Reviewed By: reames

Differential Revision: http://reviews.llvm.org/D13517

llvm-svn: 249841
2015-10-09 15:58:26 +00:00
Sanjoy Das 648956118b [SCEV] Call `StrengthenNoWrapFlags` after `GroupByComplexity`; NFCI
The current implementation of `StrengthenNoWrapFlags` is agnostic to the
order of `Ops`, so this commit should not change anything semantic.  An
upcoming change will make `StrengthenNoWrapFlags` sensitive to the order
of `Ops`.

llvm-svn: 249802
2015-10-09 02:44:45 +00:00
Sanjoy Das 413dbbb1c2 [SCEV] Bring some methods up to coding style; NFC
- Start methods with lower case
 - Reflow a comment
 - Delete header comment repeated in .cpp file

llvm-svn: 249716
2015-10-08 18:46:59 +00:00
Sanjoy Das 3bf22b1883 [SCEV] Remove comment repeated in cpp file; NFC
llvm-svn: 249713
2015-10-08 18:28:42 +00:00
Sanjoy Das dd70996a5c [SCEV] Pick backedge values for phi nodes correctly
Summary:
`getConstantEvolutionLoopExitValue` and `ComputeExitCountExhaustively`
assumed all phi nodes in the loop header have the same order of incoming
values.  This is not correct, and this commit changes
`getConstantEvolutionLoopExitValue` and `ComputeExitCountExhaustively`
to lookup the backedge value of a phi node using the loop's latch block.

Unfortunately, there is still some code duplication
`getConstantEvolutionLoopExitValue` and `ComputeExitCountExhaustively`.
At some point in the future we should extract out a helper class /
method that can evolve constant evolution phi nodes across iterations.

Fixes 25060.  Thanks to Mattias Eriksson for the spot-on analysis!

Depends on D13457.

Reviewers: atrick, hfinkel

Subscribers: materi, llvm-commits

Differential Revision: http://reviews.llvm.org/D13458

llvm-svn: 249712
2015-10-08 18:28:36 +00:00
Sanjay Patel 9115cf8c9d [ValueTracking] teach computeKnownBits that a fabs() clears sign bits
This was requested in D13076: if we're going to canonicalize to fabs(), ValueTracking
should know that fabs() clears sign bits.

In this patch (as in D13076), we're not handling vectors yet even though computeKnownBits'
fabs() case itself should be vector-ready via the splat in this patch. 
Fixing this will require follow-on patches to correct other logic that uses 'getScalarType'.

Differential Revision: http://reviews.llvm.org/D13222

llvm-svn: 249701
2015-10-08 16:56:55 +00:00
James Molloy e9d50dc9f7 Compute demanded bits for icmp instructions
Instead of bailing out when we see an icmp, we can instead at least
say that if the upper bits of both operands are known zero, they are
not demanded. This doesn't help with signed comparisons, but it's at
least better than bailing out.

llvm-svn: 249687
2015-10-08 12:40:06 +00:00
James Molloy bcd7f0ac98 Treat Mul just like Add and Subtract
Like adds and subtracts, muls ripple only to the left so we can use
the same logic.

While we're here, add a print method to DemandedBits so it can be used
with -analyze, which we'll use in the testcase.

llvm-svn: 249686
2015-10-08 12:39:59 +00:00