Commit Graph

589 Commits

Author SHA1 Message Date
David Green 7174023f57 [InstCombine] Allow common type conversions to i8/i16/i32
This, in instcombine, allows conversions to i8/i16/i32 (very
common cases) even if the resulting type is not legal according
to the data layout. This can often open up extra combine
opportunities.

Differential Revision: https://reviews.llvm.org/D42424

llvm-svn: 324174
2018-02-03 16:51:03 +00:00
David Green 184df0c35d Revert commit rL323951
Looks like it's causing timeouts out on at least ppc64le
buildbots.

llvm-svn: 323959
2018-02-01 13:05:25 +00:00
David Green e11f0545db [InstCombine] Allow common type conversions to i8/i16/i32
This, in instcombine, allows conversions to i8/i16/i32 (very
common cases) even if the resulting type is not legal according
to the data layout. This can often open up extra combine
opportunities.

Differential Revision: https://reviews.llvm.org/D42424

llvm-svn: 323951
2018-02-01 11:06:18 +00:00
Fedor Sergeev 83bcc68afa [PM][InstCombine] fixing omission of AliasAnalysis in new-pass-manager's version of InstCombine
Summary:
Passing AliasAnalysis results instead of nullptr appears to work just fine.
A couple new-pass-manager tests updated to align with new order of analyses.

Reviewers: chandlerc, spatel, craig.topper

Reviewed By: chandlerc

Subscribers: mehdi_amini, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D41203

llvm-svn: 320687
2017-12-14 10:36:31 +00:00
Reid Kleckner 72b819b8ee [InstCombine] Salvage debug info during initial DCE
InstCombine salvages debug info for every instruction it erases from its
worklist, but it wasn't doing it during its initial DCE when populating
its worklist. This fixes that.

This should help improve availability of 'this' in optimized debug info
when casts are necessary.

llvm-svn: 318320
2017-11-15 18:51:12 +00:00
Eugene Zelenko 7f0f9bc5ab [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 316503
2017-10-24 21:24:53 +00:00
Adam Nemet 0965da2055 Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*
Sync it up with the name of the class actually defined here.  This has been
bothering me for a while...

llvm-svn: 315249
2017-10-09 23:19:02 +00:00
Chad Rosier d8b4b06f5d [InstCombine] Gating select arithmetic optimization.
These changes faciliate positive behavior for arithmetic based select
expressions that match its translation criteria, keeping code size gated to
neutral or improved scenarios.

Patch by Michael Berg <michael_c_berg@apple.com>!

Differential Revision: https://reviews.llvm.org/D38263

llvm-svn: 314320
2017-09-27 17:16:51 +00:00
Reid Kleckner 0fe506bc5e Re-land r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"
The fix is to avoid invalidating our insertion point in
replaceDbgDeclare:
     Builder.insertDeclare(NewAddress, DIVar, DIExpr, Loc, InsertBefore);
+    if (DII == InsertBefore)
+      InsertBefore = &*std::next(InsertBefore->getIterator());
     DII->eraseFromParent();

I had to write a unit tests for this instead of a lit test because the
use list order matters in order to trigger the bug.

The reduced C test case for this was:
  void useit(int*);
  static inline void inlineme() {
    int x[2];
    useit(x);
  }
  void f() {
    inlineme();
    inlineme();
  }

llvm-svn: 313905
2017-09-21 19:52:03 +00:00
Daniel Jasper 7d2f38d600 Revert r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"
.. as well as the two subsequent changes r313826 and r313875.

This leads to segfaults in combination with ASAN. Will forward repro
instructions to the original author (rnk).

llvm-svn: 313876
2017-09-21 12:07:33 +00:00
Reid Kleckner 3f547e87b2 [IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare
Summary:
This implements the design discussed on llvm-dev for better tracking of
variables that live in memory through optimizations:
  http://lists.llvm.org/pipermail/llvm-dev/2017-September/117222.html

This is tracked as PR34136

llvm.dbg.addr is intended to be produced and used in almost precisely
the same way as llvm.dbg.declare is today, with the exception that it is
control-dependent. That means that dbg.addr should always have a
position in the instruction stream, and it will allow passes that
optimize memory operations on local variables to insert llvm.dbg.value
calls to reflect deleted stores. See SourceLevelDebugging.rst for more
details.

The main drawback to generating DBG_VALUE machine instrs is that they
usually cause LLVM to emit a location list for DW_AT_location. The next
step will be to teach DwarfDebug.cpp how to recognize more DBG_VALUE
ranges as not needing a location list, and possibly start setting
DW_AT_start_offset for variables whose lifetimes begin mid-scope.

Reviewers: aprantl, dblaikie, probinson

Subscribers: eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D37768

llvm-svn: 313825
2017-09-20 21:52:33 +00:00
Quentin Colombet aa103b3d86 [InstCombine] Add select simplifications
In these cases, two selects have constant selectable operands for
both the true and false components and have the same conditional
expression.
We then create two arithmetic operations of the same type and feed a
final select operation using the result of the true arithmetic for the true
operand and the result of the false arithmetic for the false operand and reuse
the original conditionl expression.
The arithmetic operations are naturally folded as a consequence, leaving
only the newly formed select to replace the old arithmetic operation.

Patch by: Michael Berg <michael_c_berg@apple.com>
Differential Revision: https://reviews.llvm.org/D37019

llvm-svn: 313774
2017-09-20 17:32:16 +00:00
Reid Kleckner 8a1cd91016 [InstCombine] Add a flag to disable LowerDbgDeclare
Summary:
This should improve optimized debug info for address-taken variables at
the cost of inaccurate debug info in some situations.

We patched this into clang and deployed this change to Chromium
developers, and this significantly improved debuggability of optimized
code. The long-term solution to PR34136 seems more and more like it's
going to take a while, so I would like to commit this change under a
flag so that it can be used as a stop-gap measure.

This flag should really help so for C++ aggregates like std::string and
std::vector, which are typically address-taken, even after inlining, and
cannot be SROA-ed.

Reviewers: aprantl, dblaikie, probinson, dberlin

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D36596

llvm-svn: 313108
2017-09-13 01:43:25 +00:00
Davide Italiano c78885818a [InstCombine] Fold branches with irrelevant conditions to a constant.
InstCombine folds instructions with irrelevant conditions to undef.
This, as Nuno confirmed is a bug.
(see https://bugs.llvm.org/show_bug.cgi?id=33409#c1 )

Given the original motivation for the change is that of removing an
USE, we now fold to false instead (which reaches the same goal
without undesired side effects).

Fixes PR33409.

Differential Revision:  https://reviews.llvm.org/D36975

llvm-svn: 311540
2017-08-23 09:14:37 +00:00
Reid Kleckner 18728822d2 Remove checks for debug info intrinsics in use lists, NFC
These haven't done anything since debug info intrinsics stopped
appearing in Value use lists in 2014.

llvm-svn: 310892
2017-08-14 22:10:54 +00:00
Craig Topper cd13ebca5f [InstCombine] Add a DEBUG_COUNTER to InstCombine to limit how many instructions are visited for debug
Sometimes it would be nice to stop InstCombine mid way through its combining to see the current IR. By using a debug counter we can place an upper limit on how many instructions to process.

This will also allow skipping the first X combines, but that has the potential to change later combines since earlier canonicalizations might have been skipped.

Differential Revision: https://reviews.llvm.org/D36553

llvm-svn: 310638
2017-08-10 17:48:12 +00:00
Adam Nemet ea06e6e865 Migrate SimplifyLibCalls to new OptimizationRemarkEmitter
Summary:
This changes SimplifyLibCalls to use the new OptimizationRemarkEmitter
API.

In fact, as SimplifyLibCalls is only ever called via InstCombine,
(as far as I can tell) the OptimizationRemarkEmitter is added there,
and then passed through to SimplifyLibCalls later.

I have avoided changing any remark text.

This closes PR33787

Patch by Sam Elliott!

Reviewers: anemet, davide

Reviewed By: anemet

Subscribers: davide, mehdi_amini, eraman, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D35608

llvm-svn: 309158
2017-07-26 19:03:18 +00:00
Craig Topper d918d5b36b [InstCombine] Improve the expansion in SimplifyUsingDistributiveLaws to handle cases where one side doesn't simplify, but the other side resolves to an identity value
Summary:
If one side simplifies to the identity value for inner opcode, we can replace the value with just the operation that can't be simplified.

I've removed a couple now unneeded special cases in visitAnd and visitOr. There are probably other cases I missed.

Reviewers: spatel, majnemer, hfinkel, dberlin

Reviewed By: spatel

Subscribers: grandinj, llvm-commits, spatel

Differential Revision: https://reviews.llvm.org/D35451

llvm-svn: 308111
2017-07-15 21:49:49 +00:00
Craig Topper fde4723ebe [IR] Add Type::isIntOrIntVectorTy(unsigned) similar to the existing isIntegerTy(unsigned), but also works for vectors.
llvm-svn: 307492
2017-07-09 07:04:03 +00:00
Craig Topper bb4069e439 [InstCombine] Make InstCombine's IRBuilder be passed by reference everywhere
Previously the InstCombiner class contained a pointer to an IR builder that had been passed to the constructor. Sometimes this would be passed to helper functions as either a pointer or the pointer would be dereferenced to be passed by reference.

This patch makes it a reference everywhere including the InstCombiner class itself so there is more inconsistency. This a large, but mechanical patch. I've done very minimal formatting changes on it despite what clang-format wanted to do.

llvm-svn: 307451
2017-07-07 23:16:26 +00:00
Craig Topper 2bb9f0f620 [InstCombine] Change a couple helper functions to only take the IRBuilder as an argument and not the whole InstCombiner object. NFC
llvm-svn: 307331
2017-07-06 23:18:41 +00:00
Craig Topper 47c8f66997 [InstCombine] Remove Builder argument from InstCombiner::tryFactorization. NFC
Builder is already a member of the InstCombiner class so we can use it with passing it.

llvm-svn: 307290
2017-07-06 18:35:52 +00:00
Keno Fischer a236dae5d1 [InstCombine] Retain TBAA when narrowing memory accesses
Summary:
As discussed on the mailing list it is legal to propagate TBAA to loads/stores
from/to smaller regions of a larger load tagged with TBAA. Do so for
(load->extractvalue)=>(gep->load) and similar foldings.

Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D31954

llvm-svn: 306615
2017-06-28 23:36:40 +00:00
Bjorn Pettersson 475fcd9cd8 [InstCombine] Make sure AddReachableCodeToWorklist sets MadeIRChange
Summary:
Some optimizations in AddReachableCodeToWorklist did not update
the MadeIRChange state. This could happen both when removing
trivially dead instructions (DCE) and at constant folds.

It is essential that changes to the IR is reported correctly,
since for example InstCombinePass::run() will indicate that all
analyses are preserved otherwise.
And the CGPassManager determines if the CallGraph is up-to-date
based on status from InstructionCombiningPass::runOnFunction().

The new test case early_dce_clobbers_callgraph.ll is a reproducer
for some asserts that started to trigger after changes in the
inliner in r305245. With this patch the test case passes again.

Reviewers: sanjoy, craig.topper, dblaikie

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34346

llvm-svn: 305725
2017-06-19 18:00:27 +00:00
Anna Thomas 6bc14c65ad [InstCombine] Set correct insertion point for selects generated while folding phis
Summary:
When we fold vector constants that are operands of phi's that feed into select,
we need to set the correct insertion point for the *new* selects that get generated.
The correct insertion point is the incoming block for the phi.
Such cases can occur with patch r298845, which fixed folding of
vector constants, but the new selects could be inserted incorrectly (as the added
test case shows).

Reviewers: majnemer, spatel, sanjoy

Reviewed by: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34162

llvm-svn: 305591
2017-06-16 21:08:37 +00:00
Craig Topper a420562257 [InstCombine] Pass a proper context instruction to all of the calls into InstSimplify
Summary: This matches the behavior we already had for compares and makes us consistent everywhere.

Reviewers: dberlin, hfinkel, spatel

Reviewed By: dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33604

llvm-svn: 305049
2017-06-09 03:21:29 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Artur Pilipenko 315eafc339 [InstCombine] Teach isAllocSiteRemovable to look through addrspacecasts
Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D28565

llvm-svn: 303870
2017-05-25 15:14:48 +00:00
Craig Topper 8205a1a9b6 [ValueTracking] Convert most of the calls to computeKnownBits to use the version that returns the KnownBits object.
This continues the changes started when computeSignBit was replaced with this new version of computeKnowBits.

Differential Revision: https://reviews.llvm.org/D33431

llvm-svn: 303773
2017-05-24 16:53:07 +00:00
Sanjay Patel b2e7003103 [InstCombine] add isCanonicalPredicate() helper function and use it; NFCI
There should be a slight efficiency improvement from handling icmp/fcmp with one matcher and reducing duplicated code.

The larger motivation is that there are questions about how predicate canonicalization is handled, and the refactoring
should make it easier if we want to change any of that behavior.

1. As noted in the code comment, we've chosen 3 of the 16 FCMP preds as not canonical. Why those 3? It goes back to 
   rL32751 from what I can tell, but I'm not sure if there's a justification for that rule.
2. We currently do not canonicalize integer select conditions. Should we use the same rule that applies to branches 
   for selects?
3. We currently do canonicalize some FP select conditions, and those rules would conflict with the rule shown here. 
   Should one or both be changed? 

No-functional-change-intended, but adding tests anyway because there's no coverage for most of the predicates.

Differential Revision: https://reviews.llvm.org/D33247

llvm-svn: 303261
2017-05-17 14:21:19 +00:00
Dmitry Mikulin fce148c568 In debug builds non-trivial amount of time is spent in InstCombine processing
@llvm.dbg.* calls in visitCallInst(). They can be safely ignored.

llvm-svn: 303202
2017-05-16 20:08:49 +00:00
Sanjay Patel 941e8dfcbf [InstCombine] use m_OneUse to reduce code; NFCI
llvm-svn: 303090
2017-05-15 18:08:17 +00:00
Craig Topper 935f7b050f [InstCombine] Prevent InstCombine from triggering an extra iteration if something changed in the initial Worklist creation
Summary:
If the Worklist build causes an IR change this change flag currently factors into the flag for running another iteration of the iteration loop. But only changes during processing should trigger another loop.

This patch captures the worklist creation change flag into the outside the loop flag currently used for DbgDeclares and only sends that flag up to the caller. Rerunning the loop only depends on IC.run() now.

This uses the debug output of InstCombine to determine if one or two iterations run. I couldn't think of a better way to detect it since the second spurious iteration shoudn't make any visible changes. Just wasted computation.

I can do a pre-commit of the test case with the CHECK-NOT as a CHECK if this is an ok way to check this.

This is a subset of D31678 as I'm still not sure how to verify the analysis behavior for that.

Reviewers: davide, majnemer, spatel, chandlerc

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32453

llvm-svn: 302982
2017-05-13 06:56:04 +00:00
Craig Topper 8df66c602a [KnownBits] Add bit counting methods to KnownBits struct and use them where possible
This patch adds min/max population count, leading/trailing zero/one bit counting methods.

The min methods return answers based on bits that are known without considering unknown bits. The max methods give answers taking into account the largest count that unknown bits could give.

Differential Revision: https://reviews.llvm.org/D32931

llvm-svn: 302925
2017-05-12 17:20:30 +00:00
Craig Topper 8189a87a1e [KnownBits] Add methods for determining if KnownBits is a constant value
This patch adds isConstant and getConstant for determining if KnownBits represents a constant value and to retrieve the value. Use them to simplify code.

Differential Revision: https://reviews.llvm.org/D32785

llvm-svn: 302091
2017-05-03 23:12:29 +00:00
Sanjoy Das e6bca0eecb Rename WeakVH to WeakTrackingVH; NFC
This relands r301424.

llvm-svn: 301812
2017-05-01 17:07:49 +00:00
Daniel Berlin 2c75c63063 InstCombine: Use the new SimplifyQuery versions of Simplify*. Use AssumptionCache, DominatorTree, TargetLibraryInfo everywhere.
llvm-svn: 301464
2017-04-26 20:56:07 +00:00
Craig Topper b45eabcf82 [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for computeKnownBits
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.

Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.

I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.

Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.

Differential Revision: https://reviews.llvm.org/D32376

llvm-svn: 301432
2017-04-26 16:39:58 +00:00
Sanjoy Das 2cbeb00f38 Reverts commit r301424, r301425 and r301426
Commits were:

"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"

The changes assumed pointers are 8 byte aligned on all architectures.

llvm-svn: 301429
2017-04-26 16:37:05 +00:00
Sanjoy Das 01de557738 Rename WeakVH to WeakTrackingVH; NFC
Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.

Reviewers: dblaikie, davide

Reviewed By: davide

Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D32266

llvm-svn: 301424
2017-04-26 16:20:52 +00:00
Craig Topper 09a5878d33 [InstCombine] Remove redundant code from SimplifyUsingDistributiveLaws
The code I've removed here exists in ExpandBinOp in InstSimplify which we call into before SimplifyUsingDistributiveLaws. The code in InstSimplify looks to have been copied from here.

I verified this code doesn't fire on any lit tests. Not that that proves its definitely dead.

Differential Revision: https://reviews.llvm.org/D32472

llvm-svn: 301341
2017-04-25 17:54:12 +00:00
Craig Topper 9b71a402c2 [APInt] Cast calls to add/sub/mul overflow methods to void if only their overflow bool out param is used.
This is preparation for a clang change to improve the [[nodiscard]] warning to not be ignored on methods that return a class marked [[nodiscard]] that are defined in the class itself. See D32207.

We should consider adding wrapper methods to APInt that return the overflow flag directly and discard the APInt result. This would eliminate the void casts and the need to create a bool before the call to pass to the out param.

llvm-svn: 300758
2017-04-19 21:09:45 +00:00
Craig Topper fb71b7d3e0 [InstCombine] Support folding a subtract with a constant LHS into a phi node
We currently only support folding a subtract into a select but not a PHI. This fixes that.

I had to fix an assumption in FoldOpIntoPhi that assumed the PHI node was always in operand 0. Now we pass it in like we do for FoldOpIntoSelect. But we still require some dancing to find the Constant when we create the BinOp or ConstantExpr. This is based code is similar to what we do for selects.

Since I touched all call sites, this also renames FoldOpIntoPhi to foldOpIntoPhi to match coding standards.

Differential Revision: https://reviews.llvm.org/D31686

llvm-svn: 300363
2017-04-14 19:20:12 +00:00
Craig Topper c22c7b1459 [InstCombine] Refactor SimplifyUsingDistributiveLaws to more explicitly skip code when LHS/RHS aren't BinaryOperators
Currently this code always makes 2 or 3 calls to tryFactorization regardless of whether the LHS/RHS are BinaryOperators. We make 3 calls when both operands are BinaryOperators with the same opcode. Or surprisingly, when neither are BinaryOperators. This is because getBinOpsForFactorization returns Instruction::BinaryOpsEnd when the operand is not a BinaryOperator. If both LHS and RHS are not BinaryOperators then they both have an Opcode of Instruction::BinaryOpsEnd. When this happens we rely on tryFactorization to early out due to A/B/C/D being null. Similar behavior occurs for the other calls, we rely on getBinOpsForFactorization having made A/B or C/D null to get tryFactorization to early out.

We also rely on these null checks to check the result of getIdentityValue and early out for it.

This patches refactors this to pull these checks up to SimplifyUsingDistributiveLaws so we don't rely on BinaryOpsEnd as a sentinel or this A/B/C/D null behavior. I think this makes this code easier to reason about. Should also give a tiny performance improvement for cases where the LHS or RHS isn't a BinaryOperator.

Differential Revision: https://reviews.llvm.org/D31913

llvm-svn: 300353
2017-04-14 17:55:41 +00:00
Chandler Carruth 927d8e610a [IR] Redesign the case iterator in SwitchInst to actually be an iterator
and to expose a handle to represent the actual case rather than having
the iterator return a reference to itself.

All of this allows the iterator to be used with common STL facilities,
standard algorithms, etc.

Doing this exposed some missing facilities in the iterator facade that
I've fixed and required some work to the actual iterator to fully
support the necessary API.

Differential Revision: https://reviews.llvm.org/D31548

llvm-svn: 300032
2017-04-12 07:27:28 +00:00
Craig Topper 271b2245f4 [InstCombine] Use ConstantExpr::getBinOpIdentity to implement getIdentityValue.
This removes a TODO in getIdentityValue and may allow some transforms to occur earlier. But I was unable to find any transforms we didn't already handle.

llvm-svn: 299966
2017-04-11 17:42:40 +00:00
Craig Topper 8c75adf95b [InstCombine] Refinement of r299915. Only consider a ConstantVector for Neg if all the elements are Undef or ConstantInt.
llvm-svn: 299917
2017-04-11 06:32:48 +00:00
Craig Topper 18f9e424e7 [InstCombine] Support weird size element types in dyn_castNegVal.
llvm-svn: 299915
2017-04-11 05:42:47 +00:00
Craig Topper 838d13e7ee [InstCombine] Make sure we preserve fast math flags when folding fp instructions into phi nodes
Summary: I noticed in the select folding code that we copied fast math flags, but did not do the same for the similar handling in phi nodes. This patch fixes that to do the same thing as select

Reviewers: spatel, davide, majnemer, hfinkel

Reviewed By: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31690

llvm-svn: 299838
2017-04-10 07:00:10 +00:00
Craig Topper d0b053d229 [InstCombine] Make foldOpWithConstantIntoOperand take a BinaryOperator instead of a generic Instruction.
It blindly assumes there are two operands so make it explicit.

llvm-svn: 299351
2017-04-03 07:08:08 +00:00
Craig Topper e625d74271 [InstCombine] When adding an Instruction and its Users to the worklist at the same time, make sure we put the Users in first. Then put in the instruction.
This way we ensure we immediately revisit the instruction and do any additional optimizations before visiting the users. Otherwise we might visit the users, then the instruction, then users again, then instruction again.

llvm-svn: 299267
2017-03-31 21:35:30 +00:00
Matthew Simpson c8f0aeccda [InstCombine] Correct the check for vector GEPs
Some of the GEP combines (e.g., descaling) can't handle vector GEPs. We have an
existing check that attempts to bail out if given a vector GEP. However, the
check only tests the GEP's pointer operand. A GEP results in a vector of
pointers if at least one of its operands is vector-typed (e.g., its pointer
operand could be a scalar, but its index could be a vector). We should just
check the type of the GEP itself. This should fix PR32414.

Reference: https://bugs.llvm.org/show_bug.cgi?id=32414
Differential Revision: https://reviews.llvm.org/D31470

llvm-svn: 299017
2017-03-29 18:23:08 +00:00
Anna Thomas 923e574bff [InstCombine] For select rule, use positive check of constant int for select operand. NFCI
llvm-svn: 298906
2017-03-28 09:32:24 +00:00
Anna Thomas f57ae33381 [InstCombine] Avoid incorrect folding of select into phi nodes when incoming element is a vector type
Summary:
We are incorrectly folding selects into phi nodes when the incoming value of a phi
node is a constant vector. This optimization is done in `FoldOpIntoPhi` when the
select condition is a phi node with constant incoming values.
Without the fix, we are miscompiling (i.e. incorrectly folding the
select into the phi node) when the vector contains non-zero
elements.
This patch fixes the miscompile and we will correctly fold based on the
select vector operand (see added test cases).

Reviewers: majnemer, sanjoy, spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31189

llvm-svn: 298845
2017-03-27 13:52:51 +00:00
Craig Topper 36f2e0eee8 [InstCombine] Use range-based for loop. NFC
llvm-svn: 298680
2017-03-24 02:58:02 +00:00
Craig Topper df73e7c5b7 [InstCombine] Fix 80 column violation I accidentally introduced. NFC
llvm-svn: 298679
2017-03-24 02:57:59 +00:00
Craig Topper d92d2fc763 [InstCombine] Print a debug message when we constant fold an operand during worklist creation
InstCombine tries to constant fold instruction operands during worklist building, but we don't print that we're doing this.

We also set a change flag here that causes us to rebuild and rerun the worklist one more time even if processing the worklist itself created no additional changes. So in the log I saw two inst combine runs that visited all instructions without printing that anything was changed. I may be submitting another patch to remove the change flag unless I can find some reason why we should be doing that.

Differential Revision: https://reviews.llvm.org/D31091

llvm-svn: 298264
2017-03-20 16:31:14 +00:00
Sanjay Patel c3b4735b6f [InstCombine] use dyn_cast instead of isa+cast; NFCI
llvm-svn: 297092
2017-03-06 23:25:28 +00:00
Davide Italiano 2133bf5562 [InstCombine] Make max size array combine a tunable.
Requested by Sanjoy/Hal a while ago, and forgotten by me
(r283612).

llvm-svn: 294323
2017-02-07 17:56:50 +00:00
Sanjay Patel cf4c90f3d3 [InstCombine] simplify dyn_cast + isa; NFCI
llvm-svn: 294198
2017-02-06 17:16:16 +00:00
Sanjay Patel 0fe32ac256 [InstCombine] treat i1 as a special type in shouldChangeType()
This patch is based on the llvm-dev discussion here:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/109631.html

Folding to i1 should always be desirable because that's better for value tracking 
and we have special folds for i1 types.

I checked for other users of shouldChangeType() where this might have an effect, 
but we already handle the i1 case differently than other types in all of those cases.

Side note: the default datalayout includes i1, so it seems we only find this gap in 
shouldChangeType + phi folding for the case when there is (1) an explicit datalayout 
without i1, (2) casting to i1 from a legal type, and (3) a phi with exactly 2 incoming
casted operands (as Björn mentioned).

Differential Revision: https://reviews.llvm.org/D29336

llvm-svn: 294066
2017-02-03 23:13:11 +00:00
Sanjay Patel 2217f75ad1 fix formatting; NFC
llvm-svn: 293652
2017-01-31 17:25:42 +00:00
Davide Italiano 2ef8c4e708 [InstCombine] Simplify gep (gep p, a), (b-a)
Patch by Andrea Canciani.

Differential Revision:  https://reviews.llvm.org/D27413

llvm-svn: 292506
2017-01-19 18:51:56 +00:00
Chandler Carruth ca68a3ec47 [PM] Introduce an analysis set used to preserve all analyses over
a function's CFG when that CFG is unchanged.

This allows transformation passes to simply claim they preserve the CFG
and analysis passes to check for the CFG being preserved to remove the
fanout of all analyses being listed in all passes.

I've gone through and removed or cleaned up as many of the comments
reminding us to do this as I could.

Differential Revision: https://reviews.llvm.org/D28627

llvm-svn: 292054
2017-01-15 06:32:49 +00:00
Chandler Carruth 2f19a324cb [PM] The assumption cache is fundamentally designed to be self-updating,
mark it as never invalidated in the new PM.

The old PM already required this to work, and after a discussion with
Hal this seems to really be the only sensible answer. The cache
gracefully degrades as the IR is mutated, and most things which do this
should already be incrementally updating the cache.

This gets rid of a bunch of logic preserving and testing the
invalidation of this analysis.

llvm-svn: 292039
2017-01-15 00:26:18 +00:00
Chandler Carruth 5edfd4d99e [PM] Fix instcombine's analysis preservation in the new pass manager to
cover domtree and alias analysis. These are the pretty clear analyses
that we would always want to survive this pass.

To make these survive, we also need to preserve the assumption cache.

Added a test that verifies the important bits of this preservation.

llvm-svn: 292037
2017-01-14 23:25:22 +00:00
Sanjay Patel db0938fd9a [InstCombine] add a wrapper for a common pair of transforms; NFCI
Some of the callers are artificially limiting this transform to integer types;
this should make it easier to incrementally remove that restriction.

llvm-svn: 291620
2017-01-10 23:49:07 +00:00
George Burgess IV 3f08914e7e [Analysis] Centralize objectsize lowering logic.
We're currently doing nearly the same thing for @llvm.objectsize in
three different places: two of them are missing checks for overflow,
and one of them could subtly break if InstCombine gets much smarter
about removing alloc sites. Seems like a good idea to not do that.

llvm-svn: 290214
2016-12-20 23:46:36 +00:00
Daniel Jasper aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Hal Finkel 3ca4a6bcf1 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
Sanjay Patel e730ce87a5 [InstCombine] fix bug when offsetting case values of a switch (PR31260)
We could truncate the condition and then try to fold the add into the
original condition value causing wrong case constants to be used.

Move the offset transform ahead of the truncate transform and return
after each transform, so there's no chance of getting confused values.

Fix for:
https://llvm.org/bugs/show_bug.cgi?id=31260

llvm-svn: 289442
2016-12-12 16:13:52 +00:00
Sanjay Patel 87e2f677d7 [InstCombine] clean up range-for-loops in visitSwitchInst(); NFCI
llvm-svn: 289439
2016-12-12 15:52:56 +00:00
Peter Collingbourne ab85225be4 IR: Change the gep_type_iterator API to avoid always exposing the "current" type.
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.

Differential Revision: https://reviews.llvm.org/D26594

llvm-svn: 288458
2016-12-02 02:24:42 +00:00
Sanjay Patel 8bd69b7ed9 [InstCombine] don't drop metadata in FoldOpIntoSelect()
llvm-svn: 287980
2016-11-26 15:23:20 +00:00
Sanjay Patel 1e6ca44a8e add and use isBitwiseLogicOp() helper function; NFCI
llvm-svn: 287712
2016-11-22 22:54:36 +00:00
Simon Pilgrim 7d18a70dac Fix spelling mistakes in Transforms comments. NFC.
Identified by Pedro Giffuni in PR27636.

llvm-svn: 287488
2016-11-20 13:19:49 +00:00
Sanjay Patel 80baf69cb5 [InstCombine] replace unreachable with assert and remove unreachable code; NFCI
llvm-svn: 287147
2016-11-16 20:40:02 +00:00
Sanjay Patel 1b9560ffd6 [InstCombine] fix formatting and add FIXMEs to foldOperationIntoSelectOperand(); NFC
llvm-svn: 287145
2016-11-16 20:18:34 +00:00
Sanjay Patel d1bf4340ef [InstCombine] fix formatting of FoldOpIntoSelect(); NFCI
llvm-svn: 286604
2016-11-11 17:42:16 +00:00
Simon Pilgrim fd0d7b21e0 [InstCombine] Fix constexpr issue in select combining
As discussed by Andrea on PR30486, we have an unsafe cast to an Instruction type in the select combine which doesn't take into account that it could be a ConstantExpr instead.

Differential Revision: https://reviews.llvm.org/D25466

llvm-svn: 284000
2016-10-12 10:20:15 +00:00
Sanjay Patel c96f6db246 [InstCombine] allow vector types for constant folding / computeKnownBits (PR24942)
computeKnownBits() already works for integer vectors, so allow vector types when calling that from InstCombine.

I don't think the change to use m_APInt in computeKnownBits is strictly necessary because we do check for 
ConstantVector later, but it's more efficient to handle the splat case without needing to loop on vector elements.

This should work with InstSimplify, but doesn't yet, so I made that a FIXME comment on the test for PR24942:
https://llvm.org/bugs/show_bug.cgi?id=24942

Differential Revision: https://reviews.llvm.org/D24677

llvm-svn: 281777
2016-09-16 21:20:36 +00:00
Jun Bum Lim ec8b8cc595 [InstCombine] Allow sinking from unique predecessor with multiple edges
Summary: We can allow sinking if the single user block has only one unique predecessor, regardless of the number of edges. Note that a switch statement with multiple cases can have the same destination.

Reviewers: mcrosier, majnemer, spatel, reames

Subscribers: reames, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23722

llvm-svn: 279448
2016-08-22 18:21:56 +00:00
Justin Bogner cd1d5aaf2e Replace a few more "fall through" comments with LLVM_FALLTHROUGH
Follow up to r278902. I had missed "fall through", with a space.

llvm-svn: 278970
2016-08-17 20:30:52 +00:00
Sean Silva 36e0d01e13 Consistently use FunctionAnalysisManager
Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.

Thanks to David for the suggestion.

llvm-svn: 278077
2016-08-09 00:28:15 +00:00
Justin Bogner 6b4422e6fe InstCombine: Remove a redundant #ifdef NDEBUG. NFC
The DEBUG() macro already does this.

llvm-svn: 278049
2016-08-08 21:02:11 +00:00
David Majnemer 4e4f4437c2 [InstCombine] Infer inbounds on geps of allocas
llvm-svn: 277950
2016-08-07 07:58:00 +00:00
Nicolai Haehnle 870bf1788c [InstCombine] try to fold (select C, (sext A), B) into logical ops
Summary:
Turn (select C, (sext A), B) into (sext (select C, A, B')) when A is i1 and
B is a compatible constant, also for zext instead of sext. This will then be
further folded into logical operations.

The transformation would be valid for non-i1 types as well, but other parts of
InstCombine prefer to have sext from non-i1 as an operand of select.

Motivated by the shader compiler frontend in Mesa for AMDGPU, which emits i32
for boolean operations. With this change, the boolean logic is fully
recovered.

Reviewers: majnemer, spatel, tstellarAMD

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22747

llvm-svn: 277801
2016-08-05 08:22:29 +00:00
Justin Bogner 9979840f59 InstCombine: Replace some never-null pointers with references. NFC
llvm-svn: 277792
2016-08-05 01:06:44 +00:00
Justin Bogner 19dd0da153 IR: Provide an IRBuilder Inserter that calls a callback after insertion
Add a generalized IRBuilderCallbackInserter, which is just given a
callback to execute after insertion. This can be used to get rid of
the custom inserter in InstCombine, which will in turn allow me to add
target specific InstCombineCalls API for intrinsics without horrible
layering violations.

llvm-svn: 277784
2016-08-04 23:41:01 +00:00
David Majnemer d536f2328e [ConstnatFolding] Teach the folder how to fold ConstantVector
A ConstantVector can have ConstantExpr operands and vice versa.
However, the folder had no ability to fold ConstantVectors which, in
some cases, was an optimization barrier.

Instead, rephrase the folder in terms of Constants instead of
ConstantExprs and teach callers how to deal with failure.

llvm-svn: 277099
2016-07-29 03:27:26 +00:00
David Majnemer 522a91181a Don't remove side effecting instructions due to ConstantFoldInstruction
Just because we can constant fold the result of an instruction does not
imply that we can delete the instruction.  It may have side effects.

This fixes PR28655.

llvm-svn: 276389
2016-07-22 04:54:44 +00:00
Sanjay Patel f9d2b20daf [InstCombine] reassociate logic ops with constants separated by a zext
This is a partial implementation of a general fold for associative+commutative operators:
(op (cast (op X, C2)), C1) --> (cast (op X, op (C1, C2)))
(op (cast (op X, C2)), C1) --> (op (cast X), op (C1, C2))

There are 7 associative operators and 13 cast types, so this could potentially go a lot further.

Differential Revision: https://reviews.llvm.org/D22421

llvm-svn: 275684
2016-07-16 15:20:19 +00:00
Sanjay Patel 7521e1b880 fix formatting, add TODO; NFC
llvm-svn: 274238
2016-06-30 15:32:45 +00:00
Sanjay Patel 7c6eab5777 [InstCombine] shrink switch conditions better (PR24766)
https://llvm.org/bugs/show_bug.cgi?id=24766#c2

This removes a hack that was added for the benefit of x86 codegen. 
It prevented shrinking the switch condition even to smaller legal (DataLayout) types.
We have a safety mechanism in CGP after:
http://reviews.llvm.org/rL251857
...so we're free to use the optimal (smallest) IR type now.

Differential Revision: http://reviews.llvm.org/D12965

llvm-svn: 274233
2016-06-30 14:51:21 +00:00
Michael Kuperstein 835facd863 [PM] Normalize FIXMEs for missing PreserveCFG to have the same wording.
llvm-svn: 273974
2016-06-28 00:54:12 +00:00
Benjamin Kramer 135f735af1 Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273808
2016-06-26 12:28:59 +00:00
Sanjay Patel 2cbe679774 [InstCombine] use m_APInt; NFCI
llvm-svn: 273715
2016-06-24 20:36:34 +00:00
David Majnemer e61e4bfd87 Replace silly uses of 'signed' with 'int'
llvm-svn: 273244
2016-06-21 05:10:24 +00:00
Saleem Abdulrasool d2f705ddf9 X86: permit using SjLj EH on x86 targets as an option
This adds support to the backed to actually support SjLj EH as an exception
model.  This is *NOT* the default model, and requires explicitly opting into it
from the frontend.  GCC supports this model and for MinGW can still be enabled
via the `--using-sjlj-exceptions` options.

Addresses PR27749!

llvm-svn: 271244
2016-05-31 01:48:07 +00:00
Sanjay Patel abbc2ac231 use 'match' for less indenting; NFCI
llvm-svn: 269494
2016-05-13 21:51:17 +00:00
Jun Bum Lim be11bdc4b0 Rename getLargestLegalIntTypeSize to getLargestLegalIntTypeSizeInBits(). NFC.
Summary: Rename DataLayout::getLargestLegalIntTypeSize to DataLayout::getLargestLegalIntTypeSizeInBits() to prevent similar mistakes  fixed in r269433.

Reviewers: joker.eph, mcrosier

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20248

llvm-svn: 269456
2016-05-13 18:38:35 +00:00
Anna Thomas 95f68aa7eb Test commit: modified comment. NFC
llvm-svn: 267406
2016-04-25 13:58:05 +00:00
Andrew Kaylor aa641a5171 Re-commit optimization bisect support (r267022) without new pass manager support.
The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231
2016-04-22 22:06:11 +00:00
Sanjoy Das f97229d6ba Fold compares for distinct allocations
Summary:
We can fold compares to false when two distinct allocations within a
function are compared for equality.

Patch by Anna Thomas!

Reviewers: majnemer, reames, sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19390

llvm-svn: 267214
2016-04-22 20:52:25 +00:00
Vedant Kumar 6013f45f92 Revert "Initial implementation of optimization bisect support."
This reverts commit r267022, due to an ASan failure:

  http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/1549

llvm-svn: 267115
2016-04-22 06:51:37 +00:00
Sanjoy Das a085cfc150 Folding compares with unescaped allocations
Summary:
If we know that the pointer allocated within a function does not escape,
we can fold away comparisons that are done with global pointers

Patch by Anna Thomas!

Reviewers: reames, majnemer, sanjoy

Subscribers: mgrang, mcrosier, majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D19276

llvm-svn: 267035
2016-04-21 19:26:45 +00:00
Andrew Kaylor f0f279291c Initial implementation of optimization bisect support.
This patch implements a optimization bisect feature, which will allow optimizations to be selectively disabled at compile time in order to track down test failures that are caused by incorrect optimizations.

The bisection is enabled using a new command line option (-opt-bisect-limit).  Individual passes that may be skipped call the OptBisect object (via an LLVMContext) to see if they should be skipped based on the bisect limit.  A finer level of control (disabling individual transformations) can be managed through an addition OptBisect method, but this is not yet used.

The skip checking in this implementation is based on (and replaces) the skipOptnoneFunction check.  Where that check was being called, a new call has been inserted in its place which checks the bisect limit and the optnone attribute.  A new function call has been added for module and SCC passes that behaves in a similar way.

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267022
2016-04-21 17:58:54 +00:00
David Majnemer fe3f9d1721 [InstCombine] Don't sink an instr after a catchswitch
A catchswitch is a terminator, instructions cannot be inserted after it.

llvm-svn: 265158
2016-04-01 17:28:17 +00:00
Bjorn Steinbrink 37ca462508 Also handle the new Rust pers fn to isCatchAll()
llvm-svn: 263585
2016-03-15 20:57:07 +00:00
Mehdi Amini ba9fba81d6 Remove PreserveNames template parameter from IRBuilder
This reapplies r263258, which was reverted in r263321 because
of issues on Clang side.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263393
2016-03-13 21:05:13 +00:00
Eric Christopher 35abd051c0 Temporarily revert:
commit ae14bf6488e8441f0f6d74f00455555f6f3943ac
Author: Mehdi Amini <mehdi.amini@apple.com>
Date:   Fri Mar 11 17:15:50 2016 +0000

    Remove PreserveNames template parameter from IRBuilder

    Summary:
    Following r263086, we are now relying on a flag on the Context to
    discard Value names in release builds.

    Reviewers: chandlerc

    Subscribers: mzolotukhin, llvm-commits

    Differential Revision: http://reviews.llvm.org/D18023

    From: Mehdi Amini <mehdi.amini@apple.com>

    git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263258
    91177308-0d34-0410-b5e6-96231b3b80d8

until we can figure out what to do about clang and Release build testing.

This reverts commit 263258.

llvm-svn: 263321
2016-03-12 01:47:22 +00:00
Mehdi Amini 99eab3dd06 Remove PreserveNames template parameter from IRBuilder
Summary:
Following r263086, we are now relying on a flag on the Context to
discard Value names in release builds.

Reviewers: chandlerc

Subscribers: mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D18023

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263258
2016-03-11 17:15:50 +00:00
Chandler Carruth b47f8010a9 [PM] Make the AnalysisManager parameter to run methods a reference.
This was originally a pointer to support pass managers which didn't use
AnalysisManagers. However, that doesn't realistically come up much and
the complexity of supporting it doesn't really make sense.

In fact, *many* parts of the pass manager were just assuming the pointer
was never null already. This at least makes it much more explicit and
clear.

llvm-svn: 263219
2016-03-11 11:05:24 +00:00
Matthias Braun c31032d607 InstCombine: Restrict computeKnownBits() on all Values to OptLevel > 2
As part of r251146 InstCombine was extended to call computeKnownBits on
every value in the function to determine whether it happens to be
constant. This increases typical compiletime by 1-3% (5% in irgen+opt
time) in my measurements. On the other hand this case did not trigger
once in the whole llvm-testsuite.

This patch introduces the notion of ExpensiveCombines which are only
enabled for OptLevel > 2. I removed the check in InstructionSimplify as
that is called from various places where the OptLevel is not known but
given the rarity of the situation I think a check in InstCombine is
enough.

Differential Revision: http://reviews.llvm.org/D16835

llvm-svn: 263047
2016-03-09 18:47:11 +00:00
Petar Jovanovic 921c2b4eb3 Reland r262337 "calculate builtin_object_size if arg is a removable pointer"
Original commit message:
 calculate builtin_object_size if argument is a removable pointer

 This patch fixes calculating correct value for builtin_object_size function
 when pointer is used only in builtin_object_size function call and never
 after that.

 Patch by Strahinja Petrovic.

 Differential Revision: http://reviews.llvm.org/D17337

Reland the original change with a small modification (first do a null check
and then do the cast) to satisfy ubsan.

llvm-svn: 263011
2016-03-09 14:12:47 +00:00
Dehao Chen 1012be120a Perform InstructioinCombiningPass before SampleProfile pass.
Summary: SampleProfile pass needs to be performed after InstructionCombiningPass, which helps eliminate un-inlinable function calls.

Reviewers: davidxl, dnovillo

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D17742

llvm-svn: 262419
2016-03-01 22:53:02 +00:00
Petar Jovanovic 6315f3f9b7 Revert "calculate builtin_object_size if argument is a removable pointer"
Revert r262337 as "check-llvm ubsan" step failed on
sanitizer-x86_64-linux-fast buildbot.

llvm-svn: 262349
2016-03-01 16:50:08 +00:00
Petar Jovanovic 8aef99aa86 calculate builtin_object_size if argument is a removable pointer
This patch fixes calculating correct value for builtin_object_size function
when pointer is used only in builtin_object_size function call and never
after that.

Patch by Strahinja Petrovic.

Differential Revision: http://reviews.llvm.org/D17337

llvm-svn: 262337
2016-03-01 14:39:55 +00:00
Chandler Carruth ac07270828 [AA] Preserve the AA results wrapper pass as well as BasicAA in a few
more places to prevent gratuitous re-"runs" of these passes.

The passes themselves don't do any work when run, but we keep spending
time scheduling and running these needlessly when we really don't need
to do so.

This is the first patch towards fixing the really horrible loop pass
pipeline fragmentation pointed out by Sanjoy in PR24804.

llvm-svn: 261302
2016-02-19 03:12:14 +00:00
Sanjay Patel 4b198802b3 function names start with a lowercase letter; NFC
llvm-svn: 259425
2016-02-01 22:23:39 +00:00
Sanjay Patel 24b77d11bc simplify; NFC
llvm-svn: 259323
2016-01-31 16:33:33 +00:00
Matthias Braun b30f2f5141 Avoid overly large SmallPtrSet/SmallSet
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.

llvm-svn: 259283
2016-01-30 01:24:31 +00:00
David Majnemer 35c46d3e0b [InstCombine, SCCP] Consolidate code used to remove instructions
InstCombine and SCCP both want to remove dead code in a very particular
way but using identical means to do so.  Share the code between the two.

No functionality change is intended.

llvm-svn: 258653
2016-01-24 05:26:18 +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
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
Chen Li c6021038f6 [InstructionCombining] prepareICWorklistFromFunction halts in infinite loop with instructions of token type
Summary: This patch fixes a bug in prepareICWorklistFromFunction, where the loop becomes infinite with instructions of token type. The patch checks if the instruction is token type, and if so it updates EndInst with the current instruction.

Reviewers: reames, majnemer

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D15859

llvm-svn: 256792
2016-01-04 23:28:57 +00:00
Mehdi Amini 1c131b37ed Instcombine: destructor loads of structs that do not contains padding
For non padded structs, we can just proceed and deaggregate them.
We don't want ot do this when there is padding in the struct as to not
lose information about this padding (the subsequents passes would then
try hard to preserve the padding, which is undesirable).

Also update extractvalue.ll and cast.ll so that they use structs with padding.

Remove the FIXME in the extractvalue of laod case as the non padded case is
handled when processing the load, and we don't want to do it on the padded
case.

Patch by: Amaury SECHET <deadalnix@gmail.com>

Differential Revision: http://reviews.llvm.org/D14483

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 255600
2015-12-15 01:44:07 +00:00
Sanjay Patel af674fbfd9 getParent() ^ 3 == getModule() ; NFCI
llvm-svn: 255511
2015-12-14 17:24:23 +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
Sanjay Patel 968e91aea0 [InstCombine] fix propagation of fast-math-flags
Noticed while working on D4583:
http://reviews.llvm.org/D4583

llvm-svn: 253997
2015-11-24 17:51:20 +00:00
Sanjay Patel 04df583a42 use ternary ops; NFC
llvm-svn: 253787
2015-11-21 16:51:19 +00:00
Sanjay Patel 1f3fa2133a remove unnecessary temp variables; NFC
llvm-svn: 253786
2015-11-21 16:37:09 +00:00
Andrew Kaylor de642cef2c [EH] Keep filter clauses for types that have been caught.
The instruction combiner previously removed types from filter clauses in Landing Pad instructions if the type had previously been seen in a catch clause.  This is incorrect and prevents unexpected exception handlers from rethrowing the caught type.

Differential Revision: http://reviews.llvm.org/D14669

llvm-svn: 253370
2015-11-17 20:13:04 +00:00
Elena Demikhovsky 121d49b640 Fixed GEP visitor in the InstCombine pass.
The current implementation of GEP visitor in InstCombine fails with assertion on Vector GEP with mix of scalar and vector types, like this:

getelementptr double, double* %a, <8 x i32> %i
(It fails to create a "sext" from <8 x i32> to <8 x i64>)

I fixed it and added some tests.

Differential Revision: http://reviews.llvm.org/D14485

llvm-svn: 253162
2015-11-15 08:19:35 +00:00
David Majnemer 7204cff0a1 [InstCombine] Don't RAUW tokens with undef
Let SimplifyCFG remove unreachable BBs which define token instructions.

llvm-svn: 252343
2015-11-06 21:26:32 +00:00
Fiona Glaser a8b653a372 InstCombine: fix sinking of convergent calls
llvm-svn: 251991
2015-11-03 22:23:39 +00:00
Silviu Baranga b892e35520 [InstCombine] Teach instcombine not to create extra PHI nodes when folding GEPs
Summary:
InstCombine tries to transform GEP(PHI(GEP1, GEP2, ..)) into GEP(GEP(PHI(...))
when possible. However, this may leave the old PHI node around. Even if we
do end up folding the GEPs, having an extra PHI node might not be beneficial.

This change makes the transformation more conservative. We now only do this if
the PHI has only one use, and can therefore be removed after the transformation.

Reviewers: jmolloy, majnemer

Subscribers: mcrosier, mssimpso, llvm-commits

Differential Revision: http://reviews.llvm.org/D13887

llvm-svn: 251281
2015-10-26 10:25:05 +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
Craig Topper 42526d3372 Use ArrayRef instead of pointer and size. NFC
llvm-svn: 251029
2015-10-22 16:35:56 +00:00
Duncan P. N. Exon Smith 9f8aaf21ba InstCombine: Remove ilist iterator implicit conversions, NFC
Stop relying on implicit conversions of ilist iterators in
LLVMInstCombine.  No functionality change intended.

llvm-svn: 250183
2015-10-13 16:59:33 +00:00
Joseph Tremoulet 2afea5438f [WinEH] Recognize CoreCLR personality function
Summary:
 - Add CoreCLR to if/else ladders and switches as appropriate.
 - Rename isMSVCEHPersonality to isFuncletEHPersonality to better
   reflect what it captures.

Reviewers: majnemer, andrew.w.kaylor, rnk

Subscribers: pgavlin, AndyAyers, llvm-commits

Differential Revision: http://reviews.llvm.org/D13449

llvm-svn: 249455
2015-10-06 20:28:16 +00:00
Sanjay Patel 55dcd40d3e add ShouldChangeType() variant that takes bitwidths
This is more efficient for cases like D12965 where we already have widths.

llvm-svn: 248170
2015-09-21 16:09:37 +00:00
Sanjay Patel 84dca494b1 don't repeat function names in comments; NFC
llvm-svn: 248166
2015-09-21 15:33:26 +00:00
Sanjay Patel 41c739b3fa typo; NFC
llvm-svn: 247454
2015-09-11 19:29:18 +00:00
Chandler Carruth 7b560d40bd [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible
with the new pass manager, and no longer relying on analysis groups.

This builds essentially a ground-up new AA infrastructure stack for
LLVM. The core ideas are the same that are used throughout the new pass
manager: type erased polymorphism and direct composition. The design is
as follows:

- FunctionAAResults is a type-erasing alias analysis results aggregation
  interface to walk a single query across a range of results from
  different alias analyses. Currently this is function-specific as we
  always assume that aliasing queries are *within* a function.

- AAResultBase is a CRTP utility providing stub implementations of
  various parts of the alias analysis result concept, notably in several
  cases in terms of other more general parts of the interface. This can
  be used to implement only a narrow part of the interface rather than
  the entire interface. This isn't really ideal, this logic should be
  hoisted into FunctionAAResults as currently it will cause
  a significant amount of redundant work, but it faithfully models the
  behavior of the prior infrastructure.

- All the alias analysis passes are ported to be wrapper passes for the
  legacy PM and new-style analysis passes for the new PM with a shared
  result object. In some cases (most notably CFL), this is an extremely
  naive approach that we should revisit when we can specialize for the
  new pass manager.

- BasicAA has been restructured to reflect that it is much more
  fundamentally a function analysis because it uses dominator trees and
  loop info that need to be constructed for each function.

All of the references to getting alias analysis results have been
updated to use the new aggregation interface. All the preservation and
other pass management code has been updated accordingly.

The way the FunctionAAResultsWrapperPass works is to detect the
available alias analyses when run, and add them to the results object.
This means that we should be able to continue to respect when various
passes are added to the pipeline, for example adding CFL or adding TBAA
passes should just cause their results to be available and to get folded
into this. The exception to this rule is BasicAA which really needs to
be a function pass due to using dominator trees and loop info. As
a consequence, the FunctionAAResultsWrapperPass directly depends on
BasicAA and always includes it in the aggregation.

This has significant implications for preserving analyses. Generally,
most passes shouldn't bother preserving FunctionAAResultsWrapperPass
because rebuilding the results just updates the set of known AA passes.
The exception to this rule are LoopPass instances which need to preserve
all the function analyses that the loop pass manager will end up
needing. This means preserving both BasicAAWrapperPass and the
aggregating FunctionAAResultsWrapperPass.

Now, when preserving an alias analysis, you do so by directly preserving
that analysis. This is only necessary for non-immutable-pass-provided
alias analyses though, and there are only three of interest: BasicAA,
GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is
preserved when needed because it (like DominatorTree and LoopInfo) is
marked as a CFG-only pass. I've expanded GlobalsAA into the preserved
set everywhere we previously were preserving all of AliasAnalysis, and
I've added SCEVAA in the intersection of that with where we preserve
SCEV itself.

One significant challenge to all of this is that the CGSCC passes were
actually using the alias analysis implementations by taking advantage of
a pretty amazing set of loop holes in the old pass manager's analysis
management code which allowed analysis groups to slide through in many
cases. Moving away from analysis groups makes this problem much more
obvious. To fix it, I've leveraged the flexibility the design of the new
PM components provides to just directly construct the relevant alias
analyses for the relevant functions in the IPO passes that need them.
This is a bit hacky, but should go away with the new pass manager, and
is already in many ways cleaner than the prior state.

Another significant challenge is that various facilities of the old
alias analysis infrastructure just don't fit any more. The most
significant of these is the alias analysis 'counter' pass. That pass
relied on the ability to snoop on AA queries at different points in the
analysis group chain. Instead, I'm planning to build printing
functionality directly into the aggregation layer. I've not included
that in this patch merely to keep it smaller.

Note that all of this needs a nearly complete rewrite of the AA
documentation. I'm planning to do that, but I'd like to make sure the
new design settles, and to flesh out a bit more of what it looks like in
the new pass manager first.

Differential Revision: http://reviews.llvm.org/D12080

llvm-svn: 247167
2015-09-09 17:55:00 +00:00
Sanjay Patel 1cd6d88e4d use minSize wrapper; NFCI
These were missed when other uses were switched over:
http://llvm.org/viewvc/llvm-project?view=revision&revision=243994

llvm-svn: 245311
2015-08-18 16:44:23 +00:00
Benjamin Kramer df005cbe19 Fix some comment typos.
llvm-svn: 244402
2015-08-08 18:27:36 +00:00
David Majnemer 60c994b985 [InstCombine] Don't try to sink EH pad instructions
Found by inspection, this change should not effect the existing
landingpad behavior.

llvm-svn: 244391
2015-08-08 03:51:49 +00:00
Pete Cooper ebcd748927 Convert a bunch of loops to foreach. NFC.
After r244074, we now have a successors() method to iterate over
all the successors of a TerminatorInst.  This commit changes a bunch
of eligible loops to use it.

llvm-svn: 244260
2015-08-06 20:22:46 +00:00
David Majnemer 33b6f82e72 [InstCombine] Generalize sub of selects optimization to all BinaryOperators
This exposes further optimization opportunities if the selects are
correlated.

llvm-svn: 242235
2015-07-14 22:39:23 +00:00
David Majnemer 25a796e148 [InstSimplify] Teach InstSimplify how to simplify extractvalue
llvm-svn: 242007
2015-07-13 01:15:46 +00:00
Bjorn Steinbrink 8350534772 [InstCombine] Employ AliasAnalysis in FindAvailableLoadedValue
llvm-svn: 241887
2015-07-10 06:55:49 +00:00
Sanjay Patel 6a24811d87 fix typo; NFC
llvm-svn: 240480
2015-06-23 23:26:22 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
David Majnemer 7fddeccb8b Move the personality function from LandingPadInst to Function
The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

llvm-svn: 239940
2015-06-17 20:52:32 +00:00
Benjamin Kramer f5e2fc474d Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types
If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


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

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

No functional change intended.

llvm-svn: 238602
2015-05-29 19:43:39 +00:00
David Majnemer 4c3753c4d4 [InstCombine] Don't eagerly propagate nsw for A*B+A*C => A*(B+C)
InstCombine transforms A *nsw B +nsw A *nsw C to A *nsw (B + C).
This is incorrect -- e.g. if A = -1, B = 1, C = INT_SMAX. Then
nothing in the LHS overflows, but the multiplication in RHS overflows.

We need to first make sure that we won't multiple by INT_SMAX + 1.

Test case `add_of_mul` contributed by Sanjoy Das.

This fixes PR23635.

Differential Revision: http://reviews.llvm.org/D9629

llvm-svn: 238066
2015-05-22 23:02:11 +00:00
James Molloy 2b21a7cf36 Reapply r237539 with a fix for the Chromium build.
Make sure if we're truncating a constant that would then be sign extended
that the sign extension of the truncated constant is the same as the
original constant.

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

llvm-svn: 237821
2015-05-20 18:41:25 +00:00
Hans Wennborg 2f21b8760e Revert r237539: "Reapply r237520 with another fix for infinite looping"
This caused PR23583.

llvm-svn: 237739
2015-05-19 23:06:30 +00:00
James Molloy 53958e187a Reapply r237520 with another fix for infinite looping
SimplifyDemandedBits was "simplifying" a constant by removing just sign bits.
This caused a canonicalization race between different parts of instcombine.

Fix and regression test added - third time lucky?

llvm-svn: 237539
2015-05-17 08:27:27 +00:00
James Molloy e8698ae3e1 Revert commits r237521 and r237520.
The AArch64 LNT bot is unhappy - I've found that the problem is in
SimpliftDemandedBits, but that's going to require another code review
so reverting in the meantime.

llvm-svn: 237528
2015-05-16 21:27:14 +00:00
James Molloy b5aa200a33 Reapply r237453 with a fix for the test timeouts.
The test timeouts were due to instcombine fighting itself. Regression test added.
Original log message:

Canonicalize min/max expressions correctly.

This patch introduces a canonical form for min/max idioms where one operand
is extended or truncated. This often happens when the other operand is a
constant. For example:

  %1 = icmp slt i32 %a, i32 0
    %2 = sext i32 %a to i64
      %3 = select i1 %1, i64 %2, i64 0

Would now be canonicalized into:

  %1 = icmp slt i32 %a, i32 0
    %2 = select i1 %1, i32 %a, i32 0
      %3 = sext i32 %2 to i64

This builds upon a patch posted by David Majenemer
(https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
passively stopped instcombine from ruining canonical patterns. This
patch additionally actively makes instcombine canonicalize too.

Canonicalization of expressions involving a change in type from int->fp
or fp->int are not yet implemented.

llvm-svn: 237520
2015-05-16 13:10:45 +00:00
James Molloy 1675b4a57f Revert "Canonicalize min/max expressions correctly."
This reverts r237453 - it was causing timeouts on some bots. Reverting
while I investigate (it's probably InstCombine fighting itself...)

llvm-svn: 237458
2015-05-15 17:45:09 +00:00
James Molloy 6edf0b4cd4 Canonicalize min/max expressions correctly.
This patch introduces a canonical form for min/max idioms where one operand
is extended or truncated. This often happens when the other operand is a
constant. For example:

  %1 = icmp slt i32 %a, i32 0
  %2 = sext i32 %a to i64
  %3 = select i1 %1, i64 %2, i64 0

Would now be canonicalized into:

  %1 = icmp slt i32 %a, i32 0
  %2 = select i1 %1, i32 %a, i32 0
  %3 = sext i32 %2 to i64

This builds upon a patch posted by David Majenemer
(https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
passively stopped instcombine from ruining canonical patterns. This
patch additionally actively makes instcombine canonicalize too.

Canonicalization of expressions involving a change in type from int->fp
or fp->int are not yet implemented.

llvm-svn: 237453
2015-05-15 16:10:59 +00:00
David Blaikie 73cf872adb [opaque pointer type] Track explicit GEP pointee type through in-memory IR
llvm-svn: 236510
2015-05-05 18:03:48 +00:00
Wei Mi a0adf9fd41 Limiting gep merging to fix the performance problem described in
https://llvm.org/bugs/show_bug.cgi?id=23163.

Gep merging sometimes behaves like a reverse CSE/LICM optimization,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.

The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.

Differential Revision: http://reviews.llvm.org/D8911

llvm-svn: 235455
2015-04-21 23:02:15 +00:00
Wei Mi 2940bc82ac Revert r235451 since it is attached to a wrong Differential Revision. Sorry.
llvm-svn: 235453
2015-04-21 22:56:09 +00:00
Wei Mi 6e3344ed98 Limiting gep merging to fix the performance problem described in
https://llvm.org/bugs/show_bug.cgi?id=23163.

Gep merging sometimes behaves like a reverse CSE/LICM optimizations,
which has negative impact on performance. In this patch we restrict
gep merging to happen only when the indexes to be merged are both consts,
which ensures such merge is always beneficial.

The patch makes gep merging only happen in very restrictive cases.
It is possible that some analysis/optimization passes rely on the merged
geps to get better result, and we havn't notice them yet. We will be ready
to further improve it once we see the cases.

Differential Revision: http://reviews.llvm.org/D9007

llvm-svn: 235451
2015-04-21 22:37:09 +00:00
David Blaikie aa41cd57e0 [opaque pointer type] More GEP IRBuilder API migrations...
llvm-svn: 234058
2015-04-03 21:33:42 +00:00
Duncan P. N. Exon Smith ec819c096b Transforms: Use the new DebugLoc API, NFC
Update lib/Analysis and lib/Transforms to use the new `DebugLoc` API.

llvm-svn: 233587
2015-03-30 19:49:49 +00:00
David Blaikie 87ca1b6e0c Constrain the type of a parameter now that callers without this constraint have been removed.
llvm-svn: 233419
2015-03-27 20:56:11 +00:00
David Blaikie 68d535c45f Opaque Pointer Types: GEP API migrations to specify the gep type explicitly
The changes to InstCombine do seem a bit silly - it doesn't make
anything obviously better to have the caller access the pointers element
type (the thing I'm trying to remove) than the GEP itself, but it's a
helpful migration step. This will allow me to more obviously lock down
GEP (& Load, etc) API usage, then fix all the code that accesses pointer
element types except the places that need to be removed (most of the
InstCombines) anyway - at which point I'll need to just remove all that
code because it won't be meaningful anymore (there will be no pointer
types, so no bitcasts to combine)

llvm-svn: 233126
2015-03-24 22:38:16 +00:00
Benjamin Kramer 799003bf8c Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.
llvm-svn: 232998
2015-03-23 19:32:43 +00:00
Daniel Jasper 5add63f21e [InstCombine] Don't fold a GEP into itself through a PHI node
This can only occur (I think) through the back-edge of the loop.

However, folding a GEP into itself means that the value of the previous
iteration needs to be stored in the meantime, thus requiring an
additional register variable to be live, but not actually achieving
anything (the gep still needs to be executed once per loop iteration).

The attached test case is derived from:
  typedef unsigned uint32;
  typedef unsigned char uint8;
  inline uint8 *f(uint32 value, uint8 *target) {
    while (value >= 0x80) {
      value >>= 7;
      ++target;
    }
    ++target;
    return target;
  }
  uint8 *g(uint32 b, uint8 *target) {
    target = f(b, f(42, target));
    return target;
  }

What happens is that the GEP stored in incptr2 is folded into itself
through the loop's back-edge and the phi-node stored in loopptr,
effectively incrementing the ptr by "2" in each iteration instead of "1".

In this case, it is actually increasing the number of GEPs required as
the GEP before the loop can't be folded away anymore. For comparison:

With this patch:
  define i8* @test4(i32 %value, i8* %buffer) {
  entry:
    %cmp = icmp ugt i32 %value, 127
    br i1 %cmp, label %loop.header, label %exit

  loop.header:                                      ; preds = %entry
    br label %loop.body

  loop.body:                                        ; preds = %loop.body, %loop.header
    %buffer.pn = phi i8* [ %buffer, %loop.header ], [ %loopptr, %loop.body ]
    %newval = phi i32 [ %value, %loop.header ], [ %shr, %loop.body ]
    %loopptr = getelementptr inbounds i8, i8* %buffer.pn, i64 1
    %shr = lshr i32 %newval, 7
    %cmp2 = icmp ugt i32 %newval, 16383
    br i1 %cmp2, label %loop.body, label %loop.exit

  loop.exit:                                        ; preds = %loop.body
    br label %exit

  exit:                                             ; preds = %loop.exit, %entry
    %0 = phi i8* [ %loopptr, %loop.exit ], [ %buffer, %entry ]
    %incptr3 = getelementptr inbounds i8, i8* %0, i64 2
    ret i8* %incptr3
  }

Without this patch:
  define i8* @test4(i32 %value, i8* %buffer) {
  entry:
    %incptr = getelementptr inbounds i8, i8* %buffer, i64 1
    %cmp = icmp ugt i32 %value, 127
    br i1 %cmp, label %loop.header, label %exit

  loop.header:                                      ; preds = %entry
    br label %loop.body

  loop.body:                                        ; preds = %loop.body, %loop.header
    %0 = phi i8* [ %buffer, %loop.header ], [ %loopptr, %loop.body ]
    %loopptr = phi i8* [ %incptr, %loop.header ], [ %incptr2, %loop.body ]
    %newval = phi i32 [ %value, %loop.header ], [ %shr, %loop.body ]
    %shr = lshr i32 %newval, 7
    %incptr2 = getelementptr inbounds i8, i8* %0, i64 2
    %cmp2 = icmp ugt i32 %newval, 16383
    br i1 %cmp2, label %loop.body, label %loop.exit

  loop.exit:                                        ; preds = %loop.body
    br label %exit

  exit:                                             ; preds = %loop.exit, %entry
    %ptr2 = phi i8* [ %incptr2, %loop.exit ], [ %incptr, %entry ]
    %incptr3 = getelementptr inbounds i8, i8* %ptr2, i64 1
    ret i8* %incptr3
  }

Review: http://reviews.llvm.org/D8245
llvm-svn: 232718
2015-03-19 11:05:08 +00:00
David Blaikie 096b1da29d [opaque pointer type] more gep API migration
llvm-svn: 232274
2015-03-14 19:53:33 +00:00
Philip Reames 71c4035c18 If a conditional branch jumps to the same target, remove the condition
Given that large parts of inst combine is restricted to instructions which have one use, getting rid of a use on the condition can help the effectiveness of the optimizer. Also, it allows the condition to potentially be deleted by instcombine rather than waiting for another pass.

I noticed this completely by accident in another test case. It's not anything that actually came from a real workload.

p.s. We should probably do the same thing for switch instructions.

Differential Revision: http://reviews.llvm.org/D8220

llvm-svn: 231881
2015-03-10 22:52:37 +00:00
Owen Anderson 58364dc4da Fix a crash in InstCombine where we could try to truncate a switch comparison to zero width.
llvm-svn: 231761
2015-03-10 06:51:39 +00:00
Mehdi Amini a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Mehdi Amini 46a43556db Make DataLayout Non-Optional in the Module
Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231270
2015-03-04 18:43:29 +00:00
Akira Hatanaka 1defd5afbd [InstCombine] Do not insert a GEP instruction before a landingpad instruction.
InstCombiner::visitGetElementPtrInst was using getFirstNonPHI to compute the
insertion point, which caused the verifier to complain when a GEP was inserted
before a landingpad instruction. This commit fixes it to use getFirstInsertionPt
instead.

rdar://problem/19394964

llvm-svn: 229619
2015-02-18 03:30:11 +00:00
Duncan P. N. Exon Smith 2c79ad974c Transforms: Canonicalize access to function attributes, NFC
Canonicalize access to function attributes to use the simpler API.

getAttributes().getAttribute(AttributeSet::FunctionIndex, Kind)
  => getFnAttribute(Kind)

getAttributes().hasAttribute(AttributeSet::FunctionIndex, Kind)
  => hasFnAttribute(Kind)

llvm-svn: 229202
2015-02-14 01:11:29 +00:00
Reid Kleckner 96d011315a Don't promote asynch EH invokes of nounwind functions to calls
If the landingpad of the invoke is using a personality function that
catches asynch exceptions, then it can catch a trap.

Also add some landingpads to invalid LLVM IR test cases that lack them.

Over-the-shoulder reviewed by David Majnemer.

llvm-svn: 228782
2015-02-11 01:23:16 +00:00
Reid Kleckner 4af6415237 Move EH personality type classification to Analysis/LibCallSemantics.h
Summary:
Also add enum types for __C_specific_handler and _CxxFrameHandler3 for
which we know a few things.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7214

llvm-svn: 227284
2015-01-28 01:17:38 +00:00
Chandler Carruth 83ba269e4b [PM] Port instcombine to the new pass manager!
This is exciting as this is a much more involved port. This is
a complex, existing transformation pass. All of the core logic is shared
between both old and new pass managers. Only the access to the analyses
is separate because the actual techniques are separate. This also uses
a bunch of different and interesting analyses and is the first time
where we need to use an analysis across an IR layer.

This also paves the way to expose instcombine utility functions. I've
got a static function that implements the core pass logic over
a function which might be mildly interesting, but more interesting is
likely exposing a routine which just uses instructions *already in* the
worklist and combines until empty.

I've switched one of my favorite instcombine tests to run with both as
well to make sure this keeps working.

llvm-svn: 226987
2015-01-24 04:19:17 +00:00
Chandler Carruth a917458203 [PM] Rename InstCombine.h to InstCombineInternal.h in preparation for
creating a non-internal header file for the InstCombine pass.

I thought about calling this InstCombiner.h or in some way more clearly
associating it with the InstCombiner clas that it is primarily defining,
but there are several other utility interfaces defined within this for
InstCombine. If, in the course of refactoring, those end up moving
elsewhere or going away, it might make more sense to make this the
combiner's header alone.

Naturally, this is a bikeshed to a certain degree, so feel free to lobby
for a different shade of paint if this name just doesn't suit you.

llvm-svn: 226783
2015-01-22 05:25:13 +00:00
Chandler Carruth df5747a900 [PM] Refactor the InstCombiner interface to use an external worklist.
Because in its primary function pass the combiner is run repeatedly over
the same function until doing so produces no changes, it is essentially
to not re-allocate the worklist. However, as a utility, the more common
pattern would be to put a limited set of instructions in the worklist
rather than the entire function body. That is also the more likely
pattern when used by the new pass manager.

The result is a very light weight combiner that does the visiting with
a separable worklist. This can then be wrapped up in a helper function
for users that want a combiner utility, or as I have here it can be
wrapped up in a pass which manages the iterations used when combining an
entire function's instructions.

Hopefully this removes some of the worst of the interface warts that
became apparant with the last patch here. However, there is clearly more
work. I've again left some FIXMEs for the most egregious. The ones that
stick out to me are the exposure of the worklist and IR builder as
public members, and the use of pointers rather than references. However,
fixing these is likely to be much more mechanical and less interesting
so I didn't want to touch them in this patch.

llvm-svn: 226655
2015-01-21 11:38:17 +00:00
Chandler Carruth ba4c5179a0 [PM] Simplify (ha! ha!) the way that instcombine calls the
SimplifyLibCalls utility by sinking it into the specific call part of
the combiner.

This will avoid us needing to do any contortions to build this object in
a subsequent refactoring I'm doing and seems generally better factored.
We don't need this utility everywhere and it carries no interesting
state so we might as well build it on demand.

llvm-svn: 226654
2015-01-21 11:23:40 +00:00
Chandler Carruth 9280382ac6 [PM] Replace an abuse of inheritance to override a single function with
a more direct approach: a type-erased glorified function pointer. Now we
can pass a function pointer into this for the easy case and we can even
pass a lambda into it in the interesting case in the instruction
combiner.

I'll be using this shortly to simplify the interfaces to InstCombiner,
but this helps pave the way and seems like a better design for the
libcall simplifier utility.

llvm-svn: 226640
2015-01-21 02:11:59 +00:00
Chandler Carruth 1edb9d63e9 [PM] Separate the InstCombiner from its pass.
This creates a small internal pass which runs the InstCombiner over
a function. This is the hard part of porting InstCombine to the new pass
manager, as at this point none of the code in InstCombine has access to
a Pass object any longer.

The resulting interface for the InstCombiner is pretty terrible. I'm not
planning on leaving it that way. The key thing missing is that we need
to separate the worklist from the combiner a touch more. Once that's
done, it should be possible for *any* part of LLVM to just create
a worklist with instructions, populate it, and then combine it until
empty. The pass will just be the (obvious and important) special case of
doing that for an entire function body.

For now, this is the first increment of factoring to make all of this
work.

llvm-svn: 226618
2015-01-20 22:44:35 +00:00
Chandler Carruth 5175b9a7b9 [PM] Move the LoopInfo analysis pointer into the InstCombiner class
along with the other analyses.

The most obvious reason why is because eventually I need to separate out
the pass layer from the rest of the instcombiner. However, it is also
probably a compile time win as every query through the pass manager
layer is pretty slow these days.

llvm-svn: 226550
2015-01-20 08:35:24 +00:00
Chandler Carruth 4f8f307c77 [PM] Split the LoopInfo object apart from the legacy pass, creating
a LoopInfoWrapperPass to wire the object up to the legacy pass manager.

This switches all the clients of LoopInfo over and paves the way to port
LoopInfo to the new pass manager. No functionality change is intended
with this iteration.

llvm-svn: 226373
2015-01-17 14:16:18 +00:00
Chandler Carruth b98f63dbdb [PM] Separate the TargetLibraryInfo object from the immutable pass.
The pass is really just a means of accessing a cached instance of the
TargetLibraryInfo object, and this way we can re-use that object for the
new pass manager as its result.

Lots of delta, but nothing interesting happening here. This is the
common pattern that is developing to allow analyses to live in both the
old and new pass manager -- a wrapper pass in the old pass manager
emulates the separation intrinsic to the new pass manager between the
result and pass for analyses.

llvm-svn: 226157
2015-01-15 10:41:28 +00:00
Chandler Carruth 62d4215baa [PM] Move TargetLibraryInfo into the Analysis library.
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

llvm-svn: 226078
2015-01-15 02:16:27 +00:00
Chandler Carruth 66b3130cda [PM] Split the AssumptionTracker immutable pass into two separate APIs:
a cache of assumptions for a single function, and an immutable pass that
manages those caches.

The motivation for this change is two fold. Immutable analyses are
really hacks around the current pass manager design and don't exist in
the new design. This is usually OK, but it requires that the core logic
of an immutable pass be reasonably partitioned off from the pass logic.
This change does precisely that. As a consequence it also paves the way
for the *many* utility functions that deal in the assumptions to live in
both pass manager worlds by creating an separate non-pass object with
its own independent API that they all rely on. Now, the only bits of the
system that deal with the actual pass mechanics are those that actually
need to deal with the pass mechanics.

Once this separation is made, several simplifications become pretty
obvious in the assumption cache itself. Rather than using a set and
callback value handles, it can just be a vector of weak value handles.
The callers can easily skip the handles that are null, and eventually we
can wrap all of this up behind a filter iterator.

For now, this adds boiler plate to the various passes, but this kind of
boiler plate will end up making it possible to port these passes to the
new pass manager, and so it will end up factored away pretty reasonably.

llvm-svn: 225131
2015-01-04 12:03:27 +00:00
Bruno Cardoso Lopes f6cf8ad4e5 Reapply: [InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr
The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. Also, fix code to also return the modified switch when only
the truncation is performed.

This fixes an assertion crash.

Differential Revision: http://reviews.llvm.org/D6644

rdar://problem/19191835

llvm-svn: 224588
2014-12-19 17:12:35 +00:00
Bruno Cardoso Lopes 3be15b2fa6 Revert "[InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr"
Reverts commit r224574 to appease buildbots:

The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. This fixes an assertion crash.

llvm-svn: 224576
2014-12-19 14:36:24 +00:00
Bruno Cardoso Lopes c9005f2f2b [InstCombine] Fix visitSwitchInst to use right operand types for sub cstexpr
The visitSwitchInst generates SUB constant expressions to recompute the
switch condition. When truncating the condition to a smaller type, SUB
expressions should use the previous type (before trunc) for both
operands. This fixes an assertion crash.

Differential Revision: http://reviews.llvm.org/D6644

rdar://problem/19191835

llvm-svn: 224574
2014-12-19 14:23:15 +00:00
David Majnemer b2a6e7458d InstCombine: Don't assume DataLayout is always available
We tried to get the result of DataLayout::getLargestLegalIntTypeSize but
we didn't have a DataLayout.  This resulted in opt crashing.

This fixes PR21651.

llvm-svn: 222645
2014-11-24 07:26:20 +00:00
Gerolf Hoflehner ec6217c929 [InstCombine] Re-commit of r218721 (Optimize icmp-select-icmp sequence)
Fixes the self-host fail. Note that this commit activates dominator
analysis in the combiner by default (like the original commit did).

llvm-svn: 222590
2014-11-21 23:36:44 +00:00