Commit Graph

311 Commits

Author SHA1 Message Date
Sanjoy Das b771eb6d69 [SCEVExpander] Have hoistIVInc preserve LCSSA
Summary:
(Note: the problematic invocation of hoistIVInc that caused PR24804 came
from IndVarSimplify, not from SCEVExpander itself)

Fixes PR24804.  Test case by David Majnemer.

Reviewers: hfinkel, majnemer, atrick, mzolotukhin

Subscribers: llvm-commits

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

llvm-svn: 254976
2015-12-08 00:13:17 +00:00
Sanjoy Das b37c4c414b [SCEVExpander] Use C++isms; NFC
llvm-svn: 253801
2015-11-21 23:20:10 +00:00
Duncan P. N. Exon Smith 83c4b68720 ADT: Remove last implicit ilist iterator conversions, NFC
Some implicit ilist iterator conversions have crept back into Analysis,
Transforms, Hexagon, and llvm-stress.  This removes them.

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

llvm-svn: 252371
2015-11-07 00:01:16 +00:00
Silviu Baranga 308a7c7ed4 Fix PR25372 - teach replaceCongruentPHIs to handle cases where SE evaluates a PHI to a SCEVConstant
Summary:
Since now Scalar Evolution can create non-add rec expressions for PHI
nodes, it can also create SCEVConstant expressions. This will confuse
replaceCongruentPHIs, which previously relied on the fact that SCEV
could not produce constants in this case.

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

Reviewers: sanjoy

Subscribers: llvm-commits, majnemer

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

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

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

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

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

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

Reviewers: mzolotukhin, anemet, hfinkel, sanjoy

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

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

llvm-svn: 251800
2015-11-02 14:41:02 +00:00
David Majnemer 235acde953 [ScalarEvolutionExpander] PHI on a catchpad can be used on both edges
A PHI on a catchpad might be used by both edges out of the catchpad,
feeding back into a loop.  In this case, just use the insertion point.
Anything more clever would require new basic blocks or PHI placement.

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

This fixes PR25326.

llvm-svn: 251393
2015-10-27 07:36:42 +00:00
Duncan P. N. Exon Smith 5a82c916b0 Analysis: Remove implicit ilist iterator conversions
Remove implicit ilist iterator conversions from LLVMAnalysis.

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

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

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

    Instruction *PrevInsertPoint = Builder.GetInsertPoint();

    /* Logic that may change insert point */

    if (PrevInsertPoint)
      Builder.SetInsertPoint(PrevInsertPoint);

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

llvm-svn: 249925
2015-10-10 00:53:03 +00:00
Igor Laevsky 06044f97d2 [ScalarEvolutionExpander] Reuse findExistingExpansion during expansion cost calculation for division
Primary purpose of this change is to reuse existing code inside findExistingExpansion. However it introduces very slight semantic change - findExistingExpansion now looks into exiting blocks instead of a loop latches. Originally heuristic was based on the fact that we want to look at the loop exit conditions. And since all exiting latches will be listed in the ExitingBlocks, heuristic stays roughly the same.

Differential Revision: http://reviews.llvm.org/D12008

llvm-svn: 245227
2015-08-17 16:37:04 +00:00
Chandler Carruth 2f1fd1658f [PM] Port ScalarEvolution to the new pass manager.
This change makes ScalarEvolution a stand-alone object and just produces
one from a pass as needed. Making this work well requires making the
object movable, using references instead of overwritten pointers in
a number of places, and other refactorings.

I've also wired it up to the new pass manager and added a RUN line to
a test to exercise it under the new pass manager. This includes basic
printing support much like with other analyses.

But there is a big and somewhat scary change here. Prior to this patch
ScalarEvolution was never *actually* invalidated!!! Re-running the pass
just re-wired up the various other analyses and didn't remove any of the
existing entries in the SCEV caches or clear out anything at all. This
might seem OK as everything in SCEV that can uses ValueHandles to track
updates to the values that serve as SCEV keys. However, this still means
that as we ran SCEV over each function in the module, we kept
accumulating more and more SCEVs into the cache. At the end, we would
have a SCEV cache with every value that we ever needed a SCEV for in the
entire module!!! Yowzers. The releaseMemory routine would dump all of
this, but that isn't realy called during normal runs of the pipeline as
far as I can see.

To make matters worse, there *is* actually a key that we don't update
with value handles -- there is a map keyed off of Loop*s. Because
LoopInfo *does* release its memory from run to run, it is entirely
possible to run SCEV over one function, then over another function, and
then lookup a Loop* from the second function but find an entry inserted
for the first function! Ouch.

To make matters still worse, there are plenty of updates that *don't*
trip a value handle. It seems incredibly unlikely that today GVN or
another pass that invalidates SCEV can update values in *just* such
a way that a subsequent run of SCEV will incorrectly find lookups in
a cache, but it is theoretically possible and would be a nightmare to
debug.

With this refactoring, I've fixed all this by actually destroying and
recreating the ScalarEvolution object from run to run. Technically, this
could increase the amount of malloc traffic we see, but then again it is
also technically correct. ;] I don't actually think we're suffering from
tons of malloc traffic from SCEV because if we were, the fact that we
never clear the memory would seem more likely to have come up as an
actual problem before now. So, I've made the simple fix here. If in fact
there are serious issues with too much allocation and deallocation,
I can work on a clever fix that preserves the allocations (while
clearing the data) between each run, but I'd prefer to do that kind of
optimization with a test case / benchmark that shows why we need such
cleverness (and that can test that we actually make it faster). It's
possible that this will make some things faster by making the SCEV
caches have higher locality (due to being significantly smaller) so
until there is a clear benchmark, I think the simple change is best.

Differential Revision: http://reviews.llvm.org/D12063

llvm-svn: 245193
2015-08-17 02:08:17 +00:00
David Majnemer 0bc0eef71c [IR] Give catchret an optional 'return value' operand
Some personality routines require funclet exit points to be clearly
marked, this is done by producing a token at the funclet pad and
consuming it at the corresponding ret instruction.  CleanupReturnInst
already had a spot for this operand but CatchReturnInst did not.
Other personality routines don't need to use this which is why it has
been made optional.

llvm-svn: 245149
2015-08-15 02:46:08 +00:00
Igor Laevsky 4709c03715 [IndVarSimplify] Make cost estimation in RewriteLoopExitValues smarter
Differential Revision: http://reviews.llvm.org/D11687

llvm-svn: 244474
2015-08-10 18:23:58 +00:00
Benjamin Kramer df005cbe19 Fix some comment typos.
llvm-svn: 244402
2015-08-08 18:27:36 +00:00
Jingyue Wu 6f72aed3ec [LSR] canonicalize Prod*(1<<C) to Prod<<C
Summary:
Because LSR happens at a late stage where mul of a power of 2 is
typically canonicalized to shl, this canonicalization emits code that
can be better CSE'ed.

Test Plan:
Transforms/LoopStrengthReduce/shl.ll shows how this change makes GVN more
powerful. Fixes some existing tests due to this change.

Reviewers: sanjoy, majnemer, atrick

Reviewed By: majnemer, atrick

Subscribers: majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D10448

llvm-svn: 240573
2015-06-24 19:28:40 +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
Eric Christopher 572e03a396 Fix "the the" in comments.
llvm-svn: 240112
2015-06-19 01:53:21 +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
Wei Mi e2538b5639 Enable exitValue rewrite only when the cost of expansion is low.
The patch evaluates the expansion cost of exitValue in indVarSimplify pass, and only does the rewriting when the expansion cost is low or loop can be deleted with the rewriting. It provides an option "-replexitval=" to control the default aggressiveness of the exitvalue rewriting. It also fixes some missing cases in SCEVExpander::isHighCostExpansionHelper to enhance the evaluation of SCEV expansion cost.

Differential Revision: http://reviews.llvm.org/D9800

llvm-svn: 238507
2015-05-28 21:49:07 +00:00
Sanjoy Das a9f1e27a04 [SCEV] Strengthen SCEVExpander::isHighCostExpansion.
Summary:

Teach `isHighCostExpansion` to consider divisions by power-of-two
constants as cheap and add a test case.  This change is needed for a new
user of `isHighCostExpansion` that will be added in a subsequent change.

Depends on D8995.

Reviewers: atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8993

llvm-svn: 234845
2015-04-14 03:20:32 +00:00
Sanjoy Das 2e6bb3b947 [SCEV] Refactor out isHighCostExpansion. NFCI.
Summary:
Move isHighCostExpansion from IndVarSimplify to SCEVExpander.  This
exposed function will be used in a subsequent change.

Reviewers: bogner, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8995

llvm-svn: 234844
2015-04-14 03:20:28 +00:00
David Blaikie 93c5444fe0 [opaque pointer type] More GEP API migrations in IRBuilder uses
The plan here is to push the API changes out from the common components
(like Constant::getGetElementPtr and IRBuilder::CreateGEP related
functions) and just update callers to either pass the type if it's
obvious, or pass null.

Do this with LoadInst as well and anything else that comes up, then to
start porting specific uses to not pass null anymore - this may require
some refactoring in each case.

llvm-svn: 234042
2015-04-03 19:41:44 +00:00
David Blaikie 4a2e73b066 [opaque pointer type] API migration for GEP constant factories
Require the pointee type to be passed explicitly and assert that it is
correct. For now it's possible to pass nullptr here (and I've done so in
a few places in this patch) but eventually that will be disallowed once
all clients have been updated or removed. It'll be a long road to get
all the way there... but if you have the cahnce to update your callers
to pass the type explicitly without depending on a pointer's element
type, that would be a good thing to do soon and a necessary thing to do
eventually.

llvm-svn: 233938
2015-04-02 18:55:32 +00:00
David Blaikie 156d46eda0 Opaque Pointer Types: GEP API migrations to specify the gep type explicitly
The changes to InstCombine (& SCEV) 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)

SCEV looks like it'll need some restructuring - we'll have to do a bit
more work for GEP canonicalization, since it'll depend on how it's used
if we can even manage to canonicalize it to a non-ugly GEP. I guess we
can do some fun stuff like voting (do 2 out of 3 load from the GEP with
a certain type that gives a pretty GEP? Does every typed use of the GEP
use either a specific type or a generic type (i8*, etc)?)

llvm-svn: 233131
2015-03-24 23:34:31 +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
Sanjoy Das f1e9e1df25 [SCEV] Fix PR22856.
Summary:
ScalarEvolutionExpander assumes that the header block of a loop is a
legal place to have a use for a phi node.  This is true only for phis
that are either in the header or dominate the header block, but it is
not true for phi nodes that are strictly internal to the loop body.

This change teaches ScalarEvolutionExpander to place uses of PHI nodes
in the basic block the PHI nodes belong to.  This is always legal, and
`hoistIVInc` ensures that the said position dominates `IsomorphicInc`.

Reviewers: atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8311

llvm-svn: 232189
2015-03-13 18:31:19 +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
Sanjoy Das 54ef895137 SCEVExpander incorrectly marks generated subtractions as nuw/nsw
It is not sound to mark the increment operation as `nuw` or `nsw`
based on a proof off of the add recurrence if the increment operation
we emit happens to be a `sub` instruction.

I could not come up with a test case for this -- the cases where
SCEVExpander decides to emit a `sub` instruction is quite small, and I
cannot think of a way I'd be able to get SCEV to prove that the
increment does not overflow in those cases.

Differential Revision: http://reviews.llvm.org/D7899

llvm-svn: 230673
2015-02-26 19:51:35 +00:00
Sanjoy Das dcc84db264 Bugfix: SCEVExpander incorrectly marks increment operations as no-wrap
(The change was landed in r230280 and caused the regression PR22674.
This version contains a fix and a test-case for PR22674).
    
When emitting the increment operation, SCEVExpander marks the
operation as nuw or nsw based on the flags on the preincrement SCEV.
This is incorrect because, for instance, it is possible that {-6,+,1}
is <nuw> while {-6,+,1}+1 = {-5,+,1} is not.
    
This change teaches SCEV to mark the increment as nuw/nsw only if it
can explicitly prove that the increment operation won't overflow.
    
Apart from the attached test case, another (more realistic)
manifestation of the bug can be seen in
Transforms/IndVarSimplify/pr20680.ll.

Differential Revision: http://reviews.llvm.org/D7778

llvm-svn: 230533
2015-02-25 20:02:59 +00:00
Hans Wennborg 953d6fb84e Revert r230280: "Bugfix: SCEVExpander incorrectly marks increment operations as no-wrap"
This caused PR22674, failing this assert:

Instructions.h:2281: llvm::Value* llvm::PHINode::getOperand(unsigned int) const: Assertion `i_nocapture < OperandTraits<PHINode>::operands(this) && "getOperand() out of range!"' failed.

llvm-svn: 230341
2015-02-24 16:19:29 +00:00
Sanjoy Das 18c243b933 Bugfix: SCEVExpander incorrectly marks increment operations as no-wrap
When emitting the increment operation, SCEVExpander marks the
operation as nuw or nsw based on the flags on the preincrement SCEV.
This is incorrect because, for instance, it is possible that {-6,+,1}
is <nuw> while {-6,+,1}+1 = {-5,+,1} is not.

This change teaches SCEV to mark the increment as nuw/nsw only if it
can explicitly prove that the increment operation won't overflow.

Apart from the attached test case, another (more realistic) manifestation
of the bug can be seen in Transforms/IndVarSimplify/pr20680.ll.

NOTE: this change was landed with an incorrect commit message in
rL230275 and was reverted for that reason in rL230279.  This commit
message is the correct one.

Differential Revision: http://reviews.llvm.org/D7778

llvm-svn: 230280
2015-02-23 23:22:58 +00:00
Sanjoy Das c9cf0151cf Revert 230275.
230275 got committed with an incorrect commit message due to a mixup
on my side.  Will re-land in a few moments with the correct commit
message.

llvm-svn: 230279
2015-02-23 23:13:22 +00:00
Sanjoy Das 913dfd8f7f Fix bug 22641
The bug was a result of getPreStartForExtend interpreting nsw/nuw
flags on an add recurrence more strongly than is legal.  {S,+,X}<nsw>
implies S+X is nsw only if the backedge of the loop is taken at least
once.

Differential Revision: http://reviews.llvm.org/D7808

llvm-svn: 230275
2015-02-23 22:55:13 +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
David Blaikie 70573dcd9f Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool>
This is to be consistent with StringSet and ultimately with the standard
library's associative container insert function.

This lead to updating SmallSet::insert to return pair<iterator, bool>,
and then to update SmallPtrSet::insert to return pair<iterator, bool>,
and then to update all the existing users of those functions...

llvm-svn: 222334
2014-11-19 07:49:26 +00:00
Hal Finkel 60db05896a Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)
This change, which allows @llvm.assume to be used from within computeKnownBits
(and other associated functions in ValueTracking), adds some (optional)
parameters to computeKnownBits and friends. These functions now (optionally)
take a "context" instruction pointer, an AssumptionTracker pointer, and also a
DomTree pointer, and most of the changes are just to pass this new information
when it is easily available from InstSimplify, InstCombine, etc.

As explained below, the significant conceptual change is that known properties
of a value might depend on the control-flow location of the use (because we
care that the @llvm.assume dominates the use because assumptions have
control-flow dependencies). This means that, when we ask if bits are known in a
value, we might get different answers for different uses.

The significant changes are all in ValueTracking. Two main changes: First, as
with the rest of the code, new parameters need to be passed around. To make
this easier, I grouped them into a structure, and I made internal static
versions of the relevant functions that take this structure as a parameter. The
new code does as you might expect, it looks for @llvm.assume calls that make
use of the value we're trying to learn something about (often indirectly),
attempts to pattern match that expression, and uses the result if successful.
By making use of the AssumptionTracker, the process of finding @llvm.assume
calls is not expensive.

Part of the structure being passed around inside ValueTracking is a set of
already-considered @llvm.assume calls. This is to prevent a query using, for
example, the assume(a == b), to recurse on itself. The context and DT params
are used to find applicable assumptions. An assumption needs to dominate the
context instruction, or come after it deterministically. In this latter case we
only handle the specific case where both the assumption and the context
instruction are in the same block, and we need to exclude assumptions from
being used to simplify their own ephemeral values (those which contribute only
to the assumption) because otherwise the assumption would prove its feeding
comparison trivial and would be removed.

This commit adds the plumbing and the logic for a simple masked-bit propagation
(just enough to write a regression test). Future commits add more patterns
(and, correspondingly, more regression tests).

llvm-svn: 217342
2014-09-07 18:57:58 +00:00
Hal Finkel 36eff0f854 Fix ScalarEvolutionExpander when creating a PHI in a block with duplicate predecessors
It seems that when I fixed this, almost exactly a year ago, I did not quite do
it correctly. When we have duplicate block predecessors, we can indeed not have
different incoming values for the same block, but we *must* have duplicate
entries. So, instead of skipping the duplicates, we explicitly add the
duplicate incoming values.

Fixes PR20442.

llvm-svn: 214423
2014-07-31 19:13:38 +00:00
Benjamin Kramer 8dd637aa04 SCEVExpander: Fold constant PHIs harder. The logic below only understands proper IVs.
PR20093.

llvm-svn: 211433
2014-06-21 11:47:18 +00:00
Craig Topper 9f008867c0 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206243
2014-04-15 04:59:12 +00:00
Chandler Carruth cdf4788401 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

llvm-svn: 203364
2014-03-09 03:16:01 +00:00
Benjamin Kramer b0f74b24fa [C++11] Convert sort predicates into lambdas.
No functionality change.

llvm-svn: 203288
2014-03-07 21:35:39 +00:00
Benjamin Kramer b6d0bd48bd [C++11] Replace llvm::next and llvm::prior with std::next and std::prev.
Remove the old functions.

llvm-svn: 202636
2014-03-02 12:27:27 +00:00
Rafael Espindola 7c68bebb9c Rename some member variables from TD to DL.
TargetData was renamed DataLayout back in r165242.

llvm-svn: 201581
2014-02-18 15:33:12 +00:00
Arnold Schwaighofer 26f567d8a4 SCEVExpander: Try hard not to create derived induction variables in other loops
During LSR of one loop we can run into a situation where we have to expand the
start of a recurrence of a loop induction variable in this loop. This start
value is a value derived of the induction variable of a preceeding loop. SCEV
has cannonicalized this value to a different recurrence than the recurrence of
the preceeding loop's induction variable (the type and/or step direction) has
changed). When we come to instantiate this SCEV we created a second induction
variable in this preceeding loop.  This patch tries to base such derived
induction variables of the preceeding loop's induction variable.

This helps twolf on arm and seems to help scimark2 on x86.

Reapply with a fix for the case of a value derived from a pointer.

radar://15970709

llvm-svn: 201496
2014-02-16 15:49:50 +00:00
Arnold Schwaighofer 847d96142c Revert "SCEVExpander: Try hard not to create derived induction variables in other loops"
This reverts commit r201465. It broke an arm bot.

llvm-svn: 201466
2014-02-15 18:16:56 +00:00
Arnold Schwaighofer 1e12f8563d SCEVExpander: Try hard not to create derived induction variables in other loops
During LSR of one loop we can run into a situation where we have to expand the
start of a recurrence of a loop induction variable in this loop. This start
value is a value derived of the induction variable of a preceeding loop. SCEV
has cannonicalized this value to a different recurrence than the recurrence of
the preceeding loop's induction variable (the type and/or step direction) has
changed). When we come to instantiate this SCEV we created a second induction
variable in this preceeding loop.  This patch tries to base such derived
induction variables of the preceeding loop's induction variable.

This helps twolf on arm and seems to help scimark2 on x86.

radar://15970709

llvm-svn: 201465
2014-02-15 17:11:56 +00:00
Chandler Carruth 5ad5f15cff [cleanup] Move the Dominators.h and Verifier.h headers into the IR
directory. These passes are already defined in the IR library, and it
doesn't make any sense to have the headers in Analysis.

Long term, I think there is going to be a much better way to divide
these matters. The dominators code should be fully separated into the
abstract graph algorithm and have that put in Support where it becomes
obvious that evn Clang's CFGBlock's can use it. Then the verifier can
manually construct dominance information from the Support-driven
interface while the Analysis library can provide a pass which both
caches, reconstructs, and supports a nice update API.

But those are very long term, and so I don't want to leave the really
confusing structure until that day arrives.

llvm-svn: 199082
2014-01-13 09:26:24 +00:00
Chandler Carruth 8a8cd2bab9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

llvm-svn: 198685
2014-01-07 11:48:04 +00:00
Jakub Staszak 3ab283c157 Don't #include heavy Dominators.h file in LoopInfo.h. This change reduces
overall time of LLVM compilation by ~1%.

llvm-svn: 196667
2013-12-07 21:20:17 +00:00
Alp Toker f907b891da Correct word hyphenations
This patch tries to avoid unrelated changes other than fixing a few
hyphen-related ambiguities and contractions in nearby lines.

llvm-svn: 196471
2013-12-05 05:44:44 +00:00
Andrew Trick 57243da70f Fix SCEVExpander: don't try to expand quadratic recurrences outside a loop.
Partial fix for PR17459: wrong code at -O3 on x86_64-linux-gnu
(affecting trunk and 3.3)

When SCEV expands a recurrence outside of a loop it attempts to scale
by the stride of the recurrence. Chained recurrences don't work that
way. We could compute binomial coefficients, but would hve to
guarantee that the chained AddRec's are in a perfectly reduced form.

llvm-svn: 193438
2013-10-25 21:35:56 +00:00
Benjamin Kramer 58f1ced564 SCEVExpander: Fix a regression I introduced by to eagerly adding RAII objects.
PR17425.

llvm-svn: 191741
2013-10-01 12:17:11 +00:00
Benjamin Kramer 6e931528fe Convert manual insert point restores to the new RAII object.
llvm-svn: 191675
2013-09-30 15:40:17 +00:00
Matt Arsenault a90a18e0ea Teach ScalarEvolution about pointer address spaces
llvm-svn: 190425
2013-09-10 19:55:24 +00:00
Hal Finkel 3f5279cc26 Fix SCEVExpander creating distinct duplicate PHI entries
This fixes SCEVExpander so that it does not create multiple distinct induction
variables for duplicate PHI entries. Specifically, given some code like this:

do.body6:                                         ; preds = %do.body6, %do.body6, %if.then5
  %end.0 = phi i8* [ undef, %if.then5 ], [ %incdec.ptr, %do.body6 ], [ %incdec.ptr, %do.body6 ]
...

Note that it is legal to have multiple entries for a basic block so long as the
associated value is the same. So the above input is okay, but expanding an
AddRec in this loop could produce code like this:

do.body6:                                         ; preds = %do.body6, %do.body6, %if.then5
  %indvar = phi i64 [ %indvar.next, %do.body6 ], [ %indvar.next1, %do.body6 ], [ 0, %if.then5 ]
  %end.0 = phi i8* [ undef, %if.then5 ], [ %incdec.ptr, %do.body6 ], [ %incdec.ptr, %do.body6 ]
...
  %indvar.next = add i64 %indvar, 1
  %indvar.next1 = add i64 %indvar, 1

And this is not legal because there are two PHI entries for %do.body6 each with
a distinct value.

Unfortunately, I don't have an in-tree test case.

llvm-svn: 188614
2013-08-18 00:16:23 +00:00
Andrew Trick aa8ceba833 Remove a bunch of old SCEVExpander FIXME's for preserving NoWrap.
The great thing about the SCEVAddRec No-Wrap flag (unlike nsw/nuw) is
that is can be preserved while normalizing (reassociating and
factoring).

The bad thing is that is can't be tranfered back to IR, which is one
of the reasons I don't like the concept of SCEVExpander.

Sorry, I can't think of a direct way to test this, which is why these
were FIXMEs for so long. I just think it's a good time to finally
clean it up.

llvm-svn: 186273
2013-07-14 03:10:08 +00:00
Andrew Trick 8eaae28693 Teach indvars to generate nsw/nuw flags when widening an induction variable.
Fixes PR16600.

llvm-svn: 186272
2013-07-14 02:50:07 +00:00
Andrew Trick d4e1b5e291 SCEVExpander fix. RAUW needs to update the InsertedExpressions cache.
Note that this bug is only exposed because LTO fails to use TTI.

Fixes self-LTO of clang. rdar://13007381.

llvm-svn: 172462
2013-01-14 21:00:37 +00:00
Chandler Carruth 26c59fa870 Switch the SCEV expander and LoopStrengthReduce to use
TargetTransformInfo rather than TargetLowering, removing one of the
primary instances of the layering violation of Transforms depending
directly on Target.

This is a really big deal because LSR used to be a "special" pass that
could only be tested fully using llc and by looking at the full output
of it. It also couldn't run with any other loop passes because it had to
be created by the backend. No longer is this true. LSR is now just
a normal pass and we should probably lift the creation of LSR out of
lib/CodeGen/Passes.cpp and into the PassManagerBuilder. =] I've not done
this, or updated all of the tests to use opt and a triple, because
I suspect someone more familiar with LSR would do a better job. This
change should be essentially without functional impact for normal
compilations, and only change behvaior of targetless compilations.

The conversion required changing all of the LSR code to refer to the TTI
interfaces, which fortunately are very similar to TargetLowering's
interfaces. However, it also allowed us to *always* expect to have some
implementation around. I've pushed that simplification through the pass,
and leveraged it to simplify code somewhat. It required some test
updates for one of two things: either we used to skip some checks
altogether but now we get the default "no" answer for them, or we used
to have no information about the target and now we do have some.

I've also started the process of removing AddrMode, as the TTI interface
doesn't use it any longer. In some cases this simplifies code, and in
others it adds some complexity, but I think it's not a bad tradeoff even
there. Subsequent patches will try to clean this up even further and use
other (more appropriate) abstractions.

Yet again, almost all of the formatting changes brought to you by
clang-format. =]

llvm-svn: 171735
2013-01-07 14:41:08 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Chandler Carruth 7ec5085e01 Revert the series of commits starting with r166578 which introduced the
getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.

These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.

Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)

After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.

Summary of reverted revisions:

r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
         Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
         since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
         on the address space.
llvm-svn: 167221
2012-11-01 08:07:29 +00:00
Micah Villmow 12d9127833 Add in support for getIntPtrType to get the pointer type based on the address space.
This checkin also adds in some tests that utilize these paths and updates some of the
clients.

llvm-svn: 166578
2012-10-24 15:52:52 +00:00
Nadav Rotem 4dc976fbcb revert r166264 because the LTO build is still failing
llvm-svn: 166340
2012-10-19 21:28:43 +00:00
Benjamin Kramer a225ed8d2b SCEVExpander: Don't crash when trying to merge two constant phis.
Just constant fold them so they can't cause any trouble. Fixes PR12627.

llvm-svn: 166286
2012-10-19 16:37:30 +00:00
Nadav Rotem 4985ddc5e0 recommit the patch that makes LSR and LowerInvoke use the TargetTransform interface.
llvm-svn: 166264
2012-10-19 04:27:49 +00:00
Bob Wilson d6d9ccca38 Temporarily revert the TargetTransform changes.
The TargetTransform changes are breaking LTO bootstraps of clang.  I am
working with Nadav to figure out the problem, but I am reverting it for now
to get our buildbots working.

This reverts svn commits: 165665 165669 165670 165786 165787 165997
and I have also reverted clang svn 165741

llvm-svn: 166168
2012-10-18 05:43:52 +00:00
Nadav Rotem e10328737d Add a new interface to allow IR-level passes to access codegen-specific information.
llvm-svn: 165665
2012-10-10 22:04:55 +00:00
Micah Villmow cdfe20b97f Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Sylvestre Ledru 35521e2310 Fix a typo (the the => the)
llvm-svn: 160621
2012-07-23 08:51:15 +00:00
Andrew Trick 653513b8dd LSR Fix: check SCEV expression safety before expansion.
All SCEV expressions used by LSR formulae must be safe to
expand. i.e. they may not contain UDiv unless we can prove nonzero
denominator.

Fixes PR11356: LSR hoists UDiv.

llvm-svn: 160205
2012-07-13 23:33:10 +00:00
Andrew Trick a7a3de1bcf LSR fix: add a missing phi check during IV hoisting.
Fixes PR12898: SCEVExpander crash.

llvm-svn: 157263
2012-05-22 17:39:59 +00:00
Rafael Espindola 09a4201d3c Fix this assert. IP can point to an instruction with strange dominance
properties (invoke). Just assert that the instruction we return dominates
the insertion point.

llvm-svn: 151511
2012-02-27 02:13:03 +00:00
Rafael Espindola ae725715ef And update the comment...
llvm-svn: 151472
2012-02-26 02:36:56 +00:00
Rafael Espindola fa75542078 Enable the assert that got all this dominator work started.
llvm-svn: 151471
2012-02-26 02:29:18 +00:00
Rafael Espindola 94df267db3 Change the implementation of dominates(inst, inst) to one based on what the
verifier does. This correctly handles invoke.
Thanks to Duncan, Andrew and Chris for the comments.
Thanks to Joerg for the early testing.

llvm-svn: 151469
2012-02-26 02:19:19 +00:00
Rafael Espindola f35c789031 Fix typo.
llvm-svn: 151238
2012-02-23 05:38:51 +00:00
Rafael Espindola 337cfaf757 Improve comment. Thanks for Andrew for the suggestion.
llvm-svn: 151127
2012-02-22 03:44:46 +00:00
Rafael Espindola cd06b482d2 Semantically revert 151015. Add a comment on why we should be able to assert
the dominance once the dominates method is fixed and why we can use the builder's
insertion point.
Fixes pr12048.

llvm-svn: 151125
2012-02-22 03:21:39 +00:00
Rafael Espindola b41b407f3d s/the the/the/
llvm-svn: 151079
2012-02-21 19:27:16 +00:00
Rafael Espindola 729e3aae92 Use more idiomatic assert.
llvm-svn: 151026
2012-02-21 03:51:14 +00:00
Rafael Espindola b2defca267 Avoid warning on non assert builds.
llvm-svn: 151025
2012-02-21 03:48:30 +00:00
Rafael Espindola 7d445e92c3 It turns out that with the current scev organization ReuseOrCreateCast cannot
know where users will be added. Because of this, it cannot use
Builder.GetInsertPoint at all.

This patch
* removes the FIXME about adding the assert.
* adds a comment explaining hy we don't have one.
* removes a broken logic that only works for some callers and is not needed
  since r150884.
* adds an assert to caller that would have caught the bug fixed by r150884.

llvm-svn: 151015
2012-02-21 01:19:51 +00:00
Rafael Espindola 991356e89b Temporarily disable this assert. Looks like it found a similar issue when
building bullet.

llvm-svn: 150885
2012-02-18 17:51:43 +00:00
Rafael Espindola 82d957593e Don't skip debug instructions when looking for the insertion point of
the cast. If we do, we can end up with

   inst1
   ---------------  < Insertion point
   dbg inst
   new inst

instead of the desired

   inst1
   new inst
   ---------------  < Insertion point
   dbg inst

Another option would be for InsertNoopCastOfTo (or its callers) to move the
insertion point and we would end up with

   inst1
   dbg inst
   new inst
   ---------------  < Insertion point

but that complicates the callers. This fixes PR12018 (and firefox's build).

llvm-svn: 150884
2012-02-18 17:22:58 +00:00
David Blaikie 46a9f016c5 More dead code removal (using -Wunreachable-code)
llvm-svn: 148578
2012-01-20 21:51:11 +00:00
Andrew Trick c908b43d9f SCEVExpander fixes. Affects LSR and indvars.
LSR has gradually been improved to more aggressively reuse existing code, particularly existing phi cycles. This exposed problems with the SCEVExpander's sloppy treatment of its insertion point. I applied some rigor to the insertion point problem that will hopefully avoid an endless bug cycle in this area. Changes:

- Always used properlyDominates to check safe code hoisting.

- The insertion point provided to SCEV is now considered a lower bound. This is usually a block terminator or the use itself. Under no cirumstance may SCEVExpander insert below this point.

- LSR is reponsible for finding a "canonical" insertion point across expansion of different expressions.

- Robust logic to determine whether IV increments are in "expanded" form and/or can be safely hoisted above some insertion point.

Fixes PR11783: SCEVExpander assert.

llvm-svn: 148535
2012-01-20 07:41:13 +00:00
Andrew Trick 23ef0d6c40 Fix a corner case hit by redundant phi elimination running after LSR.
Fixes PR11761: bad IR w/ redundant Phi elim

llvm-svn: 148177
2012-01-14 03:17:23 +00:00
Andrew Trick d5d2db9af9 Enable LSR IV Chains with sufficient heuristics.
These heuristics are sufficient for enabling IV chains by
default. Performance analysis has been done for i386, x86_64, and
thumbv7. The optimization is rarely important, but can significantly
speed up certain cases by eliminating spill code within the
loop. Unrolled loops are prime candidates for IV chains. In many
cases, the final code could still be improved with more target
specific optimization following LSR. The goal of this feature is for
LSR to make the best choice of induction variables.

Instruction selection may not completely take advantage of this
feature yet. As a result, there could be cases of slight code size
increase.

Code size can be worse on x86 because it doesn't support postincrement
addressing. In fact, when chains are formed, you may see redundant
address plus stride addition in the addressing mode. GenerateIVChains
tries to compensate for the common cases.

On ARM, code size increase can be mitigated by using postincrement
addressing, but downstream codegen currently misses some opportunities.

llvm-svn: 147826
2012-01-10 01:45:08 +00:00
Andrew Trick f730f39f3f Cleanup comments and argument types related to my previous replaceCongruentPhis checkin.
llvm-svn: 147709
2012-01-07 01:29:21 +00:00
Andrew Trick 5adedf5d47 Extended replaceCongruentPhis to handle mixed phi types.
llvm-svn: 147707
2012-01-07 01:12:09 +00:00
Andrew Trick 881a776875 Expose isNonConstantNegative to users of ScalarEvolution.
llvm-svn: 147700
2012-01-07 00:27:31 +00:00
Andrew Trick b8045cbcb1 SCEVExpander: hoistStep should check strict dominance.
llvm-svn: 147683
2012-01-06 21:23:43 +00:00
Andrew Trick cbcc98fb50 Fix SCEVExpander to handle loops with no preheader when LSR gives it a
"phony" insertion point.

Fixes rdar://10619599: "SelectionDAGBuilder shouldn't visit PHI nodes!" assert

llvm-svn: 147439
2012-01-02 21:25:10 +00:00
Andrew Trick b9aa26f8ea LSR: Fix another corner case in expansion of postinc users.
Fixes PR11571: Instruction does not dominate all uses

llvm-svn: 146950
2011-12-20 01:42:24 +00:00
Andrew Trick e0ced62119 LSR: Fold redundant bitcasts on-the-fly.
llvm-svn: 146597
2011-12-14 22:07:19 +00:00
Andrew Trick ceafa2c746 LSR: handle the expansion of phi operands that use postinc forms of the IV.
Fixes PR11431: SCEVExpander::expandAddRecExprLiterally(const llvm::SCEVAddRecExpr*): Assertion `(!isa<Instruction>(Result) || SE.DT->dominates(cast<Instruction>(Result), Builder.GetInsertPoint())) && "postinc expansion does not dominate use"' failed.

llvm-svn: 145482
2011-11-30 06:07:54 +00:00
Andrew Trick fd4ca0f4ac Fix SCEVExpander assert during LSR: "argument of incompatible type".
Just because we're dealing with a GEP doesn't mean we can assert the
SCEV has a pointer type. The fix is simply to ignore the SCEV pointer
type, which we really didn't need.
Fixes PR11138 webkit crash.

llvm-svn: 142058
2011-10-15 06:19:55 +00:00
Andrew Trick 870c1a3f15 Reapply r141870, SCEV expansion of post-inc.
Speculatively reapply to see if this test case still crashes on
linux. I may have fixed it in my last checkin.

llvm-svn: 141895
2011-10-13 21:55:29 +00:00
Andrew Trick 41c253c35c Revert r141870. The test case crashes on linux with data corruption. A deeper issue was exposed.
llvm-svn: 141873
2011-10-13 17:58:24 +00:00