Commit Graph

456 Commits

Author SHA1 Message Date
Dan Gohman 7ef0dc2163 Teach ScalarEvolution to simplify smax and umax when it can prove
that one operand is always greater than another.

llvm-svn: 101142
2010-04-13 16:51:03 +00:00
Dan Gohman fe4b29180b Minor code micro-optimizations.
llvm-svn: 101141
2010-04-13 16:49:23 +00:00
Dan Gohman ebbd05f8ce Micro-optimize a few hot spots.
llvm-svn: 101086
2010-04-12 23:08:18 +00:00
Dan Gohman 11862a6ed3 Add fast paths to ScalarEvolution::getSizeOf and getOffsetOf, as
they're used a lot by getNodeForGEP, which can be called a lot.
This speeds up -iv-users by around 15% on several testcases.

llvm-svn: 101083
2010-04-12 23:03:26 +00:00
Dan Gohman 6635bb26a6 Generalize ScalarEvolution's PHI analysis to handle loops that don't
have preheaders or dedicated exit blocks, as clients may not otherwise
need to run LoopSimplify.

llvm-svn: 101030
2010-04-12 07:49:36 +00:00
Dan Gohman f76210ead8 Rewrite the overflow checking in the get{Signed,Unsigned}Range code for
AddRecs so that it checks for overflow in the computation that it is
performing, rather than just checking hasNo{Signed,Unsigned}Wrap, since
those flags are for a different computation. This fixes a bug that
impacts an upcoming change.

llvm-svn: 101028
2010-04-12 07:39:33 +00:00
Dan Gohman 068b793614 Fix indentation.
llvm-svn: 101001
2010-04-11 23:44:58 +00:00
Dan Gohman 07591698ce Enhance ScalarEvolution::isKnownPredicate with support for
loop conditions which are invariants.

llvm-svn: 100995
2010-04-11 22:16:48 +00:00
Dan Gohman f7f28511a9 Minor code simplification.
llvm-svn: 100994
2010-04-11 22:13:11 +00:00
Dan Gohman ae4a4148ba When creating a ConstantRange for [n,UINT_MAX], special case n == 0, because
ConstantRange(0, 0) creates an empty range rather than a full one.

llvm-svn: 100993
2010-04-11 22:12:18 +00:00
Dan Gohman b50349a979 Rename isLoopGuardedByCond to isLoopEntryGuardedByCond, to emphasise
that it's only testing for the entry condition, not full loop-invariant
conditions.

llvm-svn: 100979
2010-04-11 19:27:13 +00:00
Dan Gohman 4ce1fb1448 Add variants of ult, ule, etc. which take a uint64_t RHS, for convenience.
llvm-svn: 100824
2010-04-08 23:03:40 +00:00
Dan Gohman 883105485b Revert this change from a while ago; ScalarEvolution shouldn't analyze
undef as 0, since it can't force other analyses to intepret the undef
in the same way.

llvm-svn: 100749
2010-04-08 05:58:24 +00:00
Dan Gohman 01c65a2622 Define placement new wrappers for BumpPtrAllocator and
RecyclingAllocator to allow client code to be simpler, and
simplify several clients.

llvm-svn: 98847
2010-03-18 18:49:47 +00:00
Dan Gohman 6556c8962c Add the ability to "intern" FoldingSetNodeID data into a
BumpPtrAllocator-allocated region to allow it to be stored in a more
compact form and to avoid the need for a non-trivial destructor call.

Use this new mechanism in ScalarEvolution instead of
FastFoldingSetNode to avoid leaking memory in the case where a
FoldingSetNodeID uses heap storage, and to reduce overall memory
usage.

llvm-svn: 98829
2010-03-18 16:16:38 +00:00
Dan Gohman 0052449e1a Reapply r98755 with a thinko which miscompiled gengtype fixed.
llvm-svn: 98793
2010-03-18 01:17:13 +00:00
Dan Gohman d2abecaeea Revert 98755, which may be causing trouble.
llvm-svn: 98762
2010-03-17 19:54:53 +00:00
Dan Gohman 5c9b0e1a6e Change SCEVNAryExpr's operand array from a SmallVector to a plain
pointer and length, and allocate the arrays in ScalarEvolution's
BumpPtrAllocator, so that they get released when their owning
SCEV gets released. SCEVs are immutable, so they don't need to worry
about operand array resizing. This fixes a memory leak reported
in PR6637.

llvm-svn: 98755
2010-03-17 18:51:01 +00:00
Dan Gohman 69451a0950 Avoid analyzing instructions in blocks not reachable from the entry block.
They are lots of trouble, and they don't matter. This fixes PR6559.

llvm-svn: 98103
2010-03-09 23:46:50 +00:00
Dan Gohman 8b0a419eb1 Spelling fixes.
llvm-svn: 97453
2010-03-01 17:49:51 +00:00
Dan Gohman a9c205cc88 Make LoopSimplify change conditional branches in loop exiting blocks
which branch on undef to branch on a boolean constant for the edge
exiting the loop. This helps ScalarEvolution compute trip counts for
loops.

Teach ScalarEvolution to recognize single-value PHIs, when safe, and
ForgetSymbolicName to forget such single-value PHI nodes as apprpriate
in ForgetSymbolicName.

llvm-svn: 97126
2010-02-25 06:57:05 +00:00
Dan Gohman 4aad750333 ConstantFoldInstOperands can theoretically return null if it
didn't fold anything.

llvm-svn: 97049
2010-02-24 19:31:47 +00:00
Dan Gohman 007f5041a2 Simplify this code; these casts aren't necessary.
llvm-svn: 97048
2010-02-24 19:31:06 +00:00
Dan Gohman ba820344e3 Convert a few more backedge-taken count functions to use BackedgeTakenInfo.
llvm-svn: 97042
2010-02-24 17:31:30 +00:00
Dan Gohman 8c16b38262 Remove unused variables and parameters.
llvm-svn: 96780
2010-02-22 04:11:59 +00:00
Dan Gohman cf9c64e6e3 Add a comment.
llvm-svn: 96688
2010-02-19 18:49:22 +00:00
Dan Gohman 6b1e2a829d Teach ScalarEvolution how to compute a tripcount for a loop with
true or false as its exit condition. These are usually eliminated by
SimplifyCFG, but the may be left around during a pass which wishes
to preserve the CFG.

llvm-svn: 96683
2010-02-19 18:12:07 +00:00
Dale Johannesen 1d6827adef recommit 96626, evidence that it broke things appears
to be spurious

llvm-svn: 96662
2010-02-19 07:14:22 +00:00
Dale Johannesen 1f790c28d0 Revert 96626, which causes build failure on ppc Darwin.
llvm-svn: 96653
2010-02-19 01:54:37 +00:00
Dan Gohman 60b3326435 Indvars needs to explicitly notify ScalarEvolution when it is replacing
a loop exit value, so that if a loop gets deleted, ScalarEvolution
isn't stick holding on to dangling SCEVAddRecExprs for that loop. This
fixes PR6339.

llvm-svn: 96626
2010-02-18 23:26:33 +00:00
Duncan Sands 19d0b47b1f There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344
2010-02-16 11:11:14 +00:00
Duncan Sands 9dff9bec31 Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!

llvm-svn: 96223
2010-02-15 16:12:20 +00:00
Dan Gohman fefbff9cd8 When testing whether a given SCEV depends on a temporary symbolic
name, test whether the SCEV itself is that temporary symbolic name,
in addition to checking whether the symbolic name appears as a
possibly-indirect operand.

llvm-svn: 96216
2010-02-15 10:28:37 +00:00
Dan Gohman fe873e7c10 Override dominates and properlyDominates for SCEVAddRecExpr, as a
SCEVAddRecExpr doesn't necessarily dominate blocks merely dominated
by all of its operands. This fixes an abort compiling 403.gcc.

llvm-svn: 96056
2010-02-13 00:19:39 +00:00
Dan Gohman 4a618827de Fix "the the" and similar typos.
llvm-svn: 95781
2010-02-10 16:03:48 +00:00
Dan Gohman 9946b5109c Change the argument to getIntegerSCEV to be an int64_t, rather
than int. This will make it more convenient for LSR, which does
a lot of things with int64_t offsets.

llvm-svn: 95281
2010-02-04 02:43:51 +00:00
Dan Gohman 7e5f1b2773 Various code simplifications.
llvm-svn: 95044
2010-02-02 01:38:49 +00:00
Dan Gohman e5e1b7b05a Generalize target-independent folding rules for sizeof to handle more
cases, and implement target-independent folding rules for alignof and
offsetof. Also, reassociate reassociative operators when it leads to
more folding.

Generalize ScalarEvolution's isOffsetOf to recognize offsetof on
arrays. Rename getAllocSizeExpr to getSizeOfExpr, and getFieldOffsetExpr
to getOffsetOfExpr, for consistency with analagous ConstantExpr routines.

Make the target-dependent folder promote GEP array indices to
pointer-sized integers, to make implicit casting explicit and exposed
to subsequent folding.

And add a bunch of testcases for this new functionality, and a bunch
of related existing functionality.

llvm-svn: 94987
2010-02-01 18:27:38 +00:00
Dan Gohman cf9138307d Remove SCEVAllocSizeExpr and SCEVFieldOffsetExpr, and in their place
use plain SCEVUnknowns with ConstantExpr::getSizeOf and
ConstantExpr::getOffsetOf constants. This eliminates a bunch of
special-case code.

Also add code for pattern-matching these expressions, for clients that
want to recognize them.

Move ScalarEvolution's logic for expanding array and vector sizeof
expressions into an element count times the element size, to expose
the multiplication to subsequent folding, into the regular constant
folder.

llvm-svn: 94737
2010-01-28 02:15:55 +00:00
Dan Gohman 85be4333ad Make the unsigned-range code more consistent with the signed-range code,
and clean up some loose ends.

llvm-svn: 94572
2010-01-26 19:19:05 +00:00
Dan Gohman a01418d75a Fix a typo in a comment that Duncan noticed.
llvm-svn: 94562
2010-01-26 18:32:54 +00:00
Dan Gohman fdb744b203 Rename ItCount to BECount, since it holds a backedge-taken count rather
than an iteration count.

llvm-svn: 94549
2010-01-26 16:46:18 +00:00
Dan Gohman 51aaf02821 Fix the the ceiling-division used in computing the MaxBECount so that it doesn't
have trouble with an intermediate add overflowing. Also, be more conservative
about the case where the induction variable in an SLT loop exit can step past
the RHS of the SLT and overflow in a single step.

Make getSignedRange more aggressive, to recover for some common cases which
the above fixes pessimized.

This addresses rdar://7561161.

llvm-svn: 94512
2010-01-26 04:40:18 +00:00
Dan Gohman 51ad99d2c5 Re-implement the main strength-reduction portion of LoopStrengthReduction.
This new version is much more aggressive about doing "full" reduction in
cases where it reduces register pressure, and also more aggressive about
rewriting induction variables to count down (or up) to zero when doing so
reduces register pressure.

It currently uses fairly simplistic algorithms for finding reuse
opportunities, but it introduces a new framework allows it to combine
multiple strategies at once to form hybrid solutions, instead of doing
all full-reduction or all base+index.

llvm-svn: 94061
2010-01-21 02:09:26 +00:00
Dan Gohman 8d67d2f5f8 Add a comment and tidy up some whitespace.
llvm-svn: 93932
2010-01-19 22:27:22 +00:00
Dan Gohman f86d904b7d Give ScalarEvolution access to the DominatorTree. It'll need this
to make more intellegent AddRec folding decisions.

llvm-svn: 93930
2010-01-19 22:21:27 +00:00
Dan Gohman bc694918cc Use WriteAsOperand instead of getName() to print loop header names,
so that unnamed blocks are handled.

llvm-svn: 93059
2010-01-09 18:17:45 +00:00
David Greene 2330f78075 Remove dump routine and the associated Debug.h from a header. Patch up
other files to compensate.

llvm-svn: 92075
2009-12-23 22:58:38 +00:00
David Greene df1c497c2f Convert debug messages to use dbgs(). Generally this means
s/errs/dbgs/g except for certain special cases.

llvm-svn: 92067
2009-12-23 22:18:14 +00:00
Dan Gohman 876f45d7d2 Fix a spello in a comment that Nick spotted.
llvm-svn: 91742
2009-12-19 01:46:34 +00:00