290 Commits

Author SHA1 Message Date
Evan Cheng
342053cd27 Unbreak the build.
llvm-svn: 71091
2009-05-06 18:00:56 +00:00
David Greene
0dec5b9a75 Make sure to use signed arithmetic in APInt to fix a regression.
llvm-svn: 71090
2009-05-06 17:39:26 +00:00
Dan Gohman
e58fc20f8d Fix a copy+pasto in a comment.
llvm-svn: 71035
2009-05-05 23:02:38 +00:00
Dan Gohman
96b18ccdd3 Delete a FIXME which is no longer relevant, and add a FIXME that is.
llvm-svn: 71033
2009-05-05 22:59:55 +00:00
Bill Wendling
5e2ac0cd9c Temporarily reverting r71008. It was causing this failure:
Running /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/dg.exp ...
FAIL: /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/change-compare-stride-1.ll
Failed with exit(1) at line 2
while running: grep {cmpq       $-478,} change-compare-stride-1.ll.tmp
child process exited abnormally

llvm-svn: 71013
2009-05-05 20:49:46 +00:00
David Greene
246a3dfb10 Handle overflow of 64-bit loop conditions.
llvm-svn: 71008
2009-05-05 20:22:36 +00:00
Dan Gohman
48f8222293 Re-apply 70645, converting ScalarEvolution to use
CallbackVH, with fixes. allUsesReplacedWith need to
walk the def-use chains and invalidate all users of a
value that is replaced. SCEVs of users need to be
recalcualted even if the new value is equivalent. Also,
make forgetLoopPHIs walk def-use chains, since any
SCEV that depends on a PHI should be recalculated when
more information about that PHI becomes available.

llvm-svn: 70927
2009-05-04 22:30:44 +00:00
Dan Gohman
a30370bc33 Constify a bunch of SCEV-using code.
llvm-svn: 70919
2009-05-04 22:02:23 +00:00
Dan Gohman
5036695c32 Revert r70645 for now; it's causing a variety of regressions.
llvm-svn: 70661
2009-05-03 05:46:20 +00:00
Dan Gohman
e9a38d16fe Convert ScalarEvolution to use CallbackVH for its internal map. This
makes ScalarEvolution::deleteValueFromRecords, and it's code that
subtly needed to be called before ReplaceAllUsesWith, unnecessary.

It also makes ValueDeletionListener unnecessary.

llvm-svn: 70645
2009-05-02 21:19:20 +00:00
Dan Gohman
ff08995589 Previously, RecursivelyDeleteDeadInstructions provided an option
of returning a list of pointers to Values that are deleted. This was
unsafe, because the pointers in the list are, by nature of what
RecursivelyDeleteDeadInstructions does, always dangling. Replace this
with a simple callback mechanism. This may eventually be removed if
all clients can reasonably be expected to use CallbackVH.

Use this to factor out the dead-phi-cycle-elimination code from LSR
utility function, and generalize it to use the
RecursivelyDeleteTriviallyDeadInstructions utility function.

This makes LSR more aggressive about eliminating dead PHI cycles;
adjust tests to either be less trivial or to simply expect fewer
instructions.

llvm-svn: 70636
2009-05-02 18:29:22 +00:00
Dan Gohman
6409e7d4e9 Don't split critical edges during the AddUsersIfInteresting phase
of LSR. This makes the AddUsersIfInteresting phase of LSR a pure
analysis instead of a phase that potentially does CFG modifications.

The conditions where this code would actually perform a split are
rare, and in the cases where it actually would do a split the split
is usually undone by CodeGenPrepare, and in cases where splits
actually survive into codegen, they appear to hurt more often than
they help.

llvm-svn: 70625
2009-05-02 05:36:01 +00:00
Dan Gohman
65dbe7874f Make RequiresTypeConversion canonicalize the types before calling the
target hooks canLosslesslyBitCastTo and isTruncateFree. This allows
targets to avoid worrying about handling all combinations of integer
and pointer types.

llvm-svn: 70555
2009-05-01 17:07:43 +00:00
Dan Gohman
d3aa4215ef Minor whitespace fix.
llvm-svn: 70551
2009-05-01 16:56:32 +00:00
Dan Gohman
6be8530158 Fix some code to work if TargetLowering is not available.
llvm-svn: 70546
2009-05-01 16:29:14 +00:00
Dale Johannesen
f4031bd01e Print correct instruction in dump.
llvm-svn: 70427
2009-04-29 22:57:20 +00:00
Dan Gohman
e99f98262c Permit ChangeCompareStride to rewrite a comparison when the factor
between the comparison's iv stride and the candidate stride is
exactly -1.

llvm-svn: 70244
2009-04-27 20:35:32 +00:00
Dan Gohman
4860db61be Factor out a common base class from SCEVTruncateExpr, SCEVZeroExtendExpr,
and SCEVSignExtendExpr.

llvm-svn: 69649
2009-04-21 01:25:57 +00:00
Dan Gohman
b397e1a7a2 Introduce encapsulation for ScalarEvolution's TargetData object, and refactor
the code to minimize dependencies on TargetData.

llvm-svn: 69644
2009-04-21 01:07:12 +00:00
Dan Gohman
056857aa21 Use more const qualifiers with SCEV interfaces.
llvm-svn: 69450
2009-04-18 17:56:28 +00:00
Dan Gohman
d2d6fd806c Don't create ConstantInts with pointer type. This fixes a
regression in 403.gcc in PIC_CODEGEN=1 and DISABLE_LTO=1
mode.

llvm-svn: 69344
2009-04-17 02:02:52 +00:00
Dan Gohman
fec1d086e0 Use TargetData::getTypeSizeInBits instead of getPrimitiveSizeInBits()
to get the correct answer for pointer types.

llvm-svn: 69321
2009-04-16 22:35:57 +00:00
Dan Gohman
8b6ebb1112 Minor code simplifications. Don't attempt LSR on theoretical
targets with pointers larger than 64 bits, due to the code not
yet being APInt clean.

llvm-svn: 69296
2009-04-16 16:49:48 +00:00
Dan Gohman
e2ead2c328 LSR is no longer a GEP optimizer. It is now an IV expression
optimizer, which just happen to frequently involve optimizing GEPs.

llvm-svn: 69295
2009-04-16 16:46:01 +00:00
Dan Gohman
a8be04b2db Use ConstantExpr::getIntToPtr instead of SCEVExpander::InsertCastOfTo,
since the operand is always a constant.

llvm-svn: 69291
2009-04-16 15:48:38 +00:00
Dan Gohman
71bccd3e0e Use a SCEV expression cast instead of immediately inserting a
new instruction with SCEVExpander::InsertCastOfTo.

llvm-svn: 69290
2009-04-16 15:47:35 +00:00
Dan Gohman
0a40ad93a9 Expand GEPs in ScalarEvolution expressions. SCEV expressions can now
have pointer types, though in contrast to C pointer types, SCEV
addition is never implicitly scaled. This not only eliminates the
need for special code like IndVars' EliminatePointerRecurrence
and LSR's own GEP expansion code, it also does a better job because
it lets the normal optimizations handle pointer expressions just
like integer expressions.

Also, since LLVM IR GEPs can't directly index into multi-dimensional
VLAs, moving the GEP analysis out of client code and into the SCEV
framework makes it easier for clients to handle multi-dimensional
VLAs the same way as other arrays.

Some existing regression tests show improved optimization.
test/CodeGen/ARM/2007-03-13-InstrSched.ll in particular improved to
the point where if-conversion started kicking in; I turned it off
for this test to preserve the intent of the test.

llvm-svn: 69258
2009-04-16 03:18:22 +00:00
Chris Lattner
42e9ca42ce LSR shouldn't ever try to hack on integer IV's larger than 64-bits. Right now
it is not APInt clean, but even when it is it needs to be evaluated carefully
to determine whether it is actually profitable.

This fixes a crash on PR3806

llvm-svn: 67134
2009-03-17 23:58:30 +00:00
Dan Gohman
f12436891e Don't record the increment instruction; just recompute it from the Phi
if needed. This simplifies the code a little, and is needed for an
upcoming refactoring.

llvm-svn: 66479
2009-03-09 22:04:01 +00:00
Dan Gohman
b855164751 Fix a few more places where induction variable types were used
where memory access types are needed.

llvm-svn: 66470
2009-03-09 21:22:12 +00:00
Dan Gohman
5a4e31666d Use ReplacedTy instead of recomputing the same value.
llvm-svn: 66469
2009-03-09 21:19:58 +00:00
Dan Gohman
34e52ddb7d Use LoopInfo's getLoopLatch() instead of doing what it does manualy.
llvm-svn: 66467
2009-03-09 21:14:16 +00:00
Dan Gohman
70cc9875d8 Don't use an induction variable type as a memory access type.
Use VoidTy instead, to be properly conservative.

llvm-svn: 66463
2009-03-09 21:04:19 +00:00
Dan Gohman
917ffe4592 Factor out the code that determines the memory access type
of an instruction into a helper function.

llvm-svn: 66460
2009-03-09 21:01:17 +00:00
Dan Gohman
e201f8ff1d Move the sorting of the StrideOrder array earlier so that it doesn't
have to be done twice.

llvm-svn: 66449
2009-03-09 20:46:50 +00:00
Dan Gohman
b5001909b0 Delete the isOnlyStride argument, which is unused.
llvm-svn: 66446
2009-03-09 20:41:15 +00:00
Dan Gohman
85875f7120 Tidy some LSR debug output: announce the loop it's about to process
before it does any processing.

llvm-svn: 66443
2009-03-09 20:34:59 +00:00
Dan Gohman
66476b582d Fix this comment.
llvm-svn: 66065
2009-03-04 20:50:23 +00:00
Dan Gohman
ae0035ee15 Add an assertion for a condition that's always true, and not
immediately obvious.

llvm-svn: 66062
2009-03-04 20:49:01 +00:00
Dan Gohman
0bddac16a8 Rename ScalarEvolution's getIterationCount to getBackedgeTakenCount,
to more accurately describe what it does. Expand its doxygen comment
to describe what the backedge-taken count is and how it differs
from the actual iteration count of the loop. Adjust names and
comments in associated code accordingly.

llvm-svn: 65382
2009-02-24 18:55:53 +00:00
Dan Gohman
5d1f458f0f Generalize the ChangeCompareStride code, in preparation for
handling non-constant strides. No functionality change.

llvm-svn: 65363
2009-02-24 01:58:00 +00:00
Dan Gohman
f394e58af5 Properly parenthesize this expression, fixing a real bug in the new
-full-lsr code, as well as a GCC warning.

llvm-svn: 65288
2009-02-22 16:40:52 +00:00
Evan Cheng
69decbf0b2 Only try to sink immediate when TLI is not null. It needs to check if immediate would fit in target addressing field.
llvm-svn: 65268
2009-02-22 07:31:19 +00:00
Evan Cheng
107b06c4b9 Teach LSR sink to sink the immediate portion of the common expression back into uses if they fit in address modes of all the uses.
llvm-svn: 65215
2009-02-21 02:06:47 +00:00
Evan Cheng
8a9481d50d Fix strange logic in CollectIVUsers used to determine whether all uses are
addresses, part 1. This fixes an obvious logic bug. Previously if the only
in-loop use is a PHI, it would return AllUsesAreAddresses as true.

llvm-svn: 65178
2009-02-20 22:16:49 +00:00
Dan Gohman
5e309a5bbb Simplify code and reduce indentation. No functionality change.
llvm-svn: 65167
2009-02-20 21:27:23 +00:00
Dan Gohman
2c8cb5b4ec Fix 80-column violations.
llvm-svn: 65159
2009-02-20 21:06:57 +00:00
Dan Gohman
addc50b4ee It's not necessary to check if Base is null here.
llvm-svn: 65157
2009-02-20 21:05:23 +00:00
Dan Gohman
1608df5319 Add a comment about how Imm can be used for loop-variant values.
llvm-svn: 65147
2009-02-20 20:29:04 +00:00
Dan Gohman
2a12ae7d1f Implement "superhero" strength reduction, or full strength
reduction of address calculations down to basic pointer arithmetic.
This is currently off by default, as it needs a few other features
before it becomes generally useful. And even when enabled, full
strength reduction is only performed when it doesn't increase
register pressure, and when several other conditions are true.

This also factors out a bunch of exisiting LSR code out of
StrengthReduceStridedIVUsers into separate functions, and tidies
up IV insertion. This actually decreases register pressure even
in non-superhero mode. The change in iv-users-in-other-loops.ll
is an example of this; there are two more adds because there are
two fewer leas, and there is less spilling.

llvm-svn: 65108
2009-02-20 04:17:46 +00:00