Commit Graph

5218 Commits

Author SHA1 Message Date
Evan Cheng 78a4eb844b Teach LSR to optimize more loop exit compares, i.e. change them to use postinc iv value. Previously LSR would only optimize those which are in the loop latch block. However, if LSR can prove it is safe (and profitable), it's now possible to change those not in the latch blocks to use postinc values.
Also, if the compare is the only use, LSR would place the iv increment instruction before the compare instead in the latch.

llvm-svn: 71485
2009-05-11 22:33:01 +00:00
Dale Johannesen 02cb2bf2e3 Reverse a loop that is counting up to a maximum to
count down to 0 instead, under very restricted
circumstances.  Adjust 4 testcases in which this
optimization fires.

llvm-svn: 71439
2009-05-11 17:15:42 +00:00
Duncan Sands af9eaa830a Rename PaddedSize to AllocSize, in the hope that this
will make it more obvious what it represents, and stop
it being confused with the StoreSize.

llvm-svn: 71349
2009-05-09 07:06:46 +00:00
Evan Cheng b9dcc2c0c9 Factor out code that optimize loop terminating condition.
llvm-svn: 71305
2009-05-09 01:08:24 +00:00
Chris Lattner c48091f141 fix RewriteStoreUserOfWholeAlloca to use the correct type size
method, fixing a crash on PR4146.  While the store will 
ultimately overwrite the "padded size" number of bits in memory,
the stored value may be a subset of this size.  This function
only wants to handle the case where all bits are stored.

llvm-svn: 71224
2009-05-08 15:54:41 +00:00
Nick Lewycky 702fbf94a0 This transform requires valid TargetData info. Wrap it in 'if (TD)' in
preparation for the day we use null TargetData when no target is specified.

llvm-svn: 71210
2009-05-08 06:47:37 +00:00
Eli Friedman 36b9026fa7 PR4123: don't crash when inlining a call which uses its own result.
llvm-svn: 71199
2009-05-08 00:22:04 +00:00
Dan Gohman 140a6f24f0 Perform constant folding on operands of instructions with non-void
types, such as loads and calls.

llvm-svn: 71175
2009-05-07 19:43:39 +00:00
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 9a6fef0a52 Simplify code by using SmallVector's pop_back_val() instead of
separate back() and pop_back() calls.

llvm-svn: 71089
2009-05-06 17:22:41 +00:00
Duncan Sands 9759f2e063 Fix PR3754: don't mark functions that wrap MallocInst with
the readnone.  Since MallocInst is scheduled for deletion
it doesn't seem worth doing anything more subtle, such as
having mayWriteToMemory return true for MallocInst.

llvm-svn: 71077
2009-05-06 08:42:00 +00:00
Duncan Sands 1efabaaa2a Allow readonly functions to unwind exceptions. Teach
the optimizers about this.  For example, a readonly
function with no uses cannot be removed unless it is
also marked nounwind.

llvm-svn: 71071
2009-05-06 06:49:50 +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
Chris Lattner fa552d728d fix some problems spotted by Duncan and Nicolas Geoffray
llvm-svn: 70872
2009-05-04 16:29:24 +00:00
Chris Lattner d579cb1167 * Sink 4 duplicates of edge threading validity checks and DOUT prints into
ThreadEdge directly.  This shares the code, but is just a refactoring.
* Make JumpThreading compute the set of loop headers and avoid threading
  across them.  This prevents jump threading from forming irreducible 
  loops (goodness) but also prevents it from threading in other cases that
  are beneficial (see the comment above FindFunctionBackedges).

llvm-svn: 70820
2009-05-04 02:28:08 +00:00
Chris Lattner 351134ba93 Factor loop backedge finding out of CodeGenPrepare into a new
FindFunctionBackedges function.

llvm-svn: 70819
2009-05-04 02:25:58 +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
Nick Lewycky 431f97e4f0 Revert r70630. Go back to appending ".b" to internal globals when shrinking
them to bool.

llvm-svn: 70653
2009-05-03 03:49:08 +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 b17dcbdadc The second argument to RecursivelyDeleteTriviallyDeadInstructions has
a default value, and will hopefully be going away soon.

llvm-svn: 70642
2009-05-02 20:22:10 +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 c27345f0b4 Tell ScalarEvolution that the loop is being deleted before actually
deleting it.  This will let ScalarEvolution be more complete about
updating its records.

llvm-svn: 70632
2009-05-02 17:29:26 +00:00
Nick Lewycky 462cd34332 Don't append ".b" to the names of globals that are being shrunk to booleans.
llvm-svn: 70630
2009-05-02 16:21:50 +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 8ddd0b3599 Reword and tidy up some comments.
llvm-svn: 70416
2009-04-29 22:01:05 +00:00
Dan Gohman 3e6e188ee3 Remove an obsolete comment.
llvm-svn: 70262
2009-04-27 22:12:34 +00:00
Dale Johannesen 27b4f222cf Fix PR 4086, a bug in FP IV elimination.
llvm-svn: 70247
2009-04-27 21:03:15 +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 1b5055ab7f Return null instead of false, as appropriate.
llvm-svn: 70054
2009-04-25 17:28:45 +00:00
Dan Gohman 5638e0d642 Add several more icmp simplifications. Transform signed comparisons
into unsigned ones when the operands are known to have the same
sign bit value.

llvm-svn: 70053
2009-04-25 17:12:48 +00:00
Sanjiv Gupta 46c97e626f Allow i16 type indices to gep.
llvm-svn: 69946
2009-04-24 02:37:54 +00:00
Dan Gohman 86bcd97014 Change SCEVExpander's expandCodeFor to provide more flexibility
with the persistent insertion point, and change IndVars to make
use of it. This fixes a bug where IndVars was holding on to a
stale insertion point and forcing the SCEVExpander to continue to
use it.

This fixes PR4038.

llvm-svn: 69892
2009-04-23 15:16:49 +00:00
Evan Cheng d8174d3d09 Make sure both operands have binary instructions have the same type.
llvm-svn: 69844
2009-04-22 23:39:28 +00:00
Evan Cheng 59ca33053b A few more places where the check of use_empty is needed.
llvm-svn: 69842
2009-04-22 23:09:16 +00:00
Evan Cheng cbfe9df096 Avoid deferencing use_begin() if value does not have a use.
llvm-svn: 69836
2009-04-22 22:45:37 +00:00
Owen Anderson 6cbf5bb9bb Real fix for PR3549, by using caching for predecessor counts in addition to the predecessors themselves. This halves the time
to optimize the testcase, beyond what my previous patch did.

llvm-svn: 69792
2009-04-22 08:50:12 +00:00
Owen Anderson bb754826c9 Use PredIteratorCache in LCSSA, which gives a 37% overall speedup on the testcase from PR3549. More improvements to come.
llvm-svn: 69788
2009-04-22 08:09:13 +00:00
Chris Lattner 58be2d4413 use predicate instead of hand-rolled loop
llvm-svn: 69752
2009-04-21 23:37:18 +00:00
Chris Lattner 69223bb7f5 fix a crash on a pointless but valid zero-length memset, rdar://6808691
llvm-svn: 69680
2009-04-21 16:52:12 +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