Commit Graph

272 Commits

Author SHA1 Message Date
Owen Anderson a7aed18624 Reapply r110396, with fixes to appease the Linux buildbot gods.
llvm-svn: 110460
2010-08-06 18:33:48 +00:00
Owen Anderson bda59bd247 Revert r110396 to fix buildbots.
llvm-svn: 110410
2010-08-06 00:23:35 +00:00
Owen Anderson 755aceb5d0 Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396
2010-08-05 23:42:04 +00:00
Gabor Greif dde79d8f1a mass elimination of reliance on automatic iterator dereferencing
llvm-svn: 109103
2010-07-22 13:36:47 +00:00
Owen Anderson a57b97e7e7 Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
llvm-svn: 109045
2010-07-21 22:09:45 +00:00
Dan Gohman 12725c7d46 Remember that the induction variable is always a PHINode and
use getIncomingValueForBlock instead of
LoopInfo::getCanonicalInductionVariableIncrement.

llvm-svn: 108865
2010-07-20 17:18:52 +00:00
Gabor Greif e82532a1c5 cache result of operator*
llvm-svn: 107976
2010-07-09 15:40:10 +00:00
Dan Gohman f3aea7aecf Disable indvars on loops when LoopSimplify form is not available.
This fixes PR7333.

llvm-svn: 106267
2010-06-18 01:35:11 +00:00
Dan Gohman 1d2ded75e2 Use getConstant instead of getIntegerSCEV. The two are basically the
same, now that getConstant has overloads consistent with ConstantInt::get.

llvm-svn: 102965
2010-05-03 22:09:21 +00:00
Dan Gohman 5867a56db8 Teach IndVarSimplify how to eliminate remainder operators where the
numerator is an induction variable. For example, with code like this:

  for (i=0;i<n;++i)
    x[i%n] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the remainder.

llvm-svn: 101113
2010-04-13 01:46:36 +00:00
Dan Gohman 4a645b88ef Suppress LinearFunctionTestReplace when the computed backedge-taken
expression is a UDiv and it doesn't appear that the UDiv came from
the user's source.

ScalarEvolution has recently figured out how to compute a tripcount
expression for the inner loop in
SingleSource/Benchmarks/Shootout/sieve.c, using a udiv. Emitting a
udiv instruction dramatically slows down the enclosing loop.

llvm-svn: 101068
2010-04-12 21:13:43 +00:00
Dan Gohman 07f6563e81 Move the EliminateIVUsers call back out to its original location. Now that
a ScalarEvolution bug with overflow handling is fixed, the normal analysis
code will automatically decline to operate on the icmp instructions which
are responsible for the loop exit.

llvm-svn: 101032
2010-04-12 07:56:56 +00:00
Dan Gohman 15f90c294c Use RecursivelyDeleteTriviallyDeadInstructions in EliminateIVComparisons,
instead of deleting just the user. This makes it more consistent with
other code in IndVarSimplify, and theoretically can eliminate more users
earlier.

llvm-svn: 101027
2010-04-12 07:29:15 +00:00
Dan Gohman fa5ad797e3 Re-apply r101000, with a fix: Don't eliminate an icmp which is part of
the loop exit test. This usually doesn't come up for a variety of
reasons, but it isn't impossible, so make IndVarSimplify handle it
conservatively.

llvm-svn: 101008
2010-04-12 02:21:50 +00:00
Dan Gohman c0f1efaf8d Revert 101000, which is breaking self-host builds.
llvm-svn: 101002
2010-04-12 00:17:10 +00:00
Dan Gohman af4ab1b681 Teach IndVarSimplify how to eliminate comparisons involving induction
variables. For example, with code like this:

  for (i=0;i<n;++i)
    if (i<n)
      x[i] = 0;

IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.

llvm-svn: 101000
2010-04-11 23:10:12 +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 d006ab90dd Generalize IVUsers to track arbitrary expressions rather than expressions
explicitly split into stride-and-offset pairs. Also, add the
ability to track multiple post-increment loops on the same expression.

This refines the concept of "normalizing" SCEV expressions used for
to post-increment uses, and introduces a dedicated utility routine for
normalizing and denormalizing expressions.

This fixes the expansion of expressions which are post-increment users
of more than one loop at a time. More broadly, this takes LSR another
step closer to being able to reason about more than one loop at a time.

llvm-svn: 100699
2010-04-07 22:27:08 +00:00
Chris Lattner ecb536313f require that the branch being controlled by the IV
exits the loop.  With this information we can guarantee 
the iteration count of the loop is bounded by the 
compare.  I think this xforms is finally safe now.

llvm-svn: 100285
2010-04-03 07:21:39 +00:00
Chris Lattner 40060d33f6 add integer overflow check for the fp induction variable
checker.  Amusingly, we already had tests that we should
have rejects because they would be miscompiled in the
testsuite.

The remaining issue with this is that we don't check that
the branch causes us to exit the loop if it fails, so we
don't actually know if we remain in bounds.

llvm-svn: 100284
2010-04-03 07:18:48 +00:00
Chris Lattner 69913466cb add a comment and fix some consistency issues, converting
to a signed vs unsigned value depending on the sign of the
constant fp means that we can't distinguish between a 
truly negative number and a positive number so large the
32nd bit is set.  So, do don't this!

llvm-svn: 100283
2010-04-03 06:41:49 +00:00
Chris Lattner 40ea690f39 fix PR6761, a miscompilation due to the fp->int IV conversion
stuff.  More bugs remain though.

llvm-svn: 100282
2010-04-03 06:30:03 +00:00
Chris Lattner 42202868c3 just eliminate the uitofp checks. This code isn't doing
the required validity checks in the first place, and supporting
a condition large enough to require the 32'nd bit isn't worth it.

llvm-svn: 100280
2010-04-03 06:25:21 +00:00
Chris Lattner ca25b60f4e rename PH -> PN to be consistent with WeakPN and the rest
of llvm.

llvm-svn: 100276
2010-04-03 06:17:08 +00:00
Chris Lattner 774858fc38 improve comment and drop a dead check. If PH had
no uses, it would have been deleted by 
RecursivelyDeleteTriviallyDeadInstructions

llvm-svn: 100275
2010-04-03 06:16:22 +00:00
Chris Lattner 915322bc4a strength reduce a ridiculous use of APInt.
llvm-svn: 100274
2010-04-03 06:13:12 +00:00
Chris Lattner 0b941347f9 rename stuff improve comment grammar.
llvm-svn: 100273
2010-04-03 06:11:07 +00:00
Chris Lattner d77bde5f94 simplify some code and resolve a fixme.
llvm-svn: 100272
2010-04-03 06:06:59 +00:00
Chris Lattner 2ff33f91d5 There is no guarantee that the increment and the branch
are in the same block.  Insert the new increment in the
correct location.

Also, more cleanups.

llvm-svn: 100271
2010-04-03 06:05:10 +00:00
Chris Lattner c558b49f14 first half of a pass through IndVarSimplify::HandleFloatingPointIV,
this cleans up a bunch of code and also fixes several crashes and
miscompiles.  More to come unfortunately, this optimization
is quite broken.

llvm-svn: 100270
2010-04-03 05:54:59 +00:00
Dan Gohman f7239102fe Manually notify ScalarEvolution before making an operand replacement, since
it can't currently observe such changes automatically.

llvm-svn: 100186
2010-04-02 14:48:31 +00:00
Bill Wendling 04803e8ef6 Skip debugging intrinsics when sinking unused invariants.
llvm-svn: 99324
2010-03-23 21:15:59 +00:00
Dan Gohman 1a2abe5580 Clear the SCEVExpander's insertion point after making deletions,
so that the SCEVExpander doesn't retain a dangling pointer as its
insert position. The dangling pointer in this case wasn't ever used
to insert new instructions, but it was causing trouble with
SCEVExpander's code for automatically advancing its insert position
past debug intrinsics.

This fixes use-after-free errors that valgrind noticed in
test/Transforms/IndVarSimplify/2007-06-06-DeleteDanglesPtr.ll and
test/Transforms/IndVarSimplify/exit_value_tests.ll.

llvm-svn: 99036
2010-03-20 03:53:53 +00:00
Devang Patel 45c1505bf6 Skip debug info intrinsics.
llvm-svn: 98584
2010-03-15 22:23:03 +00:00
Dan Gohman 2734ebd37f Add a DominatorTree argument to isLCSSA so that it doesn't have to
compute a set of reachable blocks for itself each time it is called, which
is fairly frequently.

llvm-svn: 98179
2010-03-10 19:38:49 +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 8c16b38262 Remove unused variables and parameters.
llvm-svn: 96780
2010-02-22 04:11:59 +00:00
Dan Gohman 740909be2d This cast<Instruction> is unnecessary.
llvm-svn: 96771
2010-02-22 02:07:36 +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
Dan Gohman c43d264cc0 Hoist this loop-invariant logic out of the loop.
llvm-svn: 96614
2010-02-18 21:34:02 +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
Dan Gohman 45774ce0ad Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.

llvm-svn: 95975
2010-02-12 10:34:29 +00:00
Dan Gohman 4a618827de Fix "the the" and similar typos.
llvm-svn: 95781
2010-02-10 16:03:48 +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 b5358003fb Set Changed properly after calling DeleteDeadPHIs.
llvm-svn: 92735
2010-01-05 16:31:45 +00:00
David Greene 0dd384cfd0 Change errs() to dbgs().
llvm-svn: 92609
2010-01-05 01:27:06 +00:00
Dan Gohman 18fa5686f6 Add Loop contains utility methods for testing whether a loop
contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

llvm-svn: 91654
2009-12-18 01:24:09 +00:00