Commit Graph

59 Commits

Author SHA1 Message Date
Nick Lewycky 367f98f000 Teach LazyValueInfo that allocas aren't NULL. Over all of llvm-test, this saves
half a million non-local queries, each of which would otherwise have triggered a
linear scan over a basic block.

Also fix a fixme for memory intrinsics which dereference pointers. With this,
we prove that a pointer is non-null because it was dereferenced by an intrinsic
112 times in llvm-test.

llvm-svn: 123533
2011-01-15 09:16:12 +00:00
Owen Anderson 6f060afbbd Reorder, rename, and document some members to make this easier to follow.
llvm-svn: 122929
2011-01-05 23:26:22 +00:00
Owen Anderson e86dacf449 When computing the value on an edge, in certain cases LVI would fail to compute the value range
in the predecessor block, leading to an incorrect conclusion for the edge value.  Found by inspection.

llvm-svn: 122908
2011-01-05 21:37:18 +00:00
Owen Anderson 118ac80c81 Re-convert several of LazyValueInfo's internal maps to Dense{Map|Set}, and fix the issue in
hasBlockValue() that was causing iterator invalidations.  Many thanks to Dimitry Andric for
tracking down those invalidations!

llvm-svn: 122906
2011-01-05 21:15:29 +00:00
Owen Anderson c6beda80ff Speculatively revert the use of DenseMap in LazyValueInfo, which may be causing Linux self-host failures.
llvm-svn: 122291
2010-12-20 23:53:19 +00:00
Owen Anderson 9be3ec6264 Attempt to appease the DragonEgg buildbots.
llvm-svn: 122288
2010-12-20 23:23:18 +00:00
Owen Anderson 813a2c45a8 Convert one of LVI's primary maps to a DenseMap, now that we know are more assured of iterator stability.
llvm-svn: 122273
2010-12-20 21:30:54 +00:00
Owen Anderson d83f98a51e More LVI cleanups, including trying to simplify the process of maintaining the OverDefinedCache.
llvm-svn: 122256
2010-12-20 19:33:41 +00:00
Owen Anderson 64c2c5798a Reuse the reference into the LVI cache throughout the solver subsystem. This is much easier to
verify as being safe thanks its recent de-recursivization.

llvm-svn: 122254
2010-12-20 18:18:16 +00:00
Nick Lewycky 55a700b0cf Make LazyValueInfo non-recursive.
llvm-svn: 122120
2010-12-18 01:00:40 +00:00
Dan Gohman a4fcd2418d Move Value::getUnderlyingObject to be a standalone
function so that it can live in Analysis instead of
VMCore.

llvm-svn: 121885
2010-12-15 20:02:24 +00:00
Nick Lewycky 11678bd299 Clean up some of LVI:
* mergeIn now uses constant folding for constants that are provably not-equal.
 * sink some sanity checks from the get*() methods into the mark*() methods, to ensure that we never have a constant/notconstant ConstantInt
 * some textual cleanups, whitespace changes, removing "else" after return, that sort of thing.

llvm-svn: 121877
2010-12-15 18:57:18 +00:00
Owen Anderson c7ed4dc932 Take the first step towards making LVI non-recursive: get rid of the LVIQuery abstraction.
llvm-svn: 121357
2010-12-09 06:14:58 +00:00
Owen Anderson df7a4f2515 Now with fewer extraneous semicolons!
llvm-svn: 115996
2010-10-07 22:25:06 +00:00
Owen Anderson 140296f5c0 It is possible, under specific circumstances involving ptrtoint ConstantExpr's, for LVI to end up trying to merge
a Constant into a ConstantRange.  Handle this conservatively for now, rather than asserting.  The testcase is
more complex that I would like, but the manifestation of the problem is sensitive to iteration orders and the state of the
LVI cache, and I have not been able to reproduce it with manually constructed or simplified cases.

Fixes PR8162.

llvm-svn: 114103
2010-09-16 18:28:33 +00:00
Owen Anderson a74fa15f32 Clean up some of the PassRegistry implementation, and pImpl-ize it to reduce #include clutter
and exposing internal details.

llvm-svn: 113252
2010-09-07 19:16:25 +00:00
Nick Lewycky ad48e01eef Add completely hokey binary-and and binary-or operations to ConstantRange and
teach LazyValueInfo to use them.

llvm-svn: 113196
2010-09-07 05:39:02 +00:00
Chris Lattner 65b48b5dfc zap dead code.
llvm-svn: 113073
2010-09-04 18:12:00 +00:00
Owen Anderson c725462245 Add support for simplifying a load from a computed value to a load from a global when it
is provable that they're equivalent.  This fixes PR4855.

llvm-svn: 112994
2010-09-03 19:08:37 +00:00
Owen Anderson 2912df072d Remove incorrect and poorly tested code for trying to reason about values on default edges of
switches.  Just return the conservatively correct answer.

llvm-svn: 112876
2010-09-02 22:16:52 +00:00
Owen Anderson a8c896b704 Fix a bug in LazyValueInfo that CorrelatedValuePropagation exposed: In the LVI lattice, undef and the full set ConstantRange should not
be treated as equivalent.

llvm-svn: 112843
2010-09-02 18:23:58 +00:00
Owen Anderson 9517943d11 It is possible to try to merge a not-constant with a constantrage, when dealing with ptrtoint ConstantExpr's.
Unfortunately, the only testcase I have for this is huge and doesn't reduce well because the error is
sensitive to iteration-order issues, since the problem only occurs when merging values in a particular order.

llvm-svn: 112489
2010-08-30 17:03:45 +00:00
Owen Anderson 38f6b7fe3b Improve the precision of getConstant().
llvm-svn: 112323
2010-08-27 23:29:38 +00:00
Owen Anderson 6ebbd92380 Use LVI to eliminate conditional branches where we've tested a related condition previously. Update tests for this change.
This fixes PR5652.

llvm-svn: 112270
2010-08-27 17:12:29 +00:00
Owen Anderson 4afea9e3c6 In the default address space, any GEP off of null results in a trap value if you try to load it. Thus,
any load in the default address space that completes implies that the base value that it GEP'd from
was not null.

llvm-svn: 112015
2010-08-25 01:16:47 +00:00
Owen Anderson a10000006e NULL loads are only invalid in the default address space.
llvm-svn: 111972
2010-08-24 22:00:55 +00:00
Owen Anderson b695c83de9 Add support for inferring values for the default cases of switches.
llvm-svn: 111971
2010-08-24 21:59:42 +00:00
Owen Anderson da34de1599 Add support for inferring that a load from a pointer implies that it is not null.
llvm-svn: 111959
2010-08-24 20:47:29 +00:00
Owen Anderson c62f704576 Don't assume that all constants with integer types are ConstantInts.
llvm-svn: 111906
2010-08-24 07:55:44 +00:00
Owen Anderson 80d19f0905 Use ConstantRange to propagate information through value definitions.
llvm-svn: 111425
2010-08-18 21:11:37 +00:00
Owen Anderson 208636fa33 Inform LazyValueInfo whenever a block is deleted, to avoid dangling pointer issues.
llvm-svn: 111382
2010-08-18 18:39:01 +00:00
Owen Anderson fa7d44687f Fix another iterator invalidation that caused a *really* nasty miscompilation in 403.gcc.
llvm-svn: 111210
2010-08-16 23:42:33 +00:00
Owen Anderson 7b974a45db Fix a subtle use-after-free issue.
llvm-svn: 110863
2010-08-11 22:36:04 +00:00
Owen Anderson 0bd61240e9 Improve indentation.
llvm-svn: 110778
2010-08-11 04:24:25 +00:00
Owen Anderson 5f1dd0967d Now that we're using ConstantRange to represent potential values, make use of that represenation to
create constraints from comparisons other than eq/neq.

llvm-svn: 110742
2010-08-10 23:20:01 +00:00
Owen Anderson 185fe00633 Switch over to using ConstantRange to track integral values.
llvm-svn: 110714
2010-08-10 20:03:09 +00:00
Owen Anderson 8afac043fb Add ConstantRange information to the debugging output.
llvm-svn: 110598
2010-08-09 20:50:46 +00:00
Owen Anderson 0f306a45ad Add the beginnings of infrastructure for range tracking.
llvm-svn: 110388
2010-08-05 22:59:19 +00:00
Owen Anderson c3a1413ea1 Split the tag and value members of LVILatticeVal in preparation for expanding the lattice to something that won't fit in two bits.
llvm-svn: 110383
2010-08-05 22:10:46 +00:00
Owen Anderson c1561b8400 Add an initial implementation of PHI translation for LazyValueInfo. This involves rolling back some
of my earlier data structure improvements until I can ensure that there are no iterator invalidation problems.

llvm-svn: 109935
2010-07-30 23:59:40 +00:00
Owen Anderson e4a0ab69d2 Revert my last two patches to LVI, which recent changes have exposed a miscompilation in.
llvm-svn: 109889
2010-07-30 20:56:07 +00:00
Owen Anderson a44f49f189 Pass the queried value by argument rather than in a member, in preparation for supporting PHI translation.
llvm-svn: 109701
2010-07-28 23:50:08 +00:00
Owen Anderson 6982dd4e1f Get rid of LVIQuery as a distinct data structure, so that we don't have to initialize a new set of maps on every query.
llvm-svn: 109679
2010-07-28 22:07:25 +00:00
Owen Anderson aac5a72139 Rearrange several datastructures in LazyValueInfo to improve compile time.
This is still not perfect, but better than it was before.

llvm-svn: 109563
2010-07-27 23:58:11 +00:00
Owen Anderson aa7f66ba67 Add an initial implementation of LazyValueInfo updating for JumpThreading. Disabled for now.
llvm-svn: 109424
2010-07-26 18:48:03 +00:00
Owen Anderson a57b97e7e7 Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
llvm-svn: 109045
2010-07-21 22:09:45 +00:00
David Greene 37e9809294 Convert debug messages to use dbgs(). Generally this means
s/errs/dbgs/g except for certain special cases.

llvm-svn: 92040
2009-12-23 20:43:58 +00:00
Chris Lattner e58c05780e typo spotted by duncan.
llvm-svn: 88884
2009-11-16 03:51:42 +00:00
Chris Lattner 7735878591 teach LVI to infer edge information from switch instructions.
This allows JT to eliminate a ton of infeasible edges when
handling code like the templates in PatternMatch.h

llvm-svn: 88869
2009-11-15 20:02:12 +00:00
Chris Lattner b0c0a0df3e fix a logic error that would cause LVI-JT to miscompile
some conditionals

llvm-svn: 88868
2009-11-15 20:01:24 +00:00