Commit Graph

129 Commits

Author SHA1 Message Date
Andrew Trick
e62289b98f When SCEV can determine the loop test is X < X, set ExactBECount=0.
When ExactBECount is a constant, use it for MaxBECount.
When MaxBECount cannot be computed, replace it with ExactBECount.
Fixes PR9424.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127342 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 17:29:58 +00:00
Chris Lattner
8ebaf90958 teach SCEV that the scale and addition of an inbounds gep don't NSW.
This fixes a FIXME in scev-aa.ll (allowing a new no-alias result) and
generally makes things more precise.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125449 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13 03:14:49 +00:00
Chris Lattner
1021236c74 Per discussion with Dan G, inbounds geps *certainly* can have
unsigned overflow (e.g. "gep P, -1"), and while they can have
signed wrap in theoretical situations, modelling an AddRec as
not having signed wrap is going enough for any case we can 
think of today.  In the future if this isn't enough, we can
revisit this.  Modeling them as having NUW isn't causing any
known problems either FWIW.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125410 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-11 21:43:33 +00:00
Nick Lewycky
76167af9b1 Simplify some code with no functionality change. Make the test a lot more
robust against smarter optimizations, using the power of FileCheck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124081 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 20:06:05 +00:00
Nick Lewycky
630d85a78c Use value ranges to fold ext(trunc) in SCEV when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124062 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-23 06:20:19 +00:00
Tobias Grosser
e906921480 Implement requiredTransitive
The PassManager did not implement the transitivity of requiredTransitive. This
was unnoticed since 2006.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123942 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-20 21:03:22 +00:00
Nick Lewycky
5c6fc1cab7 Similarly, analyze truncate through multiply.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123842 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-19 18:56:00 +00:00
Nick Lewycky
30aa8b13c9 Add a missed SCEV fold that is required to continue analyzing the IR produced
by indvars through the scev expander.

trunc(add x, y) --> add(trunc x, y). Currently SCEV largely folds the other way
which is probably wrong, but preserved to minimize churn. Instcombine doesn't
do this fold either, demonstrating a missed optz'n opportunity on code doing
add+trunc+add.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123838 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-19 16:59:46 +00:00
Nick Lewycky
73f565e754 Add a missing SCEV simplification sext(zext x) --> zext x.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123832 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-19 15:56:12 +00:00
Eric Christopher
48eec43fdb Revert the testcase from the previous reverted commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123227 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 09:20:44 +00:00
Chris Lattner
e70d7c2201 add a testcase I missed in previous commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123143 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-09 23:52:31 +00:00
Chris Lattner
6d5a2411aa teach SCEV analysis of PHI nodes that PHI recurences formed
with GEP instructions are always NUW, because PHIs cannot wrap
the end of the address space.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123105 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-09 02:28:48 +00:00
Chris Lattner
f1859891b7 reduce indentation. Print <nuw> and <nsw> when dumping SCEV AddRec's
that have the bit set.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123104 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-09 02:16:18 +00:00
Chris Lattner
042ff0358d remove some noise from tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112889 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 22:35:33 +00:00
Dan Gohman
4ee87398e8 When analyzing loop exit conditions combined with and and or, don't
make any assumptions about when the two conditions will agree on when
to permit the loop to exit. This fixes PR7845.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110758 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-11 00:12:36 +00:00
Dan Gohman
70eff63008 Revert the part of r107257 which introduced new logic for using
nsw and nuw flags from IR Instructions. On further consideration,
this isn't valid.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107298 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-30 17:27:11 +00:00
Dan Gohman
3e7f7cbea9 Add a testcase for scev-aa's new capability.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107258 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-30 07:17:47 +00:00
Dan Gohman
9d4588ffad Allow "exhaustive" trip count evaluation on phi nodes with all
constant operands.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106537 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-22 13:15:46 +00:00
Dan Gohman
b92654d9c9 Fix ScalarEvolution's "exhaustive" trip count evaluation code to avoid
assuming that loops are in canonical form, as ScalarEvolution doesn't
depend on LoopSimplify itself. Also, with indirectbr not all loops can
be simplified. This fixes PR7416.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106389 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-19 14:17:24 +00:00
Dan Gohman
3bf63768e5 Revert r106304 (105548 and friends), which are the SCEVComplexityCompare
optimizations. There is still some nondeterminism remaining.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106306 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18 19:54:20 +00:00
Dan Gohman
78db186d2d Reapply 105540, 105542, and 105548, and revert r105732.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106304 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-18 19:26:04 +00:00
Daniel Dunbar
ced8db2a2b Workaround SCEV non-determinism on this test, for now, to get buildbots back to
green. Dan, please revert this once the real problem is fixed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105732 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-09 17:54:40 +00:00
Dan Gohman
4d52c6d622 Optimize ScalarEvolution's SCEVComplexityCompare predicate: don't go
scrounging through SCEVUnknown contents and SCEVNAryExpr operands;
instead just do a simple deterministic comparison of the precomputed
hash data.

Also, since this is more precise, it eliminates the need for the slow
N^2 duplicate detection code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105540 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-07 19:06:13 +00:00
Dan Gohman
585c40129f Add a comment to this test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102387 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-26 21:37:43 +00:00
Dan Gohman
9f93d30a26 ScalarEvolution support for <= and >= loops.
Also, generalize ScalarEvolutions's min and max recognition to handle
some new forms of min and max that this change makes more common.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102234 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-24 03:09:42 +00:00
Dan Gohman
ddb3eafc32 Don't attempt to analyze values which are obviously undef. This fixes some
assertion failures in extreme cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102042 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-22 01:35:11 +00:00
Dan Gohman
27dead44e0 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101030 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-12 07:49:36 +00:00
Dan Gohman
4ecbca558f Avoid analyzing instructions in blocks not reachable from the entry block.
They are lots of trouble, and they don't matter. This fixes PR6559.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98103 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-09 23:46:50 +00:00
Dan Gohman
00cb5b7245 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96683 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-19 18:12:07 +00:00
Dan Gohman
8a977e2edd -disable-output is no longer needed with -analyze.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94574 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-26 19:25:59 +00:00
Dan Gohman
52fddd3e36 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94512 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-26 04:40:18 +00:00
Dan Gohman
3073329c53 Use WriteAsOperand instead of getName() to print loop header names,
so that unnamed blocks are handled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93059 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-09 18:17:45 +00:00
Dan Gohman
0488ecdd16 Add a comment about A[i+(j+1)].
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90185 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-01 01:38:10 +00:00
Chris Lattner
856a72cf38 update status of this. basicaa is much improved now,
only missing the one form (in this testcase).  Dan, do you
consider this example to be important?



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89953 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-26 16:42:00 +00:00
Kenneth Uildriks
b908f8ad6a Make opt default to not adding a target data string and update tests that depend on target data to supply it within the test
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85900 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-03 15:29:06 +00:00
Edward O'Callaghan
4ea7d4c3eb Convert Analysis tests to FileCheck in regards to PR5307.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85241 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-27 14:54:46 +00:00
Dan Gohman
1f96e67f78 Teach ScalarEvolution how to reason about no-wrap flags on loops
where the induction variable has a non-unit stride, such as {0,+,2}, and
there are expressions such as {1,+,2} inside the loop formed with
or or add nsw operators.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82151 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-17 18:05:20 +00:00
Dan Gohman
f2f6ce65b7 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81537 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-11 18:01:28 +00:00
Dan Gohman
3e054fe9ef Use opt -S instead of piping bitcode output through llvm-dis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81257 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 22:34:10 +00:00
Dan Gohman
b1e1e82c54 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81226 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 16:50:01 +00:00
Dan Gohman
2385e0e22c Create a ScalarEvolution-based AliasAnalysis implementation.
This is a simple AliasAnalysis implementation which works by making
ScalarEvolution queries. ScalarEvolution has a more complete understanding
of arithmetic than BasicAA's collection of ad-hoc checks, so it handles
some cases that BasicAA misses, for example p[i] and p[i+1] within the
same iteration of a loop.

This is currently experimental. It may be that the main use for this pass
will be to help find cases where BasicAA can be profitably extended, or
to help in the development of the overall AliasAnalysis infrastructure,
however it's also possible that it could grow up to become a directly
useful pass.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80098 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-26 14:53:06 +00:00
Dan Gohman
7a7be366a7 Loosen up the regex for this test so that it doesn't implicitly
depend on TargetData information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79491 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-19 23:19:36 +00:00
Dan Gohman
683e922d29 Make LLVM Assembly dramatically easier to read by aligning the comments,
using formatted_raw_ostream's PadToColumn.

Before:

bb1:            ; preds = %bb
  %2 = sext i32 %i.01 to i64            ; <i64> [#uses=1]
  %3 = getelementptr double* %p, i64 %2         ; <double*> [#uses=1]
  %4 = load double* %3, align 8         ; <double> [#uses=1]
  %5 = fmul double %4, 1.100000e+00             ; <double> [#uses=1]
  %6 = sext i32 %i.01 to i64            ; <i64> [#uses=1]
  %7 = getelementptr double* %p, i64 %6         ; <double*> [#uses=1]

After:

bb1:                                        ; preds = %bb
  %2 = sext i32 %i.01 to i64                ; <i64> [#uses=1]
  %3 = getelementptr double* %p, i64 %2     ; <double*> [#uses=1]
  %4 = load double* %3, align 8             ; <double> [#uses=1]
  %5 = fmul double %4, 1.100000e+00         ; <double> [#uses=1]
  %6 = sext i32 %i.01 to i64                ; <i64> [#uses=1]
  %7 = getelementptr double* %p, i64 %6     ; <double*> [#uses=1]

Several tests required whitespace adjustments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78816 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-12 17:23:50 +00:00
Dan Gohman
59858cf792 Change the assembly syntax for nsw, nuw, and exact, putting them
after their associated opcodes rather than before. This makes them
a little easier to read.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77194 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-27 16:11:46 +00:00
Dan Gohman
19378d622e When attempting to sign-extend an addrec by interpreting
the step value as unsigned, the start value and the addrec
itself still need to be treated as signed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77078 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-25 16:03:30 +00:00
Dan Gohman
eb490a7aa3 Teach ScalarEvolution to make use of no-overflow flags when
analyzing add recurrences.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77034 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-25 01:22:26 +00:00
Dan Gohman
0f4b285a5b Replace the original ad-hoc code for determining whether (v pred w) implies
(x pred y) with more thorough code that does more complete canonicalization
before resorting to range checks. This helps it find more cases where
the canonicalized expressions match.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76671 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-21 23:03:19 +00:00
Dan Gohman
19211b47cc Add a testcase for PR4569, which is now fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76526 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-21 00:50:52 +00:00
Dan Gohman
08d4ec0b20 Add testcases for PR4538, PR4537, and PR4534.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75533 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-13 22:30:31 +00:00
Nick Lewycky
d1ec98923e When comparing constants, consider a less wide constant to be "less complex"
than a wider one, before trying to compare their contents which will crash
if their sizes are different.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74792 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-04 17:24:52 +00:00