Commit Graph

201 Commits

Author SHA1 Message Date
Arnold Schwaighofer
2b475922e6 Optimistically analyse Phi cycles
Analyse Phis under the starting assumption that they are NoAlias. Recursively
look at their inputs.
If they MayAlias/MustAlias there must be an input that makes them so.

Addresses bug 14351.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169788 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-10 23:02:41 +00:00
Hal Finkel
c37f502d48 Phi speculation improvement for BasicAA
This is a partial solution to PR14351. It removes some of the special
significance of the first incoming phi value in the phi aliasing checking logic
in BasicAA. In the context of a loop, the old logic assumes that the first
incoming value is the interesting one (meaning that it is the one that comes
from outside the loop), but this is often not the case.  With this change, we
now test first the incoming value that comes from a block other than the parent
of the phi being tested.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168245 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-17 02:33:15 +00:00
Richard Osborne
544533301e Don't infer whether a value is captured in the current function from the
'nocapture' attribute.

The nocapture attribute only specifies that no copies are made that
outlive the function. This isn't the same as there being no copies at all.
This fixes PR14045.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167381 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-05 10:48:24 +00:00
Arnold Schwaighofer
3d5f96ee1b BasicAA: Recognize cyclic NoAlias phis
Enhances basic alias analysis to recognize phis whose first incoming values are
NoAlias and whose other incoming values are just the phi node itself through
some amount of recursion.

Example: With this change basicaa reports that ptr_phi and ptr_phi2 do not alias
each other.

bb:
 ptr = ptr2 + 1

loop:
  ptr_phi = phi [bb, ptr], [loop, ptr_plus_one]
  ptr2_phi = phi [bb, ptr2], [loop, ptr2_plus_one]
  ...
  ptr_plus_one = gep ptr_phi, 1
  ptr2_plus_one = gep ptr2_phi, 1

This enables the elimination of one load in code like the following:

extern int foo;

int test_noalias(int *ptr, int num, int* coeff) {
  int *ptr2 = ptr;
  int result = (*ptr++) * (*coeff--);
  while (num--) {
    *ptr2++ = *ptr;
    result +=  (*coeff--) * (*ptr++);
  }
  *ptr = foo;
  return result;
}

Part 2/2 of fix for PR13564.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163319 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 14:41:53 +00:00
Arnold Schwaighofer
029032693f BasicAA: GEPs of NoAlias'ing base ptr with equivalent indices are NoAlias
If we can show that the base pointers of two GEPs don't alias each other using
precise analysis and the indices and base offset are equal then the two GEPs
also don't alias each other.
This is primarily needed for the follow up patch that analyses NoAlias'ing PHI
nodes.

Part 1/2 of fix for PR13564.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163317 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 14:31:51 +00:00
Chandler Carruth
49589f0d0e Convert the uses of '|&' to use '2>&1 |' instead, which works on old
versions of Bash. In addition, I can back out the change to the lit
built-in shell test runner to support this.

This should fix the majority of fallout on Darwin, but I suspect there
will be a few straggling issues.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159544 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 18:37:59 +00:00
Bill Wendling
d5cc8b81ca FileCheck-ize these tests. Harden some of them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155432 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-24 09:15:38 +00:00
Eli Friedman
cd38485b8a Duncan pointed out that if the alignment isn't explicitly specified, it defaults to the ABI alignment. Given that, make this code a bit more aggressive in such cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151584 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-27 23:16:46 +00:00
Eli Friedman
1680a24e53 Teach BasicAA about the LLVM IR rules that allow reading past the end of an object given sufficient alignment. Fixes PR12098.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151553 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-27 20:46:07 +00:00
Eli Bendersky
0f0c411079 Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.
Patch reviewed by Daniel Dunbar. It will be followed by additional cleanup patches.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150664 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16 06:28:33 +00:00
Chandler Carruth
ddbc274169 Manually upgrade the test suite to specify the flag to cttz and ctlz.
I followed three heuristics for deciding whether to set 'true' or
'false':

- Everything target independent got 'true' as that is the expected
  common output of the GCC builtins.
- If the target arch only has one way of implementing this operation,
  set the flag in the way that exercises the most of codegen. For most
  architectures this is also the likely path from a GCC builtin, with
  'true' being set. It will (eventually) require lowering away that
  difference, and then lowering to the architecture's operation.
- Otherwise, set the flag differently dependending on which target
  operation should be tested.

Let me know if anyone has any issue with this pattern or would like
specific tests of another form. This should allow the x86 codegen to
just iteratively improve as I teach the backend how to differentiate
between the two forms, and everything else should remain exactly the
same.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146370 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-12 11:59:10 +00:00
Chris Lattner
d2bf432b2b Upgrade syntax of tests using volatile instructions to use 'load volatile' instead of 'volatile load', which is archaic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145171 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-27 06:54:59 +00:00
Eli Friedman
e6fadced87 PR10628: Fix getModRefInfo so it queries the underlying alias() implementation correctly while checking nocapture calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140666 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-28 00:34:27 +00:00
Eli Friedman
46cb5afdcd Enhance alias analysis for atomic instructions a bit. Upgrade a couple alias-analysis tests to the new atomic instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140557 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-26 20:15:28 +00:00
Eli Friedman
81ac8ddc67 Fix the logic in BasicAliasAnalysis::aliasGEP for comparing GEP's with variable differences so that it actually does something sane. Fixes PR10881.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139276 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-08 02:23:31 +00:00
Owen Anderson
69acc93b3d Teach BasicAA about the aliasing properties of memset_pattern16.
Fixes PR10872 and <rdar://problem/10065079>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139204 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-06 23:33:25 +00:00
Rafael Espindola
aecfdd3068 Move the loads after the calls so that the fix for
PR10292 doesn't show that the loads don't alias
the allocas.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134852 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-09 23:53:58 +00:00
Rafael Espindola
4fe509431b Use CHECK-NEXT.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134850 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-09 22:56:50 +00:00
Chris Lattner
b85e4eba85 rip out a ton of intrinsic modernization logic from AutoUpgrade.cpp, which is
for pre-2.9 bitcode files.  We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.

As usual, updating the testsuite is a PITA.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133337 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-18 06:05:24 +00:00
Chris Lattner
d589099eec make the asmparser reject function and type redefinitions. 'Merging' hasn't been
needed since llvm-gcc 3.4 days.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133248 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 07:06:44 +00:00
Chris Lattner
7a1b9bdd2b Remove support for using "foo" as symbols instead of %"foo". This is ancient
syntax and has been long obsolete.  As usual, updating the tests is the nasty
part of this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133242 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 06:36:20 +00:00
Chris Lattner
26b0000166 manually upgrade a bunch of tests to modern syntax, and remove some that
are either unreduced or only test old syntax.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133228 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 03:14:27 +00:00
Dan Gohman
5f1312c36e Reapply r131781, now that the GVN bug with partially-aliasing loads
is disabled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132632 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 06:50:18 +00:00
Dan Gohman
9a9d218ed0 Revert r131781 again. Apparently there is more going on here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132625 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 05:11:22 +00:00
Dan Gohman
c122c625ce Reapply r131781 (revert r131809), now that some BasicAA shortcomings
it exposed are fixed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132611 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 00:46:31 +00:00
Dan Gohman
1fc18d71de Fix BasicAA's recursion detection so that it doesn't pessimize
queries in the case of a DAG, where a query reaches a node
visited earlier, but it's not on a cycle. This avoids
MayAlias results in cases where BasicAA is expected to
return MustAlias or PartialAlias in order to protect TBAA.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132609 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 00:31:50 +00:00
Dan Gohman
965fefa1ad When merging MustAlias and PartialAlias, chose PartialAlias instead
of conservatively choosing MayAlias.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132579 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-03 20:17:36 +00:00
Dan Gohman
9adf151b3d Make DecomposeGEPExpression check SimplifyInstruction only
after checking for a GEP, so that it matches what GetUnderlyingObject
does. This fixes an obscure bug turned up by bugpoint in the testcase
for PR9931.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131971 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-24 18:24:08 +00:00
Chris Lattner
4d9255057a I missed a checking with my GVN change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131851 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-22 07:20:02 +00:00
Duncan Sands
d22920aae8 Revert commit 131781, to see if it fixes the x86-64 dragonegg buildbot.
Original log message:
When BasicAA can determine that two pointers have the same base but
differ by a dynamic offset, return PartialAlias instead of MayAlias.
See the comment in the code for details. This fixes PR9971.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131809 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-21 20:54:46 +00:00
Dan Gohman
424b777171 When BasicAA can determine that two pointers have the same base but
differ by a dynamic offset, return PartialAlias instead of MayAlias.
See the comment in the code for details. This fixes PR9971.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131781 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-21 01:05:08 +00:00
Dan Gohman
1d7e818a38 Teach BasicAA about arm.neon.vld1 and vst1.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130327 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-27 20:44:28 +00:00
Dan Gohman
bddc1ca18a When analyzing functions known to only access argument pointees,
only check arguments with pointer types. Update the documentation
of IntrReadArgMem reflect this.

While here, add support for TBAA tags on intrinsic calls.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130317 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-27 18:39:03 +00:00
Eli Friedman
0e382192c1 PR9634: Don't unconditionally tell the AliasSetTracker that the PreheaderLoad
is equivalent to any other relevant value; it isn't true in general.
If it is equivalent, the LoopPromoter will tell the AST the equivalence.
Also, delete the PreheaderLoad if it is unused.

Chris, since you were the last one to make major changes here, can you check
that this is sane?



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129049 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 01:35:06 +00:00
Anders Carlsson
fa4ebd396d Revert r128140 for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128149 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-23 15:51:12 +00:00
Anders Carlsson
90af342061 A global variable with internal linkage where all uses are in one function and whose address is never taken is a non-escaping local object and can't alias anything else.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128140 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-23 02:19:48 +00:00
Dan Gohman
640b9c8fe2 Add another rdar number.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124125 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24 17:54:01 +00:00
Dan Gohman
615da1a9bc Teach BasicAA to return PartialAlias in cases where both pointers
are pointing to the same object, one pointer is accessing the entire
object, and the other is access has a non-zero size. This prevents
TBAA from kicking in and saying NoAlias in such cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123775 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-18 21:16:06 +00:00
Chris Lattner
895ace08e0 fix rdar://8813415 - a miscompilation of 164.gzip that loop-idiom
exposed.  It turns out to be a latent bug in basicaa, scary.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122772 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 21:03:33 +00:00
Chris Lattner
135bf42187 filecheckize
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122771 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-03 21:01:26 +00:00
Duncan Sands
fea3b218d6 Move Sub simplifications and additional Add simplifications out of
instcombine and into InstructionSimplify.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121861 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 14:07:39 +00:00
Chris Lattner
9fd9f9fd57 remove fixme comment too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120493 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 23:25:01 +00:00
Chris Lattner
7fd16cef85 check in *all* files. This is now handled by my previous DSE commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120492 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 23:23:59 +00:00
Dan Gohman
32d1fe52e2 Delete unneeded ssp attributes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118836 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-11 21:08:46 +00:00
Dan Gohman
c1be92f3bb Make BasicAliasAnalysis a normal AliasAnalysis implementation which
does normal initialization and normal chaining. Change the default
AliasAnalysis implementation to NoAlias.

Update StandardCompileOpts.h and friends to explicitly request
BasicAliasAnalysis.

Update tests to explicitly request -basicaa.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116720 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-18 18:04:47 +00:00
Eli Friedman
39e30124e5 PR7959: Handle negative scales in GEPs correctly in BasicAA for non-64-bit
targets.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114015 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-15 20:08:03 +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
Michael J. Spencer
17d3983730 Fix constant-over-index.ll test on windows.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112483 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30 15:08:02 +00:00
Chris Lattner
2215c607c3 refix PR1143 by making basicaa analyze zexts of indices aggresively,
which I broke with a recent patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111452 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18 23:09:49 +00:00
Chris Lattner
285d06ca93 fix a buggy test
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111354 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18 04:55:12 +00:00