Commit Graph

34 Commits

Author SHA1 Message Date
Duncan Sands
1df9859c40 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 11:11:14 +00:00
Duncan Sands
5d8ea117a0 Be less stingy as to how many selects and phi nodes we
are prepared to look through.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92898 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07 05:48:42 +00:00
Duncan Sands
e10920d678 Fix a README item: have functionattrs look through selects and
phi nodes when deciding which pointers point to local memory.
I actually checked long ago how useful this is, and it isn't
very: it hardly ever fires in the testsuite, but since Chris
wants it here it is!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92836 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06 15:37:47 +00:00
Duncan Sands
7c422ac216 Partially address a README by having functionattrs consider calls to
memcpy, memset and other intrinsics that only access their arguments
to be readnone if the intrinsic's arguments all point to local memory.
This improves the testcase in the README to readonly, but it could in
theory be made readnone, however this would involve more sophisticated
analysis that looks through the memcpy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92829 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06 08:45:52 +00:00
Dan Gohman
f94b5edc45 Extend CaptureTracking to indicate when a value is never stored, even
if it is not ultimately captured. Teach BasicAliasAnalysis that a 
local object address which does not escape and is never stored does
not alias with a value resulting from a load.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89398 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-19 21:57:48 +00:00
Victor Hernandez
f006b183e2 Rename MallocFreeHelper as MemoryBuiltins
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85286 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-27 20:05:49 +00:00
Victor Hernandez
f2becca90b Rename MallocHelper as MallocFreeHelper, since it now also identifies calls to free()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85181 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26 23:58:56 +00:00
Nick Lewycky
f5a86f45e7 Remove includes of Support/Compiler.h that are no longer needed after the
VISIBILITY_HIDDEN removal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85043 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-25 06:57:41 +00:00
Nick Lewycky
6726b6d75a Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.
Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85042 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-25 06:33:48 +00:00
Victor Hernandez
93bb60d379 Malloc calls are marked NoAlias, so the code below the isMalloc() check makes it redundant. Removing the isMalloc() check.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84541 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-19 21:47:22 +00:00
Victor Hernandez
a276c603b8 Remove MallocInst from LLVM Instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84299 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-17 01:18:07 +00:00
Chris Lattner
439044f4f9 remove special handling of bitcast(malloc), it will be handled
when the loop inspects the bitcast operand.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82928 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-27 21:29:28 +00:00
Chris Lattner
2a9325ff2f unlike the malloc instruction, "malloc" calls do not claim to be readonly, just nounwind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82927 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-27 21:23:38 +00:00
Victor Hernandez
83d63919bd Enhance transform passes so that they apply the same tranforms to malloc calls as to MallocInst.
Reviewed by Dan Gohman.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82300 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-18 22:35:49 +00:00
Chris Lattner
98a27ce03f simplify some code by making the SCCNodes set contain Function*'s
instead of CallGraphNode*'s.  This also papers over a callgraph
problem where a pass (in this case, MemCpyOpt) introduces a new
function into the module (llvm.memset.i64) but doesn't add it to
the call graph (nor should it, since it is a function pass).

While it might be a good idea for MemCpyOpt to not synthesize 
functions in a runOnFunction(), there is no need for FunctionAttrs
to be boneheaded, so fix it there.  This fixes an assertion building
176.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80535 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-31 04:09:04 +00:00
Chris Lattner
5095e3d1d1 Fix some nasty callgraph dangling pointer problems in
argpromotion and structretpromote.  Basically, when replacing
a function, they used the 'changeFunction' api which changes
the entry in the function map (and steals/reuses the callgraph
node).

This has some interesting effects: first, the problem is that it doesn't
update the "callee" edges in any callees of the function in the call graph.
Second, this covers for a major problem in all the CGSCC pass stuff, which 
is that it is completely broken when functions are deleted if they *don't*
reuse a CGN.  (there is a cute little fixme about this though :).

This patch changes the protocol that CGSCC passes must obey: now the CGSCC 
pass manager copies the SCC and preincrements its iterator to avoid passes
invalidating it.  This allows CGSCC passes to mutate the current SCC.  However
multiple passes may be run on that SCC, so if passes do this, they are now
required to *update* the SCC to be current when they return.

Other less interesting parts of this patch are that it makes passes update
the CG more directly, eliminates changeFunction, and requires clients of
replaceCallSite to specify the new callee CGN if they are changing it.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80527 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-31 00:19:58 +00:00
Duncan Sands
cfd0ebea27 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71077 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-06 08:42:00 +00:00
Duncan Sands
ee199f72bb This debug info special case should no longer
be needed now that these intrinsics are marked
as not accessing memory.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66420 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-09 11:57:08 +00:00
Nick Lewycky
4bfba9da0a Fix comments, pointed out by Duncan Sands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66381 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-08 17:08:09 +00:00
Nick Lewycky
199aa3c09c Mark function returns as noalias.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66369 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-08 06:20:47 +00:00
Devang Patel
cd11991203 Ignore debug info intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65908 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-03 00:28:44 +00:00
Duncan Sands
8556d2a7f1 BasicAliasAnalysis and FunctionAttrs were both
doing very similar pointer capture analysis.
Factor out the common logic.  The new version
is from FunctionAttrs since it does a better
job than the version in BasicAliasAnalysis


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62461 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-18 12:19:30 +00:00
Duncan Sands
b0cea8ff39 Remove alloca tracking from nocapture analysis. Not only
was it not very helpful, it was also wrong!  The problem
is shown in the testcase: the alloca might be passed to
a nocapture callee which dereferences it and returns the
original pointer.  But because it was a nocapture call we
think we don't need to track its uses, but we do.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61876 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-07 19:39:06 +00:00
Duncan Sands
acf984417f Reorder these.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61873 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-07 19:17:02 +00:00
Duncan Sands
00e7ea98c0 Use a switch rather than a sequence of "isa" tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61872 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-07 19:10:21 +00:00
Nick Lewycky
3b3b4e3f0f Any void readonly functions are provably dead, don't waste time adding
nocapture attributes to them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61610 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-03 17:05:32 +00:00
Duncan Sands
9c5a5b01b4 Load tracking means that the value analyzed may
not have pointer type.  In particular, it may
be the condition argument for a select or a GEP
index.  While I was unable to construct a testcase
for which some bits of the original pointer are
captured due to one of these, it's very very close
to being possible - so play safe and exclude these
possibilities.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61580 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-02 15:16:38 +00:00
Duncan Sands
338cd6ba6e When calculating 'nocapture' argument attributes, allow
the argument to be stored to an alloca by tracking uses
of the alloca.  This occurs 4 times (out of 7121, 0.05%)
in MultiSource/Applications, so may not be worth it.  On
the other hand, it is easy to do and fairly cheap.  The
functions it helps are: W_addcom and W_addlit in spiff;
process_args (argv) in d (make_dparser); ercPixConcealIMB
in JM/ldecod.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61570 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-02 11:54:37 +00:00
Duncan Sands
b2f2279056 Improve comments and reorganize a bit - no functionality
change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61569 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-02 11:46:24 +00:00
Nick Lewycky
6b05686283 Make adding nocapture a bit stronger. FreeInst is nocapture. Also,
functions that don't write can't leak a pointer except through 
the return value, so a void readonly function is implicitly nocapture.

Test these, and add a test that verifies that f1 calling f2 with an 
otherwise dead pointer gets both of them marked nocapture.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61552 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-02 03:46:56 +00:00
Duncan Sands
88e76757de Mention that this pass does escape analysis in the
leading comments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61548 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-01 20:45:19 +00:00
Duncan Sands
1010941954 Look through phi nodes and select instructions when
calculating nocapture attributes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61535 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-31 20:21:34 +00:00
Duncan Sands
17da06ffbd Don't analyze arguments already marked 'nocapture'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61532 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-31 18:08:59 +00:00
Duncan Sands
9e89ba31f1 Rename AddReadAttrs to FunctionAttrs, and teach it how
to work out (in a very simplistic way) which function
arguments (pointer arguments only) are only dereferenced
and so do not escape.  Mark such arguments 'nocapture'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61525 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-31 16:14:43 +00:00