Commit Graph

76 Commits

Author SHA1 Message Date
Chris Lattner
0ee443d169 The phi translated pointer can be computed when returning a partially cached result
instead of stored.  This reduces memdep memory usage, and also eliminates a bunch of
weakvh's.  This speeds up gvn on gcc.c-torture/20001226-1.c from 23.9s to 8.45s (2.8x)
on a different machine than earlier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91885 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-22 04:25:02 +00:00
Chris Lattner
dad451cb7c enhance NonLocalDepEntry to keep the per-block phi translated address
of the query.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90958 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 07:31:04 +00:00
Chris Lattner
e18b97121c change NonLocalDepEntry from being a typedef for an std::pair to be its
own small class.  No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90956 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 07:08:01 +00:00
Chris Lattner
05e15f8897 Switch GVN and memdep to use PHITransAddr, which correctly handles
phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90926 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 01:59:31 +00:00
Nick Lewycky
750e0e0ad0 Document that memory use intrinsics may also return Def results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90651 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-05 06:37:52 +00:00
Chris Lattner
dd696052f0 Enhance InsertPHITranslatedPointer to be able to return a list of newly
inserted instructions.  No functionality change until someone starts using it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90039 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-28 15:39:14 +00:00
Chris Lattner
6f7b210b25 Rework InsertPHITranslatedPointer to handle the recursive case, this
fixes PR5630 and sets the stage for the next phase of goodness (testcase
pending).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90019 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 22:05:15 +00:00
Chris Lattner
616613d7a4 teach GVN's load PRE to insert computations of the address in predecessors
where it is not available.  It's unclear how to get this inserted 
computation into GVN's scalar availability sets, Owen, help? :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89997 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 08:25:10 +00:00
Chris Lattner
62deff066c Fix phi translation in load PRE to agree with the phi
translation done by memdep, and reenable gep translation 
again.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89992 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-27 06:31:14 +00:00
Dan Gohman
81acc554b9 Fix a typo in a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77715 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-31 19:26:54 +00:00
Chris Lattner
6a0dcc1077 now that you can put a PointerIntPair in a SmallPtrSet, remove some
hackish workarounds from memdep


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67971 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-29 00:24:04 +00:00
Bill Wendling
9817b24e74 The operator<() and operator>() were reversing their tests. Have the test the correct way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62745 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-22 03:05:10 +00:00
Chris Lattner
9e59c64c14 Implement initial support for PHI translation in memdep. This means that
memdep keeps track of how PHIs affect the pointer in dep queries, which 
allows it to eliminate the load in cases like rle-phi-translate.ll, which
basically end up being:

BB1:
   X = load P
   br BB3
BB2:
   Y = load Q
   br BB3
BB3:
   R = phi [P] [Q]
   load R

turning "load R" into a phi of X/Y.  In addition to additional exposed
opportunities, this makes memdep safe in many cases that it wasn't before
(which is required for load PRE) and also makes it substantially more 
efficient.  For example, consider:


bb1:  // has many predecessors.
   P = some_operator()
   load P

In this example, previously memdep would scan all the predecessors of BB1
to see if they had something that would mustalias P.  In some cases (e.g.
test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end
up eliminating something.  In many other cases though, it would scan and not
find anything useful.  MemDep now stops at a block if the pointer is defined
in that block and cannot be phi translated to predecessors.  This causes it
to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not
scanning tons of stuff that is unlikely to be useful.  For example, this
speeds up GVN as a whole from 3.928s to 2.448s (60%)!.  IMO, scalar GVN 
should be enhanced to simplify the rle-must-alias pointer base anyway, which
would allow the loads to be eliminated.

In the future, this should be enhanced to phi translate through geps and 
bitcasts as well (as indicated by FIXMEs) making memdep even more powerful.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61022 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 03:35:32 +00:00
Chris Lattner
bc99be10b8 Teach GVN to invalidate some memdep information when it does an RAUW
of a pointer.  This allows is to catch more equivalencies.  For example,
the type_lists_compatible_p function used to require two iterations of
the gvn pass (!) to delete its 18 redundant loads because the first pass
would CSE all the addressing computation cruft, which would unblock the
second memdep/gvn passes from recognizing them.  This change allows
memdep/gvn to catch all 18 when run just once on the function (as is 
typical :) instead of just 3.

On all of 403.gcc, this bumps up the # reundandancies found from:

     63 gvn    - Number of instructions PRE'd
 153991 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted
to:
     63 gvn    - Number of instructions PRE'd
 154137 gvn    - Number of instructions deleted
  50185 gvn    - Number of loads deleted

+120 loads deleted isn't bad.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60799 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 22:06:23 +00:00
Chris Lattner
20d6f0982a Teach BasicAA::getModRefInfo(CallSite, CallSite) some
tricks based on readnone/readonly functions.

Teach memdep to look past readonly calls when analyzing
deps for a readonly call.  This allows elimination of a
few more calls from 403.gcc:

before:
     63 gvn    - Number of instructions PRE'd
 153986 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

after:
     63 gvn    - Number of instructions PRE'd
 153991 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

5 calls isn't much, but this adds plumbing for the next change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60794 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 21:19:42 +00:00
Chris Lattner
1559b3625b rename getNonLocalDependency -> getNonLocalCallDependency, and remove
pointer stuff from it, simplifying the code a bit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60783 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 19:38:05 +00:00
Chris Lattner
9863c3f507 rename getNonLocalPointerDepInternal -> getNonLocalPointerDepFromBB
and split its inner loop out into a new GetNonLocalInfoForBlock
function.  No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60751 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 07:47:11 +00:00
Chris Lattner
4012fdda13 use hte new pred cache to speed up the new non-local memdep
queries.  This speeds up GVN using the new queries (not yet
checked in) by just over 10%.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60743 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 06:28:49 +00:00
Chris Lattner
11dcd8d38d add another level of caching for non-local pointer queries, keeping
track of whether the CachedNonLocalPointerInfo for a block is specific
to a block.  If so, just return it without any pred scanning.  This is
good for a 6% speedup on GVN (when it uses this lookup method, which
it doesn't right now).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60695 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-08 07:31:50 +00:00
Dan Gohman
c765a5acad Use bool instead of int, now that it no longer evokes a warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60678 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 21:33:27 +00:00
Chris Lattner
e91a4881e1 fix a typo duncan noticed!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60671 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 18:21:37 +00:00
Chris Lattner
6290f5cac2 add support for caching pointer dependence queries. Nothing uses this yet
so it "can't" break anything.  That said, it does appear to work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60654 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 08:50:20 +00:00
Chris Lattner
9a193fd8ae Some internal refactoring to make it easier to cache results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60650 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 02:56:57 +00:00
Chris Lattner
7ebcf03246 Introduce a new MemDep::getNonLocalPointerDependency
method.  This will eventually take over load/store dep
queries from getNonLocalDependency.  For now it works
fine, but is incredibly slow because it does no caching.
Lets not switch GVN to use it until that is fixed :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60649 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 02:15:47 +00:00
Chris Lattner
e79be944c8 push the "pointer case" up the analysis stack a bit. This causes
duplication of logic (in 2 places) to determine what pointer a 
load/store touches.  This will be addressed in a future commit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60648 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 01:50:16 +00:00
Chris Lattner
8ef57c5faf Rename getCallSiteDependency -> getCallSiteDependencyFrom to
emphasize the scanning and make it more similar to 
getDependencyFrom
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60642 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 00:35:51 +00:00
Chris Lattner
aea5a2a22a make getDependencyFrom private.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60637 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 00:16:50 +00:00
Chris Lattner
b51deb929c Make a few major changes to memdep and its clients:
1. Merge the 'None' result into 'Normal', making loads
   and stores return their dependencies on allocations as Normal.
2. Split the 'Normal' result into 'Clobber' and 'Def' to
   distinguish between the cases when memdep knows the value is
   produced from when we just know if may be changed.
3. Move some of the logic for determining whether readonly calls
   are CSEs into memdep instead of it being in GVN.  This still
   leaves verification that the arguments are hte same to GVN to
   let it know about value equivalences in different contexts.
4. Change memdep's call/call dependency analysis to use 
   getModRefInfo(CallSite,CallSite) instead of doing something 
   very weak.  This only really matters for things like DSA, but
   someday maybe we'll have some other decent context sensitive
   analyses :)
5. This reimplements the guts of memdep to handle the new results.
6. This simplifies GVN significantly:
   a) readonly call CSE is slightly simpler
   b) I eliminated the "getDependencyFrom" chaining for load 
      elimination and load CSE doesn't have to worry about 
      volatile (they are always clobbers) anymore.
   c) GVN no longer does any 'lastLoad' caching, leaving it to 
      memdep.
7. The logic in DSE is simplified a bit and sped up.  A potentially
   unsafe case was eliminated.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60607 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-05 21:04:20 +00:00
Chris Lattner
6951381995 Make it illegal to call getDependency* on non-memory instructions
like binary operators.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60600 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-05 18:46:19 +00:00
Chris Lattner
0f41ad3bc9 cleanups suggested by duncan, thanks!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60353 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 16:55:19 +00:00
Chris Lattner
bf145d6e2b Reimplement the non-local dependency data structure in terms of a sorted
vector instead of a densemap.  This shrinks the memory usage of this thing
substantially (the high water mark) as well as making operations like
scanning it faster.  This speeds up memdep slightly, gvn goes from
3.9376 to 3.9118s on 403.gcc

This also splits out the statistics for the cached non-local case to
differentiate between the dirty and clean cached case.  Here's the stats
for 403.gcc:

  6153 memdep - Number of dirty cached non-local responses
169336 memdep - Number of fully cached non-local responses
162428 memdep - Number of uncached non-local responses

yay for caching :)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60313 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 01:15:42 +00:00
Chris Lattner
fd3dcbea06 Eliminate the DepResultTy abstraction. It is now completely
redundant with MemDepResult, and MemDepResult has a nicer interface.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60308 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 23:17:19 +00:00
Chris Lattner
d777d405cd Cache TargetData/AliasAnalysis in the pass instead of calling
getAnalysis<>.  getAnalysis<> is apparently extremely expensive.
Doing this speeds up GVN on 403.gcc by 16%!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60304 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 19:24:31 +00:00
Chris Lattner
4a69bade23 Two changes: Make getDependency remove QueryInst for a dirty record's
ReverseLocalDeps when we update it.  This fixes a regression test
failure from my last commit.

Second, for each non-local cached information structure, keep a bit that
indicates whether it is dirty or not.  This saves us a scan over the whole
thing in the common case when it isn't dirty.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60274 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 02:52:26 +00:00
Chris Lattner
25f4b2b7a3 introduce a typedef, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60272 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 02:30:50 +00:00
Chris Lattner
f68f310386 Change NonLocalDeps to be a densemap of pointers to densemap
instead of containing them by value.  This increases the density
(!) of NonLocalDeps as well as making the reallocation case 
faster.  This speeds up gvn on 403.gcc by 2% and makes room for
future improvements.

I'm not super thrilled with having to explicitly manage the new/delete
of the map, but it is necesary for the next change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60271 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 02:28:25 +00:00
Chris Lattner
73ec3cdd71 implement a fixme by introducing a new getDependencyFromInternal
method that returns its result as a DepResultTy instead of as a
MemDepResult.  This reduces conversion back and forth.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60266 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 01:26:32 +00:00
Chris Lattner
0e0a5b690c REmove an old fixme, resolve another fixme by adding liberal
comments about what this class does.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60264 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 01:17:08 +00:00
Chris Lattner
4f8c18c7c7 Eliminate the dropInstruction method, which is not needed any more.
Fix a subtle iterator invalidation bug I introduced in the last commit.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60258 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 23:30:39 +00:00
Chris Lattner
0ec48ddef2 implement some fixme's: when deleting an instruction with
an entry in the nonlocal deps map, don't reset entries
referencing that instruction to [dirty, null], instead, set
them to [dirty,next] where next is the instruction after the
deleted one.  Use this information in the non-local deps
code to avoid rescanning entire blocks.

This speeds up GVN slightly by avoiding pointless work.  On
403.gcc this makes GVN 1.5% faster. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60256 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 22:02:15 +00:00
Chris Lattner
396a4a55e5 Change MemDep::getNonLocalDependency to return its results as
a smallvector instead of a DenseMap.  This speeds up GVN by 5%
on 403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60255 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 21:33:22 +00:00
Chris Lattner
86b29ef64a reimplement getNonLocalDependency with a simpler worklist
formulation that is faster and doesn't require nonLazyHelper.
Much less code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60253 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 21:22:42 +00:00
Chris Lattner
233336ebc5 tidy up some variable names.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60243 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 09:22:14 +00:00
Chris Lattner
8c4652790e rename some maps.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60242 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 09:20:15 +00:00
Chris Lattner
5391a1d804 Split getDependency into getDependency and getDependencyFrom, the
former does caching, the later doesn't.  This dramatically simplifies
the logic in getDependency and getDependencyFrom.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60234 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 03:47:00 +00:00
Chris Lattner
7f52422a3c Now that DepType is private, we can start cleaning up some of its uses:
Document the Dirty value more precisely, use it for the uninitialized
DepResultTy value.  Change reverse mappings to be from an instruction*
instead of DepResultTy, and stop tracking other forms.  This makes it more
clear that we only care about the instruction cases.

Eliminate a DepResultTy,bool pair by using Dirty in the local case as well,
shrinking the map and simplifying the code.

This speeds up GVN by ~3% on 403.gcc.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60232 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 03:22:12 +00:00
Chris Lattner
4c72400625 Introduce and use a new MemDepResult class to hold the results of a memdep
query.  This makes it crystal clear what cases can escape from MemDep that
the clients have to handle.  This also gives the clients a nice simplified
interface to it that is easy to poke at.

This patch also makes DepResultTy and MemoryDependenceAnalysis::DepType
private, yay.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60231 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 02:29:27 +00:00
Chris Lattner
39f372e23e Reimplement the internal abstraction used by MemDep in terms
of a pointer/int pair instead of a manually bitmangled pointer.
This forces clients to think a little more about checking the 
appropriate pieces and will be useful for internal 
implementation improvements later.

I'm not particularly happy with this.  After going through this
I don't think that the clients of memdep should be exposed to
the internal type at all.  I'll fix this in a subsequent commit.

This has no functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60230 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 01:43:36 +00:00
Chris Lattner
956033a4f5 comment cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60220 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28 22:41:36 +00:00
Chris Lattner
b390b1728e forward declare CallSite instead of #includ'ing it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60217 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28 21:47:19 +00:00