Commit Graph

156 Commits

Author SHA1 Message Date
Chris Lattner 25be93dfed 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? :)

llvm-svn: 89997
2009-11-27 08:25:10 +00:00
Chris Lattner a9a76ccf56 Fix phi translation in load PRE to agree with the phi
translation done by memdep, and reenable gep translation 
again.

llvm-svn: 89992
2009-11-27 06:31:14 +00:00
Chris Lattner b018bda665 redisable this, my bootstrap worked because it wasn't an optimized build, whoops.
llvm-svn: 89991
2009-11-27 05:53:01 +00:00
Chris Lattner fb8a718fc3 try again.
llvm-svn: 89990
2009-11-27 05:19:56 +00:00
Chris Lattner 14444f5c1a this is causing buildbot failures, disable for now.
llvm-svn: 89985
2009-11-27 01:52:22 +00:00
Chris Lattner 5030c6ab21 teach phi translation of GEPs to simplify geps like 'gep x, 0'.
This allows us to compile the example from PR5313 into:

LBB1_2:                                                     ## %bb
	incl	%ecx
	movb	%al, (%rsi)
	movslq	%ecx, %rax
	movb	(%rdi,%rax), %al
	testb	%al, %al
	jne	LBB1_2

instead of:

LBB1_2:                                                     ## %bb
	movslq	%eax, %rcx
	incl	%eax
	movb	(%rdi,%rcx), %cl
	movb	%cl, (%rsi)
	movslq	%eax, %rcx
	cmpb	$0, (%rdi,%rcx)
	jne	LBB1_2

llvm-svn: 89981
2009-11-27 00:34:38 +00:00
Chris Lattner 4c88e814b8 teach memdep to do trivial PHI translation of GEPs. More to
come.

llvm-svn: 89979
2009-11-27 00:07:37 +00:00
Chris Lattner 9bd2136ca3 Teach memdep to phi translate bitcasts. This allows us to compile
the example in GCC PR16799 to:

LBB1_2:                                                     ## %bb1
	movl	%eax, %eax
	subq	%rax, %rdi
	movq	%rdi, (%rcx)
	movl	(%rdi), %eax
	testl	%eax, %eax
	je	LBB1_2

instead of:

LBB1_2:                                                     ## %bb1
	movl	(%rdi), %ecx
	subq	%rcx, %rdi
	movq	%rdi, (%rax)
	cmpl	$0, (%rdi)
	je	LBB1_2

llvm-svn: 89978
2009-11-26 23:41:07 +00:00
Chris Lattner c49f5ac7d8 factor some code out into some helper functions.
llvm-svn: 89975
2009-11-26 23:18:49 +00:00
Nick Lewycky 663e0a06b0 Remove dead code. While there, also turn a few 'T* ' into 'T *' to match the
rest of the file.

llvm-svn: 89577
2009-11-22 02:38:11 +00:00
Owen Anderson 2b2bd28973 Treat lifetime begin/end markers as allocations/frees respectively for the
purposes for GVN/DSE.

llvm-svn: 85383
2009-10-28 07:05:35 +00:00
Owen Anderson fc16e5a98f Be more careful about invariance reasoning on "store" queries. Stores still need
to depend on Ref and ModRef calls within the invariant region.

llvm-svn: 85380
2009-10-28 06:30:52 +00:00
Owen Anderson d0e86d57c1 Add trivial support for the invariance intrinsics to memdep. This logic is
purely local for now.

llvm-svn: 85378
2009-10-28 06:18:42 +00:00
Victor Hernandez f390e04a47 Rename MallocFreeHelper as MemoryBuiltins
llvm-svn: 85286
2009-10-27 20:05:49 +00:00
Victor Hernandez 762195bd01 Rename MallocHelper as MallocFreeHelper, since it now also identifies calls to free()
llvm-svn: 85181
2009-10-26 23:58:56 +00:00
Victor Hernandez de5ad42aa1 Remove FreeInst.
Remove LowerAllocations pass.
Update some more passes to treate free calls just like they were treating FreeInst.

llvm-svn: 85176
2009-10-26 23:43:48 +00:00
Victor Hernandez e297149e26 Auto-upgrade free instructions to calls to the builtin free function.
Update all analysis passes and transforms to treat free calls just like FreeInst.
Remove RaiseAllocations and all its tests since FreeInst no longer needs to be raised.

llvm-svn: 84987
2009-10-24 04:23:03 +00:00
Victor Hernandez 8acf2956b8 Remove AllocationInst. Since MallocInst went away, AllocaInst is the only subclass of AllocationInst, so it no longer is necessary.
llvm-svn: 84969
2009-10-23 21:09:37 +00:00
Victor Hernandez 70e8505eb1 Memory dependence analysis was incorrectly stopping to scan for stores to a pointer at bitcast uses of a malloc call.
It should continue scanning until the malloc call, and this patch fixes that.

llvm-svn: 83931
2009-10-13 01:42:53 +00:00
Chris Lattner 7e6d56ebc5 Revert r82404, it is causing a bootstrap miscompile. This is very very
scary, as it indicates a lurking bug. yay.

llvm-svn: 82411
2009-09-20 22:44:26 +00:00
Chris Lattner eea16a168a improve memdep to eliminate bitcasts (and aliases, and noop geps)
early for the stated reasons: this allows it to find more 
equivalences and depend less on code layout.

llvm-svn: 82404
2009-09-20 21:00:18 +00:00
Victor Hernandez 537d8d99be Enhance analysis passes so that they apply the same analysis to malloc calls as to MallocInst.
Reviewed by Eli Friedman.

llvm-svn: 82281
2009-09-18 21:34:51 +00:00
Dan Gohman 1ee6057b21 Make TargetData optional in MemoryDependenceAnalysis.
llvm-svn: 77727
2009-07-31 20:53:12 +00:00
Dan Gohman f3ee7eaac3 Remove an unnecessary header.
llvm-svn: 77725
2009-07-31 20:47:45 +00:00
Chris Lattner 370aadabfc factor the 'optimized sort' code out into a static helper function
and use it from one more place.  Patch by Jakub Staszak!

llvm-svn: 75478
2009-07-13 17:20:05 +00:00
Chris Lattner 2f0c1c44d5 Move the re-sort of invalidated NonLocalPointerDeps cache earlier
so that all code paths get it.  PR4256 was about a case where the
phi translation loop would find all preds in the Visited cache, so
it could get by without re-sorting the NonLocalPointerDeps cache.
Fix this by resorting it earlier, there is no reason not to do this.

This patch inspired by Jakub Staszak's patch.

llvm-svn: 75476
2009-07-13 17:14:23 +00:00
Chris Lattner 02274a7171 make memdep use the getModRefInfo method for stores instead of the
low-level alias() method, allowing it to reason more aggressively
about pointers into constant memory.  PR4189

llvm-svn: 72403
2009-05-25 21:28:56 +00:00
Chris Lattner 8eda11bd9d now that you can put a PointerIntPair in a SmallPtrSet, remove some
hackish workarounds from memdep

llvm-svn: 67971
2009-03-29 00:24:04 +00:00
Dale Johannesen f61c8e81bd Debug intriniscs should be skipped when looking
for a dependency, not terminate the search.

llvm-svn: 66709
2009-03-11 21:13:01 +00:00
Owen Anderson f9a9cf96a1 Ignore debug intrinsics when computing dependences.
llvm-svn: 66399
2009-03-09 05:12:38 +00:00
Zhou Sheng c8e5085cd3 Remove this as dbginfo intrinsics has been defined as
IntrNoMem.

llvm-svn: 66256
2009-03-06 06:05:01 +00:00
Zhou Sheng abe4192442 Ignore the debug info intrinsics when looking for dependency through basic block.
llvm-svn: 66119
2009-03-05 01:45:43 +00:00
Chris Lattner 3f4591c89f fix two more cases where we could let the NLPDI cache get unsorted.
With this, sqlite3 now passes.

llvm-svn: 62839
2009-01-23 07:12:16 +00:00
Chris Lattner e3ea48c71e Unconditionally reset 'cache' to zero, even if we don't need to resort it.
This avoids using a dangling pointer.

Reset NumSortedEntries after restoring Cache to avoid extraneous sorts.
This fixes the reduced sqlite3 testcase, but apparently not the whole app.

llvm-svn: 62838
2009-01-23 06:48:41 +00:00
Chris Lattner 706d40e662 a minor tweak to my previous patch, handle the invalidation case
when there are multiple iterations of the loop.  This fixes PR3375.

llvm-svn: 62822
2009-01-23 00:27:03 +00:00
Chris Lattner f09619d533 Fix PR3358, a really nasty bug where recursive phi translated
analyses could be run without the caches properly sorted.  This
can fix all sorts of weirdness.  Many thanks to Bill for coming
up with the 'issorted' verification idea.

llvm-svn: 62757
2009-01-22 07:04:01 +00:00
Chris Lattner 8b4be37275 fix PR3217: fully cached queries need to be verified against the
visited set before they are used.  If used, their blocks need to be
added to the visited set so that subsequent queries don't use conflicting
pointer values in the cache result blocks.

llvm-svn: 61080
2008-12-16 07:10:09 +00:00
Chris Lattner 7ed5ccc517 if we have a phi translation failure of the start block,
return *just* a clobber of the start block, not other 
random stuff as well.

llvm-svn: 61026
2008-12-15 04:58:29 +00:00
Chris Lattner ff9f3dba12 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.

llvm-svn: 61022
2008-12-15 03:35:32 +00:00
Duncan Sands c52b616ccf Don't dereference the end() iterator. This was
causing a bunch of failures when running
"make ENABLE_EXPENSIVE_CHECKS=1 check".

llvm-svn: 60832
2008-12-10 09:38:36 +00:00
Chris Lattner 0318b56f0e loosen up an assertion that isn't valid when called from
invalidateCachedPointerInfo.  Thanks to Bill for sending me
a testcase.

llvm-svn: 60805
2008-12-09 22:45:32 +00:00
Chris Lattner fa9f99aa12 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.

llvm-svn: 60799
2008-12-09 22:06:23 +00:00
Chris Lattner 702e46ed54 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.

llvm-svn: 60794
2008-12-09 21:19:42 +00:00
Chris Lattner 41efb68c44 Fix a fixme: allow memdep to see past read-only calls when doing
load dependence queries.  This allows GVN to eliminate a few more
instructions on 403.gcc:

 152598 gvn    - Number of instructions deleted
  49240 gvn    - Number of loads deleted
after:
 153986 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

llvm-svn: 60786
2008-12-09 19:47:40 +00:00
Chris Lattner 254314e6bc rename getNonLocalDependency -> getNonLocalCallDependency, and remove
pointer stuff from it, simplifying the code a bit.

llvm-svn: 60783
2008-12-09 19:38:05 +00:00
Chris Lattner 4f10733cf3 fix typos gabor noticed
llvm-svn: 60754
2008-12-09 08:38:36 +00:00
Chris Lattner 75510d8d5c restructure the top level non-local ptr dep query to handle
the first block of a query specially.  This makes the "complete query
caching" subsystem more effective, avoiding predecessor queries.  This
speeds up GVN another 4%.

llvm-svn: 60752
2008-12-09 07:52:59 +00:00
Chris Lattner f903fe1df0 rename getNonLocalPointerDepInternal -> getNonLocalPointerDepFromBB
and split its inner loop out into a new GetNonLocalInfoForBlock
function.  No functionality change.

llvm-svn: 60751
2008-12-09 07:47:11 +00:00
Chris Lattner aeaec0838b if we have two elements, insert both, don't use std::sort.
This speeds up the new GVN by another 3%

llvm-svn: 60747
2008-12-09 07:05:45 +00:00
Chris Lattner 4d1281cdf2 If we're only adding one new element to 'Cache', insert it into its known
position instead of using a full sort. This speeds up GVN by ~4% with the
new memdep stuff.

llvm-svn: 60746
2008-12-09 06:58:04 +00:00