Commit Graph

87 Commits

Author SHA1 Message Date
Chris Lattner c053cbbc4d Make DSE only scan blocks that are reachable from the entry
block.  Other blocks may have pointer cycles that will crash
basicaa and other alias analyses.  In any case, there is no
point wasting cycles optimizing dead blocks.  This fixes 
rdar://7635088

llvm-svn: 95852
2010-02-11 05:11:54 +00:00
Dan Gohman 28943873e6 Use do+while instead of while for loops which obviously have a
non-zero trip count. Use SmallVector's pop_back_val().

llvm-svn: 92734
2010-01-05 16:27:25 +00:00
Nick Lewycky 475d3d1215 Small cleanups, refactor some duplicated code into a single method. No
functionality change.

llvm-svn: 92445
2010-01-03 04:39:07 +00:00
Chris Lattner 2764b4dc55 formatting cleanups.
llvm-svn: 90298
2009-12-02 06:35:55 +00:00
Duncan Sands 23344095de Add defensive break.
llvm-svn: 86705
2009-11-10 19:36:40 +00:00
Duncan Sands 8d4cde2b55 Fix obvious typo.
llvm-svn: 86694
2009-11-10 18:21:37 +00:00
Duncan Sands 1925d3a1d1 Teach DSE to eliminate useless trampolines.
llvm-svn: 86683
2009-11-10 13:49:50 +00:00
Nick Lewycky 5b3def9b86 Simplify.
llvm-svn: 86668
2009-11-10 07:00:43 +00:00
Nick Lewycky 9027147fb1 Reapply r86359, "Teach dead store elimination that certain intrinsics write to
memory just like a store" with bug fixed (partial-overwrite.ll is the
regression test).

llvm-svn: 86667
2009-11-10 06:46:40 +00:00
Chris Lattner 431000da21 Revert r86359, it is breaking the self host on the
llvm-gcc-i386-darwin9 build bot.

llvm-svn: 86391
2009-11-07 17:59:32 +00:00
Nick Lewycky b6a3dd48f4 Teach dead store elimination that certain intrinsics write to memory just like
a store.

llvm-svn: 86359
2009-11-07 08:34:40 +00:00
Chris Lattner a09062758b improve DSE when TargetData is not around, based on work by
Hans Wennborg!

llvm-svn: 86067
2009-11-04 23:20:12 +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
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
Chris Lattner 4916267c97 fix PR4815: some cases where DeleteDeadInstruction can delete
the instruction BBI points to.

llvm-svn: 80768
2009-09-02 06:31:02 +00:00
Chris Lattner 2dd09dbdf7 eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861
llvm-svn: 80766
2009-09-02 06:11:42 +00:00
Dan Gohman 0b5be94c79 Fix this condition I accidentally inverted.
llvm-svn: 76988
2009-07-24 18:31:07 +00:00
Dan Gohman 67243a4bec Convert several more passes to use getAnalysisIfAvailable<TargetData>()
instead of getAnalysis<TargetData>().

llvm-svn: 76982
2009-07-24 18:13:53 +00:00
Duncan Sands af9eaa830a Rename PaddedSize to AllocSize, in the hope that this
will make it more obvious what it represents, and stop
it being confused with the StoreSize.

llvm-svn: 71349
2009-05-09 07:06:46 +00:00
Duncan Sands dc020f9c3c Rename getABITypeSize to getTypePaddedSize, as
suggested by Chris.

llvm-svn: 62099
2009-01-12 20:38:59 +00:00
Chris Lattner 5df5b4cc2e don't bother touching volatile stores, they will just return clobber on
everything interesting anyway.

llvm-svn: 60640
2008-12-07 00:25:15 +00:00
Chris Lattner 57e91eaf61 Reimplement the inner loop of DSE. It now uniformly uses getDependence(),
doesn't do its own local caching, and is slightly more aggressive about
free/store dse (see testcase).  This eliminates the last external client 
of MemDep::getDependenceFrom().

llvm-svn: 60619
2008-12-06 00:53:22 +00:00
Chris Lattner 0e3d6337c6 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.

llvm-svn: 60607
2008-12-05 21:04:20 +00:00
Chris Lattner 8c5ff516c6 Fix a thinko that manifested as a crash on clamav last night.
llvm-svn: 60251
2008-11-29 20:29:04 +00:00
Chris Lattner 51ba8d0630 Split getDependency into getDependency and getDependencyFrom, the
former does caching, the later doesn't.  This dramatically simplifies
the logic in getDependency and getDependencyFrom.

llvm-svn: 60234
2008-11-29 03:47:00 +00:00
Chris Lattner 7f9c8a0f05 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.

llvm-svn: 60231
2008-11-29 02:29:27 +00:00
Chris Lattner de04e1173a 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.

llvm-svn: 60230
2008-11-29 01:43:36 +00:00
Chris Lattner f3f6a801cc don't revisit instructions off the beginning of the block.
llvm-svn: 60221
2008-11-28 22:50:08 +00:00
Chris Lattner f2a8ba4cf0 simplify some code, remove escaped newline.
llvm-svn: 60213
2008-11-28 21:29:52 +00:00
Chris Lattner 1adb6759ef rewrite a big chunk of how DSE does recursive dead operand
elimination to use more modern infrastructure.  Also do a bunch
of small cleanups.

llvm-svn: 60201
2008-11-28 00:27:14 +00:00
Duncan Sands d65a4daeea Factorize code: remove variants of "strip off
pointer bitcasts and GEP's", and centralize the
logic in Value::getUnderlyingObject.  The
difference with stripPointerCasts is that
stripPointerCasts only strips GEPs if all
indices are zero, while getUnderlyingObject
strips GEPs no matter what the indices are.

llvm-svn: 56922
2008-10-01 15:25:41 +00:00
Dan Gohman a79db30d28 Tidy up several unbeseeming casts from pointer to intptr_t.
llvm-svn: 55779
2008-09-04 17:05:41 +00:00
Owen Anderson 813bf7af7f Don't remove volatile loads. Thanks to Duncan for noticing this one.
llvm-svn: 54144
2008-07-28 20:52:42 +00:00
Owen Anderson 3f3389745d Add support for eliminating stores that store the same value that was just loaded.
This fixes PR2599.

llvm-svn: 54133
2008-07-28 16:14:26 +00:00
Nate Begeman 53c5c62d6d 80 col / tabs fixes
llvm-svn: 51021
2008-05-13 01:48:26 +00:00
Dan Gohman d78c400b5b Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.

llvm-svn: 51017
2008-05-13 00:00:25 +00:00
Dan Gohman 8cb19d967f Fix DSE to not eliminate volatile loads with no uses.
llvm-svn: 50370
2008-04-28 19:51:27 +00:00
Owen Anderson a82c9931f4 Be more precise when eliminating pointers bue to memcpy's. This allows more
stores to be deleted in some cases.

llvm-svn: 46694
2008-02-04 04:53:00 +00:00
Nick Lewycky 6b016703a9 Remove a couple more cases of "getNumUses() == 0". No need to walk the linked
list just to see if whether the list is empty.

llvm-svn: 46555
2008-01-30 08:01:28 +00:00
Nick Lewycky 625e89c8b0 Use empty() instead of comparing size() with zero.
llvm-svn: 46554
2008-01-30 07:54:16 +00:00
Nick Lewycky 0e3a5cb14a Don't DCE FreeInst's. We were using those! Patch from Owen Anderson.
llvm-svn: 46553
2008-01-30 07:45:37 +00:00
Owen Anderson 4e4b116750 Make DSE much more aggressive by performing DCE earlier. Update a testcase to reflect this increased aggressiveness.
llvm-svn: 46542
2008-01-30 01:24:47 +00:00
Owen Anderson 48d37806e2 Add support for eliminating memcpy's at the end of functions. Also fix some errors I noticed in
the handling of eliminating stores to byval arguments.

llvm-svn: 46494
2008-01-29 06:18:36 +00:00
Owen Anderson 6af19fd1e2 DeadStoreElimination can treat byval parameters as if there were alloca's for the purpose of removing end-of-function stores.
llvm-svn: 46351
2008-01-25 10:10:33 +00:00
Duncan Sands fe3bef091f Initializing an unsigned with ~0UL causes the compiler
to complain on x86-64 (gcc 4.1).  Use ~0U instead.

llvm-svn: 46197
2008-01-20 10:49:23 +00:00
Chris Lattner f3ebc3f3d2 Remove attribution from file headers, per discussion on llvmdev.
llvm-svn: 45418
2007-12-29 20:36:04 +00:00
Duncan Sands 68b6f50938 Integrate the readonly/readnone logic more deeply
into alias analysis.  This meant updating the API
which now has versions of the getModRefBehavior,
doesNotAccessMemory and onlyReadsMemory methods
which take a callsite parameter.  These should be
used unless the callsite is not known, since in
general they can do a better job than the versions
that take a function.  Also, users should no longer
call the version of getModRefBehavior that takes
both a function and a callsite.  To reduce the
chance of misuse it is now protected.

llvm-svn: 44487
2007-12-01 07:51:45 +00:00