Commit Graph

83 Commits

Author SHA1 Message Date
Duncan Sands
650c64383e Add defensive break.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86705 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 19:36:40 +00:00
Duncan Sands
e3f749b166 Fix obvious typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86694 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 18:21:37 +00:00
Duncan Sands
710c37c494 Teach DSE to eliminate useless trampolines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86683 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 13:49:50 +00:00
Nick Lewycky
7cef178176 Simplify.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86668 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 07:00:43 +00:00
Nick Lewycky
58571d663c 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).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86667 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 06:46:40 +00:00
Chris Lattner
1d95725d60 Revert r86359, it is breaking the self host on the
llvm-gcc-i386-darwin9 build bot.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86391 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07 17:59:32 +00:00
Nick Lewycky
4de9b7f51f Teach dead store elimination that certain intrinsics write to memory just like
a store.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86359 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07 08:34:40 +00:00
Chris Lattner
40dd12e708 improve DSE when TargetData is not around, based on work by
Hans Wennborg!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86067 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-04 23:20:12 +00:00
Owen Anderson
b62f792e78 Treat lifetime begin/end markers as allocations/frees respectively for the
purposes for GVN/DSE.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85383 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-28 07:05:35 +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
Victor Hernandez
046e78ce55 Remove FreeInst.
Remove LowerAllocations pass.
Update some more passes to treate free calls just like they were treating FreeInst.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85176 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26 23:43:48 +00:00
Victor Hernandez
66284e063a 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84987 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-24 04:23:03 +00:00
Chris Lattner
40ef630a46 fix PR4815: some cases where DeleteDeadInstruction can delete
the instruction BBI points to.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80768 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02 06:31:02 +00:00
Chris Lattner
3e8b6631e6 eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80766 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-02 06:11:42 +00:00
Dan Gohman
731b5d97be Fix this condition I accidentally inverted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76988 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24 18:31:07 +00:00
Dan Gohman
02a436c48e Convert several more passes to use getAnalysisIfAvailable<TargetData>()
instead of getAnalysis<TargetData>().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76982 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-24 18:13:53 +00:00
Duncan Sands
777d2306b3 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71349 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09 07:06:46 +00:00
Duncan Sands
ceb4d1aecb Rename getABITypeSize to getTypePaddedSize, as
suggested by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62099 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12 20:38:59 +00:00
Chris Lattner
f760be1c7f don't bother touching volatile stores, they will just return clobber on
everything interesting anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60640 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-07 00:25:15 +00:00
Chris Lattner
5e600e67b1 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().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60619 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-06 00:53:22 +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
3a76be584b Fix a thinko that manifested as a crash on clamav last night.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60251 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 20:29:04 +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
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
5425f22fa3 don't revisit instructions off the beginning of the block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60221 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28 22:50:08 +00:00
Chris Lattner
565f96b196 simplify some code, remove escaped newline.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60213 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28 21:29:52 +00:00
Chris Lattner
925451e020 rewrite a big chunk of how DSE does recursive dead operand
elimination to use more modern infrastructure.  Also do a bunch
of small cleanups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60201 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-28 00:27:14 +00:00
Duncan Sands
5d0392c6b3 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56922 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-01 15:25:41 +00:00
Dan Gohman
ae73dc1448 Tidy up several unbeseeming casts from pointer to intptr_t.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04 17:05:41 +00:00
Owen Anderson
80e051dfde Don't remove volatile loads. Thanks to Duncan for noticing this one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54144 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-28 20:52:42 +00:00
Owen Anderson
8aa895b19a Add support for eliminating stores that store the same value that was just loaded.
This fixes PR2599.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54133 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-28 16:14:26 +00:00
Nate Begeman
a72acf9389 80 col / tabs fixes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51021 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 01:48:26 +00:00
Dan Gohman
844731a7f1 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 00:00:25 +00:00
Dan Gohman
00acf97feb Fix DSE to not eliminate volatile loads with no uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50370 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-28 19:51:27 +00:00
Owen Anderson
c69ace3a64 Be more precise when eliminating pointers bue to memcpy's. This allows more
stores to be deleted in some cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46694 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-04 04:53:00 +00:00
Nick Lewycky
b4b0417220 Remove a couple more cases of "getNumUses() == 0". No need to walk the linked
list just to see if whether the list is empty.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46555 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 08:01:28 +00:00
Nick Lewycky
c7444498ee Use empty() instead of comparing size() with zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46554 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 07:54:16 +00:00
Nick Lewycky
d29ce1783c Don't DCE FreeInst's. We were using those! Patch from Owen Anderson.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46553 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 07:45:37 +00:00
Owen Anderson
772601a885 Make DSE much more aggressive by performing DCE earlier. Update a testcase to reflect this increased aggressiveness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46542 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-30 01:24:47 +00:00
Owen Anderson
a34d8a0d83 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46494 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-29 06:18:36 +00:00
Owen Anderson
e3c36f6758 DeadStoreElimination can treat byval parameters as if there were alloca's for the purpose of removing end-of-function stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46351 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-25 10:10:33 +00:00
Duncan Sands
02ec6e51ed Initializing an unsigned with ~0UL causes the compiler
to complain on x86-64 (gcc 4.1).  Use ~0U instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46197 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-20 10:49:23 +00:00
Chris Lattner
4ee451de36 Remove attribution from file headers, per discussion on llvmdev.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45418 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29 20:36:04 +00:00
Duncan Sands
dff6710717 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44487 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-01 07:51:45 +00:00
Chris Lattner
6390ae0a4a don't put erase or query for non-allocainst pointers in an set of allocainsts*'s
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43779 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-06 22:07:22 +00:00
Duncan Sands
514ab348fd Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize.
The meaning of getTypeSize was not clear - clarifying it is important
now that we have x86 long double and arbitrary precision integers.
The issue with long double is that it requires 80 bits, and this is
not a multiple of its alignment.  This gives a primitive type for
which getTypeSize differed from getABITypeSize.  For arbitrary precision
integers it is even worse: there is the minimum number of bits needed to
hold the type (eg: 36 for an i36), the maximum number of bits that will
be overwriten when storing the type (40 bits for i36) and the ABI size
(i.e. the storage size rounded up to a multiple of the alignment; 64 bits
for i36).

This patch removes getTypeSize (not really - it is still there but
deprecated to allow for a gradual transition).  Instead there is:

(1) getTypeSizeInBits - a number of bits that suffices to hold all
values of the type.  For a primitive type, this is the minimum number
of bits.  For an i36 this is 36 bits.  For x86 long double it is 80.
This corresponds to gcc's TYPE_PRECISION.

(2) getTypeStoreSizeInBits - the maximum number of bits that is
written when storing the type (or read when reading it).  For an
i36 this is 40 bits, for an x86 long double it is 80 bits.  This
is the size alias analysis is interested in (getTypeStoreSize
returns the number of bytes).  There doesn't seem to be anything
corresponding to this in gcc.

(3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded
up to a multiple of the alignment.  For an i36 this is 64, for an
x86 long double this is 96 or 128 depending on the OS.  This is the
spacing between consecutive elements when you form an array out of
this type (getABITypeSize returns the number of bytes).  This is
TYPE_SIZE in gcc.

Since successive elements in a SequentialType (arrays, pointers
and vectors) need to be aligned, the spacing between them will be
given by getABITypeSize.  This means that the size of an array
is the length times the getABITypeSize.  It also means that GEP
computations need to use getABITypeSize when computing offsets.
Furthermore, if an alloca allocates several elements at once then
these too need to be aligned, so the size of the alloca has to be
the number of elements multiplied by getABITypeSize.  Logically
speaking this doesn't have to be the case when allocating just
one element, but it is simpler to also use getABITypeSize in this
case.  So alloca's and mallocs should use getABITypeSize.  Finally,
since gcc's only notion of size is that given by getABITypeSize, if
you want to output assembler etc the same as gcc then getABITypeSize
is the size you want.

Since a store will overwrite no more than getTypeStoreSize bytes,
and a read will read no more than that many bytes, this is the
notion of size appropriate for alias analysis calculations.

In this patch I have corrected all type size uses except some of
those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard
cases).  I will get around to auditing these too at some point,
but I could do with some help.

Finally, I made one change which I think wise but others might
consider pointless and suboptimal: in an unpacked struct the
amount of space allocated for a field is now given by the ABI
size rather than getTypeStoreSize.  I did this because every
other place that reserves memory for a type (eg: alloca) now
uses getABITypeSize, and I didn't want to make an exception
for unpacked structs, i.e. I did it to make things more uniform.
This only effects structs containing long doubles and arbitrary
precision integers.  If someone wants to pack these types more
tightly they can always use a packed struct.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 20:53:16 +00:00
Owen Anderson
7ebba512c3 Fix test/Transforms/DeadStoreElimination/PartialStore.ll, which had been
silently failing because of an incorrect run line for some time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43605 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-01 05:29:16 +00:00
Owen Anderson
5dfcf4318a Don't DSe volatile stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41456 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-26 21:14:47 +00:00