Commit Graph

38 Commits

Author SHA1 Message Date
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
Owen Anderson
9528f11481 Make NonLocal and None const in the right way. :-)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40961 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-09 04:42:44 +00:00
Owen Anderson
8cad423d94 Change the None and NonLocal markers in memdep to be const.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40946 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 21:39:39 +00:00
Owen Anderson
838014ee5b Global values also don't undead-ify pointers in our dead alloca's set.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40936 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 19:12:31 +00:00
Owen Anderson
362bb52108 Make handleEndBlock significantly faster with one trivial improvement,
and one hack to avoid hitting a bad case when the alias analysis is imprecise.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40935 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 18:38:28 +00:00
Owen Anderson
df359c264e Small improvement: if a function doesn't access memory, we don't need to scan
it for potentially undeading pointers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40933 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 17:58:56 +00:00
Owen Anderson
bb3abf41a8 Add some comments, remove a dead argument, and simplify some control flow.
No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40932 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 17:50:09 +00:00
Owen Anderson
c182f17aed A few more small cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40922 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 06:06:02 +00:00
Owen Anderson
6ca4cb3755 First round of cleanups from Chris' feedback.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40919 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-08 04:52:29 +00:00
Owen Anderson
666f6fe0ce Fix 80 col. violations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40749 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-02 18:11:11 +00:00
Owen Anderson
f6a05f949f Rename FastDSE to just DSE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40668 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-01 06:36:51 +00:00
Owen Anderson
a56c34f90b Move FastDSE in to DeadStoreElimination.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40667 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-01 06:30:51 +00:00
Owen Anderson
e739bae8da Remove old DSE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40666 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-01 06:30:10 +00:00
Nick Lewycky
ecd94c804a Fix typo in comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36873 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-06 13:37:16 +00:00
Devang Patel
1997473cf7 Drop 'const'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36662 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-03 01:11:54 +00:00
Devang Patel
3e15bf33e0 Use 'static const char' instead of 'static const int'.
Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36652 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-02 21:39:20 +00:00
Devang Patel
794fd75c67 Do not use typeinfo to identify pass in pass manager.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36632 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-01 21:15:47 +00:00
Reid Spencer
9133fe2895 Apply the VISIBILITY_HIDDEN field to the remaining anonymous classes in
the Transforms library. This reduces debug library size by 132 KB, debug
binary size by 376 KB, and reduces link time for llvm tools slightly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33939 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-05 23:32:05 +00:00
Chris Lattner
0e5f499638 Switch over Transforms/Scalar to use the STATISTIC macro. For each statistic
converted, we lose a static initializer.  This also allows GCC to emit warnings
about unused statistics.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32690 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-19 21:40:18 +00:00
Chris Lattner
ac0b6ae358 Detemplatize the Statistic class. The only type it is instantiated with
is 'unsigned'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32279 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-06 17:46:33 +00:00
Chris Lattner
7f8897f22e eliminate RegisterOpt. It does the same thing as RegisterPass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29925 91177308-0d34-0410-b5e6-96231b3b80d8
2006-08-27 22:42:52 +00:00
Chris Lattner
2bd4cb597a Fix a bug where we didn't realize that vaarg reads memory. This fixes
Transforms/DeadStoreElimination/2005-11-30-vaarg.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24545 91177308-0d34-0410-b5e6-96231b3b80d8
2005-11-30 19:38:22 +00:00
Misha Brukman
fd93908ae8 Remove trailing whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21427 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-21 23:48:37 +00:00
Chris Lattner
5551706b0f Adjust to changes in instruction interfaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19900 91177308-0d34-0410-b5e6-96231b3b80d8
2005-01-29 00:39:08 +00:00
Chris Lattner
652f3cf76f Fix uint64_t -> unsigned VS warnings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19381 91177308-0d34-0410-b5e6-96231b3b80d8
2005-01-08 19:42:22 +00:00
Chris Lattner
da16d8c00b Fix PR491 and testcase Transforms/DeadStoreElimination/2004-12-28-PartialStore.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19180 91177308-0d34-0410-b5e6-96231b3b80d8
2004-12-29 04:36:02 +00:00
Chris Lattner
8305a64dce Make DSE potentially more aggressive by being more specific about alloca sizes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18309 91177308-0d34-0410-b5e6-96231b3b80d8
2004-11-28 20:44:37 +00:00
Chris Lattner
4b50156049 Prototype these functions more accurately
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16432 91177308-0d34-0410-b5e6-96231b3b80d8
2004-09-20 04:43:15 +00:00
Reid Spencer
551ccae044 Changes For Bug 352
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16137 91177308-0d34-0410-b5e6-96231b3b80d8
2004-09-01 22:55:40 +00:00
Chris Lattner
a000279a7d Implement DeadStoreElim/alloca.llx by observing that allocas are dead at the
end of the function (either return or unwind)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15232 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-26 06:14:11 +00:00
Chris Lattner
70e9b59b0e * Substantially simplify how free instructions are handled (potentially fixing
a bug in DSE).
* Delete dead operand uses iteratively instead of recursively, using a
  SetVector.
* Defer deletion of dead operand uses until the end of processing, which means
  we don't have to bother with updating the AliasSetTracker.  This speeds up
  DSE substantially.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15204 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-25 11:09:56 +00:00
Chris Lattner
a9e2f3d0ab Free instructions kill values too. This implements DeadStoreElim/free.llx
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15199 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-25 07:58:38 +00:00
Chris Lattner
c47b6677ae obvious fix
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15162 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-24 07:51:27 +00:00
Chris Lattner
0fb56afab1 This is a trivial dead store elimination pass. It very very simple and
can be improved in many ways.  But: stop laughing, even with -basicaa it
deletes 15% of the stores in 252.eon :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15101 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-22 08:00:28 +00:00