Commit Graph

56 Commits

Author SHA1 Message Date
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
Chris Lattner cbad11e027 don't put erase or query for non-allocainst pointers in an set of allocainsts*'s
llvm-svn: 43779
2007-11-06 22:07:22 +00:00
Duncan Sands 44b8721de8 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.

llvm-svn: 43620
2007-11-01 20:53:16 +00:00
Owen Anderson 2ed651ace7 Fix test/Transforms/DeadStoreElimination/PartialStore.ll, which had been
silently failing because of an incorrect run line for some time.

llvm-svn: 43605
2007-11-01 05:29:16 +00:00
Owen Anderson 2b9ec7ff33 Don't DSe volatile stores.
llvm-svn: 41456
2007-08-26 21:14:47 +00:00
Owen Anderson 9b1cc8cac0 Make NonLocal and None const in the right way. :-)
llvm-svn: 40961
2007-08-09 04:42:44 +00:00
Owen Anderson b84d3b1c92 Change the None and NonLocal markers in memdep to be const.
llvm-svn: 40946
2007-08-08 21:39:39 +00:00
Owen Anderson 680862880d Global values also don't undead-ify pointers in our dead alloca's set.
llvm-svn: 40936
2007-08-08 19:12:31 +00:00
Owen Anderson ddf4aee543 Make handleEndBlock significantly faster with one trivial improvement,
and one hack to avoid hitting a bad case when the alias analysis is imprecise.

llvm-svn: 40935
2007-08-08 18:38:28 +00:00
Owen Anderson 50df9685b0 Small improvement: if a function doesn't access memory, we don't need to scan
it for potentially undeading pointers.

llvm-svn: 40933
2007-08-08 17:58:56 +00:00
Owen Anderson 52aaabf74d Add some comments, remove a dead argument, and simplify some control flow.
No functionality change.

llvm-svn: 40932
2007-08-08 17:50:09 +00:00
Owen Anderson b17ab03081 A few more small cleanups.
llvm-svn: 40922
2007-08-08 06:06:02 +00:00
Owen Anderson 0aecf0ebef First round of cleanups from Chris' feedback.
llvm-svn: 40919
2007-08-08 04:52:29 +00:00
Owen Anderson e3590584b9 Fix 80 col. violations.
llvm-svn: 40749
2007-08-02 18:11:11 +00:00
Owen Anderson 10e52eddb3 Rename FastDSE to just DSE.
llvm-svn: 40668
2007-08-01 06:36:51 +00:00
Owen Anderson e4a374812b Move FastDSE in to DeadStoreElimination.
llvm-svn: 40667
2007-08-01 06:30:51 +00:00
Owen Anderson 4894e6d8bc Remove old DSE.
llvm-svn: 40666
2007-08-01 06:30:10 +00:00
Nick Lewycky e7da2d6ac3 Fix typo in comment.
llvm-svn: 36873
2007-05-06 13:37:16 +00:00
Devang Patel 8c78a0bff0 Drop 'const'
llvm-svn: 36662
2007-05-03 01:11:54 +00:00
Devang Patel e95c6ad802 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.

llvm-svn: 36652
2007-05-02 21:39:20 +00:00
Devang Patel 09f162ca6a Do not use typeinfo to identify pass in pass manager.
llvm-svn: 36632
2007-05-01 21:15:47 +00:00
Reid Spencer 557ab15e71 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.

llvm-svn: 33939
2007-02-05 23:32:05 +00:00
Chris Lattner 79a42ac941 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.

llvm-svn: 32690
2006-12-19 21:40:18 +00:00
Chris Lattner 700b873130 Detemplatize the Statistic class. The only type it is instantiated with
is 'unsigned'.

llvm-svn: 32279
2006-12-06 17:46:33 +00:00
Chris Lattner c2d3d3112e eliminate RegisterOpt. It does the same thing as RegisterPass.
llvm-svn: 29925
2006-08-27 22:42:52 +00:00
Chris Lattner dc4ffef633 Fix a bug where we didn't realize that vaarg reads memory. This fixes
Transforms/DeadStoreElimination/2005-11-30-vaarg.ll

llvm-svn: 24545
2005-11-30 19:38:22 +00:00
Misha Brukman b1c9317bb4 Remove trailing whitespace
llvm-svn: 21427
2005-04-21 23:48:37 +00:00
Chris Lattner d8e20188c6 Adjust to changes in instruction interfaces.
llvm-svn: 19900
2005-01-29 00:39:08 +00:00
Chris Lattner fdfe3e49fe Fix uint64_t -> unsigned VS warnings.
llvm-svn: 19381
2005-01-08 19:42:22 +00:00
Chris Lattner 13516fe2e7 Fix PR491 and testcase Transforms/DeadStoreElimination/2004-12-28-PartialStore.ll
llvm-svn: 19180
2004-12-29 04:36:02 +00:00
Chris Lattner 6ea2888832 Make DSE potentially more aggressive by being more specific about alloca sizes.
llvm-svn: 18309
2004-11-28 20:44:37 +00:00
Chris Lattner 3e86084641 Prototype these functions more accurately
llvm-svn: 16432
2004-09-20 04:43:15 +00:00