Commit Graph

273 Commits

Author SHA1 Message Date
Bill Wendling 9ca12c137f A limit of 500 was still a bit too high for some tests.
PR15000 has a testcase where the time to compile was bordering on 30s. When I
dropped the limit value to 100, it became a much more managable 6s. The compile
time seems to increase in a roughly linear fashion based on increasing the limit
value. (See the runtimes below.)

So, let's lower the limit to 100 so that they can get a more reasonable compile
time.

Limit Value  Time
-----------  ----
10           0.9744s
20           1.8035s
30           2.3618s
40           2.9814s
50           3.6988s
60           4.5486s
70           4.9314s
80           5.8012s
90           6.4246s
100          7.0852s
110          7.6634s
120          8.3553s
130          9.0552s
140          9.6820s
150          9.8804s
160         10.8901s
170         10.9855s
180         12.0114s
190         12.6816s
200         13.2754s
210         13.9942s
220         13.8097s
230         14.3272s
240         15.7753s
250         15.6673s
260         16.0541s
270         16.7625s
280         17.3823s
290         18.8213s
300         18.6120s
310         20.0333s
320         19.5165s
330         20.2505s
340         20.7068s
350         21.1833s
360         22.9216s
370         22.2152s
380         23.9390s
390         23.4609s
400         24.0426s
410         24.6410s
420         26.5208s
430         27.7155s
440         26.4142s
450         28.5646s
460         27.3494s
470         29.7255s
480         29.4646s
490         30.5001s

llvm-svn: 179713
2013-04-17 20:02:32 +00:00
Matt Arsenault 2080ecd107 Fix loop style
llvm-svn: 178355
2013-03-29 18:48:42 +00:00
Jakub Staszak fa41def6ce Remove 'else' after 'return'.
llvm-svn: 177607
2013-03-20 23:53:45 +00:00
Jakub Staszak b0a7eed958 Remove trailing spaces.
llvm-svn: 177584
2013-03-20 21:47:51 +00:00
Shuxin Yang 408bdad5b4 Memory Dependence Analysis (not mem-dep test) take advantage of "invariant.load" metadata.
The "invariant.load" metadata indicates the memory unit being accessed is immutable.
A load annotated with this metadata can be moved across any store.

As I am not sure if it is legal to move such loads across barrier/fence, this
change dose not allow such transformation.

rdar://11311484

Thank Arnold for code review.

llvm-svn: 176562
2013-03-06 17:48:48 +00:00
Kostya Serebryany cf880b9443 Unify clang/llvm attributes for asan/tsan/msan (LLVM part)
These are two related changes (one in llvm, one in clang).
LLVM: 
- rename address_safety => sanitize_address (the enum value is the same, so we preserve binary compatibility with old bitcode)
- rename thread_safety => sanitize_thread
- rename no_uninitialized_checks -> sanitize_memory

CLANG: 
- add __attribute__((no_sanitize_address)) as a synonym for __attribute__((no_address_safety_analysis))
- add __attribute__((no_sanitize_thread))
- add __attribute__((no_sanitize_memory))

for S in address thread memory
If -fsanitize=S is present and __attribute__((no_sanitize_S)) is not
set llvm attribute sanitize_S

llvm-svn: 176075
2013-02-26 06:58:09 +00:00
Kostya Serebryany 3838f27905 [tsan] disable load widening in ThreadSanitizer mode
llvm-svn: 175034
2013-02-13 05:59:45 +00:00
Dan Gohman 20a2ae9df5 Change GetPointerBaseWithConstantOffset's DataLayout argument from a
reference to a pointer, so that it can handle the case where DataLayout
is not available and behave conservatively.

llvm-svn: 174024
2013-01-31 02:00:45 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Bill Wendling 698e84fc4f Remove the Function::getFnAttributes method in favor of using the AttributeSet
directly.

This is in preparation for removing the use of the 'Attribute' class as a
collection of attributes. That will shift to the AttributeSet class instead.

llvm-svn: 171253
2012-12-30 10:32:01 +00:00
Bill Wendling 3d7b0b8ac7 Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.
llvm-svn: 170502
2012-12-19 07:18:57 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Bill Wendling 5858b56ce3 Ignore unreachable blocks when doing memory dependence analysis on non-local
loads. It's not really profitable and may result in GVN going into an infinite
loop when it hits constructs like this:

     %x = gep %some.type %x, ...

Found via an LTO build of LLVM.

llvm-svn: 166490
2012-10-23 18:37:11 +00:00
Bill Wendling c9b22d735a Create enums for the different attributes.
We use the enums to query whether an Attributes object has that attribute. The
opaque layer is responsible for knowing where that specific attribute is stored.

llvm-svn: 165488
2012-10-09 07:45:08 +00:00
Micah Villmow cdfe20b97f Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Bill Wendling 863bab689a Remove the `hasFnAttr' method from Function.
The hasFnAttr method has been replaced by querying the Attributes explicitly. No
intended functionality change.

llvm-svn: 164725
2012-09-26 21:48:26 +00:00
Bob Wilson 01cfbfe9d0 Be conservative about allocations that may alias the accessed pointer.
If an allocation has a must-alias relation to the access pointer, we treat it
as a Def.  Otherwise, without this check, the code here was just skipping over
the allocation call and ignoring it.  I noticed this by inspection and don't
have a specific testcase that it breaks, but it seems like we need to treat
a may-alias allocation as a Clobber.

llvm-svn: 163127
2012-09-04 03:30:13 +00:00
Bob Wilson dcc54decd5 Fix more fallout from r158919, similar to PR13547.
This code used to only handle malloc-like calls, which do not read memory.
r158919 changed it to check isNoAliasFn(), which includes strdup-like and
realloc-like calls, but it was not checking for dependencies on the memory
read by those calls.

llvm-svn: 163106
2012-09-03 05:15:15 +00:00
Benjamin Kramer 8bcc971174 Make MemoryBuiltins aware of TargetLibraryInfo.
This disables malloc-specific optimization when -fno-builtin (or -ffreestanding)
is specified. This has been a problem for a long time but became more severe
with the recent memory builtin improvements.

Since the memory builtin functions are used everywhere, this required passing
TLI in many places. This means that functions that now have an optional TLI
argument, like RecursivelyDeleteTriviallyDeadFunctions, won't remove dead
mallocs anymore if the TLI argument is missing. I've updated most passes to do
the right thing.

Fixes PR13694 and probably others.

llvm-svn: 162841
2012-08-29 15:32:21 +00:00
Nadav Rotem 5d4e205874 MemoryDependenceAnalysis attempts to find the first memory dependency for function calls.
Currently, if GetLocation reports that it did not find a valid pointer (this is the case for volatile load/stores),
we ignore the result. This patch adds code to handle the cases where we did not obtain a valid pointer.

rdar://11872864  PR12899

llvm-svn: 161802
2012-08-13 23:03:43 +00:00
Nuno Lopes 55fff83422 refactor the MemoryBuiltin analysis:
- provide more extensive set of functions to detect library allocation functions (e.g., malloc, calloc, strdup, etc)
 - provide an API to compute the size and offset of an object pointed by

Move a few clients (GVN, AA, instcombine, ...) to the new API.
This implementation is a lot more aggressive than each of the custom implementations being replaced.

Patch reviewed by Nick Lewycky and Chandler Carruth, thanks.

llvm-svn: 158919
2012-06-21 15:45:28 +00:00
Benjamin Kramer bde9176663 Fix typos found by http://github.com/lyda/misspell-check
llvm-svn: 157885
2012-06-02 10:20:22 +00:00
Chad Rosier a968caf8e0 Move the capture analysis from MemoryDependencyAnalysis to a more general place
so that it can be reused in MemCpyOptimizer.  This analysis is needed to remove
an unnecessary memcpy when returning a struct into a local variable.
rdar://11341081
PR12686

llvm-svn: 156776
2012-05-14 20:35:04 +00:00
Chad Rosier 10702d5f22 Hoist simpler checks above llvm::PointerMayBeCaptured. No functional change intended.
llvm-svn: 156687
2012-05-12 00:43:40 +00:00
Rafael Espindola b660977c67 Don't call dominates on unreachable instructions. Should fix the dragonegg
build. Testcase is still reducing.

llvm-svn: 151474
2012-02-26 05:30:08 +00:00
Kostya Serebryany 9e0d377400 The patch resolves the conflict between AddressSanitizer and load widening (GVN).
The problem initially reported by Mozilla folks (http://code.google.com/p/address-sanitizer/issues/detail?id=20),
but it also prevents us from enabling LLVM bootstrap with AddressSanitizer.

llvm-svn: 149925
2012-02-06 22:48:56 +00:00
David Blaikie 46a9f016c5 More dead code removal (using -Wunreachable-code)
llvm-svn: 148578
2012-01-20 21:51:11 +00:00
Nick Lewycky 4c378a4453 Change CaptureTracking to pass a Use* instead of a Value* when a value is
captured. This allows the tracker to look at the specific use, which may be
especially interesting for function calls.

Use this to fix 'nocapture' deduction in FunctionAttrs. The existing one does
not iterate until a fixpoint and does not guarantee that it produces the same
result regardless of iteration order. The new implementation builds up a graph
of how arguments are passed from function to function, and uses a bottom-up walk
on the argument-SCCs to assign nocapture. This gets us nocapture more often, and
does so rather efficiently and independent of iteration order.

llvm-svn: 147327
2011-12-28 23:24:21 +00:00
Nick Lewycky 063ae5897c Fix crasher in GVN due to my recent capture tracking changes.
llvm-svn: 145047
2011-11-21 19:42:56 +00:00
Nick Lewycky 6ae03c3378 Less template, more virtual! Refactoring suggested by Chris in code review.
llvm-svn: 145014
2011-11-20 19:37:06 +00:00
Nick Lewycky 612d70b19d Refactor code to use new attribute getters on CallSite for NoCapture and ByVal.
Suggested in code review by Eli.

That code in InstCombine looks kinda suspicious.

llvm-svn: 145013
2011-11-20 19:09:04 +00:00
Nick Lewycky 7013a19e8a Refactor capture tracking (which already had a couple flags for whether returns
and stores capture) to permit the caller to see each capture point and decide
whether to continue looking.

Use this inside memdep to do an analysis that basicaa won't do. This lets us
solve another devirtualization case, fixing PR8908!

llvm-svn: 144580
2011-11-14 22:49:42 +00:00
Eli Friedman c1702c8f22 Enhance the memdep interface so that users can tell the difference between a dependency which cannot be calculated and a path reaching the entry point of the function. This patch introduces isNonFuncLocal, which replaces isUnknown in some cases.
Patch by Xiaoyi Guo.

llvm-svn: 141896
2011-10-13 22:14:57 +00:00
Eli Friedman 5494adac67 Misc analysis passes that need to be aware of atomic load/store.
llvm-svn: 137650
2011-08-15 20:54:19 +00:00
Chris Lattner 229907cd11 land David Blaikie's patch to de-constify Type, with a few tweaks.
llvm-svn: 135375
2011-07-18 04:54:35 +00:00
Eli Friedman 8b098b0d57 Add a limit to the number of instructions memdep will scan in a single block. This prevents (at least in some cases) O(N^2) runtime in passes like DSE.
The limit in this patch is probably too high, but it is enough to stop DSE from going completely insane on a testcase I have (which has a single block with around 50,000 non-aliasing stores in it).

rdar://9471075

llvm-svn: 133111
2011-06-15 23:59:25 +00:00
Eli Friedman 7d58bc7bc0 Add "unknown" results for memdep, which mean "I don't know whether a dependence for the given instruction exists in the given block". This cleans up all the existing hacks in memdep which represent this concept by returning clobber with various unrelated instructions.
llvm-svn: 133031
2011-06-15 00:47:34 +00:00
Dan Gohman a471751c24 Disable the main feature of 130180, the elimination of loads that are
redundant with partially-aliasing loads.

When computing what portion of a clobbering load value is needed,
it doesn't consider phi-translation which may have occurred
between the clobbing load and the redundant load.

llvm-svn: 132631
2011-06-04 06:48:50 +00:00
Eli Friedman b576b1675c When marking a block as being unanalyzable, use "Clobber" on the terminator instead of the first instruction in the block. This is a bit of a hack; "Clobber" isn't really the right marking in the first place. memdep doesn't really have any way of properly expressing "unanalyzable" at the moment. Using it on the terminator is much less ambiguous than using it on an arbitrary instruction, though.
In the given testcase, the "Clobber" was pointing to a load, and GVN was incorrectly assuming that meant that the "Clobber" load overlapped the load being analyzed (when they are actually unrelated).

The included testcase tests both this commit and r132434.

Part two of rdar://9429882.  (r132434 was mislabeled.)

llvm-svn: 132442
2011-06-02 00:08:52 +00:00
Eli Friedman 4b6eeb9ca2 In MemoryDependenceAnalysis::getNonLocalPointerDepFromBB, if a given block is is deemed unanalyzable (and we execute one of the "goto PredTranslationFailure" statements), make sure we don't put information about the predecessors of that block into the returned data structures; this can lead to, among other things, extraneous results (which will confuse passes using memdep). Fixes an assert in GVN compiling ruby. Part of rdar://problem/9521954 .
Testcase coming up soon.

llvm-svn: 132434
2011-06-01 23:16:53 +00:00
Owen Anderson 97f0cf32ea @llvm.lifetime.begin acts as a load, not @llvm.lifetime.end.
llvm-svn: 131437
2011-05-17 00:05:49 +00:00
Chris Lattner 827a270a2a teach GVN to widen integer loads when they are overaligned, when doing an
wider load would allow elimination of subsequent loads, and when the wider
load is still a native integer type.  This eliminates a ton of loads on 
various benchmarks involving struct fields, though it is somewhat hobbled
by clang not being very aggressive about field alignment.

This is yet another step along the way towards resolving PR6627.

llvm-svn: 130390
2011-04-28 07:29:08 +00:00
Chris Lattner 7aab2799ae Enhance memdep to return clobber relation between noalias loads when
an earlier load could be widened to encompass a later load.  For example,
if we see:

  X = load i8* P, align 4
  Y = load i8* (P+3), align 1

and we have a 32-bit native integer type, we can widen the former load
to i32 which then makes the second load redundant.  GVN can't actually
do anything with this load/load relation yet, so this isn't testable, but 
it is the next step to resolving PR6627, and a fairly general class of 
"merge neighboring loads" missed optimizations.

llvm-svn: 130250
2011-04-26 22:42:01 +00:00
Chris Lattner 32dc9bd1bb use AA::isMustAlias to simplify some calls.
llvm-svn: 130248
2011-04-26 21:53:34 +00:00
Chris Lattner 6b96621a8a remove support for llvm.invariant.end from memdep. It is a
work-in-progress that is not progressing, and it has issues.

llvm-svn: 130247
2011-04-26 21:50:51 +00:00
Chris Lattner 6f83d06ffa Enhance MemDep: When alias analysis returns a partial alias result,
return it as a clobber.  This allows GVN to do smart things.

Enhance GVN to be smart about the case when a small load is clobbered
by a larger overlapping load.  In this case, forward the value.  This
allows us to compile stuff like this:

int test(void *P) {
  int tmp = *(unsigned int*)P;
  return tmp+*((unsigned char*)P+1);
}

into:

_test:                                  ## @test
	movl	(%rdi), %ecx
	movzbl	%ch, %eax
	addl	%ecx, %eax
	ret

which has one load.  We already handled the case where the smaller
load was from a must-aliased base pointer.

llvm-svn: 130180
2011-04-26 01:21:15 +00:00
Dan Gohman 0f124e1987 Give GetUnderlyingObject a TargetData, to keep it in sync
with BasicAA's DecomposeGEPExpression, which recently began
using a TargetData. This fixes PR8968, though the testcase
is awkward to reduce.

Also, update several off GetUnderlyingObject's users
which happen to have a TargetData handy to pass it in.

llvm-svn: 124134
2011-01-24 18:53:32 +00:00
Jakob Stoklund Olesen 087f207009 Revert r123207: "Turn on memdep's verifyRemoved() in an attempt to smoke out the cause of our gcc bootstrap miscompare."
It didn't.

llvm-svn: 123215
2011-01-11 04:05:39 +00:00
Jakob Stoklund Olesen 9b6853efd6 Turn on memdep's verifyRemoved() in an attempt to smoke out the cause of our gcc bootstrap miscompare.
llvm-svn: 123207
2011-01-11 01:18:03 +00:00
Jeffrey Yasskin 9b43f33620 Change all self assignments X=X to (void)X, so that we can turn on a
new gcc warning that complains on self-assignments and
self-initializations.

llvm-svn: 122458
2010-12-23 00:58:24 +00:00