Commit Graph

262 Commits

Author SHA1 Message Date
Chandler Carruth
a490793037 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
cc498d64b5 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
b53357de39 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
bb1a25cd67 Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Bill Wendling
92f3ab845d 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The hasFnAttr method has been replaced by querying the Attributes explicitly.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
00bddec249 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
8f6487007d 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
b92d13cc42 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
685bd842e2 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
c9edab11db 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
bb30e1face Fix typos found by http://github.com/lyda/misspell-check
llvm-svn: 157885
2012-06-02 10:20:22 +00:00
Chad Rosier
c3a90c47b9 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
f276b2009c Hoist simpler checks above llvm::PointerMayBeCaptured. No functional change intended.
llvm-svn: 156687
2012-05-12 00:43:40 +00:00
Rafael Espindola
c333947449 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
f4be131943 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
06ecc99a56 More dead code removal (using -Wunreachable-code)
llvm-svn: 148578
2012-01-20 21:51:11 +00:00
Nick Lewycky
7425820374 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
566ea855fd Fix crasher in GVN due to my recent capture tracking changes.
llvm-svn: 145047
2011-11-21 19:42:56 +00:00
Nick Lewycky
5cadaed864 Less template, more virtual! Refactoring suggested by Chris in code review.
llvm-svn: 145014
2011-11-20 19:37:06 +00:00
Nick Lewycky
39c6f0a5d5 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
a0b2f7ca1d 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
e702d68556 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
5acfaeab2d 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
e1fe7061ce 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
9eef1c75a5 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
47b3cd9fff 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
df07009a9a 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
884a7d08b1 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
37ed424905 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
ba8b3af7d8 @llvm.lifetime.begin acts as a load, not @llvm.lifetime.end.
llvm-svn: 131437
2011-05-17 00:05:49 +00:00
Chris Lattner
594c4c5823 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
84e88d4c96 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
0b6d07bb62 use AA::isMustAlias to simplify some calls.
llvm-svn: 130248
2011-04-26 21:53:34 +00:00
Chris Lattner
6fee27fa01 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
bad294615e 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
db0dc19c04 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
43e92a1d28 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
d8abef4798 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
a199652a3e 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
Dan Gohman
295ba3ab26 Move Value::getUnderlyingObject to be a standalone
function so that it can live in Analysis instead of
VMCore.

llvm-svn: 121885
2010-12-15 20:02:24 +00:00
Dan Gohman
f4e1d91b8e Update memdep to handle PartialAlias as MayAlias.
llvm-svn: 121723
2010-12-13 22:47:57 +00:00
Chris Lattner
84d3d220c1 strength reduce this.
llvm-svn: 120381
2010-11-30 01:56:13 +00:00
Benjamin Kramer
3fb7d5556c Initialize MemDep's TD member so buildbots don't trip over an uninitialized pointer (TD is passed to PHITransAddr).
I wonder why this didn't explode earlier.

llvm-svn: 119944
2010-11-21 15:21:46 +00:00
Chris Lattner
3a0edfb37c implement PR8576, deleting dead stores with intervening may-alias stores.
llvm-svn: 119927
2010-11-21 07:34:32 +00:00
Dan Gohman
f3bf6591e0 Add helper functions for computing the Location of load, store,
and vaarg instructions.

llvm-svn: 118845
2010-11-11 21:50:19 +00:00
Dan Gohman
50936c7c4b It's not necessary to clear out the Size and TBAATag at each of
these points.

llvm-svn: 118752
2010-11-11 00:42:22 +00:00
Dan Gohman
b476dc0f55 Set NonLocalDepInfo's Size field to UnknownSize when invalidating
it, so that it doesn't appear to be a known size.

llvm-svn: 118748
2010-11-11 00:20:27 +00:00
Dan Gohman
8895f1c5d5 When clearing a non-local pointer dependency cache entry, clear
the reverse map too. This fixes seflhost build errors.

llvm-svn: 118729
2010-11-10 22:35:02 +00:00
Dan Gohman
543edf7e84 Factor out the code for computing an AliasAnalysis::Location
for a given instruction into a helper function.

llvm-svn: 118723
2010-11-10 21:51:35 +00:00
Dan Gohman
aef3e95364 Fully invalidate cached results when a prior query's size or
type is insufficient for, or incompatible with, the current query.

llvm-svn: 118721
2010-11-10 21:45:11 +00:00