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path: root/lib/Analysis/MemoryDependenceAnalysis.cpp
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2012-10-23Ignore unreachable blocks when doing memory dependence analysis on non-localBill Wendling
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166490 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09Create enums for the different attributes.Bill Wendling
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165488 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08Move TargetData to DataLayout.Micah Villmow
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Remove the `hasFnAttr' method from Function.Bill Wendling
The hasFnAttr method has been replaced by querying the Attributes explicitly. No intended functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164725 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-04Be conservative about allocations that may alias the accessed pointer.Bob Wilson
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163127 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-03Fix more fallout from r158919, similar to PR13547.Bob Wilson
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163106 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-29Make MemoryBuiltins aware of TargetLibraryInfo.Benjamin Kramer
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162841 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-13MemoryDependenceAnalysis attempts to find the first memory dependency for ↵Nadav Rotem
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 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161802 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-21refactor the MemoryBuiltin analysis:Nuno Lopes
- 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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158919 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-02Fix typos found by http://github.com/lyda/misspell-checkBenjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157885 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-14Move the capture analysis from MemoryDependencyAnalysis to a more general placeChad Rosier
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 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156776 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-12Hoist simpler checks above llvm::PointerMayBeCaptured. No functional change ↵Chad Rosier
intended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156687 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-26Don't call dominates on unreachable instructions. Should fix the dragoneggRafael Espindola
build. Testcase is still reducing. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151474 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-06The patch resolves the conflict between AddressSanitizer and load widening ↵Kostya Serebryany
(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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149925 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-20More dead code removal (using -Wunreachable-code)David Blaikie
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148578 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-28Change CaptureTracking to pass a Use* instead of a Value* when a value isNick Lewycky
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147327 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-21Fix crasher in GVN due to my recent capture tracking changes.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145047 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-20Less template, more virtual! Refactoring suggested by Chris in code review.Nick Lewycky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145014 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-20Refactor code to use new attribute getters on CallSite for NoCapture and ByVal.Nick Lewycky
Suggested in code review by Eli. That code in InstCombine looks kinda suspicious. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145013 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-14Refactor capture tracking (which already had a couple flags for whether returnsNick Lewycky
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! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144580 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-13Enhance the memdep interface so that users can tell the difference between a ↵Eli Friedman
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141896 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-15Misc analysis passes that need to be aware of atomic load/store.Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137650 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18land David Blaikie's patch to de-constify Type, with a few tweaks.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-15Add a limit to the number of instructions memdep will scan in a single ↵Eli Friedman
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 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133111 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-15Add "unknown" results for memdep, which mean "I don't know whether a ↵Eli Friedman
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133031 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04Disable the main feature of 130180, the elimination of loads that areDan Gohman
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132631 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-02When marking a block as being unanalyzable, use "Clobber" on the terminator ↵Eli Friedman
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.) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132442 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-01In MemoryDependenceAnalysis::getNonLocalPointerDepFromBB, if a given block ↵Eli Friedman
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132434 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-17@llvm.lifetime.begin acts as a load, not @llvm.lifetime.end.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131437 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-28teach GVN to widen integer loads when they are overaligned, when doing an Chris Lattner
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130390 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-26Enhance memdep to return clobber relation between noalias loads whenChris Lattner
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130250 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-26use AA::isMustAlias to simplify some calls.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130248 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-26remove support for llvm.invariant.end from memdep. It is a Chris Lattner
work-in-progress that is not progressing, and it has issues. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130247 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-26Enhance MemDep: When alias analysis returns a partial alias result,Chris Lattner
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130180 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-24Give GetUnderlyingObject a TargetData, to keep it in syncDan Gohman
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124134 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11Revert r123207: "Turn on memdep's verifyRemoved() in an attempt to smoke out ↵Jakob Stoklund Olesen
the cause of our gcc bootstrap miscompare." It didn't. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123215 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11Turn on memdep's verifyRemoved() in an attempt to smoke out the cause of our ↵Jakob Stoklund Olesen
gcc bootstrap miscompare. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123207 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-23Change all self assignments X=X to (void)X, so that we can turn on aJeffrey Yasskin
new gcc warning that complains on self-assignments and self-initializations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122458 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15Move Value::getUnderlyingObject to be a standaloneDan Gohman
function so that it can live in Analysis instead of VMCore. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121885 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13Update memdep to handle PartialAlias as MayAlias.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121723 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30strength reduce this.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120381 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21Initialize MemDep's TD member so buildbots don't trip over an uninitialized ↵Benjamin Kramer
pointer (TD is passed to PHITransAddr). I wonder why this didn't explode earlier. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119944 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21implement PR8576, deleting dead stores with intervening may-alias stores.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119927 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-11Add helper functions for computing the Location of load, store,Dan Gohman
and vaarg instructions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118845 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-11It's not necessary to clear out the Size and TBAATag at each ofDan Gohman
these points. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118752 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-11Set NonLocalDepInfo's Size field to UnknownSize when invalidatingDan Gohman
it, so that it doesn't appear to be a known size. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118748 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10When clearing a non-local pointer dependency cache entry, clearDan Gohman
the reverse map too. This fixes seflhost build errors. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118729 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10Factor out the code for computing an AliasAnalysis::LocationDan Gohman
for a given instruction into a helper function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118723 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10Fully invalidate cached results when a prior query's size orDan Gohman
type is insufficient for, or incompatible with, the current query. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118721 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-10Enhance GVN to do more precise alias queries for non-local memoryDan Gohman
references. For example, this allows gvn to eliminate the load in this example: void foo(int n, int* p, int *q) { p[0] = 0; p[1] = 1; if (n) { *q = p[0]; } } git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118714 91177308-0d34-0410-b5e6-96231b3b80d8
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