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path: root/lib/Analysis/BasicAliasAnalysis.cpp
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2009-07-20Revert the addition of hasNoPointerOverflow to GEPOperator.Dan Gohman
Getelementptrs that are defined to wrap are virtually useless to optimization, and getelementptrs that are undefined on any kind of overflow are too restrictive -- it's difficult to ensure that all intermediate addresses are within bounds. I'm going to take a different approach. Remove a few optimizations that depended on this flag. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76437 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-17Make BasicAliasAnalysis and Value::getUnderlyingObject useDan Gohman
GEPOperator's hasNoPointer0verflow(), and make a few places in instcombine that create GEPs that may overflow clear the NoOverflow value. Among other things, this partially addresses PR2831. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76252 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16Move the ConstantInt uniquing table into LLVMContextImpl. This exposed a ↵Owen Anderson
number of issues in our current context-passing stuff, which is also fixed here git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76089 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-14llvm_unreachable->llvm_unreachable(0), LLVM_UNREACHABLE->llvm_unreachable.Torok Edwin
This adds location info for all llvm_unreachable calls (which is a macro now) in !NDEBUG builds. In NDEBUG builds location info and the message is off (it only prints "UREACHABLE executed"). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75640 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-11assert(0) -> LLVM_UNREACHABLE.Torok Edwin
Make llvm_unreachable take an optional string, thus moving the cerr<< out of line. LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for NDEBUG builds. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75379 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06"LLVMContext* " --> "LLVMContext *"Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74878 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-06Thread LLVMContext through the constant folding APIs, which touches a lot of ↵Owen Anderson
files. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74844 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-22Remove unneeded #include.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73911 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27Teach BasicAliasAnalysis to understand constant gep indices that fallDan Gohman
beyond their associated static array type. I believe that this fixes a legitimate bug, because BasicAliasAnalysis already has code to check for this condition that works for non-constant indices, however it was missing the case of constant indices. With this change, it checks for both. This fixes PR4267, and miscompiles of SPEC 188.ammp and 464.h264.href. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72451 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-09Rename PaddedSize to AllocSize, in the hope that thisDuncan Sands
will make it more obvious what it represents, and stop it being confused with the StoreSize. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71349 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-14Generalize some alias analysis logic from atomicDuncan Sands
intrinsics to any IntrWriteArgMem intrinsics. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64551 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-13BasicAA was making the assumption that a local allocation which hadn't escapedNick Lewycky
couldn't ever be the return of call instruction. However, it's quite possible that said local allocation is itself the return of a function call. That's what malloc and calloc are for, actually. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64442 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-05Refactor my previous change to maintain the distinction between ↵Owen Anderson
AliasAnalysis and BasicAliasAnalysis. This involves some wider changes because it folds away some never-used methods. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63900 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04Finish making AliasAnalysis aware of the fact that most atomic intrinsics ↵Owen Anderson
only dereference their arguments, and enhance BasicAA to make use of this fact when computing ModRef info. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63718 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-03Move isIdentifiedObject and isNoAliasCall into AliasAnalysis.cpp sinceDan Gohman
they are useful to analyses other than BasicAliasAnalysis.cpp. Include the full comment for isIdentifiedObject in the header file. Thanks to Chris for suggeseting this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63589 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-30Fix a post-RA scheduling dependency bug.Dan Gohman
If a MachineInstr doesn't have a memoperand but has an opcode that is known to load or store, assume its memory reference may alias *anything*, including stack slots which the compiler completely controls. To partially compensate for this, teach the ScheduleDAG building code to do basic getUnderlyingValue analysis. This greatly reduces the number of instructions that require restrictive dependencies. This code will need to be revisited when we start doing real alias analysis, but it should suffice for now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63370 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-18BasicAliasAnalysis and FunctionAttrs were bothDuncan Sands
doing very similar pointer capture analysis. Factor out the common logic. The new version is from FunctionAttrs since it does a better job than the version in BasicAliasAnalysis git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62461 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-18add a commentGabor Greif
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62436 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12Rename getABITypeSize to getTypePaddedSize, asDuncan Sands
suggested by Chris. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62099 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12make tblgen autogenerate the nocapture intrinsics for Chris Lattner
llvm.memcpy/memset/memmove. This allows removal of some hackish code from basicaa. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62071 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05When checking if an Argument escapes, check ifDuncan Sands
the argument is marked nocapture - no need to analyze the argument if the answer is already known! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61753 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-19Resubmit support for the 'nocapture' attribute.Nick Lewycky
The problematic part of this patch is that we were out of attribute bits, requiring some fancy bit hacking to make it fit (by shrinking alignment) without breaking existing users or the file format. This change will require users to rebuild llvm-gcc to match llvm. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61239 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16Temporarily revert r61019, r61030, and r61040. These were breaking LLVM ReleaseBill Wendling
builds. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61094 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15Teach basicaa to use the nocapture attribute when possible. When theChris Lattner
intrinsics are properly marked nocapture, the fixme should be addressed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61040 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-10Allow basicaa to walk through geps with identical indices in Chris Lattner
parallel, allowing it to decide that P/Q must alias if A/B must alias in things like: P = gep A, 0, i, 1 Q = gep B, 0, i, 1 This allows GVN to delete 62 more instructions out of 403.gcc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60820 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09Teach BasicAA::getModRefInfo(CallSite, CallSite) someChris Lattner
tricks based on readnone/readonly functions. Teach memdep to look past readonly calls when analyzing deps for a readonly call. This allows elimination of a few more calls from 403.gcc: before: 63 gvn - Number of instructions PRE'd 153986 gvn - Number of instructions deleted 50069 gvn - Number of loads deleted after: 63 gvn - Number of instructions PRE'd 153991 gvn - Number of instructions deleted 50069 gvn - Number of loads deleted 5 calls isn't much, but this adds plumbing for the next change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60794 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-08Fix comment typo.Duncan Sands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60697 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-08Some minor optimizations for isObjectSmallerThan.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60687 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-24Seriously strengthen the guarantee offered by noalias on a function's returnNick Lewycky
value. It must now be as if the pointer were allocated and has not escaped to the caller. Thanks to Dan Gohman for pointing out the error in the original and helping devise this definition. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59940 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-24Extend the 'noalias' attribute to function return values. This is intended toNick Lewycky
indicate functions that allocate, such as operator new, or list::insert. The actual definition is slightly less strict (for now). No changes to the bitcode reader/writer, asm printer or verifier were needed. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59934 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-01Factorize code: remove variants of "strip offDuncan Sands
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56922 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-23s/ParameterAttributes/Attributes/gDevang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56513 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04Tidy up several unbeseeming casts from pointer to intptr_t.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16simplify some code by using a helper function. This really reallyChris Lattner
wants a 'nocapture' predicate. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52304 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16move a bunch of predicates up into their own sectionChris Lattner
in this file, no other changes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52303 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16Other parts of this code treat noalias arguments as objects forChris Lattner
the purposes of escape analysis. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52302 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16If we are checking to see if the result of a call aliases aChris Lattner
pointer derived from a local allocation, if the local allocation never escapes, the pointers can't alias. This implements PR2436 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52301 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16Refactor basicaa's main alias function somethin' fierce. Chris Lattner
This fixes several minor bugs (such as returning noalias for comparisons between external weak functions an null) but is mostly a cleanup. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52299 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-02Fixes PR2395. Looking for a constant in a GEP tail (when the first GEP Wojciech Matyjewicz
is longer than the second one) should stop after finding one. Added break instruction guarantees it. It also changes difference between offsets to absolute value of this difference in the condition. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51875 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13Clean up the use of static and anonymous namespaces. This turned upDan Gohman
several things that were neither in an anonymous namespace nor static but not intended to be global. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21Fix a "large integer implicitly truncated to unsigned type"Duncan Sands
warning. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50033 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-15Don't assume a tail call can't reference a byvalDale Johannesen
argument to the outer function, this isn't correct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49731 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-20Restore isCFGOnly property of various analysis passes.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48579 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-19PassInfo keep tracks whether a pass is an analysis pass or not.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48554 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-19Fix a compiler warning.Duncan Sands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47328 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-19In addition to arguments passed to it, memcpy (and all other calls) can ↵Owen Anderson
ModRef pointers that alias their arguments as well. This fixes PR2057. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47317 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18don't bother calling getUnderlyingObject for non-pointers.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47272 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18Since we're not checking for the more general AllocationInst first, we need ↵Owen Anderson
to explicitly check that Object is an Argument before casting it to one. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47268 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18This check is not correct for mallocs, so exclude them earlier.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47263 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18Fix a comment, and a bug where we weren't applying the tail call logic in ↵Owen Anderson
cases that failed the first test. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47253 91177308-0d34-0410-b5e6-96231b3b80d8