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path: root/lib/Analysis/BasicAliasAnalysis.cpp
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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
2008-02-18Fix bugs that Chris noticed in my last patch.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47252 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18bitcasts of pointers are always pointers.Chris Lattner
If we see a memcpy of a pointer, make sure to check later uses of the pointer as well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47250 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-17Teach getModRefInfo that memcpy, memmove, and memset don't "capture" memory ↵Owen Anderson
addresses. Also, noalias arguments are be considered "like" stack allocated ones for this purpose, because the only way they can be modref'ed is if they escape somewhere in the current function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47247 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-24getUnderlyingObject can return null, handle this.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46318 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-24Teach basicaa that 'byval' arguments define a new memory location thatChris Lattner
can't be aliased to other known objects. This allows us to know that byval pointer args don't alias globals, etc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46315 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29Remove attribution from file headers, per discussion on llvmdev.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45418 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-13Make these loops follow GetGEPOperands() behavior.Wojciech Matyjewicz
Let: %q = GEP %p, X, ... If %p is a GEP, we can chase baseptr further, only if X==0. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44999 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-09Fix PR1782, patch by Wojtek Matyjewicz!Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44733 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-03Rather than having special rules like "intrinsics cannotDuncan Sands
throw exceptions", just mark intrinsics with the nounwind attribute. Likewise, mark intrinsics as readnone/readonly and get rid of special aliasing logic (which didn't use anything more than this anyway). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44544 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-01Integrate the readonly/readnone logic more deeplyDuncan Sands
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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44487 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-28Add some convenience methods for querying attributes, andDuncan Sands
use them. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44403 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-27Fix PR1146: parameter attributes are longer part ofDuncan Sands
the function type, instead they belong to functions and function calls. This is an updated and slightly corrected version of Reid Spencer's original patch. The only known problem is that auto-upgrading of bitcode files doesn't seem to work properly (see test/Bitcode/AutoUpgradeIntrinsics.ll). Hopefully a bitcode guru (who might that be? :) ) will fix it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44359 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-23Ding dong, the DoesntAccessMemoryFns andDuncan Sands
OnlyReadsMemoryFns tables are dead! We get more, and more accurate, information from gcc via the readnone and readonly function attributes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44288 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-22Teach alias analysis about readnone/readonly functions.Duncan Sands
Based on a patch by Török Edwin. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44279 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-16Fix for PR1801Tanya Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44193 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-06Fix PR1774 and BasicAA/2007-11-05-SizeCrash.llChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43756 91177308-0d34-0410-b5e6-96231b3b80d8