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path: root/lib/Analysis/AliasAnalysis.cpp
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2007-11-01Executive summary: getTypeSize -> getTypeStoreSize / getABITypeSize.Duncan Sands
The meaning of getTypeSize was not clear - clarifying it is important now that we have x86 long double and arbitrary precision integers. The issue with long double is that it requires 80 bits, and this is not a multiple of its alignment. This gives a primitive type for which getTypeSize differed from getABITypeSize. For arbitrary precision integers it is even worse: there is the minimum number of bits needed to hold the type (eg: 36 for an i36), the maximum number of bits that will be overwriten when storing the type (40 bits for i36) and the ABI size (i.e. the storage size rounded up to a multiple of the alignment; 64 bits for i36). This patch removes getTypeSize (not really - it is still there but deprecated to allow for a gradual transition). Instead there is: (1) getTypeSizeInBits - a number of bits that suffices to hold all values of the type. For a primitive type, this is the minimum number of bits. For an i36 this is 36 bits. For x86 long double it is 80. This corresponds to gcc's TYPE_PRECISION. (2) getTypeStoreSizeInBits - the maximum number of bits that is written when storing the type (or read when reading it). For an i36 this is 40 bits, for an x86 long double it is 80 bits. This is the size alias analysis is interested in (getTypeStoreSize returns the number of bytes). There doesn't seem to be anything corresponding to this in gcc. (3) getABITypeSizeInBits - this is getTypeStoreSizeInBits rounded up to a multiple of the alignment. For an i36 this is 64, for an x86 long double this is 96 or 128 depending on the OS. This is the spacing between consecutive elements when you form an array out of this type (getABITypeSize returns the number of bytes). This is TYPE_SIZE in gcc. Since successive elements in a SequentialType (arrays, pointers and vectors) need to be aligned, the spacing between them will be given by getABITypeSize. This means that the size of an array is the length times the getABITypeSize. It also means that GEP computations need to use getABITypeSize when computing offsets. Furthermore, if an alloca allocates several elements at once then these too need to be aligned, so the size of the alloca has to be the number of elements multiplied by getABITypeSize. Logically speaking this doesn't have to be the case when allocating just one element, but it is simpler to also use getABITypeSize in this case. So alloca's and mallocs should use getABITypeSize. Finally, since gcc's only notion of size is that given by getABITypeSize, if you want to output assembler etc the same as gcc then getABITypeSize is the size you want. Since a store will overwrite no more than getTypeStoreSize bytes, and a read will read no more than that many bytes, this is the notion of size appropriate for alias analysis calculations. In this patch I have corrected all type size uses except some of those in ScalarReplAggregates, lib/Codegen, lib/Target (the hard cases). I will get around to auditing these too at some point, but I could do with some help. Finally, I made one change which I think wise but others might consider pointless and suboptimal: in an unpacked struct the amount of space allocated for a field is now given by the ABI size rather than getTypeStoreSize. I did this because every other place that reserves memory for a type (eg: alloca) now uses getABITypeSize, and I didn't want to make an exception for unpacked structs, i.e. I did it to make things more uniform. This only effects structs containing long doubles and arbitrary precision integers. If someone wants to pack these types more tightly they can always use a packed struct. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43620 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-03Drop 'const'Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36662 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-02Use 'static const char' instead of 'static const int'.Devang Patel
Due to darwin gcc bug, one version of darwin linker coalesces static const int, which defauts PassID based pass identification. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36652 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-02Fix build error.Lauro Ramos Venancio
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36648 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-01Do not use typeinfo to identify pass in pass manager.Devang Patel
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36632 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-17Removed unneeded <iostream> #include.Bill Wendling
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31810 91177308-0d34-0410-b5e6-96231b3b80d8
2006-06-07For PR780:Reid Spencer
1. Fix the macros in IncludeFile.h to put everything in the llvm namespace 2. Replace the previous explicit mechanism in all the .h and .cpp files with the macros in IncludeFile.h This gets us a consistent mechanism throughout LLVM for ensuring linkage. Next step is to make sure its used in enough places. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28715 91177308-0d34-0410-b5e6-96231b3b80d8
2006-06-07For PR780:Reid Spencer
Break the "IncludeFile" mechanism into its own header file and adjust other files accordingly. Use this facility for the IntrinsicInst problem which was the subject of PR800. More to follow on this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28709 91177308-0d34-0410-b5e6-96231b3b80d8
2006-06-01Change from using a stub function to a stub variable for passing to theReid Spencer
IncludeFile hack to ensure linkage of analysis passes. This works around some -pedantic warnings about assigning an object to a function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28621 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-21Remove trailing whitespaceMisha Brukman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21416 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-23Make this more efficient by only making one virtual method call.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20793 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-23Make this a bit more aggressiveChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20792 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-17Fix the missing symbols problem Bill was hitting. Patch contributed byChris Lattner
Bill Wendling!! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20649 91177308-0d34-0410-b5e6-96231b3b80d8
2004-12-15Adjust to new alias analysis interfacesChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18957 91177308-0d34-0410-b5e6-96231b3b80d8
2004-12-08Properly extern this.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18664 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-29Fix #includes of i*.h => Instructions.h as per PR403.Misha Brukman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15334 91177308-0d34-0410-b5e6-96231b3b80d8
2004-07-04Add #include <iostream> since Value.h does not #include it any more.Reid Spencer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14622 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-23Changes to work with the changes to the AliasAnalysis interface. The -no-aaChris Lattner
class is now in the BasicAliasAnalysis.cpp file git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13684 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-15Deinline some virtual methods, provide better mod/ref answers through theChris Lattner
use of the boolean queries git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12410 91177308-0d34-0410-b5e6-96231b3b80d8
2004-01-30Improve mod/ref information based on the pointsToConstantMemory method.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11021 91177308-0d34-0410-b5e6-96231b3b80d8
2003-11-11Put all LLVM code into the llvm namespace, as per bug 109.Brian Gaeke
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9903 91177308-0d34-0410-b5e6-96231b3b80d8
2003-10-20Added LLVM project notice to the top of every C++ source file.John Criswell
Header files will be on the way. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9298 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-26Add new -no-aa implementationChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5641 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-26Move BasicAA pass out to it's own header fileChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5640 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-26 - Checkin of the alias analysis work:Chris Lattner
* Takes into account the size of the memory reference to determine aliasing. * Expose mod/ref information in a more consistent way * BasicAA can now disambiguate A[i][1] and A[j][2] for conservative request sizes git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5633 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-09Implement knowledge in BasicAA that &A->field != &A and (P+1) != PChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5519 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-09 - Fix BasicAA to correctly detect the non-aliasness of A[1] & A[2]Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5518 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-07Don't bother counting alias results, allow the AliasAnalysisCounter to do that.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5505 91177308-0d34-0410-b5e6-96231b3b80d8
2003-02-03Add statistics to basicAA passChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5480 91177308-0d34-0410-b5e6-96231b3b80d8
2002-11-06Make query operations non-const to allow demand-driven analyses.Vikram S. Adve
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4569 91177308-0d34-0410-b5e6-96231b3b80d8
2002-09-08* Add capability to recognize alias properties of the following common cases:Chris Lattner
- A[c1] cannot alias A[c2] where constants c1 != c2 - A[i] cannot alias B[j] if A & B are provably different arrays This should help out array based codes. For example, from bzip2 from spec, 3 additional loads can be GCSE'd, and _21_ additional loads can be LICMd due to this change. In a test example from the Spec GAP benchmark (vecffe.c), this change allows _52_ additional loads to be GCSE'd and _224_ additional LICM'd loads. Not bad for such a simple change. Other testcases show no change at all because they just don't use arrays. Not too suprising there. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3616 91177308-0d34-0410-b5e6-96231b3b80d8
2002-08-29Remove unneeded #includeChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3524 91177308-0d34-0410-b5e6-96231b3b80d8
2002-08-22doxygenize commentsChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3481 91177308-0d34-0410-b5e6-96231b3b80d8
2002-08-22Add missing #includeChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3467 91177308-0d34-0410-b5e6-96231b3b80d8
2002-08-22Check-in new alias analysis infrastructureChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3465 91177308-0d34-0410-b5e6-96231b3b80d8
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