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path: root/lib/Analysis/DependenceAnalysis.cpp
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* remove BasePointer before delinearizingSebastian Pop2014-05-27
| | | | | | | | | | No functional change is intended: instead of relying on the delinearization to come up with the base pointer as a remainder of the divisions in the delinearization, we just compute it from the array access and use that value. We substract the base pointer from the SCEV to be delinearized and that simplifies the work of the delinearizer. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209692 91177308-0d34-0410-b5e6-96231b3b80d8
* remove constant termsSebastian Pop2014-05-27
| | | | | | | | | | | | | | | | | | | | | | The delinearization is needed only to remove the non linearity induced by expressions involving multiplications of parameters and induction variables. There is no problem in dealing with constant times parameters, or constant times an induction variable. For this reason, the current patch discards all constant terms and multipliers before running the delinearization algorithm on the terms. The only thing remaining in the term expressions are parameters and multiply expressions of parameters: these simplified term expressions are passed to the array shape recognizer that will not recognize constant dimensions anymore: these will be recognized as different strides in parametric subscripts. The only important special case of a constant dimension is the size of elements. Instead of relying on the delinearization to infer the size of an element, compute the element size from the base address type. This is a much more precise way of computing the element size than before, as we would have mixed together the size of an element with the strides of the innermost dimension. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209691 91177308-0d34-0410-b5e6-96231b3b80d8
* move findArrayDimensions to ScalarEvolutionSebastian Pop2014-05-09
| | | | | | | we do not use the information from SCEVAddRecExpr to compute the shape of the array, so a better place for this function is in ScalarEvolution. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208456 91177308-0d34-0410-b5e6-96231b3b80d8
* split delinearization pass in 3 stepsSebastian Pop2014-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To compute the dimensions of the array in a unique way, we split the delinearization analysis in three steps: - find parametric terms in all memory access functions - compute the array dimensions from the set of terms - compute the delinearized access functions for each dimension The first step is executed on all the memory access functions such that we gather all the patterns in which an array is accessed. The second step reduces all this information in a unique description of the sizes of the array. The third step is delinearizing each memory access function following the common description of the shape of the array computed in step 2. This rewrite of the delinearization pass also solves a problem we had with the previous implementation: because the previous algorithm was by induction on the structure of the SCEV, it would not correctly recognize the shape of the array when the memory access was not following the nesting of the loops: for example, see polly/test/ScopInfo/multidim_only_ivs_3d_reverse.ll ; void foo(long n, long m, long o, double A[n][m][o]) { ; ; for (long i = 0; i < n; i++) ; for (long j = 0; j < m; j++) ; for (long k = 0; k < o; k++) ; A[i][k][j] = 1.0; Starting with this patch we no longer delinearize access functions that do not contain parameters, for example in test/Analysis/DependenceAnalysis/GCD.ll ;; for (long int i = 0; i < 100; i++) ;; for (long int j = 0; j < 100; j++) { ;; A[2*i - 4*j] = i; ;; *B++ = A[6*i + 8*j]; these accesses will not be delinearized as the upper bound of the loops are constants, and their access functions do not contain SCEVUnknown parameters. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208232 91177308-0d34-0410-b5e6-96231b3b80d8
* [Modules] Fix potential ODR violations by sinking the DEBUG_TYPEChandler Carruth2014-04-22
| | | | | | | | | | definition below all the header #include lines, lib/Analysis/... edition. This one has a bit extra as there were *other* #define's before #include lines in addition to DEBUG_TYPE. I've sunk all of them as a block. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206843 91177308-0d34-0410-b5e6-96231b3b80d8
* [C++11] More 'nullptr' conversion. In some cases just using a boolean check ↵Craig Topper2014-04-15
| | | | | | instead of comparing to nullptr. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206243 91177308-0d34-0410-b5e6-96231b3b80d8
* [Modules] Move InstIterator out of the Support library, where it had noChandler Carruth2014-03-04
| | | | | | | | | | | | | business. This header includes Function and BasicBlock and directly uses the interfaces of both classes. It has to do with the IR, it even has that in the name. =] Put it in the library it belongs to. This is one step toward making LLVM's Support library survive a C++ modules bootstrap. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202814 91177308-0d34-0410-b5e6-96231b3b80d8
* normalize the last delinearized dimensionSebastian Pop2014-02-21
| | | | | | | | | | | | | | | | in the dependence test, we used to discard some information that the delinearization provides: the size of the innermost dimension of an array, i.e., the size of scalars stored in the array, and the remainder of the delinearization that provides the offset from which the array reads start, i.e., the base address of the array. To avoid losing this data in the rest of the data dependence analysis, the fix is to multiply the access function in the last delinearized dimension by its size, effectively making the size of the last dimension to always be in bytes, and then add the remainder of delinearization to the last subscript, effectively making the last subscript start at the base address of the array. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201867 91177308-0d34-0410-b5e6-96231b3b80d8
* fail delinearization when the size of subscripts differsSebastian Pop2014-02-21
| | | | | | | | | | | Because the delinearization is not a global analysis pass, it will compute the delinearization independently of knowledge about the way the delinearization happened for other data accesses to the same array: the dependence analysis will only trigger the delinearization on a tuple of access functions, and thus delinearization may compute different subscripts sizes for a same array. When that happens the safest is to discard the delinearized information. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201866 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix known typosAlp Toker2014-01-24
| | | | | | | Sweep the codebase for common typos. Includes some changes to visible function names that were misspelt. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200018 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix comment of findGCD.Mingjie Xing2014-01-07
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198660 91177308-0d34-0410-b5e6-96231b3b80d8
* add more comments around the delinearization of arraysSebastian Pop2013-11-13
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194612 91177308-0d34-0410-b5e6-96231b3b80d8
* delinearization of arraysSebastian Pop2013-11-12
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194527 91177308-0d34-0410-b5e6-96231b3b80d8
* Remove extraneous semicolon.Jakub Staszak2013-08-06
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187806 91177308-0d34-0410-b5e6-96231b3b80d8
* Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector ↵Craig Topper2013-07-14
| | | | | | size. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186274 91177308-0d34-0410-b5e6-96231b3b80d8
* git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185187 ↵Preston Briggs2013-06-28
| | | | 91177308-0d34-0410-b5e6-96231b3b80d8
* Move all of the header files which are involved in modelling the LLVM IRChandler Carruth2013-01-02
| | | | | | | | | | | | | | | | | | | | | into their new header subdirectory: include/llvm/IR. This matches the directory structure of lib, and begins to correct a long standing point of file layout clutter in LLVM. There are still more header files to move here, but I wanted to handle them in separate commits to make tracking what files make sense at each layer easier. The only really questionable files here are the target intrinsic tablegen files. But that's a battle I'd rather not fight today. I've updated both CMake and Makefile build systems (I think, and my tests think, but I may have missed something). I've also re-sorted the includes throughout the project. I'll be committing updates to Clang, DragonEgg, and Polly momentarily. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
* Use the new script to sort the includes of every file under lib.Chandler Carruth2012-12-03
| | | | | | | | | | | | | | | | | 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. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
* Modified dump() to provide a littlePreston Briggs2012-11-30
| | | | | | | | | | more information for dependences between instructions that don't share a common loop. Updated the test results appropriately. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168965 91177308-0d34-0410-b5e6-96231b3b80d8
* Cleaned up a couple of comments.Preston Briggs2012-11-29
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168854 91177308-0d34-0410-b5e6-96231b3b80d8
* Modified depends() to recognize that when all levels are "=" andPreston Briggs2012-11-27
| | | | | | | | | | there's no possible loo-independent dependence, then there's no dependence. Updated all test result appropriately. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168719 91177308-0d34-0410-b5e6-96231b3b80d8
* Modify depends(Src, Dst, PossiblyLoopIndependent).Preston Briggs2012-11-27
| | | | | | | | | | | If the Src and Dst are the same instruction, no loop-independent dependence is possible, so we force the PossiblyLoopIndependent flag to false. The test case results are updated appropriately. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168678 91177308-0d34-0410-b5e6-96231b3b80d8
* Corrects a problem where we reply exclusively of GEPs to drivePreston Briggs2012-11-21
| | | | | | | | | | | | | analysis. Better is to look for cases with useful GEPs and use them when possible. When a pair of useful GEPs is not available, use the raw SCEVs directly. This approach supports better analysis of pointer dereferencing. In parallel, all the test cases are updated appropriately. Cases where we have a store to *B++ can now be analyzed! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168474 91177308-0d34-0410-b5e6-96231b3b80d8
* removes a few "const" qualifiersSebastian Pop2012-11-20
| | | | | | | | | so that I can (someday) call SE->getSCEV without complaint. No semantic change intended. Patch from Preston Briggs <preston.briggs@gmail.com>. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168391 91177308-0d34-0410-b5e6-96231b3b80d8
* DependenceAnalysis: Print all dependency pairs when dumping. Update all ↵Benjamin Kramer2012-11-13
| | | | | | | | testcases. Part of a patch by Preston Briggs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167827 91177308-0d34-0410-b5e6-96231b3b80d8
* Fix a couple of comment typos.Benjamin Kramer2012-10-31
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167113 91177308-0d34-0410-b5e6-96231b3b80d8
* DependenceAnalysis: Don't crash if there is no constant operand.Benjamin Kramer2012-10-31
| | | | | | This makes the code match the comments. Resolves a crash in loop idiom (PR14219). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167110 91177308-0d34-0410-b5e6-96231b3b80d8
* DependenceAnalysis: Push #includes down into the implementation.Benjamin Kramer2012-10-25
| | | | git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166688 91177308-0d34-0410-b5e6-96231b3b80d8
* fix warningSebastian Pop2012-10-12
| | | | | | | | | | | DependenceAnalysis.cpp:1164:32: warning: implicit truncation from 'int' to bitfield changes value from -5 to 3 [-Wconstant-conversion] Result.DV[Level].Direction &= ~Dependence::DVEntry::GT; ^ ~~~~~~~~~~~~~~~~~~~~~~~~ Patch from Preston Briggs <preston.briggs@gmail.com>. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165784 91177308-0d34-0410-b5e6-96231b3b80d8
* dependence analysisSebastian Pop2012-10-11
Patch from Preston Briggs <preston.briggs@gmail.com>. This is an updated version of the dependence-analysis patch, including an MIV test based on Banerjee's inequalities. It's a fairly complete implementation of the paper Practical Dependence Testing Gina Goff, Ken Kennedy, and Chau-Wen Tseng PLDI 1991 It cannot yet propagate constraints between coupled RDIV subscripts (discussed in Section 5.3.2 of the paper). It's organized as a FunctionPass with a single entry point that supports testing for dependence between two instructions in a function. If there's no dependence, it returns null. If there's a dependence, it returns a pointer to a Dependence which can be queried about details (what kind of dependence, is it loop independent, direction and distance vector entries, etc). I haven't included every imaginable feature, but there's a good selection that should be adequate for supporting many loop transformations. Of course, it can be extended as necessary. Included in the patch file are many test cases, commented with C code showing the loops and array references. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165708 91177308-0d34-0410-b5e6-96231b3b80d8
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