X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FScalarEvolutionExpressions.h;h=da24de281d4757e2a26383324e4345963daeddad;hb=00552e3875ee5f382db6c98286a241a7d0efe1b8;hp=ff82db19b9e7ed881d7284deff3a712d350373de;hpb=cd52a7a381a73c53ec4ef517ad87f19808cb1a28;p=oota-llvm.git diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h index ff82db19b9e..da24de281d4 100644 --- a/include/llvm/Analysis/ScalarEvolutionExpressions.h +++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h @@ -356,84 +356,6 @@ namespace llvm { static inline bool classof(const SCEV *S) { return S->getSCEVType() == scAddRecExpr; } - - /// Collect parametric terms occurring in step expressions. - void collectParametricTerms(ScalarEvolution &SE, - SmallVectorImpl &Terms) const; - - /// Return in Subscripts the access functions for each dimension in Sizes. - void computeAccessFunctions(ScalarEvolution &SE, - SmallVectorImpl &Subscripts, - SmallVectorImpl &Sizes) const; - - /// Split this SCEVAddRecExpr into two vectors of SCEVs representing the - /// subscripts and sizes of an array access. - /// - /// The delinearization is a 3 step process: the first two steps compute the - /// sizes of each subscript and the third step computes the access functions - /// for the delinearized array: - /// - /// 1. Find the terms in the step functions - /// 2. Compute the array size - /// 3. Compute the access function: divide the SCEV by the array size - /// starting with the innermost dimensions found in step 2. The Quotient - /// is the SCEV to be divided in the next step of the recursion. The - /// Remainder is the subscript of the innermost dimension. Loop over all - /// array dimensions computed in step 2. - /// - /// To compute a uniform array size for several memory accesses to the same - /// object, one can collect in step 1 all the step terms for all the memory - /// accesses, and compute in step 2 a unique array shape. This guarantees - /// that the array shape will be the same across all memory accesses. - /// - /// FIXME: We could derive the result of steps 1 and 2 from a description of - /// the array shape given in metadata. - /// - /// Example: - /// - /// A[][n][m] - /// - /// for i - /// for j - /// for k - /// A[j+k][2i][5i] = - /// - /// The initial SCEV: - /// - /// A[{{{0,+,2*m+5}_i, +, n*m}_j, +, n*m}_k] - /// - /// 1. Find the different terms in the step functions: - /// -> [2*m, 5, n*m, n*m] - /// - /// 2. Compute the array size: sort and unique them - /// -> [n*m, 2*m, 5] - /// find the GCD of all the terms = 1 - /// divide by the GCD and erase constant terms - /// -> [n*m, 2*m] - /// GCD = m - /// divide by GCD -> [n, 2] - /// remove constant terms - /// -> [n] - /// size of the array is A[unknown][n][m] - /// - /// 3. Compute the access function - /// a. Divide {{{0,+,2*m+5}_i, +, n*m}_j, +, n*m}_k by the innermost size m - /// Quotient: {{{0,+,2}_i, +, n}_j, +, n}_k - /// Remainder: {{{0,+,5}_i, +, 0}_j, +, 0}_k - /// The remainder is the subscript of the innermost array dimension: [5i]. - /// - /// b. Divide Quotient: {{{0,+,2}_i, +, n}_j, +, n}_k by next outer size n - /// Quotient: {{{0,+,0}_i, +, 1}_j, +, 1}_k - /// Remainder: {{{0,+,2}_i, +, 0}_j, +, 0}_k - /// The Remainder is the subscript of the next array dimension: [2i]. - /// - /// The subscript of the outermost dimension is the Quotient: [j+k]. - /// - /// Overall, we have: A[][n][m], and the access function: A[j+k][2i][5i]. - void delinearize(ScalarEvolution &SE, - SmallVectorImpl &Subscripts, - SmallVectorImpl &Sizes, - const SCEV *ElementSize) const; }; //===--------------------------------------------------------------------===//