diff options
Diffstat (limited to 'gcc/lambda-code.c')
| -rw-r--r-- | gcc/lambda-code.c | 2855 |
1 files changed, 0 insertions, 2855 deletions
diff --git a/gcc/lambda-code.c b/gcc/lambda-code.c deleted file mode 100644 index f462071..0000000 --- a/gcc/lambda-code.c +++ /dev/null @@ -1,2855 +0,0 @@ -/* Loop transformation code generation - Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 - Free Software Foundation, Inc. - Contributed by Daniel Berlin <dberlin@dberlin.org> - - This file is part of GCC. - - GCC is free software; you can redistribute it and/or modify it under - the terms of the GNU General Public License as published by the Free - Software Foundation; either version 3, or (at your option) any later - version. - - GCC is distributed in the hope that it will be useful, but WITHOUT ANY - WARRANTY; without even the implied warranty of MERCHANTABILITY or - FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - for more details. - - You should have received a copy of the GNU General Public License - along with GCC; see the file COPYING3. If not see - <http://www.gnu.org/licenses/>. */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tree-flow.h" -#include "cfgloop.h" -#include "tree-chrec.h" -#include "tree-data-ref.h" -#include "tree-scalar-evolution.h" -#include "lambda.h" -#include "tree-pass.h" - -/* This loop nest code generation is based on non-singular matrix - math. - - A little terminology and a general sketch of the algorithm. See "A singular - loop transformation framework based on non-singular matrices" by Wei Li and - Keshav Pingali for formal proofs that the various statements below are - correct. - - A loop iteration space represents the points traversed by the loop. A point in the - iteration space can be represented by a vector of size <loop depth>. You can - therefore represent the iteration space as an integral combinations of a set - of basis vectors. - - A loop iteration space is dense if every integer point between the loop - bounds is a point in the iteration space. Every loop with a step of 1 - therefore has a dense iteration space. - - for i = 1 to 3, step 1 is a dense iteration space. - - A loop iteration space is sparse if it is not dense. That is, the iteration - space skips integer points that are within the loop bounds. - - for i = 1 to 3, step 2 is a sparse iteration space, because the integer point - 2 is skipped. - - Dense source spaces are easy to transform, because they don't skip any - points to begin with. Thus we can compute the exact bounds of the target - space using min/max and floor/ceil. - - For a dense source space, we take the transformation matrix, decompose it - into a lower triangular part (H) and a unimodular part (U). - We then compute the auxiliary space from the unimodular part (source loop - nest . U = auxiliary space) , which has two important properties: - 1. It traverses the iterations in the same lexicographic order as the source - space. - 2. It is a dense space when the source is a dense space (even if the target - space is going to be sparse). - - Given the auxiliary space, we use the lower triangular part to compute the - bounds in the target space by simple matrix multiplication. - The gaps in the target space (IE the new loop step sizes) will be the - diagonals of the H matrix. - - Sparse source spaces require another step, because you can't directly compute - the exact bounds of the auxiliary and target space from the sparse space. - Rather than try to come up with a separate algorithm to handle sparse source - spaces directly, we just find a legal transformation matrix that gives you - the sparse source space, from a dense space, and then transform the dense - space. - - For a regular sparse space, you can represent the source space as an integer - lattice, and the base space of that lattice will always be dense. Thus, we - effectively use the lattice to figure out the transformation from the lattice - base space, to the sparse iteration space (IE what transform was applied to - the dense space to make it sparse). We then compose this transform with the - transformation matrix specified by the user (since our matrix transformations - are closed under composition, this is okay). We can then use the base space - (which is dense) plus the composed transformation matrix, to compute the rest - of the transform using the dense space algorithm above. - - In other words, our sparse source space (B) is decomposed into a dense base - space (A), and a matrix (L) that transforms A into B, such that A.L = B. - We then compute the composition of L and the user transformation matrix (T), - so that T is now a transform from A to the result, instead of from B to the - result. - IE A.(LT) = result instead of B.T = result - Since A is now a dense source space, we can use the dense source space - algorithm above to compute the result of applying transform (LT) to A. - - Fourier-Motzkin elimination is used to compute the bounds of the base space - of the lattice. */ - -static bool perfect_nestify (struct loop *, VEC(tree,heap) *, - VEC(tree,heap) *, VEC(int,heap) *, - VEC(tree,heap) *); -/* Lattice stuff that is internal to the code generation algorithm. */ - -typedef struct lambda_lattice_s -{ - /* Lattice base matrix. */ - lambda_matrix base; - /* Lattice dimension. */ - int dimension; - /* Origin vector for the coefficients. */ - lambda_vector origin; - /* Origin matrix for the invariants. */ - lambda_matrix origin_invariants; - /* Number of invariants. */ - int invariants; -} *lambda_lattice; - -#define LATTICE_BASE(T) ((T)->base) -#define LATTICE_DIMENSION(T) ((T)->dimension) -#define LATTICE_ORIGIN(T) ((T)->origin) -#define LATTICE_ORIGIN_INVARIANTS(T) ((T)->origin_invariants) -#define LATTICE_INVARIANTS(T) ((T)->invariants) - -static bool lle_equal (lambda_linear_expression, lambda_linear_expression, - int, int); -static lambda_lattice lambda_lattice_new (int, int, struct obstack *); -static lambda_lattice lambda_lattice_compute_base (lambda_loopnest, - struct obstack *); - -static bool can_convert_to_perfect_nest (struct loop *); - -/* Create a new lambda loop in LAMBDA_OBSTACK. */ - -static lambda_loop -lambda_loop_new (struct obstack * lambda_obstack) -{ - lambda_loop result = (lambda_loop) - obstack_alloc (lambda_obstack, sizeof (struct lambda_loop_s)); - memset (result, 0, sizeof (struct lambda_loop_s)); - return result; -} - -/* Create a new lambda body vector. */ - -lambda_body_vector -lambda_body_vector_new (int size, struct obstack * lambda_obstack) -{ - lambda_body_vector ret; - - ret = (lambda_body_vector) obstack_alloc (lambda_obstack, - sizeof (*ret)); - LBV_COEFFICIENTS (ret) = lambda_vector_new (size); - LBV_SIZE (ret) = size; - LBV_DENOMINATOR (ret) = 1; - return ret; -} - -/* Compute the new coefficients for the vector based on the - *inverse* of the transformation matrix. */ - -lambda_body_vector -lambda_body_vector_compute_new (lambda_trans_matrix transform, - lambda_body_vector vect, - struct obstack * lambda_obstack) -{ - lambda_body_vector temp; - int depth; - - /* Make sure the matrix is square. */ - gcc_assert (LTM_ROWSIZE (transform) == LTM_COLSIZE (transform)); - - depth = LTM_ROWSIZE (transform); - - temp = lambda_body_vector_new (depth, lambda_obstack); - LBV_DENOMINATOR (temp) = - LBV_DENOMINATOR (vect) * LTM_DENOMINATOR (transform); - lambda_vector_matrix_mult (LBV_COEFFICIENTS (vect), depth, - LTM_MATRIX (transform), depth, - LBV_COEFFICIENTS (temp)); - LBV_SIZE (temp) = LBV_SIZE (vect); - return temp; -} - -/* Print out a lambda body vector. */ - -void -print_lambda_body_vector (FILE * outfile, lambda_body_vector body) -{ - print_lambda_vector (outfile, LBV_COEFFICIENTS (body), LBV_SIZE (body)); -} - -/* Return TRUE if two linear expressions are equal. */ - -static bool -lle_equal (lambda_linear_expression lle1, lambda_linear_expression lle2, - int depth, int invariants) -{ - int i; - - if (lle1 == NULL || lle2 == NULL) - return false; - if (LLE_CONSTANT (lle1) != LLE_CONSTANT (lle2)) - return false; - if (LLE_DENOMINATOR (lle1) != LLE_DENOMINATOR (lle2)) - return false; - for (i = 0; i < depth; i++) - if (LLE_COEFFICIENTS (lle1)[i] != LLE_COEFFICIENTS (lle2)[i]) - return false; - for (i = 0; i < invariants; i++) - if (LLE_INVARIANT_COEFFICIENTS (lle1)[i] != - LLE_INVARIANT_COEFFICIENTS (lle2)[i]) - return false; - return true; -} - -/* Create a new linear expression with dimension DIM, and total number - of invariants INVARIANTS. */ - -lambda_linear_expression -lambda_linear_expression_new (int dim, int invariants, - struct obstack * lambda_obstack) -{ - lambda_linear_expression ret; - - ret = (lambda_linear_expression)obstack_alloc (lambda_obstack, - sizeof (*ret)); - LLE_COEFFICIENTS (ret) = lambda_vector_new (dim); - LLE_CONSTANT (ret) = 0; - LLE_INVARIANT_COEFFICIENTS (ret) = lambda_vector_new (invariants); - LLE_DENOMINATOR (ret) = 1; - LLE_NEXT (ret) = NULL; - - return ret; -} - -/* Print out a linear expression EXPR, with SIZE coefficients, to OUTFILE. - The starting letter used for variable names is START. */ - -static void -print_linear_expression (FILE * outfile, lambda_vector expr, int size, - char start) -{ - int i; - bool first = true; - for (i = 0; i < size; i++) - { - if (expr[i] != 0) - { - if (first) - { - if (expr[i] < 0) - fprintf (outfile, "-"); - first = false; - } - else if (expr[i] > 0) - fprintf (outfile, " + "); - else - fprintf (outfile, " - "); - if (abs (expr[i]) == 1) - fprintf (outfile, "%c", start + i); - else - fprintf (outfile, "%d%c", abs (expr[i]), start + i); - } - } -} - -/* Print out a lambda linear expression structure, EXPR, to OUTFILE. The - depth/number of coefficients is given by DEPTH, the number of invariants is - given by INVARIANTS, and the character to start variable names with is given - by START. */ - -void -print_lambda_linear_expression (FILE * outfile, - lambda_linear_expression expr, - int depth, int invariants, char start) -{ - fprintf (outfile, "\tLinear expression: "); - print_linear_expression (outfile, LLE_COEFFICIENTS (expr), depth, start); - fprintf (outfile, " constant: %d ", LLE_CONSTANT (expr)); - fprintf (outfile, " invariants: "); - print_linear_expression (outfile, LLE_INVARIANT_COEFFICIENTS (expr), - invariants, 'A'); - fprintf (outfile, " denominator: %d\n", LLE_DENOMINATOR (expr)); -} - -/* Print a lambda loop structure LOOP to OUTFILE. The depth/number of - coefficients is given by DEPTH, the number of invariants is - given by INVARIANTS, and the character to start variable names with is given - by START. */ - -void -print_lambda_loop (FILE * outfile, lambda_loop loop, int depth, - int invariants, char start) -{ - int step; - lambda_linear_expression expr; - - gcc_assert (loop); - - expr = LL_LINEAR_OFFSET (loop); - step = LL_STEP (loop); - fprintf (outfile, " step size = %d \n", step); - - if (expr) - { - fprintf (outfile, " linear offset: \n"); - print_lambda_linear_expression (outfile, expr, depth, invariants, - start); - } - - fprintf (outfile, " lower bound: \n"); - for (expr = LL_LOWER_BOUND (loop); expr != NULL; expr = LLE_NEXT (expr)) - print_lambda_linear_expression (outfile, expr, depth, invariants, start); - fprintf (outfile, " upper bound: \n"); - for (expr = LL_UPPER_BOUND (loop); expr != NULL; expr = LLE_NEXT (expr)) - print_lambda_linear_expression (outfile, expr, depth, invariants, start); -} - -/* Create a new loop nest structure with DEPTH loops, and INVARIANTS as the - number of invariants. */ - -lambda_loopnest -lambda_loopnest_new (int depth, int invariants, - struct obstack * lambda_obstack) -{ - lambda_loopnest ret; - ret = (lambda_loopnest)obstack_alloc (lambda_obstack, sizeof (*ret)); - - LN_LOOPS (ret) = (lambda_loop *) - obstack_alloc (lambda_obstack, depth * sizeof(LN_LOOPS(ret))); - LN_DEPTH (ret) = depth; - LN_INVARIANTS (ret) = invariants; - - return ret; -} - -/* Print a lambda loopnest structure, NEST, to OUTFILE. The starting - character to use for loop names is given by START. */ - -void -print_lambda_loopnest (FILE * outfile, lambda_loopnest nest, char start) -{ - int i; - for (i = 0; i < LN_DEPTH (nest); i++) - { - fprintf (outfile, "Loop %c\n", start + i); - print_lambda_loop (outfile, LN_LOOPS (nest)[i], LN_DEPTH (nest), - LN_INVARIANTS (nest), 'i'); - fprintf (outfile, "\n"); - } -} - -/* Allocate a new lattice structure of DEPTH x DEPTH, with INVARIANTS number - of invariants. */ - -static lambda_lattice -lambda_lattice_new (int depth, int invariants, struct obstack * lambda_obstack) -{ - lambda_lattice ret - = (lambda_lattice)obstack_alloc (lambda_obstack, sizeof (*ret)); - LATTICE_BASE (ret) = lambda_matrix_new (depth, depth, lambda_obstack); - LATTICE_ORIGIN (ret) = lambda_vector_new (depth); - LATTICE_ORIGIN_INVARIANTS (ret) = lambda_matrix_new (depth, invariants, - lambda_obstack); - LATTICE_DIMENSION (ret) = depth; - LATTICE_INVARIANTS (ret) = invariants; - return ret; -} - -/* Compute the lattice base for NEST. The lattice base is essentially a - non-singular transform from a dense base space to a sparse iteration space. - We use it so that we don't have to specially handle the case of a sparse - iteration space in other parts of the algorithm. As a result, this routine - only does something interesting (IE produce a matrix that isn't the - identity matrix) if NEST is a sparse space. */ - -static lambda_lattice -lambda_lattice_compute_base (lambda_loopnest nest, - struct obstack * lambda_obstack) -{ - lambda_lattice ret; - int depth, invariants; - lambda_matrix base; - - int i, j, step; - lambda_loop loop; - lambda_linear_expression expression; - - depth = LN_DEPTH (nest); - invariants = LN_INVARIANTS (nest); - - ret = lambda_lattice_new (depth, invariants, lambda_obstack); - base = LATTICE_BASE (ret); - for (i = 0; i < depth; i++) - { - loop = LN_LOOPS (nest)[i]; - gcc_assert (loop); - step = LL_STEP (loop); - /* If we have a step of 1, then the base is one, and the - origin and invariant coefficients are 0. */ - if (step == 1) - { - for (j = 0; j < depth; j++) - base[i][j] = 0; - base[i][i] = 1; - LATTICE_ORIGIN (ret)[i] = 0; - for (j = 0; j < invariants; j++) - LATTICE_ORIGIN_INVARIANTS (ret)[i][j] = 0; - } - else - { - /* Otherwise, we need the lower bound expression (which must - be an affine function) to determine the base. */ - expression = LL_LOWER_BOUND (loop); - gcc_assert (expression && !LLE_NEXT (expression) - && LLE_DENOMINATOR (expression) == 1); - - /* The lower triangular portion of the base is going to be the - coefficient times the step */ - for (j = 0; j < i; j++) - base[i][j] = LLE_COEFFICIENTS (expression)[j] - * LL_STEP (LN_LOOPS (nest)[j]); - base[i][i] = step; - for (j = i + 1; j < depth; j++) - base[i][j] = 0; - - /* Origin for this loop is the constant of the lower bound - expression. */ - LATTICE_ORIGIN (ret)[i] = LLE_CONSTANT (expression); - - /* Coefficient for the invariants are equal to the invariant - coefficients in the expression. */ - for (j = 0; j < invariants; j++) - LATTICE_ORIGIN_INVARIANTS (ret)[i][j] = - LLE_INVARIANT_COEFFICIENTS (expression)[j]; - } - } - return ret; -} - -/* Compute the least common multiple of two numbers A and B . */ - -int -least_common_multiple (int a, int b) -{ - return (abs (a) * abs (b) / gcd (a, b)); -} - -/* Perform Fourier-Motzkin elimination to calculate the bounds of the - auxiliary nest. - Fourier-Motzkin is a way of reducing systems of linear inequalities so that - it is easy to calculate the answer and bounds. - A sketch of how it works: - Given a system of linear inequalities, ai * xj >= bk, you can always - rewrite the constraints so they are all of the form - a <= x, or x <= b, or x >= constant for some x in x1 ... xj (and some b - in b1 ... bk, and some a in a1...ai) - You can then eliminate this x from the non-constant inequalities by - rewriting these as a <= b, x >= constant, and delete the x variable. - You can then repeat this for any remaining x variables, and then we have - an easy to use variable <= constant (or no variables at all) form that we - can construct our bounds from. - - In our case, each time we eliminate, we construct part of the bound from - the ith variable, then delete the ith variable. - - Remember the constant are in our vector a, our coefficient matrix is A, - and our invariant coefficient matrix is B. - - SIZE is the size of the matrices being passed. - DEPTH is the loop nest depth. - INVARIANTS is the number of loop invariants. - A, B, and a are the coefficient matrix, invariant coefficient, and a - vector of constants, respectively. */ - -static lambda_loopnest -compute_nest_using_fourier_motzkin (int size, - int depth, - int invariants, - lambda_matrix A, - lambda_matrix B, - lambda_vector a, - struct obstack * lambda_obstack) -{ - - int multiple, f1, f2; - int i, j, k; - lambda_linear_expression expression; - lambda_loop loop; - lambda_loopnest auxillary_nest; - lambda_matrix swapmatrix, A1, B1; - lambda_vector swapvector, a1; - int newsize; - - A1 = lambda_matrix_new (128, depth, lambda_obstack); - B1 = lambda_matrix_new (128, invariants, lambda_obstack); - a1 = lambda_vector_new (128); - - auxillary_nest = lambda_loopnest_new (depth, invariants, lambda_obstack); - - for (i = depth - 1; i >= 0; i--) - { - loop = lambda_loop_new (lambda_obstack); - LN_LOOPS (auxillary_nest)[i] = loop; - LL_STEP (loop) = 1; - - for (j = 0; j < size; j++) - { - if (A[j][i] < 0) - { - /* Any linear expression in the matrix with a coefficient less - than 0 becomes part of the new lower bound. */ - expression = lambda_linear_expression_new (depth, invariants, - lambda_obstack); - - for (k = 0; k < i; k++) - LLE_COEFFICIENTS (expression)[k] = A[j][k]; - - for (k = 0; k < invariants; k++) - LLE_INVARIANT_COEFFICIENTS (expression)[k] = -1 * B[j][k]; - - LLE_DENOMINATOR (expression) = -1 * A[j][i]; - LLE_CONSTANT (expression) = -1 * a[j]; - - /* Ignore if identical to the existing lower bound. */ - if (!lle_equal (LL_LOWER_BOUND (loop), - expression, depth, invariants)) - { - LLE_NEXT (expression) = LL_LOWER_BOUND (loop); - LL_LOWER_BOUND (loop) = expression; - } - - } - else if (A[j][i] > 0) - { - /* Any linear expression with a coefficient greater than 0 - becomes part of the new upper bound. */ - expression = lambda_linear_expression_new (depth, invariants, - lambda_obstack); - for (k = 0; k < i; k++) - LLE_COEFFICIENTS (expression)[k] = -1 * A[j][k]; - - for (k = 0; k < invariants; k++) - LLE_INVARIANT_COEFFICIENTS (expression)[k] = B[j][k]; - - LLE_DENOMINATOR (expression) = A[j][i]; - LLE_CONSTANT (expression) = a[j]; - - /* Ignore if identical to the existing upper bound. */ - if (!lle_equal (LL_UPPER_BOUND (loop), - expression, depth, invariants)) - { - LLE_NEXT (expression) = LL_UPPER_BOUND (loop); - LL_UPPER_BOUND (loop) = expression; - } - - } - } - - /* This portion creates a new system of linear inequalities by deleting - the i'th variable, reducing the system by one variable. */ - newsize = 0; - for (j = 0; j < size; j++) - { - /* If the coefficient for the i'th variable is 0, then we can just - eliminate the variable straightaway. Otherwise, we have to - multiply through by the coefficients we are eliminating. */ - if (A[j][i] == 0) - { - lambda_vector_copy (A[j], A1[newsize], depth); - lambda_vector_copy (B[j], B1[newsize], invariants); - a1[newsize] = a[j]; - newsize++; - } - else if (A[j][i] > 0) - { - for (k = 0; k < size; k++) - { - if (A[k][i] < 0) - { - multiple = least_common_multiple (A[j][i], A[k][i]); - f1 = multiple / A[j][i]; - f2 = -1 * multiple / A[k][i]; - - lambda_vector_add_mc (A[j], f1, A[k], f2, - A1[newsize], depth); - lambda_vector_add_mc (B[j], f1, B[k], f2, - B1[newsize], invariants); - a1[newsize] = f1 * a[j] + f2 * a[k]; - newsize++; - } - } - } - } - - swapmatrix = A; - A = A1; - A1 = swapmatrix; - - swapmatrix = B; - B = B1; - B1 = swapmatrix; - - swapvector = a; - a = a1; - a1 = swapvector; - - size = newsize; - } - - return auxillary_nest; -} - -/* Compute the loop bounds for the auxiliary space NEST. - Input system used is Ax <= b. TRANS is the unimodular transformation. - Given the original nest, this function will - 1. Convert the nest into matrix form, which consists of a matrix for the - coefficients, a matrix for the - invariant coefficients, and a vector for the constants. - 2. Use the matrix form to calculate the lattice base for the nest (which is - a dense space) - 3. Compose the dense space transform with the user specified transform, to - get a transform we can easily calculate transformed bounds for. - 4. Multiply the composed transformation matrix times the matrix form of the - loop. - 5. Transform the newly created matrix (from step 4) back into a loop nest - using Fourier-Motzkin elimination to figure out the bounds. */ - -static lambda_loopnest -lambda_compute_auxillary_space (lambda_loopnest nest, - lambda_trans_matrix trans, - struct obstack * lambda_obstack) -{ - lambda_matrix A, B, A1, B1; - lambda_vector a, a1; - lambda_matrix invertedtrans; - int depth, invariants, size; - int i, j; - lambda_loop loop; - lambda_linear_expression expression; - lambda_lattice lattice; - - depth = LN_DEPTH (nest); - invariants = LN_INVARIANTS (nest); - - /* Unfortunately, we can't know the number of constraints we'll have - ahead of time, but this should be enough even in ridiculous loop nest - cases. We must not go over this limit. */ - A = lambda_matrix_new (128, depth, lambda_obstack); - B = lambda_matrix_new (128, invariants, lambda_obstack); - a = lambda_vector_new (128); - - A1 = lambda_matrix_new (128, depth, lambda_obstack); - B1 = lambda_matrix_new (128, invariants, lambda_obstack); - a1 = lambda_vector_new (128); - - /* Store the bounds in the equation matrix A, constant vector a, and - invariant matrix B, so that we have Ax <= a + B. - This requires a little equation rearranging so that everything is on the - correct side of the inequality. */ - size = 0; - for (i = 0; i < depth; i++) - { - loop = LN_LOOPS (nest)[i]; - - /* First we do the lower bound. */ - if (LL_STEP (loop) > 0) - expression = LL_LOWER_BOUND (loop); - else - expression = LL_UPPER_BOUND (loop); - - for (; expression != NULL; expression = LLE_NEXT (expression)) - { - /* Fill in the coefficient. */ - for (j = 0; j < i; j++) - A[size][j] = LLE_COEFFICIENTS (expression)[j]; - - /* And the invariant coefficient. */ - for (j = 0; j < invariants; j++) - B[size][j] = LLE_INVARIANT_COEFFICIENTS (expression)[j]; - - /* And the constant. */ - a[size] = LLE_CONSTANT (expression); - - /* Convert (2x+3y+2+b)/4 <= z to 2x+3y-4z <= -2-b. IE put all - constants and single variables on */ - A[size][i] = -1 * LLE_DENOMINATOR (expression); - a[size] *= -1; - for (j = 0; j < invariants; j++) - B[size][j] *= -1; - - size++; - /* Need to increase matrix sizes above. */ - gcc_assert (size <= 127); - - } - - /* Then do the exact same thing for the upper bounds. */ - if (LL_STEP (loop) > 0) - expression = LL_UPPER_BOUND (loop); - else - expression = LL_LOWER_BOUND (loop); - - for (; expression != NULL; expression = LLE_NEXT (expression)) - { - /* Fill in the coefficient. */ - for (j = 0; j < i; j++) - A[size][j] = LLE_COEFFICIENTS (expression)[j]; - - /* And the invariant coefficient. */ - for (j = 0; j < invariants; j++) - B[size][j] = LLE_INVARIANT_COEFFICIENTS (expression)[j]; - - /* And the constant. */ - a[size] = LLE_CONSTANT (expression); - - /* Convert z <= (2x+3y+2+b)/4 to -2x-3y+4z <= 2+b. */ - for (j = 0; j < i; j++) - A[size][j] *= -1; - A[size][i] = LLE_DENOMINATOR (expression); - size++; - /* Need to increase matrix sizes above. */ - gcc_assert (size <= 127); - - } - } - - /* Compute the lattice base x = base * y + origin, where y is the - base space. */ - lattice = lambda_lattice_compute_base (nest, lambda_obstack); - - /* Ax <= a + B then becomes ALy <= a+B - A*origin. L is the lattice base */ - - /* A1 = A * L */ - lambda_matrix_mult (A, LATTICE_BASE (lattice), A1, size, depth, depth); - - /* a1 = a - A * origin constant. */ - lambda_matrix_vector_mult (A, size, depth, LATTICE_ORIGIN (lattice), a1); - lambda_vector_add_mc (a, 1, a1, -1, a1, size); - - /* B1 = B - A * origin invariant. */ - lambda_matrix_mult (A, LATTICE_ORIGIN_INVARIANTS (lattice), B1, size, depth, - invariants); - lambda_matrix_add_mc (B, 1, B1, -1, B1, size, invariants); - - /* Now compute the auxiliary space bounds by first inverting U, multiplying - it by A1, then performing Fourier-Motzkin. */ - - invertedtrans = lambda_matrix_new (depth, depth, lambda_obstack); - - /* Compute the inverse of U. */ - lambda_matrix_inverse (LTM_MATRIX (trans), - invertedtrans, depth, lambda_obstack); - - /* A = A1 inv(U). */ - lambda_matrix_mult (A1, invertedtrans, A, size, depth, depth); - - return compute_nest_using_fourier_motzkin (size, depth, invariants, - A, B1, a1, lambda_obstack); -} - -/* Compute the loop bounds for the target space, using the bounds of - the auxiliary nest AUXILLARY_NEST, and the triangular matrix H. - The target space loop bounds are computed by multiplying the triangular - matrix H by the auxiliary nest, to get the new loop bounds. The sign of - the loop steps (positive or negative) is then used to swap the bounds if - the loop counts downwards. - Return the target loopnest. */ - -static lambda_loopnest -lambda_compute_target_space (lambda_loopnest auxillary_nest, - lambda_trans_matrix H, lambda_vector stepsigns, - struct obstack * lambda_obstack) -{ - lambda_matrix inverse, H1; - int determinant, i, j; - int gcd1, gcd2; - int factor; - - lambda_loopnest target_nest; - int depth, invariants; - lambda_matrix target; - - lambda_loop auxillary_loop, target_loop; - lambda_linear_expression expression, auxillary_expr, target_expr, tmp_expr; - - depth = LN_DEPTH (auxillary_nest); - invariants = LN_INVARIANTS (auxillary_nest); - - inverse = lambda_matrix_new (depth, depth, lambda_obstack); - determinant = lambda_matrix_inverse (LTM_MATRIX (H), inverse, depth, - lambda_obstack); - - /* H1 is H excluding its diagonal. */ - H1 = lambda_matrix_new (depth, depth, lambda_obstack); - lambda_matrix_copy (LTM_MATRIX (H), H1, depth, depth); - - for (i = 0; i < depth; i++) - H1[i][i] = 0; - - /* Computes the linear offsets of the loop bounds. */ - target = lambda_matrix_new (depth, depth, lambda_obstack); - lambda_matrix_mult (H1, inverse, target, depth, depth, depth); - - target_nest = lambda_loopnest_new (depth, invariants, lambda_obstack); - - for (i = 0; i < depth; i++) - { - - /* Get a new loop structure. */ - target_loop = lambda_loop_new (lambda_obstack); - LN_LOOPS (target_nest)[i] = target_loop; - - /* Computes the gcd of the coefficients of the linear part. */ - gcd1 = lambda_vector_gcd (target[i], i); - - /* Include the denominator in the GCD. */ - gcd1 = gcd (gcd1, determinant); - - /* Now divide through by the gcd. */ - for (j = 0; j < i; j++) - target[i][j] = target[i][j] / gcd1; - - expression = lambda_linear_expression_new (depth, invariants, - lambda_obstack); - lambda_vector_copy (target[i], LLE_COEFFICIENTS (expression), depth); - LLE_DENOMINATOR (expression) = determinant / gcd1; - LLE_CONSTANT (expression) = 0; - lambda_vector_clear (LLE_INVARIANT_COEFFICIENTS (expression), - invariants); - LL_LINEAR_OFFSET (target_loop) = expression; - } - - /* For each loop, compute the new bounds from H. */ - for (i = 0; i < depth; i++) - { - auxillary_loop = LN_LOOPS (auxillary_nest)[i]; - target_loop = LN_LOOPS (target_nest)[i]; - LL_STEP (target_loop) = LTM_MATRIX (H)[i][i]; - factor = LTM_MATRIX (H)[i][i]; - - /* First we do the lower bound. */ - auxillary_expr = LL_LOWER_BOUND (auxillary_loop); - - for (; auxillary_expr != NULL; - auxillary_expr = LLE_NEXT (auxillary_expr)) - { - target_expr = lambda_linear_expression_new (depth, invariants, - lambda_obstack); - lambda_vector_matrix_mult (LLE_COEFFICIENTS (auxillary_expr), - depth, inverse, depth, - LLE_COEFFICIENTS (target_expr)); - lambda_vector_mult_const (LLE_COEFFICIENTS (target_expr), - LLE_COEFFICIENTS (target_expr), depth, - factor); - - LLE_CONSTANT (target_expr) = LLE_CONSTANT (auxillary_expr) * factor; - lambda_vector_copy (LLE_INVARIANT_COEFFICIENTS (auxillary_expr), - LLE_INVARIANT_COEFFICIENTS (target_expr), - invariants); - lambda_vector_mult_const (LLE_INVARIANT_COEFFICIENTS (target_expr), - LLE_INVARIANT_COEFFICIENTS (target_expr), - invariants, factor); - LLE_DENOMINATOR (target_expr) = LLE_DENOMINATOR (auxillary_expr); - - if (!lambda_vector_zerop (LLE_COEFFICIENTS (target_expr), depth)) - { - LLE_CONSTANT (target_expr) = LLE_CONSTANT (target_expr) - * determinant; - lambda_vector_mult_const (LLE_INVARIANT_COEFFICIENTS - (target_expr), - LLE_INVARIANT_COEFFICIENTS - (target_expr), invariants, - determinant); - LLE_DENOMINATOR (target_expr) = - LLE_DENOMINATOR (target_expr) * determinant; - } - /* Find the gcd and divide by it here, rather than doing it - at the tree level. */ - gcd1 = lambda_vector_gcd (LLE_COEFFICIENTS (target_expr), depth); - gcd2 = lambda_vector_gcd (LLE_INVARIANT_COEFFICIENTS (target_expr), - invariants); - gcd1 = gcd (gcd1, gcd2); - gcd1 = gcd (gcd1, LLE_CONSTANT (target_expr)); - gcd1 = gcd (gcd1, LLE_DENOMINATOR (target_expr)); - for (j = 0; j < depth; j++) - LLE_COEFFICIENTS (target_expr)[j] /= gcd1; - for (j = 0; j < invariants; j++) - LLE_INVARIANT_COEFFICIENTS (target_expr)[j] /= gcd1; - LLE_CONSTANT (target_expr) /= gcd1; - LLE_DENOMINATOR (target_expr) /= gcd1; - /* Ignore if identical to existing bound. */ - if (!lle_equal (LL_LOWER_BOUND (target_loop), target_expr, depth, - invariants)) - { - LLE_NEXT (target_expr) = LL_LOWER_BOUND (target_loop); - LL_LOWER_BOUND (target_loop) = target_expr; - } - } - /* Now do the upper bound. */ - auxillary_expr = LL_UPPER_BOUND (auxillary_loop); - - for (; auxillary_expr != NULL; - auxillary_expr = LLE_NEXT (auxillary_expr)) - { - target_expr = lambda_linear_expression_new (depth, invariants, - lambda_obstack); - lambda_vector_matrix_mult (LLE_COEFFICIENTS (auxillary_expr), - depth, inverse, depth, - LLE_COEFFICIENTS (target_expr)); - lambda_vector_mult_const (LLE_COEFFICIENTS (target_expr), - LLE_COEFFICIENTS (target_expr), depth, - factor); - LLE_CONSTANT (target_expr) = LLE_CONSTANT (auxillary_expr) * factor; - lambda_vector_copy (LLE_INVARIANT_COEFFICIENTS (auxillary_expr), - LLE_INVARIANT_COEFFICIENTS (target_expr), - invariants); - lambda_vector_mult_const (LLE_INVARIANT_COEFFICIENTS (target_expr), - LLE_INVARIANT_COEFFICIENTS (target_expr), - invariants, factor); - LLE_DENOMINATOR (target_expr) = LLE_DENOMINATOR (auxillary_expr); - - if (!lambda_vector_zerop (LLE_COEFFICIENTS (target_expr), depth)) - { - LLE_CONSTANT (target_expr) = LLE_CONSTANT (target_expr) - * determinant; - lambda_vector_mult_const (LLE_INVARIANT_COEFFICIENTS - (target_expr), - LLE_INVARIANT_COEFFICIENTS - (target_expr), invariants, - determinant); - LLE_DENOMINATOR (target_expr) = - LLE_DENOMINATOR (target_expr) * determinant; - } - /* Find the gcd and divide by it here, instead of at the - tree level. */ - gcd1 = lambda_vector_gcd (LLE_COEFFICIENTS (target_expr), depth); - gcd2 = lambda_vector_gcd (LLE_INVARIANT_COEFFICIENTS (target_expr), - invariants); - gcd1 = gcd (gcd1, gcd2); - gcd1 = gcd (gcd1, LLE_CONSTANT (target_expr)); - gcd1 = gcd (gcd1, LLE_DENOMINATOR (target_expr)); - for (j = 0; j < depth; j++) - LLE_COEFFICIENTS (target_expr)[j] /= gcd1; - for (j = 0; j < invariants; j++) - LLE_INVARIANT_COEFFICIENTS (target_expr)[j] /= gcd1; - LLE_CONSTANT (target_expr) /= gcd1; - LLE_DENOMINATOR (target_expr) /= gcd1; - /* Ignore if equal to existing bound. */ - if (!lle_equal (LL_UPPER_BOUND (target_loop), target_expr, depth, - invariants)) - { - LLE_NEXT (target_expr) = LL_UPPER_BOUND (target_loop); - LL_UPPER_BOUND (target_loop) = target_expr; - } - } - } - for (i = 0; i < depth; i++) - { - target_loop = LN_LOOPS (target_nest)[i]; - /* If necessary, exchange the upper and lower bounds and negate - the step size. */ - if (stepsigns[i] < 0) - { - LL_STEP (target_loop) *= -1; - tmp_expr = LL_LOWER_BOUND (target_loop); - LL_LOWER_BOUND (target_loop) = LL_UPPER_BOUND (target_loop); - LL_UPPER_BOUND (target_loop) = tmp_expr; - } - } - return target_nest; -} - -/* Compute the step signs of TRANS, using TRANS and stepsigns. Return the new - result. */ - -static lambda_vector -lambda_compute_step_signs (lambda_trans_matrix trans, - lambda_vector stepsigns, - struct obstack * lambda_obstack) -{ - lambda_matrix matrix, H; - int size; - lambda_vector newsteps; - int i, j, factor, minimum_column; - int temp; - - matrix = LTM_MATRIX (trans); - size = LTM_ROWSIZE (trans); - H = lambda_matrix_new (size, size, lambda_obstack); - - newsteps = lambda_vector_new (size); - lambda_vector_copy (stepsigns, newsteps, size); - - lambda_matrix_copy (matrix, H, size, size); - - for (j = 0; j < size; j++) - { - lambda_vector row; - row = H[j]; - for (i = j; i < size; i++) - if (row[i] < 0) - lambda_matrix_col_negate (H, size, i); - while (lambda_vector_first_nz (row, size, j + 1) < size) - { - minimum_column = lambda_vector_min_nz (row, size, j); - lambda_matrix_col_exchange (H, size, j, minimum_column); - - temp = newsteps[j]; - newsteps[j] = newsteps[minimum_column]; - newsteps[minimum_column] = temp; - - for (i = j + 1; i < size; i++) - { - factor = row[i] / row[j]; - lambda_matrix_col_add (H, size, j, i, -1 * factor); - } - } - } - return newsteps; -} - -/* Transform NEST according to TRANS, and return the new loopnest. - This involves - 1. Computing a lattice base for the transformation - 2. Composing the dense base with the specified transformation (TRANS) - 3. Decomposing the combined transformation into a lower triangular portion, - and a unimodular portion. - 4. Computing the auxiliary nest using the unimodular portion. - 5. Computing the target nest using the auxiliary nest and the lower - triangular portion. */ - -lambda_loopnest -lambda_loopnest_transform (lambda_loopnest nest, lambda_trans_matrix trans, - struct obstack * lambda_obstack) -{ - lambda_loopnest auxillary_nest, target_nest; - - int depth, invariants; - int i, j; - lambda_lattice lattice; - lambda_trans_matrix trans1, H, U; - lambda_loop loop; - lambda_linear_expression expression; - lambda_vector origin; - lambda_matrix origin_invariants; - lambda_vector stepsigns; - int f; - - depth = LN_DEPTH (nest); - invariants = LN_INVARIANTS (nest); - - /* Keep track of the signs of the loop steps. */ - stepsigns = lambda_vector_new (depth); - for (i = 0; i < depth; i++) - { - if (LL_STEP (LN_LOOPS (nest)[i]) > 0) - stepsigns[i] = 1; - else - stepsigns[i] = -1; - } - - /* Compute the lattice base. */ - lattice = lambda_lattice_compute_base (nest, lambda_obstack); - trans1 = lambda_trans_matrix_new (depth, depth, lambda_obstack); - - /* Multiply the transformation matrix by the lattice base. */ - - lambda_matrix_mult (LTM_MATRIX (trans), LATTICE_BASE (lattice), - LTM_MATRIX (trans1), depth, depth, depth); - - /* Compute the Hermite normal form for the new transformation matrix. */ - H = lambda_trans_matrix_new (depth, depth, lambda_obstack); - U = lambda_trans_matrix_new (depth, depth, lambda_obstack); - lambda_matrix_hermite (LTM_MATRIX (trans1), depth, LTM_MATRIX (H), - LTM_MATRIX (U)); - - /* Compute the auxiliary loop nest's space from the unimodular - portion. */ - auxillary_nest = lambda_compute_auxillary_space (nest, U, - lambda_obstack); - - /* Compute the loop step signs from the old step signs and the - transformation matrix. */ - stepsigns = lambda_compute_step_signs (trans1, stepsigns, - lambda_obstack); - - /* Compute the target loop nest space from the auxiliary nest and - the lower triangular matrix H. */ - target_nest = lambda_compute_target_space (auxillary_nest, H, stepsigns, - lambda_obstack); - origin = lambda_vector_new (depth); - origin_invariants = lambda_matrix_new (depth, invariants, lambda_obstack); - lambda_matrix_vector_mult (LTM_MATRIX (trans), depth, depth, - LATTICE_ORIGIN (lattice), origin); - lambda_matrix_mult (LTM_MATRIX (trans), LATTICE_ORIGIN_INVARIANTS (lattice), - origin_invariants, depth, depth, invariants); - - for (i = 0; i < depth; i++) - { - loop = LN_LOOPS (target_nest)[i]; - expression = LL_LINEAR_OFFSET (loop); - if (lambda_vector_zerop (LLE_COEFFICIENTS (expression), depth)) - f = 1; - else - f = LLE_DENOMINATOR (expression); - - LLE_CONSTANT (expression) += f * origin[i]; - - for (j = 0; j < invariants; j++) - LLE_INVARIANT_COEFFICIENTS (expression)[j] += - f * origin_invariants[i][j]; - } - - return target_nest; - -} - -/* Convert a gcc tree expression EXPR to a lambda linear expression, and - return the new expression. DEPTH is the depth of the loopnest. - OUTERINDUCTIONVARS is an array of the induction variables for outer loops - in this nest. INVARIANTS is the array of invariants for the loop. EXTRA - is the amount we have to add/subtract from the expression because of the - type of comparison it is used in. */ - -static lambda_linear_expression -gcc_tree_to_linear_expression (int depth, tree expr, - VEC(tree,heap) *outerinductionvars, - VEC(tree,heap) *invariants, int extra, - struct obstack * lambda_obstack) -{ - lambda_linear_expression lle = NULL; - switch (TREE_CODE (expr)) - { - case INTEGER_CST: - { - lle = lambda_linear_expression_new (depth, 2 * depth, lambda_obstack); - LLE_CONSTANT (lle) = TREE_INT_CST_LOW (expr); - if (extra != 0) - LLE_CONSTANT (lle) += extra; - - LLE_DENOMINATOR (lle) = 1; - } - break; - case SSA_NAME: - { - tree iv, invar; - size_t i; - FOR_EACH_VEC_ELT (tree, outerinductionvars, i, iv) - if (iv != NULL) - { - if (SSA_NAME_VAR (iv) == SSA_NAME_VAR (expr)) - { - lle = lambda_linear_expression_new (depth, 2 * depth, - lambda_obstack); - LLE_COEFFICIENTS (lle)[i] = 1; - if (extra != 0) - LLE_CONSTANT (lle) = extra; - - LLE_DENOMINATOR (lle) = 1; - } - } - FOR_EACH_VEC_ELT (tree, invariants, i, invar) - if (invar != NULL) - { - if (SSA_NAME_VAR (invar) == SSA_NAME_VAR (expr)) - { - lle = lambda_linear_expression_new (depth, 2 * depth, - lambda_obstack); - LLE_INVARIANT_COEFFICIENTS (lle)[i] = 1; - if (extra != 0) - LLE_CONSTANT (lle) = extra; - LLE_DENOMINATOR (lle) = 1; - } - } - } - break; - default: - return NULL; - } - - return lle; -} - -/* Return the depth of the loopnest NEST */ - -static int -depth_of_nest (struct loop *nest) -{ - size_t depth = 0; - while (nest) - { - depth++; - nest = nest->inner; - } - return depth; -} - - -/* Return true if OP is invariant in LOOP and all outer loops. */ - -static bool -invariant_in_loop_and_outer_loops (struct loop *loop, tree op) -{ - if (is_gimple_min_invariant (op)) - return true; - if (loop_depth (loop) == 0) - return true; - if (!expr_invariant_in_loop_p (loop, op)) - return false; - if (!invariant_in_loop_and_outer_loops (loop_outer (loop), op)) - return false; - return true; -} - -/* Generate a lambda loop from a gcc loop LOOP. Return the new lambda loop, - or NULL if it could not be converted. - DEPTH is the depth of the loop. - INVARIANTS is a pointer to the array of loop invariants. - The induction variable for this loop should be stored in the parameter - OURINDUCTIONVAR. - OUTERINDUCTIONVARS is an array of induction variables for outer loops. */ - -static lambda_loop -gcc_loop_to_lambda_loop (struct loop *loop, int depth, - VEC(tree,heap) ** invariants, - tree * ourinductionvar, - VEC(tree,heap) * outerinductionvars, - VEC(tree,heap) ** lboundvars, - VEC(tree,heap) ** uboundvars, - VEC(int,heap) ** steps, - struct obstack * lambda_obstack) -{ - gimple phi; - gimple exit_cond; - tree access_fn, inductionvar; - tree step; - lambda_loop lloop = NULL; - lambda_linear_expression lbound, ubound; - tree test_lhs, test_rhs; - int stepint; - int extra = 0; - tree lboundvar, uboundvar, uboundresult; - - /* Find out induction var and exit condition. */ - inductionvar = find_induction_var_from_exit_cond (loop); - exit_cond = get_loop_exit_condition (loop); - - if (inductionvar == NULL || exit_cond == NULL) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot determine exit condition or induction variable for loop.\n"); - return NULL; - } - - if (SSA_NAME_DEF_STMT (inductionvar) == NULL) - { - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot find PHI node for induction variable\n"); - - return NULL; - } - - phi = SSA_NAME_DEF_STMT (inductionvar); - if (gimple_code (phi) != GIMPLE_PHI) - { - tree op = SINGLE_SSA_TREE_OPERAND (phi, SSA_OP_USE); - if (!op) - { - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot find PHI node for induction variable\n"); - - return NULL; - } - - phi = SSA_NAME_DEF_STMT (op); - if (gimple_code (phi) != GIMPLE_PHI) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot find PHI node for induction variable\n"); - return NULL; - } - } - - /* The induction variable name/version we want to put in the array is the - result of the induction variable phi node. */ - *ourinductionvar = PHI_RESULT (phi); - access_fn = instantiate_parameters - (loop, analyze_scalar_evolution (loop, PHI_RESULT (phi))); - if (access_fn == chrec_dont_know) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Access function for induction variable phi is unknown\n"); - - return NULL; - } - - step = evolution_part_in_loop_num (access_fn, loop->num); - if (!step || step == chrec_dont_know) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot determine step of loop.\n"); - - return NULL; - } - if (TREE_CODE (step) != INTEGER_CST) - { - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Step of loop is not integer.\n"); - return NULL; - } - - stepint = TREE_INT_CST_LOW (step); - - /* Only want phis for induction vars, which will have two - arguments. */ - if (gimple_phi_num_args (phi) != 2) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: PHI node for induction variable has >2 arguments\n"); - return NULL; - } - - /* Another induction variable check. One argument's source should be - in the loop, one outside the loop. */ - if (flow_bb_inside_loop_p (loop, gimple_phi_arg_edge (phi, 0)->src) - && flow_bb_inside_loop_p (loop, gimple_phi_arg_edge (phi, 1)->src)) - { - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: PHI edges both inside loop, or both outside loop.\n"); - - return NULL; - } - - if (flow_bb_inside_loop_p (loop, gimple_phi_arg_edge (phi, 0)->src)) - { - lboundvar = PHI_ARG_DEF (phi, 1); - lbound = gcc_tree_to_linear_expression (depth, lboundvar, - outerinductionvars, *invariants, - 0, lambda_obstack); - } - else - { - lboundvar = PHI_ARG_DEF (phi, 0); - lbound = gcc_tree_to_linear_expression (depth, lboundvar, - outerinductionvars, *invariants, - 0, lambda_obstack); - } - - if (!lbound) - { - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot convert lower bound to linear expression\n"); - - return NULL; - } - /* One part of the test may be a loop invariant tree. */ - VEC_reserve (tree, heap, *invariants, 1); - test_lhs = gimple_cond_lhs (exit_cond); - test_rhs = gimple_cond_rhs (exit_cond); - - if (TREE_CODE (test_rhs) == SSA_NAME - && invariant_in_loop_and_outer_loops (loop, test_rhs)) - VEC_quick_push (tree, *invariants, test_rhs); - else if (TREE_CODE (test_lhs) == SSA_NAME - && invariant_in_loop_and_outer_loops (loop, test_lhs)) - VEC_quick_push (tree, *invariants, test_lhs); - - /* The non-induction variable part of the test is the upper bound variable. - */ - if (test_lhs == inductionvar) - uboundvar = test_rhs; - else - uboundvar = test_lhs; - - /* We only size the vectors assuming we have, at max, 2 times as many - invariants as we do loops (one for each bound). - This is just an arbitrary number, but it has to be matched against the - code below. */ - gcc_assert (VEC_length (tree, *invariants) <= (unsigned int) (2 * depth)); - - - /* We might have some leftover. */ - if (gimple_cond_code (exit_cond) == LT_EXPR) - extra = -1 * stepint; - else if (gimple_cond_code (exit_cond) == NE_EXPR) - extra = -1 * stepint; - else if (gimple_cond_code (exit_cond) == GT_EXPR) - extra = -1 * stepint; - else if (gimple_cond_code (exit_cond) == EQ_EXPR) - extra = 1 * stepint; - - ubound = gcc_tree_to_linear_expression (depth, uboundvar, - outerinductionvars, - *invariants, extra, lambda_obstack); - uboundresult = build2 (PLUS_EXPR, TREE_TYPE (uboundvar), uboundvar, - build_int_cst (TREE_TYPE (uboundvar), extra)); - VEC_safe_push (tree, heap, *uboundvars, uboundresult); - VEC_safe_push (tree, heap, *lboundvars, lboundvar); - VEC_safe_push (int, heap, *steps, stepint); - if (!ubound) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, - "Unable to convert loop: Cannot convert upper bound to linear expression\n"); - return NULL; - } - - lloop = lambda_loop_new (lambda_obstack); - LL_STEP (lloop) = stepint; - LL_LOWER_BOUND (lloop) = lbound; - LL_UPPER_BOUND (lloop) = ubound; - return lloop; -} - -/* Given a LOOP, find the induction variable it is testing against in the exit - condition. Return the induction variable if found, NULL otherwise. */ - -tree -find_induction_var_from_exit_cond (struct loop *loop) -{ - gimple expr = get_loop_exit_condition (loop); - tree ivarop; - tree test_lhs, test_rhs; - if (expr == NULL) - return NULL_TREE; - if (gimple_code (expr) != GIMPLE_COND) - return NULL_TREE; - test_lhs = gimple_cond_lhs (expr); - test_rhs = gimple_cond_rhs (expr); - - /* Find the side that is invariant in this loop. The ivar must be the other - side. */ - - if (expr_invariant_in_loop_p (loop, test_lhs)) - ivarop = test_rhs; - else if (expr_invariant_in_loop_p (loop, test_rhs)) - ivarop = test_lhs; - else - return NULL_TREE; - - if (TREE_CODE (ivarop) != SSA_NAME) - return NULL_TREE; - return ivarop; -} - -DEF_VEC_P(lambda_loop); -DEF_VEC_ALLOC_P(lambda_loop,heap); - -/* Generate a lambda loopnest from a gcc loopnest LOOP_NEST. - Return the new loop nest. - INDUCTIONVARS is a pointer to an array of induction variables for the - loopnest that will be filled in during this process. - INVARIANTS is a pointer to an array of invariants that will be filled in - during this process. */ - -lambda_loopnest -gcc_loopnest_to_lambda_loopnest (struct loop *loop_nest, - VEC(tree,heap) **inductionvars, - VEC(tree,heap) **invariants, - struct obstack * lambda_obstack) -{ - lambda_loopnest ret = NULL; - struct loop *temp = loop_nest; - int depth = depth_of_nest (loop_nest); - size_t i; - VEC(lambda_loop,heap) *loops = NULL; - VEC(tree,heap) *uboundvars = NULL; - VEC(tree,heap) *lboundvars = NULL; - VEC(int,heap) *steps = NULL; - lambda_loop newloop; - tree inductionvar = NULL; - bool perfect_nest = perfect_nest_p (loop_nest); - - if (!perfect_nest && !can_convert_to_perfect_nest (loop_nest)) - goto fail; - - while (temp) - { - newloop = gcc_loop_to_lambda_loop (temp, depth, invariants, - &inductionvar, *inductionvars, - &lboundvars, &uboundvars, - &steps, lambda_obstack); - if (!newloop) - goto fail; - - VEC_safe_push (tree, heap, *inductionvars, inductionvar); - VEC_safe_push (lambda_loop, heap, loops, newloop); - temp = temp->inner; - } - - if (!perfect_nest) - { - if (!perfect_nestify (loop_nest, lboundvars, uboundvars, steps, - *inductionvars)) - { - if (dump_file) - fprintf (dump_file, - "Not a perfect loop nest and couldn't convert to one.\n"); - goto fail; - } - else if (dump_file) - fprintf (dump_file, - "Successfully converted loop nest to perfect loop nest.\n"); - } - - ret = lambda_loopnest_new (depth, 2 * depth, lambda_obstack); - - FOR_EACH_VEC_ELT (lambda_loop, loops, i, newloop) - LN_LOOPS (ret)[i] = newloop; - - fail: - VEC_free (lambda_loop, heap, loops); - VEC_free (tree, heap, uboundvars); - VEC_free (tree, heap, lboundvars); - VEC_free (int, heap, steps); - - return ret; -} - -/* Convert a lambda body vector LBV to a gcc tree, and return the new tree. - STMTS_TO_INSERT is a pointer to a tree where the statements we need to be - inserted for us are stored. INDUCTION_VARS is the array of induction - variables for the loop this LBV is from. TYPE is the tree type to use for - the variables and trees involved. */ - -static tree -lbv_to_gcc_expression (lambda_body_vector lbv, - tree type, VEC(tree,heap) *induction_vars, - gimple_seq *stmts_to_insert) -{ - int k; - tree resvar; - tree expr = build_linear_expr (type, LBV_COEFFICIENTS (lbv), induction_vars); - - k = LBV_DENOMINATOR (lbv); - gcc_assert (k != 0); - if (k != 1) - expr = fold_build2 (CEIL_DIV_EXPR, type, expr, build_int_cst (type, k)); - - resvar = create_tmp_var (type, "lbvtmp"); - add_referenced_var (resvar); - return force_gimple_operand (fold (expr), stmts_to_insert, true, resvar); -} - -/* Convert a linear expression from coefficient and constant form to a - gcc tree. - Return the tree that represents the final value of the expression. - LLE is the linear expression to convert. - OFFSET is the linear offset to apply to the expression. - TYPE is the tree type to use for the variables and math. - INDUCTION_VARS is a vector of induction variables for the loops. - INVARIANTS is a vector of the loop nest invariants. - WRAP specifies what tree code to wrap the results in, if there is more than - one (it is either MAX_EXPR, or MIN_EXPR). - STMTS_TO_INSERT Is a pointer to the statement list we fill in with - statements that need to be inserted for the linear expression. */ - -static tree -lle_to_gcc_expression (lambda_linear_expression lle, - lambda_linear_expression offset, - tree type, - VEC(tree,heap) *induction_vars, - VEC(tree,heap) *invariants, - enum tree_code wrap, gimple_seq *stmts_to_insert) -{ - int k; - tree resvar; - tree expr = NULL_TREE; - VEC(tree,heap) *results = NULL; - - gcc_assert (wrap == MAX_EXPR || wrap == MIN_EXPR); - - /* Build up the linear expressions. */ - for (; lle != NULL; lle = LLE_NEXT (lle)) - { - expr = build_linear_expr (type, LLE_COEFFICIENTS (lle), induction_vars); - expr = fold_build2 (PLUS_EXPR, type, expr, - build_linear_expr (type, - LLE_INVARIANT_COEFFICIENTS (lle), - invariants)); - - k = LLE_CONSTANT (lle); - if (k) - expr = fold_build2 (PLUS_EXPR, type, expr, build_int_cst (type, k)); - - k = LLE_CONSTANT (offset); - if (k) - expr = fold_build2 (PLUS_EXPR, type, expr, build_int_cst (type, k)); - - k = LLE_DENOMINATOR (lle); - if (k != 1) - expr = fold_build2 (wrap == MAX_EXPR ? CEIL_DIV_EXPR : FLOOR_DIV_EXPR, - type, expr, build_int_cst (type, k)); - - expr = fold (expr); - VEC_safe_push (tree, heap, results, expr); - } - - gcc_assert (expr); - - /* We may need to wrap the results in a MAX_EXPR or MIN_EXPR. */ - if (VEC_length (tree, results) > 1) - { - size_t i; - tree op; - - expr = VEC_index (tree, results, 0); - for (i = 1; VEC_iterate (tree, results, i, op); i++) - expr = fold_build2 (wrap, type, expr, op); - } - - VEC_free (tree, heap, results); - - resvar = create_tmp_var (type, "lletmp"); - add_referenced_var (resvar); - return force_gimple_operand (fold (expr), stmts_to_insert, true, resvar); -} - -/* Remove the induction variable defined at IV_STMT. */ - -void -remove_iv (gimple iv_stmt) -{ - gimple_stmt_iterator si = gsi_for_stmt (iv_stmt); - - if (gimple_code (iv_stmt) == GIMPLE_PHI) - { - unsigned i; - - for (i = 0; i < gimple_phi_num_args (iv_stmt); i++) - { - gimple stmt; - imm_use_iterator imm_iter; - tree arg = gimple_phi_arg_def (iv_stmt, i); - bool used = false; - - if (TREE_CODE (arg) != SSA_NAME) - continue; - - FOR_EACH_IMM_USE_STMT (stmt, imm_iter, arg) - if (stmt != iv_stmt && !is_gimple_debug (stmt)) - used = true; - - if (!used) - remove_iv (SSA_NAME_DEF_STMT (arg)); - } - - remove_phi_node (&si, true); - } - else - { - gsi_remove (&si, true); - release_defs (iv_stmt); - } -} - -/* Transform a lambda loopnest NEW_LOOPNEST, which had TRANSFORM applied to - it, back into gcc code. This changes the - loops, their induction variables, and their bodies, so that they - match the transformed loopnest. - OLD_LOOPNEST is the loopnest before we've replaced it with the new - loopnest. - OLD_IVS is a vector of induction variables from the old loopnest. - INVARIANTS is a vector of loop invariants from the old loopnest. - NEW_LOOPNEST is the new lambda loopnest to replace OLD_LOOPNEST with. - TRANSFORM is the matrix transform that was applied to OLD_LOOPNEST to get - NEW_LOOPNEST. */ - -void -lambda_loopnest_to_gcc_loopnest (struct loop *old_loopnest, - VEC(tree,heap) *old_ivs, - VEC(tree,heap) *invariants, - VEC(gimple,heap) **remove_ivs, - lambda_loopnest new_loopnest, - lambda_trans_matrix transform, - struct obstack * lambda_obstack) -{ - struct loop *temp; - size_t i = 0; - unsigned j; - size_t depth = 0; - VEC(tree,heap) *new_ivs = NULL; - tree oldiv; - gimple_stmt_iterator bsi; - - transform = lambda_trans_matrix_inverse (transform, lambda_obstack); - - if (dump_file) - { - fprintf (dump_file, "Inverse of transformation matrix:\n"); - print_lambda_trans_matrix (dump_file, transform); - } - depth = depth_of_nest (old_loopnest); - temp = old_loopnest; - - while (temp) - { - lambda_loop newloop; - basic_block bb; - edge exit; - tree ivvar, ivvarinced; - gimple exitcond; - gimple_seq stmts; - enum tree_code testtype; - tree newupperbound, newlowerbound; - lambda_linear_expression offset; - tree type; - bool insert_after; - gimple inc_stmt; - - oldiv = VEC_index (tree, old_ivs, i); - type = TREE_TYPE (oldiv); - - /* First, build the new induction variable temporary */ - - ivvar = create_tmp_var (type, "lnivtmp"); - add_referenced_var (ivvar); - - VEC_safe_push (tree, heap, new_ivs, ivvar); - - newloop = LN_LOOPS (new_loopnest)[i]; - - /* Linear offset is a bit tricky to handle. Punt on the unhandled - cases for now. */ - offset = LL_LINEAR_OFFSET (newloop); - - gcc_assert (LLE_DENOMINATOR (offset) == 1 && - lambda_vector_zerop (LLE_COEFFICIENTS (offset), depth)); - - /* Now build the new lower bounds, and insert the statements - necessary to generate it on the loop preheader. */ - stmts = NULL; - newlowerbound = lle_to_gcc_expression (LL_LOWER_BOUND (newloop), - LL_LINEAR_OFFSET (newloop), - type, - new_ivs, - invariants, MAX_EXPR, &stmts); - - if (stmts) - { - gsi_insert_seq_on_edge (loop_preheader_edge (temp), stmts); - gsi_commit_edge_inserts (); - } - /* Build the new upper bound and insert its statements in the - basic block of the exit condition */ - stmts = NULL; - newupperbound = lle_to_gcc_expression (LL_UPPER_BOUND (newloop), - LL_LINEAR_OFFSET (newloop), - type, - new_ivs, - invariants, MIN_EXPR, &stmts); - exit = single_exit (temp); - exitcond = get_loop_exit_condition (temp); - bb = gimple_bb (exitcond); - bsi = gsi_after_labels (bb); - if (stmts) - gsi_insert_seq_before (&bsi, stmts, GSI_NEW_STMT); - - /* Create the new iv. */ - - standard_iv_increment_position (temp, &bsi, &insert_after); - create_iv (newlowerbound, - build_int_cst (type, LL_STEP (newloop)), - ivvar, temp, &bsi, insert_after, &ivvar, - NULL); - - /* Unfortunately, the incremented ivvar that create_iv inserted may not - dominate the block containing the exit condition. - So we simply create our own incremented iv to use in the new exit - test, and let redundancy elimination sort it out. */ - inc_stmt = gimple_build_assign_with_ops (PLUS_EXPR, SSA_NAME_VAR (ivvar), - ivvar, - build_int_cst (type, LL_STEP (newloop))); - - ivvarinced = make_ssa_name (SSA_NAME_VAR (ivvar), inc_stmt); - gimple_assign_set_lhs (inc_stmt, ivvarinced); - bsi = gsi_for_stmt (exitcond); - gsi_insert_before (&bsi, inc_stmt, GSI_SAME_STMT); - - /* Replace the exit condition with the new upper bound - comparison. */ - - testtype = LL_STEP (newloop) >= 0 ? LE_EXPR : GE_EXPR; - - /* We want to build a conditional where true means exit the loop, and - false means continue the loop. - So swap the testtype if this isn't the way things are.*/ - - if (exit->flags & EDGE_FALSE_VALUE) - testtype = swap_tree_comparison (testtype); - - gimple_cond_set_condition (exitcond, testtype, newupperbound, ivvarinced); - update_stmt (exitcond); - VEC_replace (tree, new_ivs, i, ivvar); - - i++; - temp = temp->inner; - } - - /* Rewrite uses of the old ivs so that they are now specified in terms of - the new ivs. */ - - FOR_EACH_VEC_ELT (tree, old_ivs, i, oldiv) - { - imm_use_iterator imm_iter; - use_operand_p use_p; - tree oldiv_def; - gimple oldiv_stmt = SSA_NAME_DEF_STMT (oldiv); - gimple stmt; - - if (gimple_code (oldiv_stmt) == GIMPLE_PHI) - oldiv_def = PHI_RESULT (oldiv_stmt); - else - oldiv_def = SINGLE_SSA_TREE_OPERAND (oldiv_stmt, SSA_OP_DEF); - gcc_assert (oldiv_def != NULL_TREE); - - FOR_EACH_IMM_USE_STMT (stmt, imm_iter, oldiv_def) - { - tree newiv; - gimple_seq stmts; - lambda_body_vector lbv, newlbv; - - if (is_gimple_debug (stmt)) - continue; - - /* Compute the new expression for the induction - variable. */ - depth = VEC_length (tree, new_ivs); - lbv = lambda_body_vector_new (depth, lambda_obstack); - LBV_COEFFICIENTS (lbv)[i] = 1; - - newlbv = lambda_body_vector_compute_new (transform, lbv, - lambda_obstack); - - stmts = NULL; - newiv = lbv_to_gcc_expression (newlbv, TREE_TYPE (oldiv), - new_ivs, &stmts); - - if (stmts && gimple_code (stmt) != GIMPLE_PHI) - { - bsi = gsi_for_stmt (stmt); - gsi_insert_seq_before (&bsi, stmts, GSI_SAME_STMT); - } - - FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) - propagate_value (use_p, newiv); - - if (stmts && gimple_code (stmt) == GIMPLE_PHI) - for (j = 0; j < gimple_phi_num_args (stmt); j++) - if (gimple_phi_arg_def (stmt, j) == newiv) - gsi_insert_seq_on_edge (gimple_phi_arg_edge (stmt, j), stmts); - - update_stmt (stmt); - } - - /* Remove the now unused induction variable. */ - VEC_safe_push (gimple, heap, *remove_ivs, oldiv_stmt); - } - VEC_free (tree, heap, new_ivs); -} - -/* Return TRUE if this is not interesting statement from the perspective of - determining if we have a perfect loop nest. */ - -static bool -not_interesting_stmt (gimple stmt) -{ - /* Note that COND_EXPR's aren't interesting because if they were exiting the - loop, we would have already failed the number of exits tests. */ - if (gimple_code (stmt) == GIMPLE_LABEL - || gimple_code (stmt) == GIMPLE_GOTO - || gimple_code (stmt) == GIMPLE_COND - || is_gimple_debug (stmt)) - return true; - return false; -} - -/* Return TRUE if PHI uses DEF for it's in-the-loop edge for LOOP. */ - -static bool -phi_loop_edge_uses_def (struct loop *loop, gimple phi, tree def) -{ - unsigned i; - for (i = 0; i < gimple_phi_num_args (phi); i++) - if (flow_bb_inside_loop_p (loop, gimple_phi_arg_edge (phi, i)->src)) - if (PHI_ARG_DEF (phi, i) == def) - return true; - return false; -} - -/* Return TRUE if STMT is a use of PHI_RESULT. */ - -static bool -stmt_uses_phi_result (gimple stmt, tree phi_result) -{ - tree use = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_USE); - - /* This is conservatively true, because we only want SIMPLE bumpers - of the form x +- constant for our pass. */ - return (use == phi_result); -} - -/* STMT is a bumper stmt for LOOP if the version it defines is used in the - in-loop-edge in a phi node, and the operand it uses is the result of that - phi node. - I.E. i_29 = i_3 + 1 - i_3 = PHI (0, i_29); */ - -static bool -stmt_is_bumper_for_loop (struct loop *loop, gimple stmt) -{ - gimple use; - tree def; - imm_use_iterator iter; - use_operand_p use_p; - - def = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF); - if (!def) - return false; - - FOR_EACH_IMM_USE_FAST (use_p, iter, def) - { - use = USE_STMT (use_p); - if (gimple_code (use) == GIMPLE_PHI) - { - if (phi_loop_edge_uses_def (loop, use, def)) - if (stmt_uses_phi_result (stmt, PHI_RESULT (use))) - return true; - } - } - return false; -} - - -/* Return true if LOOP is a perfect loop nest. - Perfect loop nests are those loop nests where all code occurs in the - innermost loop body. - If S is a program statement, then - - i.e. - DO I = 1, 20 - S1 - DO J = 1, 20 - ... - END DO - END DO - is not a perfect loop nest because of S1. - - DO I = 1, 20 - DO J = 1, 20 - S1 - ... - END DO - END DO - is a perfect loop nest. - - Since we don't have high level loops anymore, we basically have to walk our - statements and ignore those that are there because the loop needs them (IE - the induction variable increment, and jump back to the top of the loop). */ - -bool -perfect_nest_p (struct loop *loop) -{ - basic_block *bbs; - size_t i; - gimple exit_cond; - - /* Loops at depth 0 are perfect nests. */ - if (!loop->inner) - return true; - - bbs = get_loop_body (loop); - exit_cond = get_loop_exit_condition (loop); - - for (i = 0; i < loop->num_nodes; i++) - { - if (bbs[i]->loop_father == loop) - { - gimple_stmt_iterator bsi; - - for (bsi = gsi_start_bb (bbs[i]); !gsi_end_p (bsi); gsi_next (&bsi)) - { - gimple stmt = gsi_stmt (bsi); - - if (gimple_code (stmt) == GIMPLE_COND - && exit_cond != stmt) - goto non_perfectly_nested; - - if (stmt == exit_cond - || not_interesting_stmt (stmt) - || stmt_is_bumper_for_loop (loop, stmt)) - continue; - - non_perfectly_nested: - free (bbs); - return false; - } - } - } - - free (bbs); - - return perfect_nest_p (loop->inner); -} - -/* Replace the USES of X in STMT, or uses with the same step as X with Y. - YINIT is the initial value of Y, REPLACEMENTS is a hash table to - avoid creating duplicate temporaries and FIRSTBSI is statement - iterator where new temporaries should be inserted at the beginning - of body basic block. */ - -static void -replace_uses_equiv_to_x_with_y (struct loop *loop, gimple stmt, tree x, - int xstep, tree y, tree yinit, - htab_t replacements, - gimple_stmt_iterator *firstbsi) -{ - ssa_op_iter iter; - use_operand_p use_p; - - FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) - { - tree use = USE_FROM_PTR (use_p); - tree step = NULL_TREE; - tree scev, init, val, var; - gimple setstmt; - struct tree_map *h, in; - void **loc; - - /* Replace uses of X with Y right away. */ - if (use == x) - { - SET_USE (use_p, y); - continue; - } - - scev = instantiate_parameters (loop, - analyze_scalar_evolution (loop, use)); - - if (scev == NULL || scev == chrec_dont_know) - continue; - - step = evolution_part_in_loop_num (scev, loop->num); - if (step == NULL - || step == chrec_dont_know - || TREE_CODE (step) != INTEGER_CST - || int_cst_value (step) != xstep) - continue; - - /* Use REPLACEMENTS hash table to cache already created - temporaries. */ - in.hash = htab_hash_pointer (use); - in.base.from = use; - h = (struct tree_map *) htab_find_with_hash (replacements, &in, in.hash); - if (h != NULL) - { - SET_USE (use_p, h->to); - continue; - } - - /* USE which has the same step as X should be replaced - with a temporary set to Y + YINIT - INIT. */ - init = initial_condition_in_loop_num (scev, loop->num); - gcc_assert (init != NULL && init != chrec_dont_know); - if (TREE_TYPE (use) == TREE_TYPE (y)) - { - val = fold_build2 (MINUS_EXPR, TREE_TYPE (y), init, yinit); - val = fold_build2 (PLUS_EXPR, TREE_TYPE (y), y, val); - if (val == y) - { - /* If X has the same type as USE, the same step - and same initial value, it can be replaced by Y. */ - SET_USE (use_p, y); - continue; - } - } - else - { - val = fold_build2 (MINUS_EXPR, TREE_TYPE (y), y, yinit); - val = fold_convert (TREE_TYPE (use), val); - val = fold_build2 (PLUS_EXPR, TREE_TYPE (use), val, init); - } - - /* Create a temporary variable and insert it at the beginning - of the loop body basic block, right after the PHI node - which sets Y. */ - var = create_tmp_var (TREE_TYPE (use), "perfecttmp"); - add_referenced_var (var); - val = force_gimple_operand_gsi (firstbsi, val, false, NULL, - true, GSI_SAME_STMT); - setstmt = gimple_build_assign (var, val); - var = make_ssa_name (var, setstmt); - gimple_assign_set_lhs (setstmt, var); - gsi_insert_before (firstbsi, setstmt, GSI_SAME_STMT); - update_stmt (setstmt); - SET_USE (use_p, var); - h = ggc_alloc_tree_map (); - h->hash = in.hash; - h->base.from = use; - h->to = var; - loc = htab_find_slot_with_hash (replacements, h, in.hash, INSERT); - gcc_assert ((*(struct tree_map **)loc) == NULL); - *(struct tree_map **) loc = h; - } -} - -/* Return true if STMT is an exit PHI for LOOP */ - -static bool -exit_phi_for_loop_p (struct loop *loop, gimple stmt) -{ - if (gimple_code (stmt) != GIMPLE_PHI - || gimple_phi_num_args (stmt) != 1 - || gimple_bb (stmt) != single_exit (loop)->dest) - return false; - - return true; -} - -/* Return true if STMT can be put back into the loop INNER, by - copying it to the beginning of that loop and changing the uses. */ - -static bool -can_put_in_inner_loop (struct loop *inner, gimple stmt) -{ - imm_use_iterator imm_iter; - use_operand_p use_p; - - gcc_assert (is_gimple_assign (stmt)); - if (gimple_vuse (stmt) - || !stmt_invariant_in_loop_p (inner, stmt)) - return false; - - FOR_EACH_IMM_USE_FAST (use_p, imm_iter, gimple_assign_lhs (stmt)) - { - if (!exit_phi_for_loop_p (inner, USE_STMT (use_p))) - { - basic_block immbb = gimple_bb (USE_STMT (use_p)); - - if (!flow_bb_inside_loop_p (inner, immbb)) - return false; - } - } - return true; -} - -/* Return true if STMT can be put *after* the inner loop of LOOP. */ - -static bool -can_put_after_inner_loop (struct loop *loop, gimple stmt) -{ - imm_use_iterator imm_iter; - use_operand_p use_p; - - if (gimple_vuse (stmt)) - return false; - - FOR_EACH_IMM_USE_FAST (use_p, imm_iter, gimple_assign_lhs (stmt)) - { - if (!exit_phi_for_loop_p (loop, USE_STMT (use_p))) - { - basic_block immbb = gimple_bb (USE_STMT (use_p)); - - if (!dominated_by_p (CDI_DOMINATORS, - immbb, - loop->inner->header) - && !can_put_in_inner_loop (loop->inner, stmt)) - return false; - } - } - return true; -} - -/* Return true when the induction variable IV is simple enough to be - re-synthesized. */ - -static bool -can_duplicate_iv (tree iv, struct loop *loop) -{ - tree scev = instantiate_parameters - (loop, analyze_scalar_evolution (loop, iv)); - - if (!automatically_generated_chrec_p (scev)) - { - tree step = evolution_part_in_loop_num (scev, loop->num); - - if (step && step != chrec_dont_know && TREE_CODE (step) == INTEGER_CST) - return true; - } - - return false; -} - -/* If this is a scalar operation that can be put back into the inner - loop, or after the inner loop, through copying, then do so. This - works on the theory that any amount of scalar code we have to - reduplicate into or after the loops is less expensive that the win - we get from rearranging the memory walk the loop is doing so that - it has better cache behavior. */ - -static bool -cannot_convert_modify_to_perfect_nest (gimple stmt, struct loop *loop) -{ - use_operand_p use_a, use_b; - imm_use_iterator imm_iter; - ssa_op_iter op_iter, op_iter1; - tree op0 = gimple_assign_lhs (stmt); - - /* The statement should not define a variable used in the inner - loop. */ - if (TREE_CODE (op0) == SSA_NAME - && !can_duplicate_iv (op0, loop)) - FOR_EACH_IMM_USE_FAST (use_a, imm_iter, op0) - if (gimple_bb (USE_STMT (use_a))->loop_father == loop->inner) - return true; - - FOR_EACH_SSA_USE_OPERAND (use_a, stmt, op_iter, SSA_OP_USE) - { - gimple node; - tree op = USE_FROM_PTR (use_a); - - /* The variables should not be used in both loops. */ - if (!can_duplicate_iv (op, loop)) - FOR_EACH_IMM_USE_FAST (use_b, imm_iter, op) - if (gimple_bb (USE_STMT (use_b))->loop_father == loop->inner) - return true; - - /* The statement should not use the value of a scalar that was - modified in the loop. */ - node = SSA_NAME_DEF_STMT (op); - if (gimple_code (node) == GIMPLE_PHI) - FOR_EACH_PHI_ARG (use_b, node, op_iter1, SSA_OP_USE) - { - tree arg = USE_FROM_PTR (use_b); - - if (TREE_CODE (arg) == SSA_NAME) - { - gimple arg_stmt = SSA_NAME_DEF_STMT (arg); - - if (gimple_bb (arg_stmt) - && (gimple_bb (arg_stmt)->loop_father == loop->inner)) - return true; - } - } - } - - return false; -} -/* Return true when BB contains statements that can harm the transform - to a perfect loop nest. */ - -static bool -cannot_convert_bb_to_perfect_nest (basic_block bb, struct loop *loop) -{ - gimple_stmt_iterator bsi; - gimple exit_condition = get_loop_exit_condition (loop); - - for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi)) - { - gimple stmt = gsi_stmt (bsi); - - if (stmt == exit_condition - || not_interesting_stmt (stmt) - || stmt_is_bumper_for_loop (loop, stmt)) - continue; - - if (is_gimple_assign (stmt)) - { - if (cannot_convert_modify_to_perfect_nest (stmt, loop)) - return true; - - if (can_duplicate_iv (gimple_assign_lhs (stmt), loop)) - continue; - - if (can_put_in_inner_loop (loop->inner, stmt) - || can_put_after_inner_loop (loop, stmt)) - continue; - } - - /* If the bb of a statement we care about isn't dominated by the - header of the inner loop, then we can't handle this case - right now. This test ensures that the statement comes - completely *after* the inner loop. */ - if (!dominated_by_p (CDI_DOMINATORS, - gimple_bb (stmt), - loop->inner->header)) - return true; - } - - return false; -} - - -/* Return TRUE if LOOP is an imperfect nest that we can convert to a - perfect one. At the moment, we only handle imperfect nests of - depth 2, where all of the statements occur after the inner loop. */ - -static bool -can_convert_to_perfect_nest (struct loop *loop) -{ - basic_block *bbs; - size_t i; - gimple_stmt_iterator si; - - /* Can't handle triply nested+ loops yet. */ - if (!loop->inner || loop->inner->inner) - return false; - - bbs = get_loop_body (loop); - for (i = 0; i < loop->num_nodes; i++) - if (bbs[i]->loop_father == loop - && cannot_convert_bb_to_perfect_nest (bbs[i], loop)) - goto fail; - - /* We also need to make sure the loop exit only has simple copy phis in it, - otherwise we don't know how to transform it into a perfect nest. */ - for (si = gsi_start_phis (single_exit (loop)->dest); - !gsi_end_p (si); - gsi_next (&si)) - if (gimple_phi_num_args (gsi_stmt (si)) != 1) - goto fail; - - free (bbs); - return true; - - fail: - free (bbs); - return false; -} - - -DEF_VEC_I(source_location); -DEF_VEC_ALLOC_I(source_location,heap); - -/* Transform the loop nest into a perfect nest, if possible. - LOOP is the loop nest to transform into a perfect nest - LBOUNDS are the lower bounds for the loops to transform - UBOUNDS are the upper bounds for the loops to transform - STEPS is the STEPS for the loops to transform. - LOOPIVS is the induction variables for the loops to transform. - - Basically, for the case of - - FOR (i = 0; i < 50; i++) - { - FOR (j =0; j < 50; j++) - { - <whatever> - } - <some code> - } - - This function will transform it into a perfect loop nest by splitting the - outer loop into two loops, like so: - - FOR (i = 0; i < 50; i++) - { - FOR (j = 0; j < 50; j++) - { - <whatever> - } - } - - FOR (i = 0; i < 50; i ++) - { - <some code> - } - - Return FALSE if we can't make this loop into a perfect nest. */ - -static bool -perfect_nestify (struct loop *loop, - VEC(tree,heap) *lbounds, - VEC(tree,heap) *ubounds, - VEC(int,heap) *steps, - VEC(tree,heap) *loopivs) -{ - basic_block *bbs; - gimple exit_condition; - gimple cond_stmt; - basic_block preheaderbb, headerbb, bodybb, latchbb, olddest; - int i; - gimple_stmt_iterator bsi, firstbsi; - bool insert_after; - edge e; - struct loop *newloop; - gimple phi; - tree uboundvar; - gimple stmt; - tree oldivvar, ivvar, ivvarinced; - VEC(tree,heap) *phis = NULL; - VEC(source_location,heap) *locations = NULL; - htab_t replacements = NULL; - - /* Create the new loop. */ - olddest = single_exit (loop)->dest; - preheaderbb = split_edge (single_exit (loop)); - headerbb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb); - - /* Push the exit phi nodes that we are moving. */ - for (bsi = gsi_start_phis (olddest); !gsi_end_p (bsi); gsi_next (&bsi)) - { - phi = gsi_stmt (bsi); - VEC_reserve (tree, heap, phis, 2); - VEC_reserve (source_location, heap, locations, 1); - VEC_quick_push (tree, phis, PHI_RESULT (phi)); - VEC_quick_push (tree, phis, PHI_ARG_DEF (phi, 0)); - VEC_quick_push (source_location, locations, - gimple_phi_arg_location (phi, 0)); - } - e = redirect_edge_and_branch (single_succ_edge (preheaderbb), headerbb); - - /* Remove the exit phis from the old basic block. */ - for (bsi = gsi_start_phis (olddest); !gsi_end_p (bsi); ) - remove_phi_node (&bsi, false); - - /* and add them back to the new basic block. */ - while (VEC_length (tree, phis) != 0) - { - tree def; - tree phiname; - source_location locus; - def = VEC_pop (tree, phis); - phiname = VEC_pop (tree, phis); - locus = VEC_pop (source_location, locations); - phi = create_phi_node (phiname, preheaderbb); - add_phi_arg (phi, def, single_pred_edge (preheaderbb), locus); - } - flush_pending_stmts (e); - VEC_free (tree, heap, phis); - - bodybb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb); - latchbb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb); - make_edge (headerbb, bodybb, EDGE_FALLTHRU); - cond_stmt = gimple_build_cond (NE_EXPR, integer_one_node, integer_zero_node, - NULL_TREE, NULL_TREE); - bsi = gsi_start_bb (bodybb); - gsi_insert_after (&bsi, cond_stmt, GSI_NEW_STMT); - e = make_edge (bodybb, olddest, EDGE_FALSE_VALUE); - make_edge (bodybb, latchbb, EDGE_TRUE_VALUE); - make_edge (latchbb, headerbb, EDGE_FALLTHRU); - - /* Update the loop structures. */ - newloop = duplicate_loop (loop, olddest->loop_father); - newloop->header = headerbb; - newloop->latch = latchbb; - add_bb_to_loop (latchbb, newloop); - add_bb_to_loop (bodybb, newloop); - add_bb_to_loop (headerbb, newloop); - set_immediate_dominator (CDI_DOMINATORS, bodybb, headerbb); - set_immediate_dominator (CDI_DOMINATORS, headerbb, preheaderbb); - set_immediate_dominator (CDI_DOMINATORS, preheaderbb, - single_exit (loop)->src); - set_immediate_dominator (CDI_DOMINATORS, latchbb, bodybb); - set_immediate_dominator (CDI_DOMINATORS, olddest, - recompute_dominator (CDI_DOMINATORS, olddest)); - /* Create the new iv. */ - oldivvar = VEC_index (tree, loopivs, 0); - ivvar = create_tmp_var (TREE_TYPE (oldivvar), "perfectiv"); - add_referenced_var (ivvar); - standard_iv_increment_position (newloop, &bsi, &insert_after); - create_iv (VEC_index (tree, lbounds, 0), - build_int_cst (TREE_TYPE (oldivvar), VEC_index (int, steps, 0)), - ivvar, newloop, &bsi, insert_after, &ivvar, &ivvarinced); - - /* Create the new upper bound. This may be not just a variable, so we copy - it to one just in case. */ - - exit_condition = get_loop_exit_condition (newloop); - uboundvar = create_tmp_var (TREE_TYPE (VEC_index (tree, ubounds, 0)), - "uboundvar"); - add_referenced_var (uboundvar); - stmt = gimple_build_assign (uboundvar, VEC_index (tree, ubounds, 0)); - uboundvar = make_ssa_name (uboundvar, stmt); - gimple_assign_set_lhs (stmt, uboundvar); - - if (insert_after) - gsi_insert_after (&bsi, stmt, GSI_SAME_STMT); - else - gsi_insert_before (&bsi, stmt, GSI_SAME_STMT); - update_stmt (stmt); - gimple_cond_set_condition (exit_condition, GE_EXPR, uboundvar, ivvarinced); - update_stmt (exit_condition); - replacements = htab_create_ggc (20, tree_map_hash, - tree_map_eq, NULL); - bbs = get_loop_body_in_dom_order (loop); - /* Now move the statements, and replace the induction variable in the moved - statements with the correct loop induction variable. */ - oldivvar = VEC_index (tree, loopivs, 0); - firstbsi = gsi_start_bb (bodybb); - for (i = loop->num_nodes - 1; i >= 0 ; i--) - { - gimple_stmt_iterator tobsi = gsi_last_bb (bodybb); - if (bbs[i]->loop_father == loop) - { - /* If this is true, we are *before* the inner loop. - If this isn't true, we are *after* it. - - The only time can_convert_to_perfect_nest returns true when we - have statements before the inner loop is if they can be moved - into the inner loop. - - The only time can_convert_to_perfect_nest returns true when we - have statements after the inner loop is if they can be moved into - the new split loop. */ - - if (dominated_by_p (CDI_DOMINATORS, loop->inner->header, bbs[i])) - { - gimple_stmt_iterator header_bsi - = gsi_after_labels (loop->inner->header); - - for (bsi = gsi_start_bb (bbs[i]); !gsi_end_p (bsi);) - { - gimple stmt = gsi_stmt (bsi); - - if (stmt == exit_condition - || not_interesting_stmt (stmt) - || stmt_is_bumper_for_loop (loop, stmt)) - { - gsi_next (&bsi); - continue; - } - - gsi_move_before (&bsi, &header_bsi); - } - } - else - { - /* Note that the bsi only needs to be explicitly incremented - when we don't move something, since it is automatically - incremented when we do. */ - for (bsi = gsi_start_bb (bbs[i]); !gsi_end_p (bsi);) - { - gimple stmt = gsi_stmt (bsi); - - if (stmt == exit_condition - || not_interesting_stmt (stmt) - || stmt_is_bumper_for_loop (loop, stmt)) - { - gsi_next (&bsi); - continue; - } - - replace_uses_equiv_to_x_with_y - (loop, stmt, oldivvar, VEC_index (int, steps, 0), ivvar, - VEC_index (tree, lbounds, 0), replacements, &firstbsi); - - gsi_move_before (&bsi, &tobsi); - - /* If the statement has any virtual operands, they may - need to be rewired because the original loop may - still reference them. */ - if (gimple_vuse (stmt)) - mark_sym_for_renaming (gimple_vop (cfun)); - } - } - - } - } - - free (bbs); - htab_delete (replacements); - return perfect_nest_p (loop); -} - -/* Return true if TRANS is a legal transformation matrix that respects - the dependence vectors in DISTS and DIRS. The conservative answer - is false. - - "Wolfe proves that a unimodular transformation represented by the - matrix T is legal when applied to a loop nest with a set of - lexicographically non-negative distance vectors RDG if and only if - for each vector d in RDG, (T.d >= 0) is lexicographically positive. - i.e.: if and only if it transforms the lexicographically positive - distance vectors to lexicographically positive vectors. Note that - a unimodular matrix must transform the zero vector (and only it) to - the zero vector." S.Muchnick. */ - -bool -lambda_transform_legal_p (lambda_trans_matrix trans, - int nb_loops, - VEC (ddr_p, heap) *dependence_relations) -{ - unsigned int i, j; - lambda_vector distres; - struct data_dependence_relation *ddr; - - gcc_assert (LTM_COLSIZE (trans) == nb_loops - && LTM_ROWSIZE (trans) == nb_loops); - - /* When there are no dependences, the transformation is correct. */ - if (VEC_length (ddr_p, dependence_relations) == 0) - return true; - - ddr = VEC_index (ddr_p, dependence_relations, 0); - if (ddr == NULL) - return true; - - /* When there is an unknown relation in the dependence_relations, we - know that it is no worth looking at this loop nest: give up. */ - if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) - return false; - - distres = lambda_vector_new (nb_loops); - - /* For each distance vector in the dependence graph. */ - FOR_EACH_VEC_ELT (ddr_p, dependence_relations, i, ddr) - { - /* Don't care about relations for which we know that there is no - dependence, nor about read-read (aka. output-dependences): - these data accesses can happen in any order. */ - if (DDR_ARE_DEPENDENT (ddr) == chrec_known - || (DR_IS_READ (DDR_A (ddr)) && DR_IS_READ (DDR_B (ddr)))) - continue; - - /* Conservatively answer: "this transformation is not valid". */ - if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know) - return false; - - /* If the dependence could not be captured by a distance vector, - conservatively answer that the transform is not valid. */ - if (DDR_NUM_DIST_VECTS (ddr) == 0) - return false; - - /* Compute trans.dist_vect */ - for (j = 0; j < DDR_NUM_DIST_VECTS (ddr); j++) - { - lambda_matrix_vector_mult (LTM_MATRIX (trans), nb_loops, nb_loops, - DDR_DIST_VECT (ddr, j), distres); - - if (!lambda_vector_lexico_pos (distres, nb_loops)) - return false; - } - } - return true; -} - - -/* Collects parameters from affine function ACCESS_FUNCTION, and push - them in PARAMETERS. */ - -static void -lambda_collect_parameters_from_af (tree access_function, - struct pointer_set_t *param_set, - VEC (tree, heap) **parameters) -{ - if (access_function == NULL) - return; - - if (TREE_CODE (access_function) == SSA_NAME - && pointer_set_contains (param_set, access_function) == 0) - { - pointer_set_insert (param_set, access_function); - VEC_safe_push (tree, heap, *parameters, access_function); - } - else - { - int i, num_operands = tree_operand_length (access_function); - - for (i = 0; i < num_operands; i++) - lambda_collect_parameters_from_af (TREE_OPERAND (access_function, i), - param_set, parameters); - } -} - -/* Collects parameters from DATAREFS, and push them in PARAMETERS. */ - -void -lambda_collect_parameters (VEC (data_reference_p, heap) *datarefs, - VEC (tree, heap) **parameters) -{ - unsigned i, j; - struct pointer_set_t *parameter_set = pointer_set_create (); - data_reference_p data_reference; - - FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, data_reference) - for (j = 0; j < DR_NUM_DIMENSIONS (data_reference); j++) - lambda_collect_parameters_from_af (DR_ACCESS_FN (data_reference, j), - parameter_set, parameters); - pointer_set_destroy (parameter_set); -} - -/* Translates BASE_EXPR to vector CY. AM is needed for inferring - indexing positions in the data access vector. CST is the analyzed - integer constant. */ - -static bool -av_for_af_base (tree base_expr, lambda_vector cy, struct access_matrix *am, - int cst) -{ - bool result = true; - - switch (TREE_CODE (base_expr)) - { - case INTEGER_CST: - /* Constant part. */ - cy[AM_CONST_COLUMN_INDEX (am)] += int_cst_value (base_expr) * cst; - return true; - - case SSA_NAME: - { - int param_index = - access_matrix_get_index_for_parameter (base_expr, am); - - if (param_index >= 0) - { - cy[param_index] = cst + cy[param_index]; - return true; - } - - return false; - } - - case PLUS_EXPR: - return av_for_af_base (TREE_OPERAND (base_expr, 0), cy, am, cst) - && av_for_af_base (TREE_OPERAND (base_expr, 1), cy, am, cst); - - case MINUS_EXPR: - return av_for_af_base (TREE_OPERAND (base_expr, 0), cy, am, cst) - && av_for_af_base (TREE_OPERAND (base_expr, 1), cy, am, -1 * cst); - - case MULT_EXPR: - if (TREE_CODE (TREE_OPERAND (base_expr, 0)) == INTEGER_CST) - result = av_for_af_base (TREE_OPERAND (base_expr, 1), - cy, am, cst * - int_cst_value (TREE_OPERAND (base_expr, 0))); - else if (TREE_CODE (TREE_OPERAND (base_expr, 1)) == INTEGER_CST) - result = av_for_af_base (TREE_OPERAND (base_expr, 0), - cy, am, cst * - int_cst_value (TREE_OPERAND (base_expr, 1))); - else - result = false; - - return result; - - case NEGATE_EXPR: - return av_for_af_base (TREE_OPERAND (base_expr, 0), cy, am, -1 * cst); - - default: - return false; - } - - return result; -} - -/* Translates ACCESS_FUN to vector CY. AM is needed for inferring - indexing positions in the data access vector. */ - -static bool -av_for_af (tree access_fun, lambda_vector cy, struct access_matrix *am) -{ - switch (TREE_CODE (access_fun)) - { - case POLYNOMIAL_CHREC: - { - tree left = CHREC_LEFT (access_fun); - tree right = CHREC_RIGHT (access_fun); - unsigned var; - - if (TREE_CODE (right) != INTEGER_CST) - return false; - - var = am_vector_index_for_loop (am, CHREC_VARIABLE (access_fun)); - cy[var] = int_cst_value (right); - - if (TREE_CODE (left) == POLYNOMIAL_CHREC) - return av_for_af (left, cy, am); - else - return av_for_af_base (left, cy, am, 1); - } - - case INTEGER_CST: - /* Constant part. */ - return av_for_af_base (access_fun, cy, am, 1); - - default: - return false; - } -} - -/* Initializes the access matrix for DATA_REFERENCE. */ - -static bool -build_access_matrix (data_reference_p data_reference, - VEC (tree, heap) *parameters, - VEC (loop_p, heap) *nest, - struct obstack * lambda_obstack) -{ - struct access_matrix *am = (struct access_matrix *) - obstack_alloc(lambda_obstack, sizeof (struct access_matrix)); - unsigned i, ndim = DR_NUM_DIMENSIONS (data_reference); - unsigned nivs = VEC_length (loop_p, nest); - unsigned lambda_nb_columns; - - AM_LOOP_NEST (am) = nest; - AM_NB_INDUCTION_VARS (am) = nivs; - AM_PARAMETERS (am) = parameters; - - lambda_nb_columns = AM_NB_COLUMNS (am); - AM_MATRIX (am) = VEC_alloc (lambda_vector, gc, ndim); - - for (i = 0; i < ndim; i++) - { - lambda_vector access_vector = lambda_vector_new (lambda_nb_columns); - tree access_function = DR_ACCESS_FN (data_reference, i); - - if (!av_for_af (access_function, access_vector, am)) - return false; - - VEC_quick_push (lambda_vector, AM_MATRIX (am), access_vector); - } - - DR_ACCESS_MATRIX (data_reference) = am; - return true; -} - -/* Returns false when one of the access matrices cannot be built. */ - -bool -lambda_compute_access_matrices (VEC (data_reference_p, heap) *datarefs, - VEC (tree, heap) *parameters, - VEC (loop_p, heap) *nest, - struct obstack * lambda_obstack) -{ - data_reference_p dataref; - unsigned ix; - - FOR_EACH_VEC_ELT (data_reference_p, datarefs, ix, dataref) - if (!build_access_matrix (dataref, parameters, nest, lambda_obstack)) - return false; - - return true; -} |