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Diffstat (limited to 'gcc-4.4.0/gcc/tree-data-ref.h')
| -rw-r--r-- | gcc-4.4.0/gcc/tree-data-ref.h | 610 |
1 files changed, 610 insertions, 0 deletions
diff --git a/gcc-4.4.0/gcc/tree-data-ref.h b/gcc-4.4.0/gcc/tree-data-ref.h new file mode 100644 index 000000000..4a12f3946 --- /dev/null +++ b/gcc-4.4.0/gcc/tree-data-ref.h @@ -0,0 +1,610 @@ +/* Data references and dependences detectors. + Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 + Free Software Foundation, Inc. + Contributed by Sebastian Pop <pop@cri.ensmp.fr> + +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/>. */ + +#ifndef GCC_TREE_DATA_REF_H +#define GCC_TREE_DATA_REF_H + +#include "graphds.h" +#include "lambda.h" +#include "omega.h" +#include "tree-chrec.h" + +/* + innermost_loop_behavior describes the evolution of the address of the memory + reference in the innermost enclosing loop. The address is expressed as + BASE + STEP * # of iteration, and base is further decomposed as the base + pointer (BASE_ADDRESS), loop invariant offset (OFFSET) and + constant offset (INIT). Examples, in loop nest + + for (i = 0; i < 100; i++) + for (j = 3; j < 100; j++) + + Example 1 Example 2 + data-ref a[j].b[i][j] *(p + x + 16B + 4B * j) + + + innermost_loop_behavior + base_address &a p + offset i * D_i x + init 3 * D_j + offsetof (b) 28 + step D_j 4 + + */ +struct innermost_loop_behavior +{ + tree base_address; + tree offset; + tree init; + tree step; + + /* Alignment information. ALIGNED_TO is set to the largest power of two + that divides OFFSET. */ + tree aligned_to; +}; + +/* Describes the evolutions of indices of the memory reference. The indices + are indices of the ARRAY_REFs and the operands of INDIRECT_REFs. + For ARRAY_REFs, BASE_OBJECT is the reference with zeroed indices + (note that this reference does not have to be valid, if zero does not + belong to the range of the array; hence it is not recommended to use + BASE_OBJECT in any code generation). For INDIRECT_REFs, the address is + set to the loop-invariant part of the address of the object, except for + the constant offset. For the examples above, + + base_object: a[0].b[0][0] *(p + x + 4B * j_0) + indices: {j_0, +, 1}_2 {16, +, 4}_2 + {i_0, +, 1}_1 + {j_0, +, 1}_2 +*/ + +struct indices +{ + /* The object. */ + tree base_object; + + /* A list of chrecs. Access functions of the indices. */ + VEC(tree,heap) *access_fns; +}; + +struct dr_alias +{ + /* The alias information that should be used for new pointers to this + location. SYMBOL_TAG is either a DECL or a SYMBOL_MEMORY_TAG. */ + tree symbol_tag; + struct ptr_info_def *ptr_info; + + /* The set of virtual operands corresponding to this memory reference, + serving as a description of the alias information for the memory + reference. This could be eliminated if we had alias oracle. */ + bitmap vops; +}; + +typedef struct scop *scop_p; + +/* Each vector of the access matrix represents a linear access + function for a subscript. First elements correspond to the + leftmost indices, ie. for a[i][j] the first vector corresponds to + the subscript in "i". The elements of a vector are relative to + the loop nests in which the data reference is considered, + i.e. the vector is relative to the SCoP that provides the context + in which this data reference occurs. + + For example, in + + | loop_1 + | loop_2 + | a[i+3][2*j+n-1] + + if "i" varies in loop_1 and "j" varies in loop_2, the access + matrix with respect to the loop nest {loop_1, loop_2} is: + + | loop_1 loop_2 param_n cst + | 1 0 0 3 + | 0 2 1 -1 + + whereas the access matrix with respect to loop_2 considers "i" as + a parameter: + + | loop_2 param_i param_n cst + | 0 1 0 3 + | 2 0 1 -1 +*/ +struct access_matrix +{ + VEC (loop_p, heap) *loop_nest; + int nb_induction_vars; + VEC (tree, heap) *parameters; + VEC (lambda_vector, gc) *matrix; +}; + +#define AM_LOOP_NEST(M) (M)->loop_nest +#define AM_NB_INDUCTION_VARS(M) (M)->nb_induction_vars +#define AM_PARAMETERS(M) (M)->parameters +#define AM_MATRIX(M) (M)->matrix +#define AM_NB_PARAMETERS(M) (VEC_length (tree, AM_PARAMETERS(M))) +#define AM_CONST_COLUMN_INDEX(M) (AM_NB_INDUCTION_VARS (M) + AM_NB_PARAMETERS (M)) +#define AM_NB_COLUMNS(M) (AM_NB_INDUCTION_VARS (M) + AM_NB_PARAMETERS (M) + 1) +#define AM_GET_SUBSCRIPT_ACCESS_VECTOR(M, I) VEC_index (lambda_vector, AM_MATRIX (M), I) +#define AM_GET_ACCESS_MATRIX_ELEMENT(M, I, J) AM_GET_SUBSCRIPT_ACCESS_VECTOR (M, I)[J] + +/* Return the column in the access matrix of LOOP_NUM. */ + +static inline int +am_vector_index_for_loop (struct access_matrix *access_matrix, int loop_num) +{ + int i; + loop_p l; + + for (i = 0; VEC_iterate (loop_p, AM_LOOP_NEST (access_matrix), i, l); i++) + if (l->num == loop_num) + return i; + + gcc_unreachable(); +} + +int access_matrix_get_index_for_parameter (tree, struct access_matrix *); + +struct data_reference +{ + /* A pointer to the statement that contains this DR. */ + gimple stmt; + + /* A pointer to the memory reference. */ + tree ref; + + /* Auxiliary info specific to a pass. */ + void *aux; + + /* True when the data reference is in RHS of a stmt. */ + bool is_read; + + /* Behavior of the memory reference in the innermost loop. */ + struct innermost_loop_behavior innermost; + + /* Subscripts of this data reference. */ + struct indices indices; + + /* Alias information for the data reference. */ + struct dr_alias alias; + + /* The SCoP in which the data reference was analyzed. */ + scop_p scop; + + /* Matrix representation for the data access functions. */ + struct access_matrix *access_matrix; +}; + +#define DR_SCOP(DR) (DR)->scop +#define DR_STMT(DR) (DR)->stmt +#define DR_REF(DR) (DR)->ref +#define DR_BASE_OBJECT(DR) (DR)->indices.base_object +#define DR_ACCESS_FNS(DR) (DR)->indices.access_fns +#define DR_ACCESS_FN(DR, I) VEC_index (tree, DR_ACCESS_FNS (DR), I) +#define DR_NUM_DIMENSIONS(DR) VEC_length (tree, DR_ACCESS_FNS (DR)) +#define DR_IS_READ(DR) (DR)->is_read +#define DR_BASE_ADDRESS(DR) (DR)->innermost.base_address +#define DR_OFFSET(DR) (DR)->innermost.offset +#define DR_INIT(DR) (DR)->innermost.init +#define DR_STEP(DR) (DR)->innermost.step +#define DR_SYMBOL_TAG(DR) (DR)->alias.symbol_tag +#define DR_PTR_INFO(DR) (DR)->alias.ptr_info +#define DR_VOPS(DR) (DR)->alias.vops +#define DR_ALIGNED_TO(DR) (DR)->innermost.aligned_to +#define DR_ACCESS_MATRIX(DR) (DR)->access_matrix + +typedef struct data_reference *data_reference_p; +DEF_VEC_P(data_reference_p); +DEF_VEC_ALLOC_P (data_reference_p, heap); + +enum data_dependence_direction { + dir_positive, + dir_negative, + dir_equal, + dir_positive_or_negative, + dir_positive_or_equal, + dir_negative_or_equal, + dir_star, + dir_independent +}; + +/* The description of the grid of iterations that overlap. At most + two loops are considered at the same time just now, hence at most + two functions are needed. For each of the functions, we store + the vector of coefficients, f[0] + x * f[1] + y * f[2] + ..., + where x, y, ... are variables. */ + +#define MAX_DIM 2 + +/* Special values of N. */ +#define NO_DEPENDENCE 0 +#define NOT_KNOWN (MAX_DIM + 1) +#define CF_NONTRIVIAL_P(CF) ((CF)->n != NO_DEPENDENCE && (CF)->n != NOT_KNOWN) +#define CF_NOT_KNOWN_P(CF) ((CF)->n == NOT_KNOWN) +#define CF_NO_DEPENDENCE_P(CF) ((CF)->n == NO_DEPENDENCE) + +typedef VEC (tree, heap) *affine_fn; + +typedef struct +{ + unsigned n; + affine_fn fns[MAX_DIM]; +} conflict_function; + +/* What is a subscript? Given two array accesses a subscript is the + tuple composed of the access functions for a given dimension. + Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three + subscripts: (f1, g1), (f2, g2), (f3, g3). These three subscripts + are stored in the data_dependence_relation structure under the form + of an array of subscripts. */ + +struct subscript +{ + /* A description of the iterations for which the elements are + accessed twice. */ + conflict_function *conflicting_iterations_in_a; + conflict_function *conflicting_iterations_in_b; + + /* This field stores the information about the iteration domain + validity of the dependence relation. */ + tree last_conflict; + + /* Distance from the iteration that access a conflicting element in + A to the iteration that access this same conflicting element in + B. The distance is a tree scalar expression, i.e. a constant or a + symbolic expression, but certainly not a chrec function. */ + tree distance; +}; + +typedef struct subscript *subscript_p; +DEF_VEC_P(subscript_p); +DEF_VEC_ALLOC_P (subscript_p, heap); + +#define SUB_CONFLICTS_IN_A(SUB) SUB->conflicting_iterations_in_a +#define SUB_CONFLICTS_IN_B(SUB) SUB->conflicting_iterations_in_b +#define SUB_LAST_CONFLICT(SUB) SUB->last_conflict +#define SUB_DISTANCE(SUB) SUB->distance + +/* A data_dependence_relation represents a relation between two + data_references A and B. */ + +struct data_dependence_relation +{ + + struct data_reference *a; + struct data_reference *b; + + /* A "yes/no/maybe" field for the dependence relation: + + - when "ARE_DEPENDENT == NULL_TREE", there exist a dependence + relation between A and B, and the description of this relation + is given in the SUBSCRIPTS array, + + - when "ARE_DEPENDENT == chrec_known", there is no dependence and + SUBSCRIPTS is empty, + + - when "ARE_DEPENDENT == chrec_dont_know", there may be a dependence, + but the analyzer cannot be more specific. */ + tree are_dependent; + + /* For each subscript in the dependence test, there is an element in + this array. This is the attribute that labels the edge A->B of + the data_dependence_relation. */ + VEC (subscript_p, heap) *subscripts; + + /* The analyzed loop nest. */ + VEC (loop_p, heap) *loop_nest; + + /* The classic direction vector. */ + VEC (lambda_vector, heap) *dir_vects; + + /* The classic distance vector. */ + VEC (lambda_vector, heap) *dist_vects; + + /* An index in loop_nest for the innermost loop that varies for + this data dependence relation. */ + unsigned inner_loop; + + /* Is the dependence reversed with respect to the lexicographic order? */ + bool reversed_p; + + /* When the dependence relation is affine, it can be represented by + a distance vector. */ + bool affine_p; + + /* Set to true when the dependence relation is on the same data + access. */ + bool self_reference_p; +}; + +typedef struct data_dependence_relation *ddr_p; +DEF_VEC_P(ddr_p); +DEF_VEC_ALLOC_P(ddr_p,heap); + +#define DDR_A(DDR) DDR->a +#define DDR_B(DDR) DDR->b +#define DDR_AFFINE_P(DDR) DDR->affine_p +#define DDR_ARE_DEPENDENT(DDR) DDR->are_dependent +#define DDR_SUBSCRIPTS(DDR) DDR->subscripts +#define DDR_SUBSCRIPT(DDR, I) VEC_index (subscript_p, DDR_SUBSCRIPTS (DDR), I) +#define DDR_NUM_SUBSCRIPTS(DDR) VEC_length (subscript_p, DDR_SUBSCRIPTS (DDR)) + +#define DDR_LOOP_NEST(DDR) DDR->loop_nest +/* The size of the direction/distance vectors: the number of loops in + the loop nest. */ +#define DDR_NB_LOOPS(DDR) (VEC_length (loop_p, DDR_LOOP_NEST (DDR))) +#define DDR_INNER_LOOP(DDR) DDR->inner_loop +#define DDR_SELF_REFERENCE(DDR) DDR->self_reference_p + +#define DDR_DIST_VECTS(DDR) ((DDR)->dist_vects) +#define DDR_DIR_VECTS(DDR) ((DDR)->dir_vects) +#define DDR_NUM_DIST_VECTS(DDR) \ + (VEC_length (lambda_vector, DDR_DIST_VECTS (DDR))) +#define DDR_NUM_DIR_VECTS(DDR) \ + (VEC_length (lambda_vector, DDR_DIR_VECTS (DDR))) +#define DDR_DIR_VECT(DDR, I) \ + VEC_index (lambda_vector, DDR_DIR_VECTS (DDR), I) +#define DDR_DIST_VECT(DDR, I) \ + VEC_index (lambda_vector, DDR_DIST_VECTS (DDR), I) +#define DDR_REVERSED_P(DDR) DDR->reversed_p + + + +/* Describes a location of a memory reference. */ + +typedef struct data_ref_loc_d +{ + /* Position of the memory reference. */ + tree *pos; + + /* True if the memory reference is read. */ + bool is_read; +} data_ref_loc; + +DEF_VEC_O (data_ref_loc); +DEF_VEC_ALLOC_O (data_ref_loc, heap); + +bool get_references_in_stmt (gimple, VEC (data_ref_loc, heap) **); +bool dr_analyze_innermost (struct data_reference *); +extern bool compute_data_dependences_for_loop (struct loop *, bool, + VEC (data_reference_p, heap) **, + VEC (ddr_p, heap) **); +extern tree find_data_references_in_loop (struct loop *, + VEC (data_reference_p, heap) **); +extern void print_direction_vector (FILE *, lambda_vector, int); +extern void print_dir_vectors (FILE *, VEC (lambda_vector, heap) *, int); +extern void print_dist_vectors (FILE *, VEC (lambda_vector, heap) *, int); +extern void dump_subscript (FILE *, struct subscript *); +extern void dump_ddrs (FILE *, VEC (ddr_p, heap) *); +extern void dump_dist_dir_vectors (FILE *, VEC (ddr_p, heap) *); +extern void dump_data_reference (FILE *, struct data_reference *); +extern void dump_data_references (FILE *, VEC (data_reference_p, heap) *); +extern void debug_data_dependence_relation (struct data_dependence_relation *); +extern void dump_data_dependence_relation (FILE *, + struct data_dependence_relation *); +extern void dump_data_dependence_relations (FILE *, VEC (ddr_p, heap) *); +extern void debug_data_dependence_relations (VEC (ddr_p, heap) *); +extern void dump_data_dependence_direction (FILE *, + enum data_dependence_direction); +extern void free_dependence_relation (struct data_dependence_relation *); +extern void free_dependence_relations (VEC (ddr_p, heap) *); +extern void free_data_ref (data_reference_p); +extern void free_data_refs (VEC (data_reference_p, heap) *); +extern bool find_data_references_in_stmt (struct loop *, gimple, + VEC (data_reference_p, heap) **); +struct data_reference *create_data_ref (struct loop *, tree, gimple, bool); +extern bool find_loop_nest (struct loop *, VEC (loop_p, heap) **); +extern void compute_all_dependences (VEC (data_reference_p, heap) *, + VEC (ddr_p, heap) **, VEC (loop_p, heap) *, + bool); + +extern void create_rdg_vertices (struct graph *, VEC (gimple, heap) *); +extern bool dr_may_alias_p (const struct data_reference *, + const struct data_reference *); +extern bool stmt_simple_memref_p (struct loop *, gimple, tree); + +/* Return true when the DDR contains two data references that have the + same access functions. */ + +static inline bool +same_access_functions (const struct data_dependence_relation *ddr) +{ + unsigned i; + + for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++) + if (!eq_evolutions_p (DR_ACCESS_FN (DDR_A (ddr), i), + DR_ACCESS_FN (DDR_B (ddr), i))) + return false; + + return true; +} + +/* Return true when DDR is an anti-dependence relation. */ + +static inline bool +ddr_is_anti_dependent (ddr_p ddr) +{ + return (DDR_ARE_DEPENDENT (ddr) == NULL_TREE + && DR_IS_READ (DDR_A (ddr)) + && !DR_IS_READ (DDR_B (ddr)) + && !same_access_functions (ddr)); +} + +/* Return true when DEPENDENCE_RELATIONS contains an anti-dependence. */ + +static inline bool +ddrs_have_anti_deps (VEC (ddr_p, heap) *dependence_relations) +{ + unsigned i; + ddr_p ddr; + + for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++) + if (ddr_is_anti_dependent (ddr)) + return true; + + return false; +} + +/* Return the dependence level for the DDR relation. */ + +static inline unsigned +ddr_dependence_level (ddr_p ddr) +{ + unsigned vector; + unsigned level = 0; + + if (DDR_DIST_VECTS (ddr)) + level = dependence_level (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr)); + + for (vector = 1; vector < DDR_NUM_DIST_VECTS (ddr); vector++) + level = MIN (level, dependence_level (DDR_DIST_VECT (ddr, vector), + DDR_NB_LOOPS (ddr))); + return level; +} + + + +/* A Reduced Dependence Graph (RDG) vertex representing a statement. */ +typedef struct rdg_vertex +{ + /* The statement represented by this vertex. */ + gimple stmt; + + /* True when the statement contains a write to memory. */ + bool has_mem_write; + + /* True when the statement contains a read from memory. */ + bool has_mem_reads; +} *rdg_vertex_p; + +#define RDGV_STMT(V) ((struct rdg_vertex *) ((V)->data))->stmt +#define RDGV_HAS_MEM_WRITE(V) ((struct rdg_vertex *) ((V)->data))->has_mem_write +#define RDGV_HAS_MEM_READS(V) ((struct rdg_vertex *) ((V)->data))->has_mem_reads +#define RDG_STMT(RDG, I) RDGV_STMT (&(RDG->vertices[I])) +#define RDG_MEM_WRITE_STMT(RDG, I) RDGV_HAS_MEM_WRITE (&(RDG->vertices[I])) +#define RDG_MEM_READS_STMT(RDG, I) RDGV_HAS_MEM_READS (&(RDG->vertices[I])) + +void dump_rdg_vertex (FILE *, struct graph *, int); +void debug_rdg_vertex (struct graph *, int); +void dump_rdg_component (FILE *, struct graph *, int, bitmap); +void debug_rdg_component (struct graph *, int); +void dump_rdg (FILE *, struct graph *); +void debug_rdg (struct graph *); +void dot_rdg (struct graph *); +int rdg_vertex_for_stmt (struct graph *, gimple); + +/* Data dependence type. */ + +enum rdg_dep_type +{ + /* Read After Write (RAW). */ + flow_dd = 'f', + + /* Write After Read (WAR). */ + anti_dd = 'a', + + /* Write After Write (WAW). */ + output_dd = 'o', + + /* Read After Read (RAR). */ + input_dd = 'i' +}; + +/* Dependence information attached to an edge of the RDG. */ + +typedef struct rdg_edge +{ + /* Type of the dependence. */ + enum rdg_dep_type type; + + /* Levels of the dependence: the depth of the loops that carry the + dependence. */ + unsigned level; + + /* Dependence relation between data dependences, NULL when one of + the vertices is a scalar. */ + ddr_p relation; +} *rdg_edge_p; + +#define RDGE_TYPE(E) ((struct rdg_edge *) ((E)->data))->type +#define RDGE_LEVEL(E) ((struct rdg_edge *) ((E)->data))->level +#define RDGE_RELATION(E) ((struct rdg_edge *) ((E)->data))->relation + +struct graph *build_rdg (struct loop *); +struct graph *build_empty_rdg (int); +void free_rdg (struct graph *); + +/* Return the index of the variable VAR in the LOOP_NEST array. */ + +static inline int +index_in_loop_nest (int var, VEC (loop_p, heap) *loop_nest) +{ + struct loop *loopi; + int var_index; + + for (var_index = 0; VEC_iterate (loop_p, loop_nest, var_index, loopi); + var_index++) + if (loopi->num == var) + break; + + return var_index; +} + +void stores_from_loop (struct loop *, VEC (gimple, heap) **); +void remove_similar_memory_refs (VEC (gimple, heap) **); +bool rdg_defs_used_in_other_loops_p (struct graph *, int); +bool have_similar_memory_accesses (gimple, gimple); + +/* Determines whether RDG vertices V1 and V2 access to similar memory + locations, in which case they have to be in the same partition. */ + +static inline bool +rdg_has_similar_memory_accesses (struct graph *rdg, int v1, int v2) +{ + return have_similar_memory_accesses (RDG_STMT (rdg, v1), + RDG_STMT (rdg, v2)); +} + +/* In lambda-code.c */ +bool lambda_transform_legal_p (lambda_trans_matrix, int, + VEC (ddr_p, heap) *); +void lambda_collect_parameters (VEC (data_reference_p, heap) *, + VEC (tree, heap) **); +bool lambda_compute_access_matrices (VEC (data_reference_p, heap) *, + VEC (tree, heap) *, VEC (loop_p, heap) *); + +/* In tree-data-ref.c */ +void split_constant_offset (tree , tree *, tree *); + +/* Strongly connected components of the reduced data dependence graph. */ + +typedef struct rdg_component +{ + int num; + VEC (int, heap) *vertices; +} *rdgc; + +DEF_VEC_P (rdgc); +DEF_VEC_ALLOC_P (rdgc, heap); + +DEF_VEC_P (bitmap); +DEF_VEC_ALLOC_P (bitmap, heap); + +#endif /* GCC_TREE_DATA_REF_H */ |