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Diffstat (limited to 'gcc/tree-flow.h')
| -rw-r--r-- | gcc/tree-flow.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h index f9f8115..102b6ea 100644 --- a/gcc/tree-flow.h +++ b/gcc/tree-flow.h @@ -597,6 +597,50 @@ extern void propagate_tree_value (tree *, tree); extern void replace_exp (use_operand_p, tree); extern bool may_propagate_copy (tree, tree); +/* Description of number of iterations of a loop. All the expressions inside + the structure can be evaluated at the end of the loop's preheader + (and due to ssa form, also anywhere inside the body of the loop). */ + +struct tree_niter_desc +{ + tree assumptions; /* The boolean expression. If this expression evalutes + to false, then the other fields in this structure + should not be used; there is no guarantee that they + will be correct. */ + tree may_be_zero; /* The booleand expression. If it evaluates to true, + the loop will exit in the first iteration (i.e. + its latch will not be executed), even if the niter + field says otherwise. */ + tree niter; /* The expression giving the number of iterations of + a loop (provided that assumptions == true and + may_be_zero == false), more precisely the number + of executions of the latch of the loop. */ + tree additional_info; /* The boolean expression. Sometimes we use additional + knowledge to simplify the other expressions + contained in this structure (for example the + knowledge about value ranges of operands on entry to + the loop). If this is a case, conjunction of such + condition is stored in this field, so that we do not + lose the information: for example if may_be_zero + is (n <= 0) and niter is (unsigned) n, we know + that the number of iterations is at most + MAX_SIGNED_INT. However if the (n <= 0) assumption + is eliminated (by looking at the guard on entry of + the loop), then the information would be lost. */ +}; + +/* In tree-ssa-loop*.c */ + +void number_of_iterations_cond (tree, tree, tree, enum tree_code, tree, tree, + struct tree_niter_desc *); +bool number_of_iterations_exit (struct loop *, edge, + struct tree_niter_desc *niter); +tree loop_niter_by_eval (struct loop *, edge); +tree find_loop_niter_by_eval (struct loop *, edge *); +void estimate_numbers_of_iterations (struct loops *); +tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree); +void free_numbers_of_iterations_estimates (struct loops *); + /* In tree-flow-inline.h */ static inline int phi_arg_from_edge (tree, edge); static inline bool is_call_clobbered (tree); |