unsigned times;
};
+/* The structure describing a bound on number of iterations of a loop. */
+
+struct nb_iter_bound
+{
+ tree bound; /* The expression whose value is an upper bound on the
+ number of executions of anything after ... */
+ tree at_stmt; /* ... this statement during one execution of loop. */
+ tree additional; /* A conjunction of conditions the operands of BOUND
+ satisfy. The additional information about the value
+ of the bound may be derived from it. */
+ struct nb_iter_bound *next;
+ /* The next bound in a list. */
+};
+
/* Structure to hold information for each natural loop. */
struct loop
{
the loop latch. */
basic_block last;
- /* Bitmap of blocks contained within the loop. */
- sbitmap nodes;
-
/* Number of blocks contained within the loop. */
unsigned num_nodes;
void *aux;
/* The following are currently used by loop.c but they are likely to
- disappear as loop.c is converted to use the CFG. */
-
- /* Nonzero if the loop has a NOTE_INSN_LOOP_VTOP. */
- rtx vtop;
-
- /* Nonzero if the loop has a NOTE_INSN_LOOP_CONT.
- A continue statement will generate a branch to NEXT_INSN (cont). */
- rtx cont;
-
- /* The dominator of cont. */
- rtx cont_dominator;
+ disappear when loop.c is replaced and removed. */
/* The NOTE_INSN_LOOP_BEG. */
rtx start;
loops nested inside it. */
int exit_count;
+ /* The probable number of times the loop is executed at runtime.
+ This is an INTEGER_CST or an expression containing symbolic
+ names. Don't access this field directly:
+ number_of_iterations_in_loop computes and caches the computed
+ information in this field. */
+ tree nb_iterations;
+
+ /* An INTEGER_CST estimation of the number of iterations. NULL_TREE
+ if there is no estimation. */
+ tree estimated_nb_iterations;
+
/* Upper bound on number of iterations of a loop. */
struct nb_iter_bound *bounds;
+
+ /* If not NULL, loop has just single exit edge stored here (edges to the
+ EXIT_BLOCK_PTR do not count. */
+ edge single_exit;
+
+ /* True when the loop does not carry data dependences, and
+ consequently the iterations can be executed in any order. False
+ when the loop carries data dependences, or when the property is
+ not decidable. */
+ bool parallel_p;
};
/* Flags for state of loop structure. */
{
LOOPS_HAVE_PREHEADERS = 1,
LOOPS_HAVE_SIMPLE_LATCHES = 2,
- LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4
+ LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4,
+ LOOPS_HAVE_MARKED_SINGLE_EXITS = 8
};
/* Structure to hold CFG information about natural loops within a function. */
/* Number of natural loops in the function. */
unsigned num;
- /* Maximum nested loop level in the function. */
- unsigned levels;
-
/* Array of natural loop descriptors (scanning this array in reverse order
will find the inner loops before their enclosing outer loops). */
struct loop *array;
/* The above array is unused in new loop infrastructure and is kept only for
purposes of the old loop optimizer. Instead we store just pointers to
- loops here. */
+ loops here.
+ Note that a loop in this array may actually be NULL, if the loop
+ has been removed and the entire loops structure has not been
+ recomputed since that time. */
struct loop **parray;
/* Pointer to root of loop hierarchy tree. */
int state;
};
+/* The loop tree currently optimized. */
+
+extern struct loops *current_loops;
+
/* Flags for loop discovery. */
#define LOOP_TREE 1 /* Build loop hierarchy tree. */
/* Loop recognition. */
extern int flow_loops_find (struct loops *, int flags);
-extern int flow_loops_update (struct loops *, int flags);
extern void flow_loops_free (struct loops *);
extern void flow_loops_dump (const struct loops *, FILE *,
void (*)(const struct loop *, FILE *, int), int);
extern int flow_loop_scan (struct loop *, int);
extern void flow_loop_free (struct loop *);
void mark_irreducible_loops (struct loops *);
+void mark_single_exit_loops (struct loops *);
extern void create_loop_notes (void);
/* Loop data structure manipulation/querying. */
extern bool flow_bb_inside_loop_p (const struct loop *, const basic_block);
extern struct loop * find_common_loop (struct loop *, struct loop *);
struct loop *superloop_at_depth (struct loop *, unsigned);
+extern unsigned tree_num_loop_insns (struct loop *);
extern int num_loop_insns (struct loop *);
extern int average_num_loop_insns (struct loop *);
extern unsigned get_loop_level (const struct loop *);
/* Loops & cfg manipulation. */
extern basic_block *get_loop_body (const struct loop *);
extern basic_block *get_loop_body_in_dom_order (const struct loop *);
+extern basic_block *get_loop_body_in_bfs_order (const struct loop *);
extern edge *get_loop_exit_edges (const struct loop *, unsigned *);
extern unsigned num_loop_branches (const struct loop *);
#define DLTHE_FLAG_UPDATE_FREQ 1 /* Update frequencies in
duplicate_loop_to_header_edge. */
+extern struct loop * duplicate_loop (struct loops *, struct loop *,
+ struct loop *);
extern int duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
unsigned, sbitmap, edge, edge *,
unsigned *, int);
-extern struct loop *loopify (struct loops *, edge, edge, basic_block);
-extern void unloop (struct loops *, struct loop *);
+extern struct loop *loopify (struct loops *, edge, edge,
+ basic_block, edge, edge, bool);
extern bool remove_path (struct loops *, edge);
-extern edge split_loop_bb (basic_block, rtx);
+extern edge split_loop_bb (basic_block, void *);
/* Induction variable analysis. */
If first_special is true, the value in the first iteration is
delta + mult * base
- If extend = NIL, first_special must be false, delta 0, mult 1 and value is
+ If extend = UNKNOWN, first_special must be false, delta 0, mult 1 and value is
subreg_{mode} (base + i * step)
The get_iv_value function can be used to obtain these expressions.
see the description above). */
rtx base, step;
- /* The type of extend applied to it (SIGN_EXTEND, ZERO_EXTEND or NIL). */
+ /* The type of extend applied to it (SIGN_EXTEND, ZERO_EXTEND or UNKNOWN). */
enum rtx_code extend;
/* Operations applied in the extended mode. */
extern rtx iv_get_reaching_def (rtx, rtx);
extern bool iv_analyze (rtx, rtx, struct rtx_iv *);
extern rtx get_iv_value (struct rtx_iv *, rtx);
+extern bool biv_p (rtx, rtx);
extern void find_simple_exit (struct loop *, struct niter_desc *);
-extern void iv_number_of_iterations (struct loop *, rtx, rtx,
- struct niter_desc *);
extern void iv_analysis_done (void);
extern struct niter_desc *get_simple_loop_desc (struct loop *loop);
return loop->aux;
}
+/* The properties of the target. */
+
+extern unsigned target_avail_regs; /* Number of available registers. */
+extern unsigned target_res_regs; /* Number of reserved registers. */
+extern unsigned target_small_cost; /* The cost for register when there
+ is a free one. */
+extern unsigned target_pres_cost; /* The cost for register when there are
+ not too many free ones. */
+extern unsigned target_spill_cost; /* The cost for register when we need
+ to spill. */
+
/* Register pressure estimation for induction variable optimizations & loop
invariant motion. */
extern unsigned global_cost_for_size (unsigned, unsigned, unsigned);
extern void unroll_and_peel_loops (struct loops *, int);
extern void doloop_optimize_loops (struct loops *);
extern void move_loop_invariants (struct loops *);
+extern void record_estimate (struct loop *, tree, tree, tree);
+
+/* Old loop optimizer interface. */
+
+/* Flags passed to loop_optimize. */
+#define LOOP_PREFETCH 1
+
+extern void loop_optimize (rtx, FILE *, int);
#endif /* GCC_CFGLOOP_H */
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