/* Natural loop functions
- Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003
- Free Software Foundation, Inc.
+ Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
+ 2005, 2006, 2007 Free Software Foundation, Inc.
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 2, or (at your option) any later
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#ifndef GCC_CFGLOOP_H
+#define GCC_CFGLOOP_H
+
+#include "basic-block.h"
+/* For rtx_code. */
+#include "rtl.h"
+#include "vecprim.h"
+#include "double-int.h"
/* Structure to hold decision about unrolling/peeling. */
enum lpt_dec
LPT_UNROLL_STUPID
};
-struct lpt_decision
+struct lpt_decision GTY (())
{
enum lpt_dec decision;
unsigned times;
};
-/* Description of loop for simple loop unrolling. */
-struct loop_desc
+/* The structure describing a bound on number of iterations of a loop. */
+
+struct nb_iter_bound GTY ((chain_next ("%h.next")))
+{
+ /* The statement STMT is executed at most ... */
+ tree stmt;
+
+ /* ... BOUND + 1 times (BOUND must be an unsigned constant).
+ The + 1 is added for the following reasons:
+
+ a) 0 would otherwise be unused, while we would need to care more about
+ overflows (as MAX + 1 is sometimes produced as the estimate on number
+ of executions of STMT).
+ b) it is consistent with the result of number_of_iterations_exit. */
+ double_int bound;
+
+ /* True if the statement will cause the loop to be leaved the (at most)
+ BOUND + 1-st time it is executed, that is, all the statements after it
+ are executed at most BOUND times. */
+ bool is_exit;
+
+ /* The next bound in the list. */
+ struct nb_iter_bound *next;
+};
+
+/* Description of the loop exit. */
+
+struct loop_exit GTY (())
{
- int postincr; /* 1 if increment/decrement is done after loop exit condition. */
- rtx stride; /* Value added to VAR in each iteration. */
- rtx var; /* Loop control variable. */
- rtx var_alts; /* List of definitions of its initial value. */
- rtx lim; /* Expression var is compared with. */
- rtx lim_alts; /* List of definitions of its initial value. */
- bool const_iter; /* True if it iterates constant number of times. */
- unsigned HOST_WIDE_INT niter;
- /* Number of iterations if it is constant. */
- bool may_be_zero; /* If we cannot determine that the first iteration will pass. */
- enum rtx_code cond; /* Exit condition. */
- int neg; /* Set to 1 if loop ends when condition is satisfied. */
- edge out_edge; /* The exit edge. */
- edge in_edge; /* And the other one. */
- int n_branches; /* Number of branches inside the loop. */
+ /* The exit edge. */
+ struct edge_def *e;
+
+ /* Previous and next exit in the list of the exits of the loop. */
+ struct loop_exit *prev;
+ struct loop_exit *next;
+
+ /* Next element in the list of loops from that E exits. */
+ struct loop_exit *next_e;
+};
+
+typedef struct loop *loop_p;
+DEF_VEC_P (loop_p);
+DEF_VEC_ALLOC_P (loop_p, heap);
+DEF_VEC_ALLOC_P (loop_p, gc);
+
+/* An integer estimation of the number of iterations. Estimate_state
+ describes what is the state of the estimation. */
+enum loop_estimation
+{
+ /* Estimate was not computed yet. */
+ EST_NOT_COMPUTED,
+ /* Estimate is ready. */
+ EST_AVAILABLE
};
/* Structure to hold information for each natural loop. */
-struct loop
+struct loop GTY ((chain_next ("%h.next")))
{
/* Index into loops array. */
int num;
/* Basic block of loop header. */
- basic_block header;
+ struct basic_block_def *header;
/* Basic block of loop latch. */
- basic_block latch;
-
- /* Basic block of loop preheader or NULL if it does not exist. */
- basic_block pre_header;
+ struct basic_block_def *latch;
/* For loop unrolling/peeling decision. */
struct lpt_decision lpt_decision;
- /* Simple loop description. */
- int simple;
- struct loop_desc desc;
- int has_desc;
-
/* Number of loop insns. */
unsigned ninsns;
/* Average number of executed insns per iteration. */
unsigned av_ninsns;
- /* Array of edges along the preheader extended basic block trace.
- The source of the first edge is the root node of preheader
- extended basic block, if it exists. */
- edge *pre_header_edges;
+ /* Number of blocks contained within the loop. */
+ unsigned num_nodes;
- /* Number of edges along the pre_header extended basic block trace. */
- int num_pre_header_edges;
+ /* Superloops of the loop, starting with the outermost loop. */
+ VEC (loop_p, gc) *superloops;
- /* The first block in the loop. This is not necessarily the same as
- the loop header. */
- basic_block first;
+ /* The first inner (child) loop or NULL if innermost loop. */
+ struct loop *inner;
- /* The last block in the loop. This is not necessarily the same as
- the loop latch. */
- basic_block last;
+ /* Link to the next (sibling) loop. */
+ struct loop *next;
- /* Bitmap of blocks contained within the loop. */
- sbitmap nodes;
+ /* Auxiliary info specific to a pass. */
+ PTR GTY ((skip (""))) aux;
- /* Number of blocks contained within the loop. */
- unsigned num_nodes;
+ /* The number of times the latch of the loop is executed.
+ This is an INTEGER_CST or an expression containing symbolic
+ names. Don't access this field directly:
+ number_of_latch_executions computes and caches the computed
+ information in this field. */
+ tree nb_iterations;
- /* Array of edges that enter the loop. */
- edge *entry_edges;
+ /* An integer estimation of the number of iterations. Estimate_state
+ describes what is the state of the estimation. */
+ enum loop_estimation estimate_state;
- /* Number of edges that enter the loop. */
- int num_entries;
+ /* An integer guaranteed to bound the number of iterations of the loop
+ from above. */
+ bool any_upper_bound;
+ double_int nb_iterations_upper_bound;
- /* Array of edges that exit the loop. */
- edge *exit_edges;
+ /* An integer giving the expected number of iterations of the loop. */
+ bool any_estimate;
+ double_int nb_iterations_estimate;
- /* Number of edges that exit the loop. */
- int num_exits;
+ /* Upper bound on number of iterations of a loop. */
+ struct nb_iter_bound *bounds;
- /* Bitmap of blocks that dominate all exits of the loop. */
- sbitmap exits_doms;
+ /* Head of the cyclic list of the exits of the loop. */
+ struct loop_exit *exits;
+};
- /* The loop nesting depth. */
- int depth;
+/* Flags for state of loop structure. */
+enum
+{
+ LOOPS_HAVE_PREHEADERS = 1,
+ LOOPS_HAVE_SIMPLE_LATCHES = 2,
+ LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4,
+ LOOPS_HAVE_RECORDED_EXITS = 8,
+ LOOPS_MAY_HAVE_MULTIPLE_LATCHES = 16,
+ LOOP_CLOSED_SSA = 32,
+ LOOPS_NEED_FIXUP = 64
+};
- /* Superloops of the loop. */
- struct loop **pred;
+#define LOOPS_NORMAL (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES \
+ | LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
+#define AVOID_CFG_MODIFICATIONS (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)
- /* The height of the loop (enclosed loop levels) within the loop
- hierarchy tree. */
- int level;
+/* Structure to hold CFG information about natural loops within a function. */
+struct loops GTY (())
+{
+ /* State of loops. */
+ int state;
- /* The outer (parent) loop or NULL if outermost loop. */
- struct loop *outer;
+ /* Array of the loops. */
+ VEC (loop_p, gc) *larray;
- /* The first inner (child) loop or NULL if innermost loop. */
- struct loop *inner;
+ /* Maps edges to the list of their descriptions as loop exits. Edges
+ whose sources or destinations have loop_father == NULL (which may
+ happen during the cfg manipulations) should not appear in EXITS. */
+ htab_t GTY((param_is (struct loop_exit))) exits;
- /* Link to the next (sibling) loop. */
- struct loop *next;
+ /* Pointer to root of loop hierarchy tree. */
+ struct loop *tree_root;
+};
- /* Loop that is copy of this loop. */
- struct loop *copy;
+/* Loop recognition. */
+extern int flow_loops_find (struct loops *);
+extern void disambiguate_loops_with_multiple_latches (void);
+extern void flow_loops_free (struct loops *);
+extern void flow_loops_dump (FILE *,
+ void (*)(const struct loop *, FILE *, int), int);
+extern void flow_loop_dump (const struct loop *, FILE *,
+ void (*)(const struct loop *, FILE *, int), int);
+struct loop *alloc_loop (void);
+extern void flow_loop_free (struct loop *);
+int flow_loop_nodes_find (basic_block, struct loop *);
+void fix_loop_structure (bitmap changed_bbs);
+void mark_irreducible_loops (void);
+void release_recorded_exits (void);
+void record_loop_exits (void);
+void rescan_loop_exit (edge, bool, bool);
+
+/* Loop data structure manipulation/querying. */
+extern void flow_loop_tree_node_add (struct loop *, struct loop *);
+extern void flow_loop_tree_node_remove (struct loop *);
+extern void add_loop (struct loop *, struct loop *);
+extern bool flow_loop_nested_p (const struct loop *, const struct loop *);
+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);
+struct eni_weights_d;
+extern unsigned tree_num_loop_insns (struct loop *, struct eni_weights_d *);
+extern int num_loop_insns (const struct loop *);
+extern int average_num_loop_insns (const struct loop *);
+extern unsigned get_loop_level (const struct loop *);
+extern bool loop_exit_edge_p (const struct loop *, const_edge);
+extern void mark_loop_exit_edges (void);
- /* Non-zero if the loop is invalid (e.g., contains setjmp.). */
- int invalid;
+/* Loops & cfg manipulation. */
+extern basic_block *get_loop_body (const struct loop *);
+extern unsigned get_loop_body_with_size (const struct loop *, basic_block *,
+ unsigned);
+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 VEC (edge, heap) *get_loop_exit_edges (const struct loop *);
+edge single_exit (const struct loop *);
+extern unsigned num_loop_branches (const struct loop *);
- /* Auxiliary info specific to a pass. */
- void *aux;
+extern edge loop_preheader_edge (const struct loop *);
+extern edge loop_latch_edge (const struct loop *);
- /* The following are currently used by loop.c but they are likely to
- disappear as loop.c is converted to use the CFG. */
+extern void add_bb_to_loop (basic_block, struct loop *);
+extern void remove_bb_from_loops (basic_block);
- /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP. */
- rtx vtop;
+extern void cancel_loop_tree (struct loop *);
+extern void delete_loop (struct loop *);
- /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
- A continue statement will generate a branch to NEXT_INSN (cont). */
- rtx cont;
+enum
+{
+ CP_SIMPLE_PREHEADERS = 1
+};
- /* The dominator of cont. */
- rtx cont_dominator;
+basic_block create_preheader (struct loop *, int);
+extern void create_preheaders (int);
+extern void force_single_succ_latches (void);
- /* The NOTE_INSN_LOOP_BEG. */
- rtx start;
+extern void verify_loop_structure (void);
- /* The NOTE_INSN_LOOP_END. */
- rtx end;
+/* Loop analysis. */
+extern bool just_once_each_iteration_p (const struct loop *, const_basic_block);
+gcov_type expected_loop_iterations_unbounded (const struct loop *);
+extern unsigned expected_loop_iterations (const struct loop *);
+extern rtx doloop_condition_get (rtx);
- /* For a rotated loop that is entered near the bottom,
- this is the label at the top. Otherwise it is zero. */
- rtx top;
+void estimate_numbers_of_iterations_loop (struct loop *);
+HOST_WIDE_INT estimated_loop_iterations_int (struct loop *, bool);
+bool estimated_loop_iterations (struct loop *, bool, double_int *);
- /* Place in the loop where control enters. */
- rtx scan_start;
+/* Loop manipulation. */
+extern bool can_duplicate_loop_p (const struct loop *loop);
- /* The position where to sink insns out of the loop. */
- rtx sink;
+#define DLTHE_FLAG_UPDATE_FREQ 1 /* Update frequencies in
+ duplicate_loop_to_header_edge. */
+#define DLTHE_RECORD_COPY_NUMBER 2 /* Record copy number in the aux
+ field of newly create BB. */
+#define DLTHE_FLAG_COMPLETTE_PEEL 4 /* Update frequencies expecting
+ a complete peeling. */
- /* List of all LABEL_REFs which refer to code labels outside the
- loop. Used by routines that need to know all loop exits, such as
- final_biv_value and final_giv_value.
+extern struct loop * duplicate_loop (struct loop *, struct loop *);
+extern bool duplicate_loop_to_header_edge (struct loop *, edge,
+ unsigned, sbitmap, edge,
+ VEC (edge, heap) **, int);
+extern struct loop *loopify (edge, edge,
+ basic_block, edge, edge, bool,
+ unsigned, unsigned);
+struct loop * loop_version (struct loop *, void *,
+ basic_block *, unsigned, unsigned, unsigned, bool);
+extern bool remove_path (edge);
+void scale_loop_frequencies (struct loop *, int, int);
- This does not include loop exits due to return instructions.
- This is because all bivs and givs are pseudos, and hence must be
- dead after a return, so the presence of a return does not affect
- any of the optimizations that use this info. It is simpler to
- just not include return instructions on this list. */
- rtx exit_labels;
+/* Induction variable analysis. */
- /* The number of LABEL_REFs on exit_labels for this loop and all
- loops nested inside it. */
- int exit_count;
-};
+/* The description of induction variable. The things are a bit complicated
+ due to need to handle subregs and extends. The value of the object described
+ by it can be obtained as follows (all computations are done in extend_mode):
-/* Flags for state of loop structure. */
-enum
+ Value in i-th iteration is
+ delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)).
+
+ If first_special is true, the value in the first iteration is
+ delta + mult * base
+
+ 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.
+
+ ??? Add a third mode field that would specify the mode in that inner
+ computation is done, which would enable it to be different from the
+ outer one? */
+
+struct rtx_iv
{
- LOOPS_HAVE_PREHEADERS = 1,
- LOOPS_HAVE_SIMPLE_LATCHES = 2,
- LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4
+ /* Its base and step (mode of base and step is supposed to be extend_mode,
+ see the description above). */
+ rtx base, step;
+
+ /* The type of extend applied to it (SIGN_EXTEND, ZERO_EXTEND or UNKNOWN). */
+ enum rtx_code extend;
+
+ /* Operations applied in the extended mode. */
+ rtx delta, mult;
+
+ /* The mode it is extended to. */
+ enum machine_mode extend_mode;
+
+ /* The mode the variable iterates in. */
+ enum machine_mode mode;
+
+ /* Whether the first iteration needs to be handled specially. */
+ unsigned first_special : 1;
};
-/* Structure to hold CFG information about natural loops within a function. */
-struct loops
+/* The description of an exit from the loop and of the number of iterations
+ till we take the exit. */
+
+struct niter_desc
{
- /* Number of natural loops in the function. */
- unsigned num;
+ /* The edge out of the loop. */
+ edge out_edge;
- /* Maximum nested loop level in the function. */
- unsigned levels;
+ /* The other edge leading from the condition. */
+ edge in_edge;
- /* Array of natural loop descriptors (scanning this array in reverse order
- will find the inner loops before their enclosing outer loops). */
- struct loop *array;
+ /* True if we are able to say anything about number of iterations of the
+ loop. */
+ bool simple_p;
- /* 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. */
- struct loop **parray;
+ /* True if the loop iterates the constant number of times. */
+ bool const_iter;
- /* Pointer to root of loop hierarchy tree. */
- struct loop *tree_root;
+ /* Number of iterations if constant. */
+ unsigned HOST_WIDEST_INT niter;
- /* Information derived from the CFG. */
- struct cfg
- {
- /* The bitmap vector of dominators or NULL if not computed. */
- dominance_info dom;
+ /* Upper bound on the number of iterations. */
+ unsigned HOST_WIDEST_INT niter_max;
- /* The ordering of the basic blocks in a depth first search. */
- int *dfs_order;
+ /* Assumptions under that the rest of the information is valid. */
+ rtx assumptions;
- /* The reverse completion ordering of the basic blocks found in a
- depth first search. */
- int *rc_order;
- } cfg;
+ /* Assumptions under that the loop ends before reaching the latch,
+ even if value of niter_expr says otherwise. */
+ rtx noloop_assumptions;
- /* Headers shared by multiple loops that should be merged. */
- sbitmap shared_headers;
+ /* Condition under that the loop is infinite. */
+ rtx infinite;
- /* State of loops. */
- int state;
+ /* Whether the comparison is signed. */
+ bool signed_p;
+
+ /* The mode in that niter_expr should be computed. */
+ enum machine_mode mode;
+
+ /* The number of iterations of the loop. */
+ rtx niter_expr;
};
-/* Flags for loop discovery. */
+extern void iv_analysis_loop_init (struct loop *);
+extern bool iv_analyze (rtx, rtx, struct rtx_iv *);
+extern bool iv_analyze_result (rtx, rtx, struct rtx_iv *);
+extern bool iv_analyze_expr (rtx, rtx, enum machine_mode, 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_analysis_done (void);
-#define LOOP_TREE 1 /* Build loop hierarchy tree. */
-#define LOOP_PRE_HEADER 2 /* Analyze loop preheader. */
-#define LOOP_ENTRY_EDGES 4 /* Find entry edges. */
-#define LOOP_EXIT_EDGES 8 /* Find exit edges. */
-#define LOOP_EDGES (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
-#define LOOP_ALL 15 /* All of the above */
+extern struct niter_desc *get_simple_loop_desc (struct loop *loop);
+extern void free_simple_loop_desc (struct loop *loop);
-/* Loop recognition. */
-extern int flow_loops_find PARAMS ((struct loops *, int flags));
-extern int flow_loops_update PARAMS ((struct loops *, int flags));
-extern void flow_loops_free PARAMS ((struct loops *));
-extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
- void (*)(const struct loop *,
- FILE *, int), int));
-extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
- void (*)(const struct loop *,
- FILE *, int), int));
-extern int flow_loop_scan PARAMS ((struct loops *,
- struct loop *, int));
-void mark_irreducible_loops PARAMS ((struct loops *));
-
-/* Loop datastructure manipulation/querying. */
-extern void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *));
-extern void flow_loop_tree_node_remove PARAMS ((struct loop *));
-extern bool flow_loop_outside_edge_p PARAMS ((const struct loop *, edge));
-extern bool flow_loop_nested_p PARAMS ((const struct loop *,
- const struct loop *));
-extern bool flow_bb_inside_loop_p PARAMS ((const struct loop *,
- const basic_block));
-extern struct loop * find_common_loop PARAMS ((struct loop *, struct loop *));
-extern int num_loop_insns PARAMS ((struct loop *));
-extern int average_num_loop_insns PARAMS ((struct loop *));
+static inline struct niter_desc *
+simple_loop_desc (struct loop *loop)
+{
+ return (struct niter_desc *) loop->aux;
+}
-/* Loops & cfg manipulation. */
-extern basic_block *get_loop_body PARAMS ((const struct loop *));
+/* Accessors for the loop structures. */
-extern edge loop_preheader_edge PARAMS ((const struct loop *));
-extern edge loop_latch_edge PARAMS ((const struct loop *));
+/* Returns the loop with index NUM from current_loops. */
-extern void add_bb_to_loop PARAMS ((basic_block, struct loop *));
-extern void remove_bb_from_loops PARAMS ((basic_block));
+static inline struct loop *
+get_loop (unsigned num)
+{
+ return VEC_index (loop_p, current_loops->larray, num);
+}
-extern void cancel_loop PARAMS ((struct loops *, struct loop *));
-extern void cancel_loop_tree PARAMS ((struct loops *, struct loop *));
+/* Returns the number of superloops of LOOP. */
-extern basic_block loop_split_edge_with PARAMS ((edge, rtx, struct loops *));
-extern int fix_loop_placement PARAMS ((struct loop *));
+static inline unsigned
+loop_depth (const struct loop *loop)
+{
+ return VEC_length (loop_p, loop->superloops);
+}
-enum
+/* Returns the immediate superloop of LOOP, or NULL if LOOP is the outermost
+ loop. */
+
+static inline struct loop *
+loop_outer (const struct loop *loop)
{
- CP_SIMPLE_PREHEADERS = 1,
- CP_INSIDE_CFGLAYOUT = 2
-};
+ unsigned n = VEC_length (loop_p, loop->superloops);
-extern void create_preheaders PARAMS ((struct loops *, int));
-extern void force_single_succ_latches PARAMS ((struct loops *));
+ if (n == 0)
+ return NULL;
-extern void verify_loop_structure PARAMS ((struct loops *));
+ return VEC_index (loop_p, loop->superloops, n - 1);
+}
-/* Loop analysis. */
-extern bool simple_loop_p PARAMS ((struct loops *, struct loop *,
- struct loop_desc *));
-extern rtx count_loop_iterations PARAMS ((struct loop_desc *, rtx, rtx));
-extern bool just_once_each_iteration_p PARAMS ((struct loops *,struct loop *,
- basic_block));
-extern unsigned expected_loop_iterations PARAMS ((const struct loop *));
+/* Returns the list of loops in current_loops. */
-/* Loop manipulation. */
-extern bool can_duplicate_loop_p PARAMS ((struct loop *loop));
+static inline VEC (loop_p, gc) *
+get_loops (void)
+{
+ if (!current_loops)
+ return NULL;
-#define DLTHE_FLAG_UPDATE_FREQ 1 /* Update frequencies in
- duplicate_loop_to_header_edge. */
+ return current_loops->larray;
+}
+
+/* Returns the number of loops in current_loops (including the removed
+ ones and the fake loop that forms the root of the loop tree). */
+
+static inline unsigned
+number_of_loops (void)
+{
+ if (!current_loops)
+ return 0;
+
+ return VEC_length (loop_p, current_loops->larray);
+}
+
+/* Returns true if state of the loops satisfies all properties
+ described by FLAGS. */
+
+static inline bool
+loops_state_satisfies_p (unsigned flags)
+{
+ return (current_loops->state & flags) == flags;
+}
+
+/* Sets FLAGS to the loops state. */
+
+static inline void
+loops_state_set (unsigned flags)
+{
+ current_loops->state |= flags;
+}
+
+/* Clears FLAGS from the loops state. */
+
+static inline void
+loops_state_clear (unsigned flags)
+{
+ if (!current_loops)
+ return;
+ current_loops->state &= ~flags;
+}
+
+/* Loop iterators. */
-extern int duplicate_loop_to_header_edge PARAMS ((struct loop *, edge,
- struct loops *, unsigned,
- sbitmap, edge, edge *,
- unsigned *, int));
-extern struct loop *loopify PARAMS ((struct loops *, edge,
- edge, basic_block));
-extern bool remove_path PARAMS ((struct loops *, edge));
-extern edge split_loop_bb PARAMS ((struct loops *, basic_block,
- rtx));
+/* Flags for loop iteration. */
+
+enum li_flags
+{
+ LI_INCLUDE_ROOT = 1, /* Include the fake root of the loop tree. */
+ LI_FROM_INNERMOST = 2, /* Iterate over the loops in the reverse order,
+ starting from innermost ones. */
+ LI_ONLY_INNERMOST = 4 /* Iterate only over innermost loops. */
+};
+
+/* The iterator for loops. */
+
+typedef struct
+{
+ /* The list of loops to visit. */
+ VEC(int,heap) *to_visit;
+
+ /* The index of the actual loop. */
+ unsigned idx;
+} loop_iterator;
+
+static inline void
+fel_next (loop_iterator *li, loop_p *loop)
+{
+ int anum;
+
+ while (VEC_iterate (int, li->to_visit, li->idx, anum))
+ {
+ li->idx++;
+ *loop = get_loop (anum);
+ if (*loop)
+ return;
+ }
+
+ VEC_free (int, heap, li->to_visit);
+ *loop = NULL;
+}
+
+static inline void
+fel_init (loop_iterator *li, loop_p *loop, unsigned flags)
+{
+ struct loop *aloop;
+ unsigned i;
+ int mn;
+
+ li->idx = 0;
+ if (!current_loops)
+ {
+ li->to_visit = NULL;
+ *loop = NULL;
+ return;
+ }
+
+ li->to_visit = VEC_alloc (int, heap, number_of_loops ());
+ mn = (flags & LI_INCLUDE_ROOT) ? 0 : 1;
+
+ if (flags & LI_ONLY_INNERMOST)
+ {
+ for (i = 0; VEC_iterate (loop_p, current_loops->larray, i, aloop); i++)
+ if (aloop != NULL
+ && aloop->inner == NULL
+ && aloop->num >= mn)
+ VEC_quick_push (int, li->to_visit, aloop->num);
+ }
+ else if (flags & LI_FROM_INNERMOST)
+ {
+ /* Push the loops to LI->TO_VISIT in postorder. */
+ for (aloop = current_loops->tree_root;
+ aloop->inner != NULL;
+ aloop = aloop->inner)
+ continue;
+
+ while (1)
+ {
+ if (aloop->num >= mn)
+ VEC_quick_push (int, li->to_visit, aloop->num);
+
+ if (aloop->next)
+ {
+ for (aloop = aloop->next;
+ aloop->inner != NULL;
+ aloop = aloop->inner)
+ continue;
+ }
+ else if (!loop_outer (aloop))
+ break;
+ else
+ aloop = loop_outer (aloop);
+ }
+ }
+ else
+ {
+ /* Push the loops to LI->TO_VISIT in preorder. */
+ aloop = current_loops->tree_root;
+ while (1)
+ {
+ if (aloop->num >= mn)
+ VEC_quick_push (int, li->to_visit, aloop->num);
+
+ if (aloop->inner != NULL)
+ aloop = aloop->inner;
+ else
+ {
+ while (aloop != NULL && aloop->next == NULL)
+ aloop = loop_outer (aloop);
+ if (aloop == NULL)
+ break;
+ aloop = aloop->next;
+ }
+ }
+ }
+
+ fel_next (li, loop);
+}
+
+#define FOR_EACH_LOOP(LI, LOOP, FLAGS) \
+ for (fel_init (&(LI), &(LOOP), FLAGS); \
+ (LOOP); \
+ fel_next (&(LI), &(LOOP)))
+
+#define FOR_EACH_LOOP_BREAK(LI) \
+ { \
+ VEC_free (int, heap, (LI)->to_visit); \
+ break; \
+ }
+
+/* The properties of the target. */
+
+extern unsigned target_avail_regs;
+extern unsigned target_res_regs;
+extern unsigned target_reg_cost;
+extern unsigned target_spill_cost;
+
+/* Register pressure estimation for induction variable optimizations & loop
+ invariant motion. */
+extern unsigned estimate_reg_pressure_cost (unsigned, unsigned);
+extern void init_set_costs (void);
/* Loop optimizer initialization. */
-extern struct loops *loop_optimizer_init PARAMS ((FILE *));
-extern void loop_optimizer_finalize PARAMS ((struct loops *, FILE *));
+extern void loop_optimizer_init (unsigned);
+extern void loop_optimizer_finalize (void);
/* Optimization passes. */
-extern void unswitch_loops PARAMS ((struct loops *));
+extern void unswitch_loops (void);
+
+enum
+{
+ UAP_PEEL = 1, /* Enables loop peeling. */
+ UAP_UNROLL = 2, /* Enables unrolling of loops if it seems profitable. */
+ UAP_UNROLL_ALL = 4 /* Enables unrolling of all loops. */
+};
+
+extern void unroll_and_peel_loops (int);
+extern void doloop_optimize_loops (void);
+extern void move_loop_invariants (void);
+#endif /* GCC_CFGLOOP_H */
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