flow.c (flow_nodes_print, [...]): New functions.

	* flow.c (flow_nodes_print, flow_loops_cfg_dump): New functions.
	(flow_loop_nested_p, flow_loops_dump, flow_loops_free): Likewise.
	(flow_loop_exits_find, flow_loop_nodes_find): Likewise.
	(flow_depth_first_order_compute, flow_loop_pre_header_find): Likewise.
	(flow_loop_tree_node_add, flow_loops_tree_build): Likewise.
	(flow_loop_level_compute, low_loops_level_compute): Likewise.
	(flow_loops_find, flow_loop_outside_edge_p): Likewise.
	* basic-block.h: Protect from multiple inclusion.
	(flow_loops_find, flow_loops_free, flow_loop_dump): Add protoypes.
	(struct loops, struct loop): Define structures.
	* sbitmap.c (sbitmap_a_subset_b_p): New function.
	* sbitmap.h: Protect from multiple inclusion.
	(sbitmap_a_subset_b_p): Add prototype.
	* Makefile.in (LOOP_H): New macro.
	(stmt.o, integrate.o, loop.o, unroll.o): Replace loop.h with LOOP_H.

From-SVN: r30720

gcc/ChangeLog

+1999-11-30  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
+
+	* flow.c (flow_nodes_print, flow_loops_cfg_dump): New functions.
+	(flow_loop_nested_p, flow_loops_dump, flow_loops_free): Likewise.
+	(flow_loop_exits_find, flow_loop_nodes_find): Likewise.
+	(flow_depth_first_order_compute, flow_loop_pre_header_find): Likewise.
+	(flow_loop_tree_node_add, flow_loops_tree_build): Likewise.
+	(flow_loop_level_compute, low_loops_level_compute): Likewise.
+	(flow_loops_find, flow_loop_outside_edge_p): Likewise.
+	* basic-block.h: Protect from multiple inclusion.
+	(flow_loops_find, flow_loops_free, flow_loop_dump): Add protoypes.
+	(struct loops, struct loop): Define structures.
+	* sbitmap.c (sbitmap_a_subset_b_p): New function.
+	* sbitmap.h: Protect from multiple inclusion.
+	(sbitmap_a_subset_b_p): Add prototype.
+	* Makefile.in (LOOP_H): New macro.
+	(stmt.o, integrate.o, loop.o, unroll.o): Replace loop.h with LOOP_H.
+
 Tue Nov 30 01:34:47 1999  Philippe De Muyter  <phdm@macqel.be>
 
 	* cppinit.c (CAT): The argument list of this macro may not contain

gcc/Makefile.in

@@ -748,6 +748,7 @@ DEMANGLE_H = $(srcdir)/../include/demangle.h
 RECOG_H = recog.h
 EXPR_H = expr.h insn-codes.h
 REGS_H = regs.h varray.h $(MACHMODE_H)
+LOOP_H = loop.h varray.h
 #
 # Language makefile fragments.
 
@@ -1484,7 +1485,7 @@ function.o : function.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h \
    insn-config.h $(RECOG_H) output.h toplev.h except.h hash.h ggc.h
 stmt.o : stmt.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h function.h  \
    insn-flags.h insn-config.h insn-codes.h hard-reg-set.h $(EXPR_H) except.h \
-   loop.h $(RECOG_H) toplev.h output.h varray.h ggc.h
+   $(LOOP_H) $(RECOG_H) toplev.h output.h varray.h ggc.h
 except.o : except.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h \
    function.h insn-flags.h $(EXPR_H) $(REGS_H) hard-reg-set.h \
    insn-config.h $(RECOG_H) output.h except.h toplev.h intl.h ggc.h
@@ -1527,7 +1528,7 @@ emit-rtl.o : emit-rtl.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h \
 real.o : real.c $(CONFIG_H) system.h $(TREE_H) toplev.h
 integrate.o : integrate.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h \
    integrate.h insn-flags.h insn-config.h $(EXPR_H) real.h $(REGS_H) \
-   intl.h function.h output.h $(RECOG_H) except.h toplev.h loop.h
+   intl.h function.h output.h $(RECOG_H) except.h toplev.h $(LOOP_H)
 jump.o : jump.c $(CONFIG_H) system.h $(RTL_H) flags.h hard-reg-set.h $(REGS_H) \
    insn-config.h insn-flags.h $(RECOG_H) $(EXPR_H) real.h except.h function.h \
    toplev.h insn-attr.h
@@ -1550,11 +1551,11 @@ lcm.o : lcm.c $(CONFIG_H) system.h $(RTL_H) $(REGS_H) hard-reg-set.h flags.h \
 profile.o : profile.c $(CONFIG_H) system.h $(RTL_H) flags.h insn-flags.h \
    gcov-io.h $(TREE_H) output.h $(REGS_H) toplev.h function.h insn-config.h \
    ggc.h
-loop.o : loop.c $(CONFIG_H) system.h $(RTL_H) flags.h loop.h insn-config.h \
+loop.o : loop.c $(CONFIG_H) system.h $(RTL_H) flags.h $(LOOP_H) insn-config.h \
    insn-flags.h $(REGS_H) hard-reg-set.h $(RECOG_H) $(EXPR_H) real.h \
    $(BASIC_BLOCK_H) function.h toplev.h varray.h except.h
 unroll.o : unroll.c $(CONFIG_H) system.h $(RTL_H) insn-config.h function.h \
-   integrate.h $(REGS_H) $(RECOG_H) flags.h $(EXPR_H) loop.h toplev.h varray.h
+   integrate.h $(REGS_H) $(RECOG_H) flags.h $(EXPR_H) $(LOOP_H) toplev.h varray.h
 flow.o : flow.c $(CONFIG_H) system.h $(RTL_H) $(TREE_H) flags.h insn-config.h \
    $(BASIC_BLOCK_H) $(REGS_H) hard-reg-set.h output.h toplev.h $(RECOG_H) \
    insn-flags.h function.h except.h

gcc/basic-block.h

@@ -18,6 +18,8 @@ along with GNU CC; see the file COPYING.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
+#ifndef _BASIC_BLOCK_H
+#define _BASIC_BLOCK_H 1
 
 #include "bitmap.h"
 #include "sbitmap.h"
@@ -222,6 +224,92 @@ extern void remove_fake_edges		PROTO ((void));
 extern void add_noreturn_fake_exit_edges	PROTO ((void));
 extern void flow_delete_insn_chain	PROTO((rtx, rtx));
 
+
+/* Structure to hold information for each natural loop.  */
+struct loop
+{
+  int num;
+
+  /* Basic block of loop header.  */
+  basic_block header;
+
+  /* Basic block of loop latch.  */
+  basic_block latch;
+
+  /* Basic block of loop pre-header or NULL if it does not exist.  */
+  basic_block pre_header;
+
+  /* Bitmap of blocks contained within the loop.  */
+  sbitmap nodes;
+
+  /* Number of blocks contained within the loop.  */
+  int num_nodes;
+
+  /* Array of edges that exit the loop.  */
+  edge *exits;
+
+  /* Number of edges that exit the loop.  */
+  int num_exits;
+
+  /* The loop nesting depth.  */
+  int depth;
+
+  /* The height of the loop (enclosed loop levels) within the loop
+     hierarchy tree.  */
+  int level;
+
+  /* The outer (parent) loop or NULL if outermost loop.  */
+  struct loop *outer;
+
+  /* The first inner (child) loop or NULL if innermost loop.  */
+  struct loop *inner;
+
+  /* Link to the next (sibling) loop.  */
+  struct loop *next;
+
+  /* Non-zero if the loop shares a header with another loop.  */
+  int shared;
+
+  /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
+  int invalid;
+
+  /* Auxiliary info specific to a pass.  */
+  void *info;
+};
+
+
+/* Structure to hold CFG information about natural loops within a function.  */
+struct loops
+{
+  /* Number of natural loops in the function.  */
+  int num;
+
+  /* Array of natural loop descriptors (scanning this array in reverse order
+     will find the inner loops before their enclosing outer loops).  */
+  struct loop *array;
+
+  /* Pointer to root of loop heirachy tree.  */
+  struct loop *tree;
+
+  /* Information derived from the CFG.  */
+  struct cfg
+  {
+    /* The bitmap vector of dominators or NULL if not computed.  */
+    sbitmap *dom;
+
+    /* The ordering of the basic blocks in a depth first search.  */
+    int *dfs_order;
+  } cfg;
+
+  /* Headers shared by multiple loops that should be merged.  */
+  sbitmap shared_headers;
+};
+
+extern int flow_loops_find PROTO ((struct loops *));
+extern void flow_loops_free PROTO ((struct loops *));
+extern void flow_loops_dump PROTO ((const struct loops *, FILE *, int));
+
+
 /* This structure maintains an edge list vector.  */
 struct edge_list 
 {
@@ -295,3 +383,5 @@ extern void compute_available		PROTO ((sbitmap *, sbitmap *,
 /* In emit-rtl.c.  */
 extern rtx emit_block_insn_after	PROTO((rtx, rtx, basic_block));
 extern rtx emit_block_insn_before	PROTO((rtx, rtx, basic_block));
+
+#endif /* _BASIC_BLOCK_H */

gcc/sbitmap.c

@@ -265,6 +265,25 @@ sbitmap_a_or_b (dst, a, b)
     }
   return changed;
 }
+/* Return non-zero if A is a subset of B.  */
+
+int
+sbitmap_a_subset_b_p (a, b)
+     sbitmap a, b;
+{
+  int i;
+  sbitmap_ptr ap, bp;
+
+  ap = a->elms;
+  bp = b->elms;
+  for (i = 0; i < a->size; i++)
+    {
+      if ((*ap | *bp) != *bp)
+	return 0;
+      ap++; bp++;
+    }
+  return 1;
+}
 
 /* Set DST to be (A or (B and C)).
    Return non-zero if any change is made.  */

gcc/sbitmap.h

@@ -18,6 +18,9 @@ along with GNU CC; see the file COPYING.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.  */
 
+#ifndef _SBITMAP_H
+#define _SBITMAP_H 1
+
 /* It's not clear yet whether using bitmap.[ch] will be a win.
    It should be straightforward to convert so for now we keep things simple
    while more important issues are dealt with.  */
@@ -109,6 +112,7 @@ extern int sbitmap_a_or_b_and_c PROTO ((sbitmap, sbitmap, sbitmap, sbitmap));
 extern int sbitmap_a_and_b_or_c PROTO ((sbitmap, sbitmap, sbitmap, sbitmap));
 extern int sbitmap_a_and_b PROTO ((sbitmap, sbitmap, sbitmap));
 extern int sbitmap_a_or_b PROTO ((sbitmap, sbitmap, sbitmap));
+extern int sbitmap_a_subset_b_p PROTO ((sbitmap, sbitmap));
 
 struct int_list;
 extern void sbitmap_intersect_of_predsucc PROTO ((sbitmap, sbitmap *,
@@ -129,3 +133,4 @@ extern void sbitmap_intersection_of_preds    PROTO ((sbitmap, sbitmap *, int));
 extern void sbitmap_union_of_succs	     PROTO ((sbitmap, sbitmap *, int));
 extern void sbitmap_union_of_preds	     PROTO ((sbitmap, sbitmap *, int));
 
+#endif /* _SBITMAP_H */