basic-block.h (LOOP_TREE, [...]): New.

2000-09-12  Michael Hayes  <mhayes@cygnus.com>

	* basic-block.h (LOOP_TREE, LOOP_PRE_HEADER, LOOP_EDGES): New.
	(LOOP_EXITS_DOMS, LOOP_ALL): Likewise.
	(flow_loops_update): New prototype.
	(flow_loops_find): Add flags to prototype.
	(struct loop): Add `pre_header_root' and `pre_header_trace' fields.
	* flow.c (flow_loop_pre_header_scan): New.
	(flow_loop_dump): Dump pre-header root and trace and exit dominators.
	(flow_loop_free): Free pre-header root and trace and exit dominators.
	(flow_loops_find): New argument flags.
	(flow_loops_update): New function.
	* toplev.c (rest_of_compilation): Add flag argument to flow_loops_find.

From-SVN: r36333

gcc/ChangeLog

 2000-09-12  Michael Hayes  <mhayes@cygnus.com>
 
+	* basic-block.h (LOOP_TREE, LOOP_PRE_HEADER, LOOP_EDGES): New.
+	(LOOP_EXITS_DOMS, LOOP_ALL): Likewise.
+	(flow_loops_update): New prototype.
+	(flow_loops_find): Add flags to prototype.
+	(struct loop): Add `pre_header_root' and `pre_header_trace' fields.
+	* flow.c (flow_loop_pre_header_scan): New.
+	(flow_loop_dump): Dump pre-header root and trace and exit dominators.
+	(flow_loop_free): Free pre-header root and trace and exit dominators.
+	(flow_loops_find): New argument flags.
+	(flow_loops_update): New function.
+	* toplev.c (rest_of_compilation): Add flag argument to flow_loops_find.
+
+2000-09-12  Michael Hayes  <mhayes@cygnus.com>
+
 	* basic-block.h (split_block, update_bb_for_insn): New prototypes.
 	* flow.c (split_block, update_bb_for_insn): New functions.
 

gcc/basic-block.h

@@ -276,6 +276,12 @@ struct loop
   /* Basic block of loop pre-header or NULL if it does not exist.  */
   basic_block pre_header;
 
+  /* Root node of pre_header extended basic block.  */
+  basic_block pre_header_root;
+
+  /* Bitmap of blocks of trace from pre_header root to pre_header.  */
+  sbitmap pre_header_trace;
+
   /* The first block in the loop.  This is not necessarily the same as
      the loop header.  */
   basic_block first;
@@ -302,6 +308,9 @@ struct loop
   /* Number of edges that exit the loop.  */
   int num_exits;
 
+  /* Bitmap of blocks that dominate all exits of the loop.  */
+  sbitmap exits_doms;
+
   /* The loop nesting depth.  */
   int depth;
 
@@ -404,7 +413,8 @@ struct loops
   sbitmap shared_headers;
 };
 
-extern int flow_loops_find PARAMS ((struct loops *));
+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 *,
@@ -468,6 +478,15 @@ enum update_life_extent
 #define PROP_AUTOINC		32	/* Create autoinc mem references.  */
 #define PROP_FINAL		63	/* All of the above.  */
 
+
+/* Flags for loop discovery.  */
+
+#define LOOP_TREE		1 	/* Build loop hierarchy tree.  */
+#define LOOP_PRE_HEADER		2	/* Analyse loop pre-header.  */
+#define LOOP_EDGES		4 	/* Find entry and exit edges.  */
+#define LOOP_EXITS_DOMS		8 	/* Find nodes that dom. all exits.  */
+#define LOOP_ALL	       15 	/* All of the above  */
+
 extern void life_analysis	PARAMS ((rtx, FILE *, int));
 extern void update_life_info	PARAMS ((sbitmap, enum update_life_extent,
 					 int));

gcc/toplev.c

@@ -3211,7 +3211,7 @@ rest_of_compilation (decl)
 
       /* Discover and record the loop depth at the head of each basic
 	 block.  The loop infrastructure does the real job for us.  */
-      flow_loops_find (&loops);
+      flow_loops_find (&loops, LOOP_TREE);
 
       /* Estimate using heuristics if no profiling info is available.  */
       estimate_probability (&loops);