loop.c (loop_giv_reduce_benefit): Break out from strength_reduce.

	* loop.c (loop_giv_reduce_benefit): Break out from strength_reduce.
	(loop_givs_dead_check, loop_givs_reduce, loop_givs_rescan): Likewise.
	(prescan_loop): Set pre_header_has_call in loop_info.
	* loop.h (struct_iv_class): Add `final_value' and `all_reduced'.
	(struct loop_info): Add `pre_header_has_call'.

From-SVN: r38578

gcc/ChangeLog

 2001-01-01  Michael Hayes  <mhayes@redhat.com>
 
+	* loop.c (loop_giv_reduce_benefit): Break out from strength_reduce.
+	(loop_givs_dead_check, loop_givs_reduce, loop_givs_rescan): Likewise.
+	(prescan_loop): Set pre_header_has_call in loop_info.
+	* loop.h (struct_iv_class): Add `final_value' and `all_reduced'.
+	(struct loop_info): Add `pre_header_has_call'.
+	
+2001-01-01  Michael Hayes  <mhayes@redhat.com>
+
 	* loop.c (loop_bivs_find): Break out from strength_reduce.
 	(loop_bivs_init_find, loop_bivs_check, loop_givs_find): Likewise.
 	(loop_givs_check, loop_biv_eliminable_p): Likewise.

gcc/loop.h

@@ -164,17 +164,22 @@ struct iv_class
 				   check_dbra_loop.  */
   struct induction *giv;	/* List of all insns that compute a giv
 				   from this reg.  */
-  int total_benefit;		/* Sum of BENEFITs of all those givs */
-  rtx initial_value;		/* Value of reg at loop start */
-  rtx initial_test;		/* Test performed on BIV before loop */
-  struct iv_class *next;	/* Links all class structures together */
+  int total_benefit;		/* Sum of BENEFITs of all those givs.  */
+  rtx initial_value;		/* Value of reg at loop start.  */
+  rtx initial_test;		/* Test performed on BIV before loop.  */
+  rtx final_value;		/* Value of reg at loop end, if known.  */
+  struct iv_class *next;	/* Links all class structures together.  */
   rtx init_insn;		/* insn which initializes biv, 0 if none.  */
   rtx init_set;			/* SET of INIT_INSN, if any.  */
   unsigned incremented : 1;	/* 1 if somewhere incremented/decremented */
-  unsigned eliminable : 1;	/* 1 if plausible candidate for elimination.  */
-  unsigned nonneg : 1;		/* 1 if we added a REG_NONNEG note for this.  */
+  unsigned eliminable : 1;	/* 1 if plausible candidate for
+                                   elimination.  */
+  unsigned nonneg : 1;		/* 1 if we added a REG_NONNEG note for
+                                   this.  */
   unsigned reversed : 1;	/* 1 if we reversed the loop that this
 				   biv controls.  */
+  unsigned all_reduced : 1;	/* 1 if all givs using this biv have
+                                   been reduced. */
 };
 
 typedef struct loop_mem_info
@@ -333,6 +338,8 @@ struct loop_info
   struct loop_regs regs;
   /* The induction variable information in loop.  */
   struct loop_ivs ivs;
+  /* Non-zero if call is in pre_header extended basic block.  */
+  int pre_header_has_call;
 };
 
 /* Definitions used by the basic induction variable discovery code.  */