loop.c (this_loop_info): New variable.

        * loop.c (this_loop_info): New variable.
        (loop_has_call, loop_has_volatile, loop_has_tablejump,
        loop_continue, loops_enclosed): Replace with fields in this_loop_info.
        All uses updated.
        (prescan_loop, strength_reduce): New argument loop_info.  All callers
        updated.
        (scan_loop): New variable loop_info, initialise to address of
        this_loop_info.
        (prescan_loop): Set loop_info->vtop if find NOTE_INSN_LOOP_VTOP.
        Delete variable loop_has_multiple_exit targets and replace with
        field in this_loop_info.
        (find_and_verify_loops): Rename this_loop to this_loop_num.
        (strength_reduce): Delete loop_iteration_info.  Replace variable
        loop_info with function argument of same name.
        (insert_bct): Rework test for loop being completely unrolled.

        * loop.h (struct loop_info): New fields num, loops_enclosed,
        has_call, has_volatile, has_tablejump, has_multiple_exit_targets,
        has_indirect_jump, and cont.  Redefine use of unroll_number.
        (loop_unroll_number): Delete.

        * unroll.c (unroll_loop): Store loop unroll count in unroll_number
        field of loop_info.
        (loop_iterations): Delete variable vtop and instead use
        loop_info->vtop computed in prescan_loop.

From-SVN: r28961

gcc/ChangeLog

+1999-08-29  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
+
+	* loop.c (this_loop_info): New variable.
+	(loop_has_call, loop_has_volatile, loop_has_tablejump,
+	loop_continue, loops_enclosed): Replace with fields in this_loop_info.
+	All uses updated.
+	(prescan_loop, strength_reduce): New argument loop_info.  All callers
+	updated.
+	(scan_loop): New variable loop_info, initialise to address of
+	this_loop_info.
+	(prescan_loop): Set loop_info->vtop if find NOTE_INSN_LOOP_VTOP.
+	Delete variable loop_has_multiple_exit targets and replace with
+	field in this_loop_info.
+	(find_and_verify_loops): Rename this_loop to this_loop_num.
+	(strength_reduce): Delete loop_iteration_info.  Replace variable
+	loop_info with function argument of same name.
+	(insert_bct): Rework test for loop being completely unrolled.
+
+	* loop.h (struct loop_info): New fields num, loops_enclosed,
+	has_call, has_volatile, has_tablejump, has_multiple_exit_targets,
+	has_indirect_jump, and cont.  Redefine use of unroll_number.
+	(loop_unroll_number): Delete.
+
+	* unroll.c (unroll_loop): Store loop unroll count in unroll_number
+	field of loop_info.
+	(loop_iterations): Delete variable vtop and instead use
+	loop_info->vtop computed in prescan_loop.
+
 Sun Aug 29 03:27:23 1999  Scott Weikart <scott@igc.apc.org>
 
 	* fix-header.c (main): Do not pass a null pointer to strcmp.

gcc/loop.h

@@ -158,6 +158,22 @@ struct iv_class {
 
 struct loop_info
 {
+  /* Loop number.  */
+  int num;
+  /* Loops enclosed by this loop including itself.  */
+  int loops_enclosed;
+  /* Nonzero if there is a subroutine call in the current loop.  */
+  int has_call;
+  /* Nonzero if there is a volatile memory reference in the current
+     loop.  */
+  int has_volatile;
+  /* Nonzero if there is a tablejump in the current loop.  */
+  int has_tablejump;
+  /* Nonzero if there are ways to leave the loop other than falling
+     off the end.  */
+  int has_multiple_exit_targets;
+  /* Nonzero if there is an indirect jump in the current function.  */
+  int has_indirect_jump;
   /* Register or constant initial loop value.  */
   rtx initial_value;
   /* Register or constant value used for comparison test.  */
@@ -181,15 +197,13 @@ struct loop_info
      wider iterator, this number will be zero if the number of loop
      iterations is too large for an unsigned integer to hold.  */
   unsigned HOST_WIDE_INT n_iterations;
-  /* The loop unrolling factor.
-     Potential values:
-     0: unrolled
-     1: not unrolled.
-     -1: completely unrolled
-     >0: holds the unroll exact factor.  */
+  /* The number of times the loop body was unrolled.  */
   unsigned int unroll_number;
   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
   rtx vtop;
+  /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
+     A continue statement will generate a branch to NEXT_INSN (cont).  */
+  rtx cont;
 };
 
 /* Definitions used by the basic induction variable discovery code.  */
@@ -240,10 +254,10 @@ rtx final_giv_value PROTO((struct induction *, rtx, rtx,
 			   unsigned HOST_WIDE_INT));
 void emit_unrolled_add PROTO((rtx, rtx, rtx));
 int back_branch_in_range_p PROTO((rtx, rtx, rtx));
-int loop_insn_first_p PROTO((rtx, rtx));
 
-extern int *loop_unroll_number;
+int loop_insn_first_p PROTO((rtx, rtx));
 
 /* Forward declarations for non-static functions declared in stmt.c.  */
 void find_loop_tree_blocks PROTO((void));
 void unroll_block_trees PROTO((void));
+

gcc/unroll.c

@@ -1117,11 +1117,7 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
   /* At this point, we are guaranteed to unroll the loop.  */
 
   /* Keep track of the unroll factor for the loop.  */
-  if (unroll_type == UNROLL_COMPLETELY)
-    loop_info->unroll_number = -1;
-  else
-    loop_info->unroll_number = unroll_number;
-
+  loop_info->unroll_number = unroll_number;
 
   /* For each biv and giv, determine whether it can be safely split into
      a different variable for each unrolled copy of the loop body.
@@ -3500,7 +3496,6 @@ loop_find_equiv_value (loop_start, reg)
   return ret;
 }
 
-
 /* Return a simplified rtx for the expression OP - REG.
 
    REG must appear in OP, and OP must be a register or the sum of a register
@@ -3566,7 +3561,6 @@ find_common_reg_term (op0, op1)
   return NULL_RTX;
 }
 
-
 /* Calculate the number of loop iterations.  Returns the exact number of loop
    iterations if it can be calculated, otherwise returns zero.  */
 
@@ -3584,7 +3578,6 @@ loop_iterations (loop_start, loop_end, loop_info)
   int increment_dir;
   int unsigned_p, compare_dir, final_larger;
   rtx last_loop_insn;
-  rtx vtop;
   rtx reg_term;
 
   loop_info->n_iterations = 0;
@@ -3596,7 +3589,6 @@ loop_iterations (loop_start, loop_end, loop_info)
   loop_info->increment = 0;
   loop_info->iteration_var = 0;
   loop_info->unroll_number = 1;
-  loop_info->vtop = 0;
 
   /* We used to use prev_nonnote_insn here, but that fails because it might
      accidentally get the branch for a contained loop if the branch for this
@@ -3645,25 +3637,6 @@ loop_iterations (loop_start, loop_end, loop_info)
   iteration_var = XEXP (comparison, 0);
   comparison_value = XEXP (comparison, 1);
 
-  /* Check if there is a NOTE_INSN_LOOP_VTOP note.  If there is,
-     that means that this is a for or while style loop, with
-     a loop exit test at the start.  Thus, we can assume that
-     the loop condition was true when the loop was entered.
-
-     We start at the end and search backwards for the previous
-     NOTE.  If there is no NOTE_INSN_LOOP_VTOP for this loop,
-     the search will stop at the NOTE_INSN_LOOP_CONT.  */
-  vtop = loop_end;
-  do
-    vtop = PREV_INSN (vtop);
-  while (GET_CODE (vtop) != NOTE
-	 || NOTE_LINE_NUMBER (vtop) > 0
-	 || NOTE_LINE_NUMBER (vtop) == NOTE_REPEATED_LINE_NUMBER
-	 || NOTE_LINE_NUMBER (vtop) == NOTE_INSN_DELETED);
-  if (NOTE_LINE_NUMBER (vtop) != NOTE_INSN_LOOP_VTOP)
-    vtop = NULL_RTX;
-  loop_info->vtop = vtop;
-
   if (GET_CODE (iteration_var) != REG)
     {
       if (loop_dump_stream)