jump.c (squeeze_notes): Return true if no real insns were found.

* jump.c (squeeze_notes): Return true if no real insns were found.
	* rtl.h (squeeze_notes): Adjust prototype.
	* cfgcleanup.c (merge_blocks_move_predecessor_nojumps): If
	squeeze_notes finds no real instructions, abort.
	(merge_blocks_move_successor_nojumps): Likewise.
	* loop.c (find_and_verify_loops): Likewise.
	* stmt.c (expand_end_case): Likewise.
	* ifcvt.c (dead_or_predicable): Return TRUE if squeeze_notes doesn't
	find any real instructions.

	* gcc.c-torture/compile/20011114-4.c: New test.

From-SVN: r47048

gcc/ChangeLog

@@ -1,3 +1,15 @@
+2001-11-15  Jakub Jelinek  <jakub@redhat.com>
+
+	* jump.c (squeeze_notes): Return true if no real insns were found.
+	* rtl.h (squeeze_notes): Adjust prototype.
+	* cfgcleanup.c (merge_blocks_move_predecessor_nojumps): If
+	squeeze_notes finds no real instructions, abort.
+	(merge_blocks_move_successor_nojumps): Likewise.
+	* loop.c (find_and_verify_loops): Likewise.
+	* stmt.c (expand_end_case): Likewise.
+	* ifcvt.c (dead_or_predicable): Return TRUE if squeeze_notes doesn't
+	find any real instructions.
+
 2001-11-15  Neil Booth  <neil@daikokuya.demon.co.uk>
 
 	* c-common.c: Include c-lex.h.

gcc/cfgcleanup.c

@@ -329,7 +329,8 @@ merge_blocks_move_predecessor_nojumps (a, b)
      and adjust the block trees appropriately.   Even better would be to have
      a tighter connection between block trees and rtl so that this is not
      necessary.  */
-  squeeze_notes (&a->head, &a->end);
+  if (squeeze_notes (&a->head, &a->end))
+    abort ();
 
   /* Scramble the insn chain.  */
   if (a->end != PREV_INSN (b->head))
@@ -393,7 +394,8 @@ merge_blocks_move_successor_nojumps (a, b)
      and adjust the block trees appropriately.   Even better would be to have
      a tighter connection between block trees and rtl so that this is not
      necessary.  */
-  squeeze_notes (&b->head, &b->end);
+  if (squeeze_notes (&b->head, &b->end))
+    abort ();
 
   /* Scramble the insn chain.  */
   reorder_insns_nobb (b->head, b->end, a->end);

gcc/ifcvt.c

@@ -2659,7 +2659,8 @@ dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep)
       if (end == merge_bb->end)
 	merge_bb->end = PREV_INSN (head);
 
-      squeeze_notes (&head, &end);
+      if (squeeze_notes (&head, &end))
+	return TRUE;
 
       reorder_insns (head, end, PREV_INSN (earliest));
     }

gcc/jump.c

@@ -541,9 +541,10 @@ duplicate_loop_exit_test (loop_start)
 /* Move all block-beg, block-end, loop-beg, loop-cont, loop-vtop, loop-end,
    notes between START and END out before START.  START and END may be such
    notes.  Returns the values of the new starting and ending insns, which
-   may be different if the original ones were such notes.  */
+   may be different if the original ones were such notes.
+   Return true if there were only such notes and no real instructions.  */
 
-void
+bool
 squeeze_notes (startp, endp)
      rtx* startp;
      rtx* endp;
@@ -584,15 +585,15 @@ squeeze_notes (startp, endp)
 	last = insn;
     }
 
-  /* There were no real instructions, and we can't represent an empty
-     range.  Die.  */
+  /* There were no real instructions.  */
   if (start == past_end)
-    abort ();
+    return true;
 
   end = last;
 
   *startp = start;
   *endp = end;
+  return false;
 }
 
 /* Return the label before INSN, or put a new label there.  */

gcc/loop.c

@@ -2748,7 +2748,8 @@ find_and_verify_loops (f, loops)
 
 			/* Include the BARRIER after INSN and copy the
 			   block after LOC.  */
-			squeeze_notes (&new_label, &last_insn_to_move);
+			if (squeeze_notes (&new_label, &last_insn_to_move))
+			  abort ();
 			reorder_insns (new_label, last_insn_to_move, loc);
 
 			/* All those insns are now in TARGET_LOOP.  */

gcc/rtl.h

@@ -1340,7 +1340,7 @@ extern void mark_jump_label		PARAMS ((rtx, rtx, int));
 extern void cleanup_barriers		PARAMS ((void));
 
 /* In jump.c */
-extern void squeeze_notes		PARAMS ((rtx *, rtx *));
+extern bool squeeze_notes		PARAMS ((rtx *, rtx *));
 extern rtx delete_related_insns			PARAMS ((rtx));
 extern void delete_jump			PARAMS ((rtx));
 extern void delete_barrier		PARAMS ((rtx));

gcc/stmt.c

@@ -5598,7 +5598,8 @@ expand_end_case (orig_index)
 
       before_case = NEXT_INSN (before_case);
       end = get_last_insn ();
-      squeeze_notes (&before_case, &end);
+      if (squeeze_notes (&before_case, &end))
+	abort ();
       reorder_insns (before_case, end,
 		     thiscase->data.case_stmt.start);
     }

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2001-11-15  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.c-torture/compile/20011114-4.c: New test.
+
 2001-11-15  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* g++.dg/other/init1.C: New test.

gcc/testsuite/gcc.c-torture/compile/20011114-4.c

@@ -0,0 +1,38 @@
+static inline int foo (long x)
+{
+  register int a = 0;
+  register unsigned b;
+
+  do
+    {
+      b = (x & 0x7f);
+      x = (x >> 7) | ~(-1L >> 7);
+      a += 1;
+    }
+  while ((x != 0 || (b & 0x40) != 0) && (x != -1 || (b & 0x40) == 0));
+  return a;
+}
+
+static inline int bar (unsigned long x)
+{
+  register int a = 0;
+  register unsigned b;
+
+  do
+    {
+      b = (x & 0x7f);
+      x >>= 7;
+      a++;
+    }
+  while (x != 0);
+  return a;
+}
+
+int
+baz (unsigned long x, int y)
+{
+  if (y)
+    return foo ((long) x);
+  else
+    return bar (x);
+}