regmove.c (perhaps_ends_bb_p): Use can_throw_internal to reduce false positives.

        * regmove.c (perhaps_ends_bb_p): Use can_throw_internal to
        reduce false positives.
        (regmove_optimize): Disable if flag_non_call_exceptions.

From-SVN: r40917

gcc/ChangeLog

 2001-03-27  Richard Henderson  <rth@redhat.com>
 
+	* regmove.c (perhaps_ends_bb_p): Use can_throw_internal to
+	reduce false positives.
+	(regmove_optimize): Disable if flag_non_call_exceptions.
+
 	* stmt.c (expand_return): Remove always true predicate.
 	(expand_decl_cleanup_no_eh): Remove dead code.
 

gcc/regmove.c

@@ -395,11 +395,11 @@ static int perhaps_ends_bb_p (insn)
       /* A CALL_INSN might be the last insn of a basic block, if it is inside
 	 an EH region or if there are nonlocal gotos.  Note that this test is
 	 very conservative.  */
-      return flag_exceptions || nonlocal_goto_handler_labels;
-
+      if (nonlocal_goto_handler_labels)
+	return 1;
+      /* FALLTHRU */
     default:
-      /* All others never end a basic block.  */
-      return 0;
+      return can_throw_internal (insn);
     }
 }
 
@@ -1062,6 +1062,11 @@ regmove_optimize (f, nregs, regmove_dump_file)
   int i;
   rtx copy_src, copy_dst;
 
+  /* ??? Hack.  Regmove doesn't examine the CFG, and gets mightily
+     confused by non-call exceptions ending blocks.  */
+  if (flag_non_call_exceptions)
+    return;
+
   /* Find out where a potential flags register is live, and so that we
      can supress some optimizations in those zones.  */
   mark_flags_life_zones (discover_flags_reg ());