dce.c (find_call_stack_args, [...]): Fixed comments.

2009-01-15  Kenneth Zadeck <zadeck@naturalbridge.com>

	* dce.c (find_call_stack_args, delete_unmarked_insns): Fixed
	comments.

From-SVN: r143398

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index aeab680011ba311667c1dab8767828a2d730d1ea..bb99b6fbf47ddd4c82c9d50630ffcd65b4457970 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-01-15  Kenneth Zadeck <zadeck@naturalbridge.com>
+
+       * dce.c (find_call_stack_args, delete_unmarked_insns): Fixed
+       comments.
+       
 2009-01-14  Jakub Jelinek  <jakub@redhat.com>
 
        PR rtl-optimization/38245

diff --git a/gcc/dce.c b/gcc/dce.c
index 75e148cf434151d20bda20f5f69a8380789d8ad5..5a64fb2ecf831ab8dfa0e4423e257cf7e075184e 100644 (file)
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -358,7 +358,7 @@ find_call_stack_args (rtx call_insn, bool do_mark, bool fast,
       }
 
   /* Walk backwards, looking for argument stores.  The search stops
-     when seeting another call, sp adjustment or memory store other than
+     when seeing another call, sp adjustment or memory store other than
      argument store.  */
   ret = false;
   for (insn = PREV_INSN (call_insn); insn; insn = prev_insn)
@@ -522,9 +522,13 @@ delete_unmarked_insns (void)
          else if (marked_insn_p (insn))
            continue;
 
-         /* Beware that reaching a dbg counter limit here can easily result
-            in miscompiled file, whenever some insn is eliminated, but
-            insn that depends on it is not.  */
+         /* Beware that reaching a dbg counter limit here can rarely
+            result in miscompiled file.  This occurs when a group of
+            insns must be deleted together.  Currently this only
+            can happen on non-looping pure and constant calls
+            on machines where ACCUMULATE_OUTGOING_ARGS is true.  By
+            using the dbg_cnt, it is possible to remove the call, but
+            leave the argument pushes to the stack.  */
          if (!dbg_cnt (dce))
            continue;