Re: RFC: SMS problem with emit_copy_of_insn_after copying REG_NOTEs

[Andrew Pinski]

> 
> Andrew Pinski <[EMAIL PROTECTED]> writes:
> 
> > > 
> > > > Hi,
> > > > thanks for testing.  I've bootstrapped/regtested this variant of patch
> > > > and comitted it as obvious.
> > > 
> > > Since this is an insn, we should not be copying it as it is just a link 
> > > to that
> > > insn.
> > > 
> > > Attached is a patch which fixes the ICE though I have not bootstrapped 
> > > and tested
> > > it yet.
> > 
> > Lets try to attach the patch this time.
> 
> It seems to me this code should just be 
> 
>   for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
>     if (REG_NOTE_KIND (link) != REG_LABEL)
>       {
>       if (GET_CODE (link) == EXPR_LIST)
>         REG_NOTES (new)
>               = gen_rtx_EXPR_LIST (REG_NOTE_KIND (link),
>                 copy_rtx (XEXP (link, 0)),  REG_NOTES (new));
>       else
>         REG_NOTES (new)
>              = gen_rtx_INSN_LIST (REG_NOTE_KIND (link),
>                copy_rtx (XEXP (link, 0)),  REG_NOTES (new));
>       }
> 
> What do we expect to find in a REG_NOTE that requires the machinery of
> copy_insn_1?  And calling copy_insn_1 without going through copy_insn
> looks very wrong.

Here is a better patch which also speeds up this code by fixing up
the libcall notes in that loop.

I tested it on the preprocessed source that Andreas sent me but
I don't have time to do a full bootstrap till tommorrow.

ChangeLog:

        * emit-rtl.c (emit_copy_of_insn_after): Copy REG_LIBCALL note specially.
        Copy REG_RETVAL not specially and fix it and the referencing 
REG_LIBCALL note.
        Use copy_rtx instead of copy_insn_1 for EXPR_LIST note.
        Abort if we get a INSN_LIST for the note.

Thanks,
Andrew Pinski

Index: emit-rtl.c
===================================================================
--- emit-rtl.c  (revision 120287)
+++ emit-rtl.c  (working copy)
@@ -5255,7 +5255,7 @@
 emit_copy_of_insn_after (rtx insn, rtx after)
 {
   rtx new;
-  rtx note1, note2, link;
+  rtx note2, link;
 
   switch (GET_CODE (insn))
     {
@@ -5295,25 +5295,30 @@
   for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
     if (REG_NOTE_KIND (link) != REG_LABEL)
       {
-       if (GET_CODE (link) == EXPR_LIST)
+        /* REG_LIBCALL will be fixed up when the insn with REG_RETVAL is 
added. */
+        if (REG_NOTE_KIND (link) == REG_LIBCALL)
+         REG_NOTES (new) = gen_rtx_INSN_LIST (REG_NOTE_KIND (link),
+                            XEXP (link, 0), REG_NOTES (new));
+       /* Copy REG_RETVAL and fix up it and the previous REG_LIBCALL at the 
same time.  */
+        else if (REG_NOTE_KIND (link) == REG_RETVAL)
+         {
+            rtx p = new;
+           /* Find the previous REG_LIBCALL which had the old original in it.  
 */
+            while ((note2 = find_reg_note (p, REG_LIBCALL, NULL_RTX)) == NULL
+                  || XEXP (note2, 0) != insn)
+             p = PREV_INSN (p);
+            XEXP (note2, 0) = new;
+           REG_NOTES (new) = gen_rtx_INSN_LIST (REG_NOTE_KIND (link),
+                              p, REG_NOTES (new));
+         }
+       else if (GET_CODE (link) == EXPR_LIST)
          REG_NOTES (new)
                = gen_rtx_EXPR_LIST (REG_NOTE_KIND (link),
-                 copy_insn_1 (XEXP (link, 0)),  REG_NOTES (new));
+                 copy_rtx (XEXP (link, 0)),  REG_NOTES (new));
        else
-         REG_NOTES (new)
-              = gen_rtx_INSN_LIST (REG_NOTE_KIND (link),
-                copy_insn_1 (XEXP (link, 0)),  REG_NOTES (new));
+         gcc_unreachable ();
       }
 
-  /* Fix the libcall sequences.  */
-  if ((note1 = find_reg_note (new, REG_RETVAL, NULL_RTX)) != NULL)
-    {
-      rtx p = new;
-      while ((note2 = find_reg_note (p, REG_LIBCALL, NULL_RTX)) == NULL)
-       p = PREV_INSN (p);
-      XEXP (note1, 0) = p;
-      XEXP (note2, 0) = new;
-    }
   INSN_CODE (new) = INSN_CODE (insn);
   return new;
 }