labels-2.c / -Os fix

[Richard Henderson]

On Thu, Apr 27, 2000 at 12:34:39PM +0200, Jan Hubicka wrote:
> > Seems like output_constant_def couldn't really do it's job
> > this way?  Perhaps you can rely on pointer equivalence of
> > the referenced CODE_LABEL rather than on the UID?
> I was thinking about this, but I am not sure if the CODE_LABELs can't
> be garbage collected and dropped.

Certainly they can.  But not when there's a valid reference to it.

> Also this would require me to figure out the CODE_LABEL pointer...

Eh?  No, you misunderstand my intent.  Not the address of .L3, but
literally the address of the CODE_LABEL rtx.  I've checked this in.


r~

        * varasm.c (record_constant_1): Record the CODE_LABEL when
        taking the address of a LABEL_REF.

Index: varasm.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/varasm.c,v
retrieving revision 1.111
diff -c -p -d -r1.111 varasm.c
*** varasm.c	2000/04/15 15:44:19	1.111
--- varasm.c	2000/04/28 20:23:46
*************** record_constant_1 (exp)
*** 2867,2875 ****
  	/* Record the offset.  */
  	obstack_grow (&permanent_obstack,
  		      (char *) &value.offset, sizeof value.offset);
! 	/* Record the symbol name.  */
! 	obstack_grow (&permanent_obstack, XSTR (value.base, 0),
! 		      strlen (XSTR (value.base, 0)) + 1);
        }
        return;
  
--- 2867,2890 ----
  	/* Record the offset.  */
  	obstack_grow (&permanent_obstack,
  		      (char *) &value.offset, sizeof value.offset);
! 
! 	switch (GET_CODE (value.base))
! 	  {
! 	  case SYMBOL_REF:
! 	    /* Record the symbol name.  */
! 	    obstack_grow (&permanent_obstack, XSTR (value.base, 0),
! 			  strlen (XSTR (value.base, 0)) + 1);
! 	    break;
! 	  case LABEL_REF:
! 	    /* Record the address of the CODE_LABEL.  It may not have
! 	       been emitted yet, so it's UID may be zero.  But pointer
! 	       identity is good enough.  */
! 	    obstack_grow (&permanent_obstack, &XEXP (value.base, 0),
! 			  sizeof (rtx));
! 	    break;
! 	  default:
! 	    abort ();
! 	  }
        }
        return;