purge_addressof not purging reg-notes

[Andrew Haley <aph at cambridge dot redhat dot com>]

I'm getting a problem where purge_addressof is doing the wrong thing.
This is ARM, current top-of-trunk gcc.

The original insn looks like this:

(insn 955 953 957 (set (reg:SI 2 r2)
        (reg:SI 179)) 177 {*arm_movsi_insn} (nil)
    (expr_list:REG_EQUAL (addressof:SI (reg/v:SI 163) 162 0x84b2478)
        (nil)))

And purge_addressof_1() is called on the note, which calls
put_addressof_into_stack() with

(addressof:SI (reg/v:SI 163) 162 0x84b2478)

which returns 

(addressof:SI (mem/f:SI (plus:SI (reg/f:SI 25 sfp)
            (const_int -8336 [0xffffdf70])) 8) 162 0x84b2478)

leaving the insn like this:

(insn 955 953 957 (set (reg:SI 2 r2)
        (reg:SI 179)) 177 {*arm_movsi_insn} (nil)
    (expr_list:REG_EQUAL (addressof:SI (mem/f:SI (plus:SI (reg/f:SI 25 sfp)
                    (const_int -8336 [0xffffdf70])) 8) 162 0x84b2478)
        (nil)))

So, it has put the reg into the stack but it's left the addressof.

I've added a little code to fixup_var_refs_insn() so that it nukes any
notes that contain ADDRESSOFs.  This is easier than trying to repair
them.

Is this OK?

Andrew.


2001-06-22  Andrew Haley  <aph@cambridge.redhat.com>

	* function.c (fixup_var_refs_insn): Remove any ADDRESSOFs from an
	insn's notes.
	(is_addressof): Robustify: allow NULL rtxes.

Index: function.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/function.c,v
retrieving revision 1.276
diff -c -2 -p -r1.276 function.c
*** function.c	2001/06/15 22:08:42	1.276
--- function.c	2001/06/22 15:11:29
*************** fixup_var_refs_insn (insn, var, promoted
*** 1873,1879 ****
      {
        if (GET_CODE (note) != INSN_LIST)
! 	XEXP (note, 0)
! 	  = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
!       note = XEXP (note, 1);
      }
  }
--- 1873,1887 ----
      {
        if (GET_CODE (note) != INSN_LIST)
! 	{	  
! 	  XEXP (note, 0)
! 	    = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
! 
! 	  /* We may have an (addressof (mem)) where mem used to be a
!              pseudo in reg-notes.  Remove it now.  */
! 	  if (for_each_rtx (&note, is_addressof, NULL))
! 	    remove_note (insn, note);
! 
! 	  note = XEXP (note, 1);
! 	}
      }
  }
*************** is_addressof (rtl, data)
*** 3353,3357 ****
       void *data ATTRIBUTE_UNUSED;
  {
!   return GET_CODE (*rtl) == ADDRESSOF;
  }
  
--- 3361,3365 ----
       void *data ATTRIBUTE_UNUSED;
  {
!   return *rtl && GET_CODE (*rtl) == ADDRESSOF;
  }