small CSE bugfix

[Denis Chertykov <denisc at overta dot ru>]

I got an internal error (unrecognizable insn) in
target whithout the memory access by constant address.
IE:

int
legitimate_address_p (mode, x, strict)
     enum machine_mode mode;
     rtx x;
     int strict;
{
  if (CONSTANT_ADDRESS_P (x))
    return 0;



This small patch make the `cse_process_notes' more close to his
description.

/* Process X, part of the REG_NOTES of an insn.  Look at any REG_EQUAL notes
   and replace any registers in them with either an equivalent constant
   or the canonical form of the register.  If we are inside an address,
                                           ---------------------------
   only do this if the address remains valid.
   ------------------------------------------
   OBJECT is 0 except when within a MEM in which case it is the MEM.

   Return the replacement for X.  */


Ok to apply to GCC-3.0.1 and to GCC-3.1 ?



Mon Jul 23 23:34:19 2001  Denis Chertykov  <denisc@overta.ru>

	* cse.c (cse_process_notes): Replace any registers if the address
	remains valid.


diff -c3p /root/d/cvs/gcc-3.0/gcc/ /root/d/Work/gcc-3.0/gcc/cse.c
*** /root/d/cvs/gcc-3.0/gcc/cse.c	Sat Jun  2 00:10:17 2001
--- /root/d/Work/gcc-3.0/gcc/cse.c	Mon Jul 23 23:36:01 2001
*************** cse_process_notes (x, object)
*** 6485,6493 ****
  	      && (CONSTANT_P (ent->const_rtx)
  		  || GET_CODE (ent->const_rtx) == REG))
  	    {
! 	      rtx new = gen_lowpart_if_possible (GET_MODE (x), ent->const_rtx);
! 	      if (new)
! 		return new;
  	    }
  	}
  
--- 6485,6498 ----
  	      && (CONSTANT_P (ent->const_rtx)
  		  || GET_CODE (ent->const_rtx) == REG))
  	    {
! 	      if (object &&
! 		  memory_address_p (GET_MODE (object), ent->const_rtx))
! 		{
! 		  rtx new;
! 		  new = gen_lowpart_if_possible (GET_MODE (x), ent->const_rtx);
! 		  if (new)
! 		    return new;
! 		}
  	    }
  	}