Patch to fix rtx_unstable_p & rtx_varies_p volatile asm handling

[John Wehle <john at feith dot com>]

Volatile asms are unstable and can vary.  This patch passes make bootstrap
and make check on Compaq Tru64 UNIX 4.0f and FreeBSD-3.5 x86.

ChangeLog:

Fri Sep 15 01:37:10 EDT 2000  John Wehle  (john@feith.com)

	* rtlanal.c (rtx_varies_p): Volatile asms vary.
	(rtx_unstable_p): Restructure code.  Volatile asms
	are unstable.

Enjoy!

-- John Wehle
------------------8<------------------------8<------------------------
*** gcc/rtlanal.c.ORIGINAL	Tue Aug 22 23:49:55 2000
--- gcc/rtlanal.c	Fri Sep 15 01:34:47 2000
*************** rtx_unstable_p (x)
*** 52,71 ****
    register int i;
    register const char *fmt;
  
!   if (code == MEM)
!     return ! RTX_UNCHANGING_P (x) || rtx_unstable_p (XEXP (x, 0));
  
!   if (code == QUEUED)
!     return 1;
  
!   if (CONSTANT_P (x))
!     return 0;
  
!   if (code == REG)
!     /* As in rtx_varies_p, we have to use the actual rtx, not reg number.  */
!     return ! (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
! 	      || x == arg_pointer_rtx || x == pic_offset_table_rtx
! 	      || RTX_UNCHANGING_P (x));
  
    fmt = GET_RTX_FORMAT (code);
    for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
--- 52,87 ----
    register int i;
    register const char *fmt;
  
!   switch (code)
!     {
!     case MEM:
!       return ! RTX_UNCHANGING_P (x) || rtx_unstable_p (XEXP (x, 0));
! 
!     case QUEUED:
!       return 1;
  
!     case CONST:
!     case CONST_INT:
!     case CONST_DOUBLE:
!     case SYMBOL_REF:
!     case LABEL_REF:
!       return 0;
  
!     case REG:
!       /* As in rtx_varies_p, we have to use the actual rtx, not reg number.  */
!       return ! (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
! 		|| x == arg_pointer_rtx || x == pic_offset_table_rtx
! 		|| RTX_UNCHANGING_P (x));
  
!     case ASM_OPERANDS:
!       if (MEM_VOLATILE_P (x))
! 	return 1;
! 
!       /* FALLTHROUGH */
! 
!     default:
!       break;
!     }
  
    fmt = GET_RTX_FORMAT (code);
    for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
*************** rtx_varies_p (x)
*** 126,131 ****
--- 142,153 ----
  	 (in fact is it related specifically to operand 1).  */
        return rtx_varies_p (XEXP (x, 1));
        
+     case ASM_OPERANDS:
+       if (MEM_VOLATILE_P (x))
+ 	return 1;
+ 
+       /* FALLTHROUGH */
+ 
      default:
        break;
      }
-------------------------------------------------------------------------
|   Feith Systems  |   Voice: 1-215-646-8000  |  Email: john@feith.com  |
|    John Wehle    |     Fax: 1-215-540-5495  |                         |
-------------------------------------------------------------------------