From mboxrd@z Thu Jan  1 00:00:00 1970
From: "John David Anglin" <dave@hiauly1.hia.nrc.ca>
To: dave@hiauly1.hia.nrc.ca (John David Anglin)
Cc: gcc@gcc.gnu.org, gcc-bugs@gcc.gnu.org
Subject: Re: pa reload problem
Date: Mon, 01 Jan 2001 16:37:00 -0000
Message-id: <200101020037.TAA26820@hiauly1.hia.nrc.ca>
References: <no.id>
X-SW-Source: 2001-01/msg00016.html

> (insn 1067 1063 2002 (set (reg/f:SI 403)
>         (mem/u:SI (lo_sum:SI (reg/f:SI 611)
>                 (unspec:SI[ 
>                         (symbol_ref:SI ("target_flags"))
>                     ]  0)) 0)) 69 {*pa.md:2099} (nil)
>     (expr_list:REG_EQUIV (mem/u:SI (lo_sum:SI (reg/f:SI 611)
>                 (unspec:SI[ 
>                         (symbol_ref:SI ("target_flags"))
>                     ]  0)) 0)
>         (expr_list:REG_DEAD (reg/f:SI 611)
>             (nil))))

The REG_EQUIV note gets added in local-alloc.c here:

      /* If this register is known to be equal to a constant, record that
         it is always equivalent to the constant.  */
     if (note && ! rtx_varies_p (XEXP (note, 0)))
       PUT_MODE (note, (enum machine_mode) REG_EQUIV);

The problem appears to be that the "constant" part of the lo_sum (the
symbol_ref) should be the first operand:

    case LO_SUM:
      /* The operand 0 of a LO_SUM is considered constant
         (in fact is it related specifically to operand 1).  */
      return rtx_varies_p (XEXP (x, 1));

This problem appears to prevalent in a number of places in pa.md and pa.c.
It looks like the argument order for lo_sums in hte pa port needs to be
switched.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)