RFA: alignment computed by get_inner_reference

[Nick Clifton <nickc at redhat dot com>]

Hi Guys,

  I ran into a seg fault whilst running the gcc compile testcase
  20000606-1.c for the arm-ellf toolchain.  I have tracked down the
  problem to what I believe to be a bug in get_inner_reference, but I
  am not familiar enough with this code to be sure.

  The problem is that get_inner_reference is return an alignment value
  of 1 in the parameter 'palignment'.  This alignment is supposed to
  be in bits, so an alignment of 1 does not really make much sense.
  The effect of returning this value is an infinite loop between
  store_split_bit_field and store_fixed_bit_field in expmed.c.

  The cause of the bug, I think, is that the code in
  get_inner_reference uses the macros DECL_ALIGN and TYPE_ALIGN without
  converting them from byte alignments to bit alignments.  The patch
  below fixes this (and allows the testcase to compile).

  Is this patch OK to apply ?

Cheers
	Nick

2000-08-27  Nick Clifton  <nickc@redhat.com>

	* expr.c (get_inner_reference): Convert DECL_ALIGN and
	TYPE_ALIGN to bit alignments.

Index: gcc/expr.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/expr.c,v
retrieving revision 1.254
diff -p -r1.254 expr.c
*** expr.c	2000/08/24 20:31:31	1.254
--- expr.c	2000/08/27 20:14:48
*************** get_inner_reference (exp, pbitsize, pbit
*** 5162,5170 ****
      }
  
    if (DECL_P (exp))
!     alignment = MIN (alignment, DECL_ALIGN (exp));
    else if (TREE_TYPE (exp) != 0)
!     alignment = MIN (alignment, TYPE_ALIGN (TREE_TYPE (exp)));
  
    /* If OFFSET is constant, see if we can return the whole thing as a
       constant bit position.  Otherwise, split it up.  */
--- 5162,5170 ----
      }
  
    if (DECL_P (exp))
!     alignment = MIN (alignment, DECL_ALIGN (exp) * BITS_PER_UNIT);
    else if (TREE_TYPE (exp) != 0)
!     alignment = MIN (alignment, TYPE_ALIGN (TREE_TYPE (exp)) * BITS_PER_UNIT);
  
    /* If OFFSET is constant, see if we can return the whole thing as a
       constant bit position.  Otherwise, split it up.  */