Word length != 2^n

[lars@brinkhoff.se]

I'm writing a new processor backend.  When porting the backend from
GCC 2.95.2 to the current CVS tree I stumbled accross this code, which
does not work on processors which does not have 2^n word length.

   /* Return the alignment of MODE. This will be bounded by 1 and
      BIGGEST_ALIGNMENT.  */
   
   unsigned int
   get_mode_alignment (mode)
        enum machine_mode mode;
   {
     unsigned int alignment = GET_MODE_UNIT_SIZE (mode) * BITS_PER_UNIT;
   
     /* Extract the LSB of the size.  */
     alignment = alignment & -alignment;
   
     alignment = MIN (BIGGEST_ALIGNMENT, MAX (1, alignment));
     return alignment;
   }

Here's the corresponding ChangeLog entry:

   2000-02-24  Nathan Sidwell  <nathan@codesourcery.com>
   
           * machmode.h (get_mode_alignment): Declare.
           (GET_MODE_ALIGNMENT): Call it.
           * stor-layout.c (get_mode_alignment): New function. Make
           sure alignment is always power of 2.

A tentative patch would thus be:

2001-01-13  lars brinkhoff  <lars@brinkhoff.se>

        * stor-layout.c (get_mode_alignment): Remove the restriction
        that alignment is always a power of 2.

diff -u -r1.92 stor-layout.c
--- stor-layout.c       2000/12/17 17:22:41     1.92
+++ stor-layout.c       2001/01/13 09:24:50
@@ -1797,9 +1797,6 @@
 {
   unsigned int alignment = GET_MODE_UNIT_SIZE (mode) * BITS_PER_UNIT;

-  /* Extract the LSB of the size.  */
-  alignment = alignment & -alignment;
-
   alignment = MIN (BIGGEST_ALIGNMENT, MAX (1, alignment));
   return alignment;
 }