[Bug inline-asm/23200] [4.0/4.1/4.2 regression] rejects "i"(&var + 1)

["mrs at apple dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #17 from mrs at apple dot com  2006-02-04 00:16 -------
I've found a way to fix this at -O0 for my code with something like:

  /* APPLE LOCAL begin CW asm blocks */
  {
    tree array = ptrop;
    STRIP_NOPS (array);

    /* We want to canonicalize PLUS_EXPR into ARRAY_REF for data
       pointers as ARRAY_REFs can be converted into RTL code without
       introducing additional temporaries when not optimizing, which
       is useful as otherwise when all registers are in use by the
       assembly code, we can run reload out of registers.  */

    if (inside_cw_asm_block
        && flag_ms_asms
        && resultcode == PLUS_EXPR
        && TREE_CODE (array) == ADDR_EXPR
        && !(TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE
             || TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == METHOD_TYPE))
      {
        tree type;
        tree r;
        tree new_i;

        size_exp = convert (TREE_TYPE (intop), size_exp);

        /* We have to ensure that when ARRAY_REF is used, it will
           calculate the offset correctly as it is element based, and we
           are byte based.  */
        new_i = fold (build_binary_op (CEIL_DIV_EXPR, intop, size_exp, 1));
        if (build_binary_op (MULT_EXPR, new_i, size_exp, 1) == intop)
          {
            array = TREE_OPERAND (array, 0);
            type = TREE_TYPE (TREE_TYPE (array));
            if (TREE_CODE (type) != ARRAY_TYPE)
              type = TYPE_MAIN_VARIANT (type);
            r = build4 (ARRAY_REF, type, array, new_i, NULL_TREE, NULL_TREE);
            TREE_READONLY (r)
              |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
                  | TREE_READONLY (array));
            TREE_SIDE_EFFECTS (r)
              |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
                  | TREE_SIDE_EFFECTS (array));
            TREE_THIS_VOLATILE (r)
              |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
                  /* This was added by rms on 16 Nov 91.
                     It fixes  vol struct foo *a;  a->elts[1]
                     in an inline function.
                     Hope it doesn't break something else.  */
                  | TREE_THIS_VOLATILE (array));
            r = fold (r);
            r = build1 (ADDR_EXPR, result_type, r);
            r = fold (r);
            return r;
          }
      }
  }

inside pointer_int_sum just before:

  /* Replace the integer argument with a suitable product by the object size.
     Do this multiplication as signed, then convert to the appropriate
     pointer type (actually unsigned integral).  */

  intop = convert (result_type,
                   build_binary_op (MULT_EXPR, intop,
                                    convert (TREE_TYPE (intop), size_exp), 1));

This makes it though gimple without creating any decls and makes it through rtl
expansion without creating any new pseduo registers when using an "m"
constraint and putting an INDIRECT_REF on it.

You can see this working on the apple-local-200502-branch, Radar 4399388.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23200