[tree-ssa] bootstrap problem on powerpc-apple-darwin6.6

[Andrew Pinski]

Here is more reduced sources:
union tree_node;
typedef union tree_node *tree;
typedef enum fallback_t {
   fb_none = 0,
   fb_rvalue=1,
   fb_lvalue=2,
   fb_either=1|2
} fallback_t;

int
gimplify_expr (tree *expr_p, fallback_t fallback)
{
if ((fallback & fb_rvalue) && *expr_p)
     {
         f_temp_2();
     }
   else
     {
         abort();
     }
   return 1;
}


The problem is gimplify_expr (which is weird as this is the function 
which is causing this ICE)
These lines on 491-494:
	  /* Strip away as many useless type conversions as possible
	     at the toplevel.  */
	  while (tree_ssa_useless_type_conversion (*expr_p))
	    *expr_p = TREE_OPERAND (*expr_p, 0);
is removing the conversion to boolean_type:
 From tree_ssa_useless_type_conversion:
       /* If both the inner and outer types are integral types, then
          we can enter the equivalence if they have the same mode
          and signedness.  */
       else if (INTEGRAL_TYPE_P (inner_type) && INTEGRAL_TYPE_P 
(outer_type)
	       && TYPE_MODE (inner_type) == TYPE_MODE (outer_type)
	       && TREE_UNSIGNED (inner_type) == TREE_UNSIGNED (outer_type))
	return true;
which is true in this case which cause it to remove the nop_expr which 
converts to boolean_type.

Jeff you added tree_ssa_useless_type_conversion can you say what is 
going on and why is this happening?


Thanks,
Andrew Pinski