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does gcc support multiple sizes, or not?
- From: DJ Delorie <dj at redhat dot com>
- To: gcc at gcc dot gnu dot org
- Date: Fri, 4 Aug 2006 21:17:54 -0400
- Subject: does gcc support multiple sizes, or not?
In cp/cvt.c we have this code in cp_convert_to_pointer:
if (INTEGRAL_CODE_P (form))
if (TYPE_PRECISION (intype) == POINTER_SIZE)
return build1 (CONVERT_EXPR, type, expr);
expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr);
/* Modes may be different but sizes should be the same. There
is supposed to be some integral type that is the same width
as a pointer. */
gcc_assert (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr)))
== GET_MODE_SIZE (TYPE_MODE (type)));
return convert_to_pointer (type, expr);
Note that it always converts to a POINTER_SIZE pointer, regardless of
the size of TYPE (the target type), then asserts that the result is
the same size as TYPE.
However, in s390.c, we have:
s390_valid_pointer_mode (enum machine_mode mode)
return (mode == SImode || (TARGET_64BIT && mode == DImode));
Note that more than one mode is supported simultaneously. Thus, it's
legal for the application to specify SI or DI mode for pointer (via
__attribute__((mode))), but cc1plus then aborts.
So... who is right? Are we supposed to support multiple pointer sizes
in the same compilation unit, or not?