On 10/07/2015 12:18 PM, Bernd Schmidt wrote:
On 10/07/2015 09:04 AM, Christian Bruel wrote:
+ /* Similarly, relayout function's alignment if not forced. */
+ if (!DECL_USER_ALIGN (fndecl)
+ && (TREE_CODE (fntype) != METHOD_TYPE
+ || TARGET_PTRMEMFUNC_VBIT_LOCATION !=
ptrmemfunc_vbit_in_pfn))
+ DECL_ALIGN (fndecl) = FUNCTION_BOUNDARY;
}
That's a very odd-looking condition. Why the vbit location test?
This is for member functions to make sure that the lsb address is
reserved for the virtual function bit.
see cp/decl.c:
/* If pointers to member functions use the least significant bit to
indicate whether a function is virtual, ensure a pointer
to this function will have that bit clear. */
if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn
&& TREE_CODE (type) == METHOD_TYPE
&& DECL_ALIGN (decl) < 2 * BITS_PER_UNIT)
DECL_ALIGN (decl) = 2 * BITS_PER_UNIT;
This happens for instance on i386 that aligns member functions on 2
bytes, bigger than the one byte required boundary. So we cannot
re-layout bellow that.