inline assembly operands

[Luchezar Belev <l_belev at yahoo dot com>]

hi all,

why out-of-function asm statements can't have operands?
An example for case when it would be useful is to
make the compiler calculate offsetof-s or sizeof-s (because
it knows best how to do it, taking into account alignment
rules, etc).

I used the following ugly hack to get around this limitation:

	asm (".if 0");
	void dymmy_func(void) {
	asm (".endif"::);

	/* here I can use operands. for example: */
	asm (".equ A, %0"::"i"(sizeof(something)));
	/* and compile with -masm=intel to make the
	 * compiler not to prefix the "immediate operand" */

	asm (".if 0"::);
	}
	asm (".endif");

but now it seems unreliable since with the new
unit-at-a-time feature the compiler may reorder
the functions and top-level asm statements arbitrarily.

Is it so hardly implementatiable to permit operands
in the top-level asm statements?

lucho



	
		
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