On Sun, 27 Feb 2011, Dimitry Andric wrote:
Log: Clang's integrated assembler can now handle sys/boot/i386/boot2/sio.S. It used to choke on the notation "inb (%dx),%al" for "inb %dx,%al"; GNU as accepts both forms. Which notation is more 'correct' is an open question. :)
Nah, the former is just a syntax error since %dx is not dereferenced :-). It is a syntax error at the design level that parentheses are used for indirection. In better assembler syntaxes like Intel/Microsoft's one for x86 and Motorola's one for 6809, brackets are used for indirections so parentheses are not context-dependent. Then extra parentheses around expressions can have no effect. But dx isn't an expression, so (dx) should still be a syntax error. I think it is in I/M syntax but I can't test that easily. It is a syntax error in my x86/6809 assembler. My assembler doesn't check, but emits a diagnostic for this :-). (My assembler wants brackets for indirection, but it has an option to to implement some bugs including use of parentheses for indirection.) Bruce _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
