I have two questions related to the modifiers that can be used with
operands in inline assembly.
1) What does the 'z' mean when added to the operand modifier (e.g.
%z0)?
2) In the Input operands list, what is the meaning of 'J' (e.g. ... :
.... : "Jr" (0) )?
I tried to look them up in the online GCC manual but I couldn't find
them.
You need the GCC internals manual instead, "info gccint".
Look at the "machine description" -> "constraints" ->
"machine constraints" section for the "J" thing. I don't
know where the "%z" thing is documented, perhaps somewhere
in that manual, perhaps in the GCC source code only :-/
Segher