GCC Assembler Modifiers

[Segher Boessenkool]

> 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