Re: register variables: list?

[Andrew Haley <aph-gcc at littlepinkcloud dot COM>]

This is not appropriate for gcc@gcc.gnu.org, which is for gcc
development.  I'm redirecting this reply to gcc-help.

skaller writes:
 > In
 > 
 > http://gcc.gnu.org/onlinedocs/gcc-4.2.2/gcc/Explicit-Reg-Vars.html#Explicit-Reg-Vars
 > 
 > it explains how to use register variables .. but doesn't list them.
 > 
 > Is there a document somewhere which lists
 > 
 > a) each CPU macro name
 > b) all the registers supported
 > 
 > ?

Not as far as I'm aware.  All of this information is in the
gcc/config/<cpu> directory, so can fairly easily be extracted.

 > I need to get the stack pointer when __builtin_frame_address(0) isn't
 > working .. on amd64 this:
 > 
 > 
 > register void *stack asm ("%rsp");
 > 
 > appears to work. Also this is the current stack pointer .. not
 > the frame pointer, which could be different.

Right, and in fact there need not even be a frame pointer, which is
why you have to use __builtin_frame_address.

Andrew.