re: Stack bias

[matthew green <mrg%eterna.com.au@localhost>]

   Hi, I'm reading Sparc V9 ABI document, which talks about stack bias.
   Could anyone explain why there is a stack bias and what the stack looks
   like with the bias, i.e. is it something I need to worry about when
   writing sparc assembly?


the stack bias is -2047 in 64 bit mode.  i understand it has 2 main
benefits.  (a) %sp & 1 == 1 means we have 64 bit mode.  (b) it allows
the 13-bit offset instructions to access a larger stack frame directly.

you need to worry about it.  i recommend reading some of the low
level kernel assembler for sparc64 port for examples on how to use
it sanely.


.mrg.