continuing egcs-1.1 problems

[Joern Rennecke]

> >>>>> Gary Thomas writes:
> 
> Gary> How is it possible that the stack remain 16 byte aligned when an object
> Gary> (the trampoline code) of only 40 bytes is being created [on the stack]?
> 
> 	While a 40 byte object may be created on the stack, the next
> allocation of an object that must be aligned, like a new stack frame, will
> round up the address to the stack alignment boundary.

If you don't define your own special way to allocate a trampoline, the
trampoline will be allocated very much like a structure-typed variable
on the stack, i.e. it is part of the stack frame of the caller, which
gets allocated as a single chunk.
The only thing special about trampolines is that the alignment is not
done when the trampoline is allocated in the stack frame; if you need
alignment, you have to define TRAMPOLINE_ALIGNMENT, and a bit more space
will be reserved in the stack frame, and the alignment will be done at run
time.
That allows to have a stricter alignment for the trampoline than for the
stack, but it wastes some space because it doesn't take the known alignment
of the stack into account.