On Wed, Dec 01, 2004 at 09:50:45PM +0000, Maciej W. Rozycki wrote:
> No surprise as the "o" constraint doesn't mean anything particular for
> MIPS. All addresses are offsettable -- there is no addressing mode that
> would preclude it, so "o" is exactly the same as "m".
This is what the gcc docs say:
[...]
`o'
A memory operand is allowed, but only if the address is
"offsettable". This means that adding a small integer (actually,
the width in bytes of the operand, as determined by its machine
mode) may be added to the address and the result is also a valid
memory address.
For example, an address which is constant is offsettable; so is an
address that is the sum of a register and a constant (as long as a
slightly larger constant is also within the range of
address-offsets supported by the machine); but an autoincrement or
autodecrement address is not offsettable. More complicated
indirect/indexed addresses may or may not be offsettable depending
on the other addressing modes that the machine supports.
[...]
So it is not the same as "m".
Ralf
