In message <[EMAIL PROTECTED]>
Nicholas Clark <[EMAIL PROTECTED]> wrote:
> Specific example where you can't:
> on ARM, the branch instructions (B and BL) are PC relative, but only have
> a 24 bit offset field. The address space is (now) 32 bit, so there's parts
> you can't reach without either calculating addresses (in another register)
> and MOVing them to the PC, or loading the PC from a branch table in memory.
That is actually a word offset of course, so it can actually reach
up to 26 bits away in bytes. Still not the full 32 though.
Of course that only becomes a problem if your program is big enough
to exceed 26 bits of address space, which is pretty unlikely. That
or if the program occupies seriously disjoint areas of address space.
Tom
--
Tom Hughes ([EMAIL PROTECTED])
http://www.compton.nu/
...Don't believe in astrology. We Scorpios aren't taken in by such things.
