I want to put some trivial code into the prologue of gcc (actually
g++) compiled code.
Reverse engineering the relevant file is, er, a bit tedious, and
gcc won't build if I insert some testing code that makes it generate
bad code (yes, I disabled the three-stage build), so I shall have
to get it largely right first time.
Is anyone familiar enough with this to help? What I want to do is
to generate the equivalent of the following, preferably tuned to
use only offsets from fixed registers:
if (%sp < __stack_limit) __stack_trap();
This SHOULD be possible for two executed instructions in the normal
case, and four generated instructions in all, but I can live with
slower code for now.
Examples of how to generate suitable instructions and so on are all
I really need, or pointers to where I can look that up. Almost all
the sources I have found are assuming that you are prepared to spend
a lot of timing learning how to do a full porting job.
Regards,
Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QH, England.
Email: nmm1@xxxxxxxxx
Tel.: +44 1223 334761 Fax: +44 1223 334679
