On Wed, Apr 21, 2010 at 11:03:06AM -0400, [email protected] wrote:
> If you think that shift operators aren't being translated
> to shift instructions, you can examine the output of 8c -S.
>
> x/2 is equal to x>>1 for non-negative integer x; for negative x,
> the two expressions may yield different values, even if
> x is a signed integer. The book Hacker's Delight, among others,
> explores these sorts of optimisations.
Thanks for the reference. Having spent 3 days trying to understand
"generally" what was going on, I will now isolate one drawing that leads
to problem and add trace for gcc and for ken-cc to see where they do not
compute the same values. This will narrow the things and assembly, on
this, will give clues.
--
Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
http://www.kergis.com/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C
