powerpc32: optimise a few instructions in csum_partial()
r5 does contain the value to be updated, so lets use r5 all way long for that. It makes the code more readable. To avoid confusion, it is better to use adde instead of addc The first addition is useless. Its only purpose is to clear carry. As r4 is a signed int that is always positive, this can be done by using srawi instead of srwi Let's also remove the comment about bdnz having no overhead as it is not correct on all powerpc, at least on MPC8xx In the last part, in our situation, the remaining quantity of bytes to be proceeded is between 0 and 3. Therefore, we can base that part on the value of bit 31 and bit 30 of r4 instead of anding r4 with 3 then proceding on comparisons and substractions. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
Showing
Please register or sign in to comment