Greg Kurz <gk...@linux.vnet.ibm.com> writes: > On Wed, 27 May 2015 10:41:06 +0530 > Nikunj A Dadhania <nik...@linux.vnet.ibm.com> wrote: > >> Greg Kurz <gk...@linux.vnet.ibm.com> writes: >> >> > SLOF currently calls hv-logical-load and hv-logical-store for every pixel >> > when enabling or disabling the cursor. This is suboptimal when writing one >> > char at a time to the console since terminal-write always toggles the >> > cursor. >> > And this is precisely what grub is doing when the user wants to edit a menu >> > entry... the result is an incredibly slow and barely usable interface. >> > >> > The inner loop in fb8-toggle-cursor handles a contiguous region: it can be >> > converted to hv-logical-memop. The result is 32 times less hcalls per char >> > and a serious improvement in grub usability. >> > >> > Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com> >> > --- >> > slof/fs/fbuffer.fs | 4 ++-- >> > 1 file changed, 2 insertions(+), 2 deletions(-) >> > >> > diff --git a/slof/fs/fbuffer.fs b/slof/fs/fbuffer.fs >> > index 756f05a..46b59bf 100644 >> > --- a/slof/fs/fbuffer.fs >> > +++ b/slof/fs/fbuffer.fs >> > @@ -99,8 +99,8 @@ CREATE bitmap-buffer 400 4 * allot >> > : fb8-toggle-cursor ( -- ) >> > line# fb8-line2addr column# fb8-columns2bytes + >> > char-height 0 ?DO >> > - char-width screen-depth * 0 ?DO dup dup rb@ -1 xor swap rb! 1+ >> > LOOP >> > - screen-width screen-depth * + char-width screen-depth * - >> > + dup dup 0 char-width screen-depth * 1 hv-logical-memop drop >> > + screen-width screen-depth * + >> >> Why did you drop "char-width screen-depth * -" in the new code? This is >> not me mentioned in the description. >> > > This is because the current inner loop increments the address. When the loop > ends, we're pointing at the next char, that is char-width * screen-depth bytes > too far. > > In the new code, the address is duped on the stack before calling > hv-logical-memop, > so we don't need to fix it when proceeding to next line.
Ah ok, i missed that 1+ in the loop. > In my first attempt, I forgot to drop the subtraction and got an interesting > visual result :) Regards Nikunj _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
