11 Dec
2005
11 Dec
'05
10:59 p.m.
On Sun, 11 Dec 2005, Jim Leonard wrote:
and al,15
add al,90h
daa
adc al,40h
daa
...is only 8 bytes.
If DAA were slow, I'd say ditch it. But DAA is only 4 cycles and according to
my real-world 8088 timings (slow night tonight), the DAA approach is only just
a hair slower than the XLAT method.
So I guess there *is* a need for DAA ;-)
Howzbout:
AND AL, 0Fh
DAA
ADD AL, 0F0h
ADC AL, 40h
or:
AND AL, 0Fh
ADD AL, 0
ADC AL,28h
DAA