------- Comment #2 from r dot leitgeb at x-pin dot com 2006-10-24 07:31 -------
Here's an excerpt of the assembly code obtained with -Os -S
with some comments from me:
----------------------------------------------------
setpin:
/* prologue: frame size=0 */
/* prologue end (size=0) */
mov r20,r24
clr r21
cpi r22,lo8(1) <--- The compare is done byte wide
brne .L2
in r18,53-0x20
ldi r24,lo8(1) <--- Here we load 1 sixteen bit wide
ldi r25,hi8(1)
rjmp 2f
1: lsl r24 <--- Here we shift 1 sixteen bit wide
rol r25
2: dec r20
brpl 1b
or r18,r24 <--- r25 is not used. Why would we compute it ?
rjmp .L6
.L2:
in r18,53-0x20
----------------------------------------------------
Cheers
Rudi
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29560
