Hi
Does anyone have some code that creates tablejump in Avr-gcc? This is
where gcc will create table instead of long line of if-then-else tests
I cant seem to create enough switch cases to force one!
I have been looking at compilation patterns and noticed that gcc address
is multiplied by 2 to form address for LPM (table being in ROM). LPM
needs byte address and gcc has word address.
"lsl r30
rol r31
lpm __tmp_reg__,Z+
lpm r31,Z
mov r30,__tmp_reg__
ijmp"
Asm Pattern currently expects value to be in R30. However, it would
appear that this would be better with a symbol rather than value in
register - thus providing a means to multiply that value by 2 at compile
time. (and I cant see any reason it would be called with other than
constant address in ROM)
Obviously, I'd like to test it.
Andy
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