CODEWITHSUNDEEP
assemblyboolean-logic68000
MortalMan
MortalMan

Reputation: 2612

Using AND and OR in 68k language

I need something like this:

if((ch > 'g' && ch < 'm') || (A >= 0 && A <= 100)) {
    // Do some stuff
} else {
    // Do some other stuff
}

ch is an 8-bit char, while A is a 32 bit integer.

I suspect I will need this code:

CMPI.B    #$67, ch
BLT       SOMELABEL

CMPI.B    #$6D, ch
BGT       SOMELABEL

and

CMPI.W    #0, A
BLE       SOMELABEL

CMPI.W    #100, A
BGE       SOMELABEL

How do I combine these using the OR and AND operators?

Upvotes: 1

Views: 395

Answers (1)

lvd
lvd

Reputation: 812

Instead of creating spaghetti code with all those conditional branches, consider using Scc command, where cc is a condition. This command sets destination byte to $FF if condition is true and to zero otherwise. So you can have code like this:

cmpi.b #'g',ch
shi.b  d0
cmpi.b #'m',ch
slo.b  d1
and.b  d1,d0 ;now d0 is nonzero if all conditions for 'ch' are true
... same for A with result in d1
or.b   d1,d0
beq    else_branch
... here is 'if' branch

Upvotes: 2

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