avsdS:avsdT:jon (03/03/83)
I compiled some code with the Ritchie C compiler to run on an 11/23. There was one long division in the code and I found that the LSWord of the dividend was being ignored (treated as zero) for a particluar range of MSWords. I decided writing a quick long division routine in C was a faster solution than debugging ldiv(). Anyone know why ldiv() should fail on an 11/23??? -jonathan hahn ...!ucbvax!atd!avsdT:jon Ampex Corp.
dave@Ucla-Security (04/02/83)
From: David Butterfield <ica!dave@Ucla-Security> I ran into this last year. The divide routine does a divide instruction and then looks to see if it worked (condition codes or something). On the 11/45, the dividend was left untouched if it didn't work. On the 11/23 it was garbaged. (The processor handbook leaves it "undefined"). The ldiv routine assumes and depends on the value being untouched. If you save the value and restore it in the cases that don't work, it will suddenly start working. I no longer run a 23 and that is why this message is so vague. If you are interested and can't figure it out, send me a message and I will see about digging out the code. Dave