Richard Zidlicky writes:
> Also very nice source of desaster are div and mod routines wrt
negative
> values and overflow. Those are often used in direct disk access
> programs.
viz:
DIV/MOD
SMSQ/E and Minerva say:
7 div 3 , 7 mod 3 => 2 , 1
-7 div 3 , -7 mod 3 => -3 , 2
7 div -3 , 7 mod -3 => -3 , -2
-7 div -3 , -7 mod -3 => 2 , -1
Prospero Pascal says:
7 div 3 , 7 mod 3 => 2 , 1
-7 div 3 , -7 mod 3 => -2 , 1
7 div -3 , 7 mod -3 => -2 , error
-7 div -3 , -7 mod -3 => 2 , error
C68 Release 3.05 using the div_t structure says:
7 div 3 , 7 mod 3 => 2 , 1
-7 div 3 , -7 mod 3 => -2 , -1
7 div -3 , 7 mod -3 => -1 , -4 ?!
-7 div -3 , -7 mod -3 => 2 , -1
Using school maths I get:
7 div 3 , 7 mod 3 => 2 , 1
-7 div 3 , -7 mod 3 => -2 , -1
7 div -3 , 7 mod -3 => -2 , 1
-7 div -3 , -7 mod -3 => 2 , -1
Who says we're hard up for choice!
Per
