[TUHS] unsigned division in V7's C

Wolfgang Helbig helbig at Informatik.BA-Stuttgart.DE
Sat Jan 11 10:20:01 AEST 2003

while wondering how unsigned integer division is implemented in C 
I found a bug in V7: a/b and a%b with b >= 2^15 does not give the expected
results, if a and b are unsigned int's.

Was this bug ever noticed or even fixed?



Here is a program showing the bug:
        unsigned int a, b;
        a = 60000;
        b = 40000;
        printf("a/b: %u, a%%b: %u\n", a/b, a%b);
        b = 25000;
        printf("a/b: %u, a%%b: %u\n", a/b, a%b);

The above program prints
a/b: 65534, a%b: 8928
a/b: 2, a%b: 10000

The first line should be of course
a/b: 1, a%b: 20000

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