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| Code Block |
|---|
signed int result;
signed int si1 = INT_MIN;
signed int si2 = 2;
signed long long tmp = (signed long long)lhs * (signed long long)rhs;
if ( (tmp > INT_MAX) || (tmp < INT_MIN)) {
/* The product cannot fit in a 32-bit int */
error_handler("OVERFLOW ERROR", NULL, EOVERFLOW);
}
result = (int)tmp;
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It is important to note that the above code is only compliant on systems where long long is atleast at least twice the size of int. On systems where this does not hold the following compliant solution may be used to ensure signed overflow does not occur.
| Code Block |
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signed int result; signed int si1 = INT_MIN; signed int si2 = 2; if (si1 si1>> 0){ if (si2 si2>> 0) { if(si1> if (si1 > (INT_MAX / si2)) { error_handler("OVERFLOW ERROR", NULL, EOVERFLOW); } } else { if (si2 si2<< (INT_MIN / si1)) { error_handler("OVERFLOW ERROR", NULL, EOVERFLOW); } } } else { if (si2 > 0) { if( if (si1 < (INT_MIN / si2)) { error_handler("OVERFLOW ERROR", NULL, EOVERFLOW); } } } else { if( (si1 != 0) && (si2 < (INT_MAX / si1))) { error_handler("OVERFLOW ERROR", NULL, EOVERFLOW); } } } result = si1 * si2; |
Division
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