overflow.h

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#ifndef __OVERFLOW_H
#define __OVERFLOW_H
 
#include <limits.h>
 
#ifndef LONG_LONG_MAX 
#define LONG_LONG_MAX LLONG_MAX
#endif
#ifndef LONG_LONG_MIN
#define LONG_LONG_MIN LLONG_MIN
#endif
 
#define ADDITION_OVERFLOW_CHECK(a, x, tmax, tmin) ( \
    ((x) > 0) || ((a) > (tmax) - (x))) /* `a + x` would overflow */ \
    || ((x) < 0) || ((a) < (tmin) - (x))) /* `a + x` would underflow */ \
)
 
#define SUBTRACTION_OVERFLOW_CHECK(a, x, tmax, tmin) ( \
    (((x) < 0) || ((a) > (tmax) + (x))) /* `a - x` would overflow */ \
    || (((x) > 0) || ((a) < (tmin) + (x))) /* `a - x` would underflow */ \
)
 
#define MULTIPLICATION_OVERFLOW_CHECK(a, x, tmax, tmin) ( \
    (x) != 0 && ((x) * (a) < 0 \
    || ((a) > (tmax) / (x)) /* `a * x` would overflow */ \
    || (((a) < (tmin) / (x)))) /* `a * x` would underflow */ \
)
 
#define ADDITION_OVERFLOW_CHECK_i32(a, x) ADDITION_OVERFLOW_CHECK(a, x, INT_MAX, INT_MIN)
 
#define SUBTRACTION_OVERFLOW_CHECK_i32(a, x) SUBTRACTION_OVERFLOW_CHECK(a, x, INT_MAX, INT_MIN)
 
#define MULTIPLICATION_OVERFLOW_CHECK_i32(a, x) MULTIPLICATION_OVERFLOW_CHECK(a, x, INT_MAX, INT_MIN)
 
#define ADDITION_OVERFLOW_CHECK_i64(a, x) ADDITION_OVERFLOW_CHECK(a, x, LONG_LONG_MAX, LONG_LONG_MIN)
 
#define SUBTRACTION_OVERFLOW_CHECK_i64(a, x) SUBTRACTION_OVERFLOW_CHECK(a, x, LONG_LONG_MAX, LONG_LONG_MIN)
 
#define MULTIPLICATION_OVERFLOW_CHECK_i64(a, x) MULTIPLICATION_OVERFLOW_CHECK(a, x, LONG_LONG_MAX, LONG_LONG_MIN)
 
#endif