common/math/integer.go


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package math

import gmath "math"

/*
 * NOTE: The following methods need to be optimised using either bit checking or asm
 */

// SafeSub returns subtraction result and whether overflow occurred.
func SafeSub(x, y uint64) (uint64, bool) {
    return x - y, x < y
}

// SafeAdd returns the result and whether overflow occurred.
func SafeAdd(x, y uint64) (uint64, bool) {
    return x + y, y > gmath.MaxUint64-x
}

// SafeMul returns multiplication result and whether overflow occurred.
func SafeMul(x, y uint64) (uint64, bool) {
    if x == 0 {
        return 0, false
    }
    return x * y, x != 0 && y != 0 && y > gmath.MaxUint64/x
}