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Diffstat (limited to 'common/math/integer.go')
-rw-r--r-- | common/math/integer.go | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/common/math/integer.go b/common/math/integer.go new file mode 100644 index 000000000..8162b1985 --- /dev/null +++ b/common/math/integer.go @@ -0,0 +1,25 @@ +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 +} |