mirror of
https://github.com/fluencelabs/tendermint
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27 lines
507 B
Go
27 lines
507 B
Go
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package vm
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import (
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"math/big"
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)
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// To256
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//
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// "cast" the big int to a 256 big int (i.e., limit to)
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var tt256 = new(big.Int).Lsh(big.NewInt(1), 256)
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var tt256m1 = new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(1))
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var tt255 = new(big.Int).Lsh(big.NewInt(1), 255)
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func U256(x *big.Int) *big.Int {
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x.And(x, tt256m1)
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return x
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}
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func S256(x *big.Int) *big.Int {
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if x.Cmp(tt255) < 0 {
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return x
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} else {
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// We don't want to modify x, ever
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return new(big.Int).Sub(x, tt256)
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}
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}
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