diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/ecc/jacobian_mul.se')
-rw-r--r-- | Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/ecc/jacobian_mul.se | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/ecc/jacobian_mul.se b/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/ecc/jacobian_mul.se new file mode 100644 index 000000000..bf5b96bb4 --- /dev/null +++ b/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/examples/ecc/jacobian_mul.se @@ -0,0 +1,37 @@ +# Expected gas cost +# +# def expect(n, point_at_infinity=False): +# n = n % (2**256 - 432420386565659656852420866394968145599) +# if point_at_infinity: +# return 79 +# if n == 0: +# return 34479 +# L = int(1 + math.log(n) / math.log(2)) +# H = len([x for x in b.encode(n, 2) if x == '1']) +# return 34221 + 94 * L + 343 * H + +data DOUBLE +data ADD + +def init(): + self.DOUBLE = create('jacobian_double.se') + self.ADD = create('jacobian_add.se') + +def call(axn, axd, ayn, ayd, n): + n = mod(n, -432420386565659656852420866394968145599) + if !axn * !ayn + !n: # Constant-gas version of !axn and !ayn or !n + return([0, 1, 0, 1], 4) + with o = [0, 0, 1, 0, 1, 0, 0, 0, 0]: + with b = 2 ^ 255: + while gt(b, 0): + if n & b: + ~call(20000, self.DOUBLE, 0, o + 31, 129, o + 32, 128) + o[5] = axn + o[6] = axd + o[7] = ayn + o[8] = ayd + ~call(20000, self.ADD, 0, o + 31, 257, o + 32, 128) + else: + ~call(20000, self.DOUBLE, 0, o + 31, 129, o + 32, 128) + b = div(b, 2) + return(o + 32, 4) |