1 files changed, 112 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/bignum.cpp b/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/bignum.cpp
new file mode 100644
index 000000000..108b1eb04
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/ethereum/serpent-go/serpent/bignum.cpp
@@ -0,0 +1,112 @@
+#include <stdio.h>
+#include <iostream>
+#include <vector>
+#include <map>
+#include "bignum.h"
+
+//Integer to string conversion
+std::string unsignedToDecimal(unsigned branch) {
+    if (branch < 10) return nums.substr(branch, 1);
+    else return unsignedToDecimal(branch / 10) + nums.substr(branch % 10,1);
+}
+
+//Add two strings representing decimal values
+std::string decimalAdd(std::string a, std::string b) {
+    std::string o = a;
+    while (b.length() < a.length()) b = "0" + b;
+    while (o.length() < b.length()) o = "0" + o;
+    bool carry = false;
+    for (int i = o.length() - 1; i >= 0; i--) {
+        o[i] = o[i] + b[i] - '0';
+        if (carry) o[i]++;
+        if (o[i] > '9') {
+            o[i] -= 10;
+            carry = true;
+        }
+        else carry = false;
+    }
+    if (carry) o = "1" + o;
+    return o;
+}
+
+//Helper function for decimalMul
+std::string decimalDigitMul(std::string a, int dig) {
+    if (dig == 0) return "0";
+    else return decimalAdd(a, decimalDigitMul(a, dig - 1));
+}
+
+//Multiply two strings representing decimal values
+std::string decimalMul(std::string a, std::string b) {
+    std::string o = "0";
+	for (unsigned i = 0; i < b.length(); i++) {
+        std::string n = decimalDigitMul(a, b[i] - '0');
+        if (n != "0") {
+			for (unsigned j = i + 1; j < b.length(); j++) n += "0";
+        }
+        o = decimalAdd(o, n);
+    }
+    return o;
+}
+
+//Modexp
+std::string decimalModExp(std::string b, std::string e, std::string m) {
+    if (e == "0") return "1";
+    else if (e == "1") return b;
+    else if (decimalMod(e, "2") == "0") {
+        std::string o = decimalModExp(b, decimalDiv(e, "2"), m);
+        return decimalMod(decimalMul(o, o), m);
+    }
+    else {
+        std::string o = decimalModExp(b, decimalDiv(e, "2"), m);
+        return decimalMod(decimalMul(decimalMul(o, o), b), m);
+    }
+}
+
+//Is a greater than b? Flag allows equality
+bool decimalGt(std::string a, std::string b, bool eqAllowed) {
+    if (a == b) return eqAllowed;
+    return (a.length() > b.length()) || (a.length() >= b.length() && a > b);
+}
+
+//Subtract the two strings representing decimal values
+std::string decimalSub(std::string a, std::string b) {
+    if (b == "0") return a;
+    if (b == a) return "0";
+    while (b.length() < a.length()) b = "0" + b;
+    std::string c = b;
+	for (unsigned i = 0; i < c.length(); i++) c[i] = '0' + ('9' - c[i]);
+    std::string o = decimalAdd(decimalAdd(a, c).substr(1), "1");
+    while (o.size() > 1 && o[0] == '0') o = o.substr(1);
+    return o;
+}
+
+//Divide the two strings representing decimal values
+std::string decimalDiv(std::string a, std::string b) {
+    std::string c = b;
+    if (decimalGt(c, a)) return "0";
+    int zeroes = -1;
+    while (decimalGt(a, c, true)) {
+        zeroes += 1;
+        c = c + "0";
+    }
+    c = c.substr(0, c.size() - 1);
+    std::string quot = "0";
+    while (decimalGt(a, c, true)) {
+        a = decimalSub(a, c);
+        quot = decimalAdd(quot, "1");
+    }
+    for (int i = 0; i < zeroes; i++) quot += "0";
+    return decimalAdd(quot, decimalDiv(a, b));
+}
+
+//Modulo the two strings representing decimal values
+std::string decimalMod(std::string a, std::string b) {
+    return decimalSub(a, decimalMul(decimalDiv(a, b), b));
+}
+
+//String to int conversion
+unsigned decimalToUnsigned(std::string a) {
+    if (a.size() == 0) return 0;
+    else return (a[a.size() - 1] - '0') 
+        + decimalToUnsigned(a.substr(0,a.size()-1)) * 10;
+}