+static Value *getPow(Value *InnerChain[33], unsigned Exp, IRBuilder<> &B) {
+ // Multiplications calculated using Addition Chains.
+ // Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
+
+ assert(Exp != 0 && "Incorrect exponent 0 not handled");
+
+ if (InnerChain[Exp])
+ return InnerChain[Exp];
+
+ static const unsigned AddChain[33][2] = {
+ {0, 0}, // Unused.
+ {0, 0}, // Unused (base case = pow1).
+ {1, 1}, // Unused (pre-computed).
+ {1, 2}, {2, 2}, {2, 3}, {3, 3}, {2, 5}, {4, 4},
+ {1, 8}, {5, 5}, {1, 10}, {6, 6}, {4, 9}, {7, 7},
+ {3, 12}, {8, 8}, {8, 9}, {2, 16}, {1, 18}, {10, 10},
+ {6, 15}, {11, 11}, {3, 20}, {12, 12}, {8, 17}, {13, 13},
+ {3, 24}, {14, 14}, {4, 25}, {15, 15}, {3, 28}, {16, 16},
+ };
+
+ InnerChain[Exp] = B.CreateFMul(getPow(InnerChain, AddChain[Exp][0], B),
+ getPow(InnerChain, AddChain[Exp][1], B));
+ return InnerChain[Exp];
+}
+