Add operator*(BigInt, word)

Gets hit about 2 million times in the test suite, avoids creating
a temp BigInt (with alloc+free) or checking size of y.

2 files changed, 21 insertions, 0 deletions

diff --git a/src/lib/math/bigint/big_ops3.cpp b/src/lib/math/bigint/big_ops3.cpp
index 492a69ad0..3f34e0bf1 100644
--- a/src/lib/math/bigint/big_ops3.cpp
+++ b/src/lib/math/bigint/big_ops3.cpp
@@ -126,6 +126,24 @@ BigInt operator*(const BigInt& x, const BigInt& y)
    }
 
 /*
+* Multiplication Operator
+*/
+BigInt operator*(const BigInt& x, word y)
+   {
+   const size_t x_sw = x.sig_words();
+
+   BigInt z(BigInt::Positive, x_sw + 1);
+
+   if(x_sw && y)
+      {
+      bigint_linmul3(z.mutable_data(), x.data(), x_sw, y);
+      z.set_sign(x.sign());
+      }
+
+   return z;
+   }
+
+/*
 * Division Operator
 */
 BigInt operator/(const BigInt& x, const BigInt& y)
diff --git a/src/lib/math/bigint/bigint.h b/src/lib/math/bigint/bigint.h
index 0d35cbbeb..8a434e6bb 100644
--- a/src/lib/math/bigint/bigint.h
+++ b/src/lib/math/bigint/bigint.h
@@ -842,6 +842,9 @@ BigInt BOTAN_PUBLIC_API(2,0) operator-(const BigInt& x, const BigInt& y);
 BigInt BOTAN_PUBLIC_API(2,7) operator-(const BigInt& x, word y);
 
 BigInt BOTAN_PUBLIC_API(2,0) operator*(const BigInt& x, const BigInt& y);
+BigInt BOTAN_PUBLIC_API(2,8) operator*(const BigInt& x, word y);
+inline BigInt operator*(word x, const BigInt& y) { return y*x; }
+
 BigInt BOTAN_PUBLIC_API(2,0) operator/(const BigInt& x, const BigInt& d);
 BigInt BOTAN_PUBLIC_API(2,0) operator%(const BigInt& x, const BigInt& m);
 word   BOTAN_PUBLIC_API(2,0) operator%(const BigInt& x, word m);