Inline the round functions of RC2. This is about 15% faster on my machine,

and actually reduced the total line count.

2 files changed, 49 insertions, 56 deletions

diff --git a/include/rc2.h b/include/rc2.h
index c29ba0d66..e83b44eb2 100644
--- a/include/rc2.h
+++ b/include/rc2.h
@@ -26,10 +26,7 @@ class RC2 : public BlockCipher
       void enc(const byte[], byte[]) const;
       void dec(const byte[], byte[]) const;
       void key(const byte[], u32bit);
-      void mash(u16bit&, u16bit&, u16bit&, u16bit&) const;
-      void rmash(u16bit&, u16bit&, u16bit&, u16bit&) const;
-      void mix(u16bit&, u16bit&, u16bit&, u16bit&, u32bit) const;
-      void rmix(u16bit&, u16bit&, u16bit&, u16bit&, u32bit) const;
+
       SecureBuffer<u16bit, 64> K;
    };
 
diff --git a/src/rc2.cpp b/src/rc2.cpp
index fb81b2d1f..0e35950e7 100644
--- a/src/rc2.cpp
+++ b/src/rc2.cpp
@@ -15,12 +15,30 @@ void RC2::enc(const byte in[], byte out[]) const
    {
    u16bit R0 = make_u16bit(in[1], in[0]), R1 = make_u16bit(in[3], in[2]),
           R2 = make_u16bit(in[5], in[4]), R3 = make_u16bit(in[7], in[6]);
-   mix(R0, R1, R2, R3, 0); mix(R0, R1, R2, R3, 1); mix(R0, R1, R2, R3, 2);
-   mix(R0, R1, R2, R3, 3); mix(R0, R1, R2, R3, 4); mash(R0, R1, R2, R3);
-   mix(R0, R1, R2, R3, 5); mix(R0, R1, R2, R3, 6); mix(R0, R1, R2, R3, 7);
-   mix(R0, R1, R2, R3, 8); mix(R0, R1, R2, R3, 9); mix(R0, R1, R2, R3,10);
-   mash(R0, R1, R2, R3);   mix(R0, R1, R2, R3,11); mix(R0, R1, R2, R3,12);
-   mix(R0, R1, R2, R3,13); mix(R0, R1, R2, R3,14); mix(R0, R1, R2, R3,15);
+
+   for(u32bit j = 0; j != 16; j++)
+      {
+      R0 += (R1 & ~R3) + (R2 & R3) + K[4*j];
+      R0 = rotate_left(R0, 1);
+
+      R1 += (R2 & ~R0) + (R3 & R0) + K[4*j + 1];
+      R1 = rotate_left(R1, 2);
+
+      R2 += (R3 & ~R1) + (R0 & R1) + K[4*j + 2];
+      R2 = rotate_left(R2, 3);
+
+      R3 += (R0 & ~R2) + (R1 & R2) + K[4*j + 3];
+      R3 = rotate_left(R3, 5);
+
+      if(j == 4 || j == 10)
+         {
+         R0 += K[R3 % 64];
+         R1 += K[R0 % 64];
+         R2 += K[R1 % 64];
+         R3 += K[R2 % 64];
+         }
+      }
+
    out[0] = get_byte(1, R0); out[1] = get_byte(0, R0);
    out[2] = get_byte(1, R1); out[3] = get_byte(0, R1);
    out[4] = get_byte(1, R2); out[5] = get_byte(0, R2);
@@ -34,56 +52,34 @@ void RC2::dec(const byte in[], byte out[]) const
    {
    u16bit R0 = make_u16bit(in[1], in[0]), R1 = make_u16bit(in[3], in[2]),
           R2 = make_u16bit(in[5], in[4]), R3 = make_u16bit(in[7], in[6]);
-   rmix(R0, R1, R2, R3,15); rmix(R0, R1, R2, R3,14); rmix(R0, R1, R2, R3,13);
-   rmix(R0, R1, R2, R3,12); rmix(R0, R1, R2, R3,11); rmash(R0, R1, R2, R3);
-   rmix(R0, R1, R2, R3,10); rmix(R0, R1, R2, R3, 9); rmix(R0, R1, R2, R3, 8);
-   rmix(R0, R1, R2, R3, 7); rmix(R0, R1, R2, R3, 6); rmix(R0, R1, R2, R3, 5);
-   rmash(R0, R1, R2, R3);   rmix(R0, R1, R2, R3, 4); rmix(R0, R1, R2, R3, 3);
-   rmix(R0, R1, R2, R3, 2); rmix(R0, R1, R2, R3, 1); rmix(R0, R1, R2, R3, 0);
-   out[0] = get_byte(1, R0); out[1] = get_byte(0, R0);
-   out[2] = get_byte(1, R1); out[3] = get_byte(0, R1);
-   out[4] = get_byte(1, R2); out[5] = get_byte(0, R2);
-   out[6] = get_byte(1, R3); out[7] = get_byte(0, R3);
-   }
 
-/*************************************************
-* RC2 Mix Function                               *
-*************************************************/
-void RC2::mix(u16bit& R0, u16bit& R1, u16bit& R2,
-              u16bit& R3, u32bit round) const
-   {
-   R0 += (R1 & ~R3) + (R2 & R3) + K[4*round    ]; R0 = rotate_left(R0, 1);
-   R1 += (R2 & ~R0) + (R3 & R0) + K[4*round + 1]; R1 = rotate_left(R1, 2);
-   R2 += (R3 & ~R1) + (R0 & R1) + K[4*round + 2]; R2 = rotate_left(R2, 3);
-   R3 += (R0 & ~R2) + (R1 & R2) + K[4*round + 3]; R3 = rotate_left(R3, 5);
-   }
+   for(u32bit j = 0; j != 16; j++)
+      {
+      R3 = rotate_right(R3, 5);
+      R3 -= (R0 & ~R2) + (R1 & R2) + K[63 - (4*j + 0)];
 
-/*************************************************
-* RC2 R-Mix Function                             *
-*************************************************/
-void RC2::rmix(u16bit& R0, u16bit& R1, u16bit& R2,
-               u16bit& R3, u32bit round) const
-   {
-   R3 = rotate_right(R3, 5); R3 -= (R0 & ~R2) + (R1 & R2) + K[4*round + 3];
-   R2 = rotate_right(R2, 3); R2 -= (R3 & ~R1) + (R0 & R1) + K[4*round + 2];
-   R1 = rotate_right(R1, 2); R1 -= (R2 & ~R0) + (R3 & R0) + K[4*round + 1];
-   R0 = rotate_right(R0, 1); R0 -= (R1 & ~R3) + (R2 & R3) + K[4*round + 0];
-   }
+      R2 = rotate_right(R2, 3);
+      R2 -= (R3 & ~R1) + (R0 & R1) + K[63 - (4*j + 1)];
 
-/*************************************************
-* RC2 Mash Function                              *
-*************************************************/
-void RC2::mash(u16bit& R0, u16bit& R1, u16bit& R2, u16bit& R3) const
-   {
-   R0 += K[R3 % 64]; R1 += K[R0 % 64]; R2 += K[R1 % 64]; R3 += K[R2 % 64];
-   }
+      R1 = rotate_right(R1, 2);
+      R1 -= (R2 & ~R0) + (R3 & R0) + K[63 - (4*j + 2)];
 
-/*************************************************
-* RC2 R-Mash Function                            *
-*************************************************/
-void RC2::rmash(u16bit& R0, u16bit& R1, u16bit& R2, u16bit& R3) const
-   {
-   R3 -= K[R2 % 64]; R2 -= K[R1 % 64]; R1 -= K[R0 % 64]; R0 -= K[R3 % 64];
+      R0 = rotate_right(R0, 1);
+      R0 -= (R1 & ~R3) + (R2 & R3) + K[63 - (4*j + 3)];
+
+      if(j == 4 || j == 10)
+         {
+         R3 -= K[R2 % 64];
+         R2 -= K[R1 % 64];
+         R1 -= K[R0 % 64];
+         R0 -= K[R3 % 64];
+         }
+      }
+
+   out[0] = get_byte(1, R0); out[1] = get_byte(0, R0);
+   out[2] = get_byte(1, R1); out[3] = get_byte(0, R1);
+   out[4] = get_byte(1, R2); out[5] = get_byte(0, R2);
+   out[6] = get_byte(1, R3); out[7] = get_byte(0, R3);
    }
 
 /*************************************************