diff --git a/fft/fft_tuning.h b/fft/fft_tuning.h
new file mode 100644
index 00000000..0500fdcb
--- /dev/null
+++ b/fft/fft_tuning.h
@@ -0,0 +1,52 @@
+/* mul_fft -- radix 2 fft routines for MPIR.
+
+Copyright 2009, 2011 William Hart. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are
+permitted provided that the following conditions are met:
+
+   1. Redistributions of source code must retain the above copyright notice, this list of
+      conditions and the following disclaimer.
+
+   2. Redistributions in binary form must reproduce the above copyright notice, this list
+      of conditions and the following disclaimer in the documentation and/or other materials
+      provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY William Hart ``AS IS'' AND ANY EXPRESS OR IMPLIED
+WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL William Hart OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+The views and conclusions contained in the software and documentation are those of the
+authors and should not be interpreted as representing official policies, either expressed
+or implied, of William Hart.
+
+*/
+
+/******************************************************************************
+
+    Copyright (C) 2011 William Hart
+ 
+******************************************************************************/
+
+#ifndef FFT_TUNING_H
+#define FFT_TUNING_H
+
+#include "mpir.h"
+
+#define FFT_MULMOD_2EXPP1_CUTOFF 250
+#define FFT_N_NUM 7
+
+#define MULMOD_TAB \
+    { { 3, 3 }, { 3, 3 }, { 3, 3 }, { 3, 2 }, { 2, 2 }, { 2, 2 }, { 1, 1 } }
+
+#define FFT_TAB \
+    { { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 1 }, { 1, 1 } }
+
+#endif
+
diff --git a/fft/mul_fft_main.c b/fft/mul_fft_main.c
new file mode 100644
index 00000000..e8642f06
--- /dev/null
+++ b/fft/mul_fft_main.c
@@ -0,0 +1,96 @@
+/* 
+
+Copyright 2009, 2011 William Hart. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are
+permitted provided that the following conditions are met:
+
+   1. Redistributions of source code must retain the above copyright notice, this list of
+      conditions and the following disclaimer.
+
+   2. Redistributions in binary form must reproduce the above copyright notice, this list
+      of conditions and the following disclaimer in the documentation and/or other materials
+      provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY William Hart ``AS IS'' AND ANY EXPRESS OR IMPLIED
+WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL William Hart OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+The views and conclusions contained in the software and documentation are those of the
+authors and should not be interpreted as representing official policies, either expressed
+or implied, of William Hart.
+
+*/
+
+#include "mpir.h"
+#include "gmp-impl.h"
+#include "longlong.h"
+#include "fft_tuning.h"
+
+static int fft_tuning_table[5][2] = FFT_TAB;
+
+void mpn_mul_fft_main(mp_limb_t * r1, mp_limb_t * i1, mp_size_t n1, 
+                        mp_limb_t * i2, mp_size_t n2)
+{
+   mp_size_t off, depth = 6;
+   mp_size_t w = 1;
+   mp_size_t n = ((mp_size_t) 1 << depth);
+   mp_bitcnt_t bits = (n*w - (depth+1))/2;
+
+   mp_bitcnt_t bits1 = n1*GMP_LIMB_BITS;
+   mp_bitcnt_t bits2 = n2*GMP_LIMB_BITS;
+
+   mp_size_t j1 = (bits1 - 1)/bits + 1;
+   mp_size_t j2 = (bits2 - 1)/bits + 1;
+
+   ASSERT(n1 > 0);
+   ASSERT(n2 > 0);
+   ASSERT(j1 + j2 - 1 > 2*n);
+
+   while (j1 + j2 - 1 > 4*n) /* find initial n, w */
+   {
+      if (w == 1) w = 2;
+      else 
+      {
+         depth++;
+         w = 1;
+         n *= 2;
+      }
+
+      bits = (n*w - (depth+1))/2;
+      j1 = (bits1 - 1)/bits + 1;
+      j2 = (bits2 - 1)/bits + 1;
+   }
+
+   if (depth < 11)
+   {
+      mp_size_t wadj = 1;
+      
+      off = fft_tuning_table[depth - 6][w]; /* adjust n and w */
+      depth -= off;
+      n = ((mp_size_t) 1 << depth);
+      w *= ((mp_size_t) 1 << (2*off));
+      
+      if (depth < 6) wadj = ((mp_size_t) 1 << (6 - depth));
+
+      if (w > wadj)
+      {
+         do { /* see if a smaller w will work */
+            w -= wadj;
+            bits = (n*w - (depth+1))/2;
+            j1 = (bits1 - 1)/bits + 1;
+            j2 = (bits2 - 1)/bits + 1;
+         } while (j1 + j2 - 1 <= 4*n && w > wadj);  
+         w += wadj;
+      }
+
+      mpn_mul_truncate_sqrt2(r1, i1, n1, i2, n2, depth, w);
+   } else
+      mpn_mul_mfa_truncate_sqrt2(r1, i1, n1, i2, n2, depth, w);
+}
\ No newline at end of file