ALL: Add flint

external/flint-2.4.3/fft/split_bits.c

@@ -0,0 +1,110 @@
+/* 
+
+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 "gmp.h"
+#include "flint.h"
+#include "fft.h"
+
+mp_size_t fft_split_limbs(mp_limb_t ** poly, mp_srcptr limbs, 
+                mp_size_t total_limbs, mp_size_t coeff_limbs, mp_size_t output_limbs)
+{
+   mp_size_t i, skip, length = (total_limbs - 1)/coeff_limbs + 1;
+   
+   for (skip = 0, i = 0; skip + coeff_limbs <= total_limbs; skip += coeff_limbs, i++)
+   {
+      flint_mpn_zero(poly[i], output_limbs + 1);
+      flint_mpn_copyi(poly[i], limbs + skip, coeff_limbs);
+   }
+   
+   if (i < length) 
+      flint_mpn_zero(poly[i], output_limbs + 1);
+   
+   if (total_limbs > skip) 
+      flint_mpn_copyi(poly[i], limbs + skip, total_limbs - skip);
+   
+   return length;
+}
+
+mp_size_t fft_split_bits(mp_limb_t ** poly, mp_srcptr limbs, 
+               mp_size_t total_limbs, mp_bitcnt_t bits, mp_size_t output_limbs)
+{
+   mp_size_t i, coeff_limbs, limbs_left, length = (FLINT_BITS*total_limbs - 1)/bits + 1;
+   mp_bitcnt_t shift_bits, top_bits = ((FLINT_BITS - 1) & bits);
+   mp_srcptr limb_ptr;
+   mp_limb_t mask;
+   
+   if (top_bits == 0)
+      return fft_split_limbs(poly, limbs, total_limbs, bits/FLINT_BITS, output_limbs);
+
+   coeff_limbs = (bits/FLINT_BITS) + 1;
+   mask = (WORD(1)<<top_bits) - WORD(1);
+   shift_bits = WORD(0);
+   limb_ptr = limbs;                      
+    
+   for (i = 0; i < length - 1; i++)
+   {
+      flint_mpn_zero(poly[i], output_limbs + 1);
+      
+      if (!shift_bits)
+      {
+         flint_mpn_copyi(poly[i], limb_ptr, coeff_limbs);
+         poly[i][coeff_limbs - 1] &= mask;
+         limb_ptr += (coeff_limbs - 1);
+         shift_bits += top_bits;
+      } else
+      {
+         mpn_rshift(poly[i], limb_ptr, coeff_limbs, shift_bits);
+         limb_ptr += (coeff_limbs - 1);
+         shift_bits += top_bits;
+
+         if (shift_bits >= FLINT_BITS)
+         {
+            limb_ptr++;
+            poly[i][coeff_limbs - 1] += (limb_ptr[0] << (FLINT_BITS - (shift_bits - top_bits)));
+            shift_bits -= FLINT_BITS; 
+         }
+         
+         poly[i][coeff_limbs - 1] &= mask;
+         
+      } 
+   }
+   
+   flint_mpn_zero(poly[i], output_limbs + 1);
+   
+   limbs_left = total_limbs - (limb_ptr - limbs);
+   
+   if (!shift_bits)
+      flint_mpn_copyi(poly[i], limb_ptr, limbs_left);
+   else
+      mpn_rshift(poly[i], limb_ptr, limbs_left, shift_bits);                   
+     
+   return length;
+}
+