116 lines
3.7 KiB
C
116 lines
3.7 KiB
C
/*
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Copyright 2009, 2011 William Hart. All rights reserved.
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Redistribution and use in source and binary forms, with or without modification, are
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permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright notice, this list of
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conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright notice, this list
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of conditions and the following disclaimer in the documentation and/or other materials
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provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY William Hart ``AS IS'' AND ANY EXPRESS OR IMPLIED
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WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL William Hart OR
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CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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The views and conclusions contained in the software and documentation are those of the
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authors and should not be interpreted as representing official policies, either expressed
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or implied, of William Hart.
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*/
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#include "stdlib.h"
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#include "mpir.h"
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#include "gmp-impl.h"
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void fft_combine_limbs(mp_limb_t * res, mp_limb_t ** poly, long length,
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mp_size_t coeff_limbs, mp_size_t output_limbs, mp_size_t total_limbs)
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{
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mp_size_t skip, i;
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for (skip = 0, i = 0; i < length && skip + output_limbs <= total_limbs; i++, skip += coeff_limbs)
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mpn_add(res + skip, res + skip, output_limbs + 1, poly[i], output_limbs);
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while ((skip < total_limbs) && (i < length))
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{
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mpn_add(res + skip, res + skip, total_limbs - skip, poly[i], MIN(total_limbs - skip, output_limbs));
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i++;
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skip += coeff_limbs;
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}
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}
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void fft_combine_bits(mp_limb_t * res, mp_limb_t ** poly, long length,
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mp_bitcnt_t bits, mp_size_t output_limbs, mp_size_t total_limbs)
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{
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mp_bitcnt_t shift_bits, top_bits = ((GMP_LIMB_BITS - 1) & bits);
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mp_size_t coeff_limbs, i;
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mp_limb_t * temp, * limb_ptr, * end;
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TMP_DECL;
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if (top_bits == 0)
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{
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fft_combine_limbs(res, poly, length, bits/GMP_LIMB_BITS, output_limbs, total_limbs);
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return;
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}
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TMP_MARK;
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coeff_limbs = (bits/GMP_LIMB_BITS) + 1;
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temp = TMP_BALLOC_LIMBS(output_limbs + 1);
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shift_bits = 0;
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limb_ptr = res;
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end = res + total_limbs;
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for (i = 0; i < length && limb_ptr + output_limbs < end; i++)
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{
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if (shift_bits)
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{
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mpn_lshift(temp, poly[i], output_limbs + 1, shift_bits);
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mpn_add_n(limb_ptr, limb_ptr, temp, output_limbs + 1);
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} else
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mpn_add(limb_ptr, limb_ptr, output_limbs + 1, poly[i], output_limbs);
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shift_bits += top_bits;
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limb_ptr += (coeff_limbs - 1);
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if (shift_bits >= GMP_LIMB_BITS)
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{
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limb_ptr++;
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shift_bits -= GMP_LIMB_BITS;
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}
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}
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while (limb_ptr < end && i < length)
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{
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if (shift_bits)
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{
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mpn_lshift(temp, poly[i], output_limbs + 1, shift_bits);
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mpn_add_n(limb_ptr, limb_ptr, temp, end - limb_ptr);
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} else
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mpn_add_n(limb_ptr, limb_ptr, poly[i], end - limb_ptr);
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shift_bits += top_bits;
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limb_ptr += (coeff_limbs - 1);
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if (shift_bits >= GMP_LIMB_BITS)
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{
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limb_ptr++;
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shift_bits -= GMP_LIMB_BITS;
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}
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i++;
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}
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TMP_FREE;
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}
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