104 lines
3.1 KiB
C
104 lines
3.1 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 "mpir.h"
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#include "gmp-impl.h"
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#include "longlong.h"
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static int mpir_fft_tuning_table[5][2] = FFT_TAB;
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void
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mpn_mul_fft_main(mp_ptr r1, mp_srcptr i1, mp_size_t n1, mp_srcptr i2, mp_size_t n2)
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{
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mp_size_t off, depth = 6;
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mp_size_t w = 1;
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mp_size_t n = ((mp_size_t) 1 << depth);
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mp_bitcnt_t bits = (n*w - (depth+1))/2;
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mp_bitcnt_t bits1 = n1*GMP_LIMB_BITS;
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mp_bitcnt_t bits2 = n2*GMP_LIMB_BITS;
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mp_size_t j1 = (bits1 - 1)/bits + 1;
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mp_size_t j2 = (bits2 - 1)/bits + 1;
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ASSERT(n1 > 0);
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ASSERT(n2 > 0);
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ASSERT(j1 + j2 - 1 > 2*n);
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while (j1 + j2 - 1 > 4*n) /* find initial n, w */
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{
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if (w == 1) w = 2;
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else
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{
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depth++;
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w = 1;
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n *= 2;
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}
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bits = (n*w - (depth+1))/2;
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j1 = (bits1 - 1)/bits + 1;
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j2 = (bits2 - 1)/bits + 1;
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}
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if (depth < 11)
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{
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mp_size_t wadj = 1;
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off = mpir_fft_tuning_table[depth - 6][w - 1]; /* adjust n and w */
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depth -= off;
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n = ((mp_size_t) 1 << depth);
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w *= ((mp_size_t) 1 << (2*off));
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if (depth < 6) wadj = ((mp_size_t) 1 << (6 - depth));
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if (w > wadj)
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{
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do { /* see if a smaller w will work */
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w -= wadj;
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bits = (n*w - (depth+1))/2;
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j1 = (bits1 - 1)/bits + 1;
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j2 = (bits2 - 1)/bits + 1;
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} while (j1 + j2 - 1 <= 4*n && w > wadj);
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w += wadj;
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}
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mpn_mul_trunc_sqrt2(r1, i1, n1, i2, n2, depth, w);
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} else
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{
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if (j1 + j2 - 1 <= 3*n)
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{
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depth--;
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w *= 3;
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}
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mpn_mul_mfa_trunc_sqrt2(r1, i1, n1, i2, n2, depth, w);
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}
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}
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