--- /dev/null
+/* mpn_toom3_sqr -- Square {ap,an}.
+
+ Contributed to the GNU project by Torbjorn Granlund.
+
+ THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE. IT IS ONLY
+ SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST
+ GUARANTEED THAT IT WILL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
+
+Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
+
+
+/*
+ Things to work on:
+
+ 1. Trim allocation. The allocations for as1 and asm1 could be
+ avoided by instead reusing the pp area and the scratch area.
+ 2. Use new toom functions for the recursive calls.
+*/
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+/* Evaluate in: -1, 0, +1, +2, +inf
+
+ <-s-><--n--><--n--><--n-->
+ ___ ______ ______ ______
+ |a3_|___a2_|___a1_|___a0_|
+ |_b1_|___b0_|
+ <-t--><--n-->
+
+ v0 = a0 * b0 # A(0)*B(0)
+ v1 = (a0+ a1+ a2)*(b0+ b1+ b2) # A(1)*B(1) ah <= 2 bh <= 2
+ vm1 = (a0- a1+ a2)*(b0- b1+ b2) # A(-1)*B(-1) |ah| <= 1 bh <= 1
+ v2 = (a0+2a1+4a2)*(b0+2b1+4b2) # A(2)*B(2) ah <= 6 bh <= 6
+ vinf= a2 * b2 # A(inf)*B(inf)
+*/
+
+#if TUNE_PROGRAM_BUILD
+#define MAYBE_sqr_basecase 1
+#define MAYBE_sqr_toom3 1
+#else
+#define MAYBE_sqr_basecase \
+ (SQR_TOOM3_THRESHOLD < 3 * SQR_KARATSUBA_THRESHOLD)
+#define MAYBE_sqr_toom3 \
+ (SQR_TOOM4_THRESHOLD >= 3 * SQR_TOOM3_THRESHOLD)
+#endif
+
+#define TOOM3_SQR_N_REC(p, a, n, ws) \
+ do { \
+ if (MAYBE_sqr_basecase \
+ && BELOW_THRESHOLD (n, SQR_KARATSUBA_THRESHOLD)) \
+ mpn_sqr_basecase (p, a, n); \
+ else if (! MAYBE_sqr_toom3 \
+ || BELOW_THRESHOLD (n, SQR_TOOM3_THRESHOLD)) \
+ mpn_kara_sqr_n (p, a, n, ws); \
+ else \
+ mpn_toom3_sqr_n (p, a, n, ws); \
+ } while (0)
+
+void
+mpn_toom3_sqr (mp_ptr pp,
+ mp_srcptr ap, mp_size_t an,
+ mp_ptr scratch)
+{
+ mp_size_t n, s;
+ mp_limb_t cy, vinf0;
+ mp_ptr gp;
+ mp_ptr as1, asm1, as2;
+ TMP_DECL;
+
+#define a0 ap
+#define a1 (ap + n)
+#define a2 (ap + 2*n)
+
+ n = (an + 2) / (size_t) 3;
+
+ s = an - 2 * n;
+
+ ASSERT (0 < s && s <= n);
+
+ TMP_MARK;
+
+ as1 = TMP_SALLOC_LIMBS (n + 1);
+ asm1 = TMP_SALLOC_LIMBS (n + 1);
+ as2 = TMP_SALLOC_LIMBS (n + 1);
+
+ gp = pp;
+
+ /* Compute as1 and asm1. */
+ cy = mpn_add (gp, a0, n, a2, s);
+#if HAVE_NATIVE_mpn_addsub_n
+ if (cy == 0 && mpn_cmp (gp, a1, n) < 0)
+ {
+ cy = mpn_addsub_n (as1, asm1, a1, gp, n);
+ as1[n] = 0;
+ asm1[n] = 0;
+ }
+ else
+ {
+ cy2 = mpn_addsub_n (as1, asm1, gp, a1, n);
+ as1[n] = cy + (cy2 >> 1);
+ asm1[n] = cy - (cy & 1);
+ }
+#else
+ as1[n] = cy + mpn_add_n (as1, gp, a1, n);
+ if (cy == 0 && mpn_cmp (gp, a1, n) < 0)
+ {
+ mpn_sub_n (asm1, a1, gp, n);
+ asm1[n] = 0;
+ }
+ else
+ {
+ cy -= mpn_sub_n (asm1, gp, a1, n);
+ asm1[n] = cy;
+ }
+#endif
+
+ /* Compute as2. */
+#if HAVE_NATIVE_mpn_addlsh1_n
+ cy = mpn_addlsh1_n (as2, a1, a2, s);
+ if (s != n)
+ cy = mpn_add_1 (as2 + s, a1 + s, n - s, cy);
+ cy = 2 * cy + mpn_addlsh1_n (as2, a0, as2, n);
+#else
+ cy = mpn_lshift (as2, a2, s, 1);
+ cy += mpn_add_n (as2, a1, as2, s);
+ if (s != n)
+ cy = mpn_add_1 (as2 + s, a1 + s, n - s, cy);
+ cy = 2 * cy + mpn_lshift (as2, as2, n, 1);
+ cy += mpn_add_n (as2, a0, as2, n);
+#endif
+ as2[n] = cy;
+
+ ASSERT (as1[n] <= 2);
+ ASSERT (asm1[n] <= 1);
+
+#define v0 pp /* 2n */
+#define v1 (pp + 2 * n) /* 2n+1 */
+#define vinf (pp + 4 * n) /* s+s */
+#define vm1 scratch /* 2n+1 */
+#define v2 (scratch + 2 * n + 1) /* 2n+2 */
+#define scratch_out (scratch + 4 * n + 4)
+
+ /* vm1, 2n+1 limbs */
+#ifdef SMALLER_RECURSION
+ TOOM3_SQR_N_REC (vm1, asm1, n, scratch_out);
+ cy = 0;
+ if (asm1[n] != 0)
+ cy = asm1[n] + mpn_add_n (vm1 + n, vm1 + n, asm1, n);
+ if (asm1[n] != 0)
+ cy += mpn_add_n (vm1 + n, vm1 + n, asm1, n);
+ vm1[2 * n] = cy;
+#else
+ TOOM3_SQR_N_REC (vm1, asm1, n + 1, scratch_out);
+#endif
+
+ TOOM3_SQR_N_REC (v2, as2, n + 1, scratch_out); /* v2, 2n+1 limbs */
+
+ TOOM3_SQR_N_REC (vinf, a2, s, scratch_out); /* vinf, s+s limbs */
+
+ vinf0 = vinf[0]; /* v1 overlaps with this */
+
+#ifdef SMALLER_RECURSION
+ /* v1, 2n+1 limbs */
+ TOOM3_SQR_N_REC (v1, as1, n, scratch_out);
+ if (as1[n] == 1)
+ {
+ cy = as1[n] + mpn_add_n (v1 + n, v1 + n, as1, n);
+ }
+ else if (as1[n] != 0)
+ {
+#if HAVE_NATIVE_mpn_addlsh1_n
+ cy = 2 * as1[n] + mpn_addlsh1_n (v1 + n, v1 + n, as1, n);
+#else
+ cy = 2 * as1[n] + mpn_addmul_1 (v1 + n, as1, n, CNST_LIMB(2));
+#endif
+ }
+ else
+ cy = 0;
+ if (as1[n] == 1)
+ {
+ cy += mpn_add_n (v1 + n, v1 + n, as1, n);
+ }
+ else if (as1[n] != 0)
+ {
+#if HAVE_NATIVE_mpn_addlsh1_n
+ cy += mpn_addlsh1_n (v1 + n, v1 + n, as1, n);
+#else
+ cy += mpn_addmul_1 (v1 + n, as1, n, CNST_LIMB(2));
+#endif
+ }
+ v1[2 * n] = cy;
+#else
+ cy = vinf[1];
+ TOOM3_SQR_N_REC (v1, as1, n + 1, scratch_out);
+ vinf[1] = cy;
+#endif
+
+ TOOM3_SQR_N_REC (v0, ap, n, scratch_out); /* v0, 2n limbs */
+
+ mpn_toom_interpolate_5pts (pp, v2, vm1, n, s + s, 1, vinf0, scratch_out);
+
+ TMP_FREE;
+}
projects / msp430-gcc.git / blobdiff