--- /dev/null
+/* mpn_toom_interpolate_5pts -- Interpolate for toom3, 33, 42.
+
+ Contributed to the GNU project by Robert Harley.
+ Improvements by Paul Zimmermann and Marco Bodrato.
+
+ 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 2000, 2001, 2002, 2003, 2005, 2006, 2007 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/. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+void
+mpn_toom_interpolate_5pts (mp_ptr c, mp_ptr v2, mp_ptr vm1,
+ mp_size_t k, mp_size_t twor, int sa,
+ mp_limb_t vinf0, mp_ptr ws)
+{
+ mp_limb_t cy, saved;
+ mp_size_t twok = k + k;
+ mp_size_t kk1 = twok + 1;
+ mp_ptr c1, v1, c3, vinf, c5;
+ mp_limb_t cout; /* final carry, should be zero at the end */
+
+ c1 = c + k;
+ v1 = c1 + k;
+ c3 = v1 + k;
+ vinf = c3 + k;
+ c5 = vinf + k;
+
+#define v0 (c)
+ /* (1) v2 <- v2-vm1 < v2+|vm1|, (16 8 4 2 1) - (1 -1 1 -1 1) =
+ thus 0 <= v2 < 50*B^(2k) < 2^6*B^(2k) (15 9 3 3 0)
+ */
+ if (sa <= 0)
+ mpn_add_n (v2, v2, vm1, kk1);
+ else
+ mpn_sub_n (v2, v2, vm1, kk1);
+
+ /* {c,2k} {c+2k,2k+1} {c+4k+1,2r-1} {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 v1 hi(vinf) |vm1| v2-vm1 EMPTY */
+
+ ASSERT_NOCARRY (mpn_divexact_by3 (v2, v2, kk1)); /* v2 <- v2 / 3 */
+ /* (5 3 1 1 0)*/
+
+ /* {c,2k} {c+2k,2k+1} {c+4k+1,2r-1} {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 v1 hi(vinf) |vm1| (v2-vm1)/3 EMPTY */
+
+ /* (2) vm1 <- tm1 := (v1 - sa*vm1) / 2 [(1 1 1 1 1) - (1 -1 1 -1 1)] / 2 =
+ tm1 >= 0 (0 1 0 1 0)
+ No carry comes out from {v1, kk1} +/- {vm1, kk1},
+ and the division by two is exact */
+ if (sa <= 0)
+ {
+#ifdef HAVE_NATIVE_mpn_rsh1add_n
+ mpn_rsh1add_n (vm1, v1, vm1, kk1);
+#else
+ mpn_add_n (vm1, v1, vm1, kk1);
+ mpn_rshift (vm1, vm1, kk1, 1);
+#endif
+ }
+ else
+ {
+#ifdef HAVE_NATIVE_mpn_rsh1sub_n
+ mpn_rsh1sub_n (vm1, v1, vm1, kk1);
+#else
+ mpn_sub_n (vm1, v1, vm1, kk1);
+ mpn_rshift (vm1, vm1, kk1, 1);
+#endif
+ }
+
+ /* {c,2k} {c+2k,2k+1} {c+4k+1,2r-1} {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 v1 hi(vinf) tm1 (v2-vm1)/3 EMPTY */
+
+ /* (3) v1 <- t1 := v1 - v0 (1 1 1 1 1) - (0 0 0 0 1) = (1 1 1 1 0)
+ t1 >= 0
+ */
+ vinf[0] -= mpn_sub_n (v1, v1, c, twok);
+
+ /* {c,2k} {c+2k,2k+1} {c+4k+1,2r-1} {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 v1-v0 hi(vinf) tm1 (v2-vm1)/3 EMPTY */
+
+ /* (4) v2 <- t2 := ((v2-vm1)/3-t1)/2 = (v2-vm1-3*t1)/6
+ t2 >= 0 [(5 3 1 1 0) - (1 1 1 1 0)]/2 = (2 1 0 0 0)
+ */
+#ifdef HAVE_NATIVE_mpn_rsh1sub_n
+ mpn_rsh1sub_n (v2, v2, v1, kk1);
+#else
+ mpn_sub_n (v2, v2, v1, kk1);
+ mpn_rshift (v2, v2, kk1, 1);
+#endif
+
+ /* {c,2k} {c+2k,2k+1} {c+4k+1,2r-1} {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 v1-v0 hi(vinf) tm1 (v2-vm1-3t1)/6 EMPTY */
+
+ /* (5) v1 <- t1-tm1 (1 1 1 1 0) - (0 1 0 1 0) = (1 0 1 0 0)
+ result is v1 >= 0
+ */
+ mpn_sub_n (v1, v1, vm1, kk1);
+
+ /* {c,2k} {c+2k,2k+1} {c+4k+1,2r-1} {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 v1-v0-tm1 hi(vinf) tm1 (v2-vm1-3t1)/6 EMPTY */
+
+ /* (6) v2 <- v2 - 2*vinf, (2 1 0 0 0) - 2*(1 0 0 0 0) = (0 1 0 0 0)
+ result is v2 >= 0 */
+ saved = vinf[0]; /* Remember v1's highest byte (will be overwritten). */
+ vinf[0] = vinf0; /* Set the right value for vinf0 */
+#ifdef HAVE_NATIVE_mpn_sublsh1_n
+ cy = mpn_sublsh1_n (v2, v2, vinf, twor);
+#else
+ cy = mpn_lshift (ws, vinf, twor, 1);
+ cy += mpn_sub_n (v2, v2, ws, twor);
+#endif
+ MPN_DECR_U (v2 + twor, kk1 - twor, cy);
+
+ /* (7) v1 <- v1 - vinf, (1 0 1 0 0) - (1 0 0 0 0) = (0 0 1 0 0)
+ result is >= 0 */
+ cy = mpn_sub_n (v1, v1, vinf, twor); /* vinf is at most twor long. */
+ vinf[0] = saved;
+ MPN_DECR_U (v1 + twor, kk1 - twor, cy); /* Treat the last bytes. */
+ __GMPN_ADD_1 (cout, vinf, vinf, twor, vinf0); /* Add vinf0, propagate carry. */
+
+ /* (8) vm1 <- vm1-t2 (0 1 0 1 0) - (0 1 0 0 0) = (0 0 0 1 0)
+ vm1 >= 0
+ */
+ mpn_sub_n (vm1, vm1, v2, kk1); /* No overlapping here. */
+
+ /********************* Beginning the final phase **********************/
+
+ /* {c,2k} {c+2k,2k } {c+4k ,2r } {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 t1 hi(t1)+vinf tm1 (v2-vm1-3t1)/6 EMPTY */
+
+ /* (9) add t2 in {c+3k, ...} */
+ cy = mpn_add_n (c3, c3, v2, kk1);
+ __GMPN_ADD_1 (cout, c5 + 1, c5 + 1, twor - k - 1, cy); /* 2n-(5k+1) = 2r-k-1 */
+
+ /* {c,2k} {c+2k,2k } {c+4k ,2r } {t,2k+1} {t+2k+1,2k+1} {t+4k+2,2r}
+ v0 t1 hi(t1)+vinf tm1 (v2-vm1-3t1)/6 EMPTY */
+ /* c c+k c+2k c+3k c+4k t t+2k+1 t+4k+2
+ v0 t1 vinf tm1 t2
+ +t2 */
+
+ /* add vm1 in {c+k, ...} */
+ cy = mpn_add_n (c1, c1, vm1, kk1);
+ __GMPN_ADD_1 (cout, c3 + 1, c3 + 1, twor + k - 1, cy); /* 2n-(3k+1) = 2r+k-1 */
+
+ /* c c+k c+2k c+3k c+4k t t+2k+1 t+4k+2
+ v0 t1 vinf tm1 t2
+ +tm1 +t2 */
+
+#undef v0
+#undef t2
+}
projects / msp430-gcc.git / blobdiff