Reorganisation of the source tree

[ghc-hetmet.git] / rts / gmp / mpn / generic / sqr_basecase.c

diff --git a/rts/gmp/mpn/generic/sqr_basecase.c b/rts/gmp/mpn/generic/sqr_basecase.c
new file mode 100644 (file)
index 0000000..760258a
--- /dev/null
+++ b/rts/gmp/mpn/generic/sqr_basecase.c
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+/* mpn_sqr_basecase -- Internal routine to square two natural numbers
+   of length m and n.
+
+   THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE.  IT IS ONLY
+   SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
+
+
+Copyright (C) 1991, 1992, 1993, 1994, 1996, 1997, 2000 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 2.1 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; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "longlong.h"
+
+void
+#if __STDC__
+mpn_sqr_basecase (mp_ptr prodp, mp_srcptr up, mp_size_t n)
+#else
+mpn_sqr_basecase (prodp, up, n)
+     mp_ptr prodp;
+     mp_srcptr up;
+     mp_size_t n;
+#endif
+{
+  mp_size_t i;
+
+  {
+    /* N.B.!  We need the superfluous indirection through argh to work around
+       a reloader bug in GCC 2.7.*.  */
+    mp_limb_t x;
+    mp_limb_t argh;
+    x = up[0];
+    umul_ppmm (argh, prodp[0], x, x);
+    prodp[1] = argh;
+  }
+  if (n > 1)
+    {
+      mp_limb_t tarr[2 * KARATSUBA_SQR_THRESHOLD];
+      mp_ptr tp = tarr;
+      mp_limb_t cy;
+
+      /* must fit 2*n limbs in tarr */
+      ASSERT (n <= KARATSUBA_SQR_THRESHOLD);
+
+      cy = mpn_mul_1 (tp, up + 1, n - 1, up[0]);
+      tp[n - 1] = cy;
+      for (i = 2; i < n; i++)
+       {
+         mp_limb_t cy;
+         cy = mpn_addmul_1 (tp + 2 * i - 2, up + i, n - i, up[i - 1]);
+         tp[n + i - 2] = cy;
+       }
+      for (i = 1; i < n; i++)
+       {
+         mp_limb_t x;
+         x = up[i];
+         umul_ppmm (prodp[2 * i + 1], prodp[2 * i], x, x);
+       }
+      {
+       mp_limb_t cy;
+       cy = mpn_lshift (tp, tp, 2 * n - 2, 1);
+       cy += mpn_add_n (prodp + 1, prodp + 1, tp, 2 * n - 2);
+       prodp[2 * n - 1] += cy;
+      }
+    }
+}