Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / generic / redc_2.c

diff --git a/gmp/mpn/generic/redc_2.c b/gmp/mpn/generic/redc_2.c
new file mode 100644 (file)
index 0000000..0efbd9d
--- /dev/null
+++ b/gmp/mpn/generic/redc_2.c
@@ -0,0 +1,97 @@
+/* mpn_redc_2.  Set cp[] <- up[]/R^n mod mp[].  Clobber up[].
+   mp[] is n limbs; up[] is 2n limbs.
+
+   THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE.  IT IS ONLY
+   SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
+
+Copyright (C) 2000, 2001, 2002, 2004, 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/.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "longlong.h"
+
+
+#if GMP_NAIL_BITS != 0
+you lose
+#endif
+
+/* For testing purposes, define our own mpn_addmul_2 if there is none already
+   available.  */
+#ifndef HAVE_NATIVE_mpn_addmul_2
+mp_limb_t
+mpn_addmul_2 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_srcptr vp)
+{
+  rp[n] = mpn_addmul_1 (rp, up, n, vp[0]);
+  return mpn_addmul_1 (rp + 1, up, n, vp[1]);
+}
+#endif
+
+#if defined (__ia64) && W_TYPE_SIZE == 64
+#define umul2low(ph, pl, uh, ul, vh, vl) \
+  do {                                                                 \
+    mp_limb_t _ph, _pl;                                                        \
+    __asm__ ("xma.hu %0 = %3, %5, f0\n\t"                              \
+            "xma.l %1 = %3, %5, f0\n\t"                                \
+            ";;\n\t"                                                   \
+            "xma.l %0 = %3, %4, %0\n\t"                                \
+            ";;\n\t"                                                   \
+            "xma.l %0 = %2, %5, %0"                                    \
+            : "=&f" (ph), "=&f" (pl)                                   \
+            : "f" (uh), "f" (ul), "f" (vh), "f" (vl));                 \
+  } while (0)
+#endif
+
+#ifndef umul2low
+#define umul2low(ph, pl, uh, ul, vh, vl) \
+  do {                                                                 \
+    mp_limb_t _ph, _pl;                                                        \
+    umul_ppmm (_ph, _pl, ul, vl);                                      \
+    (ph) = _ph + (ul) * (vh) + (uh) * (vl);                            \
+    (pl) = _pl;                                                                \
+  } while (0)
+#endif
+
+void
+mpn_redc_2 (mp_ptr rp, mp_ptr up, mp_srcptr mp, mp_size_t n, mp_srcptr mip)
+{
+  mp_limb_t q[2];
+  mp_size_t j;
+  mp_limb_t upn;
+  mp_limb_t cy;
+
+  ASSERT_MPN (up, 2*n);
+
+  if ((n & 1) != 0)
+    {
+      up[0] = mpn_addmul_1 (up, mp, n, (up[0] * mip[0]) & GMP_NUMB_MASK);
+      up++;
+    }
+
+  for (j = n - 2; j >= 0; j -= 2)
+    {
+      umul2low (q[1], q[0], mip[1], mip[0], up[1], up[0]);
+      upn = up[n];             /* mpn_addmul_2 overwrites this */
+      up[1] = mpn_addmul_2 (up, mp, n, q);
+      up[0] = up[n];
+      up[n] = upn;
+      up += 2;
+    }
+  cy = mpn_add_n (rp, up, up - n, n);
+  if (cy != 0)
+    mpn_sub_n (rp, rp, mp, n);
+}