Imported gcc-4.4.3

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

diff --git a/gmp/mpn/generic/popham.c b/gmp/mpn/generic/popham.c
new file mode 100644 (file)
index 0000000..be7c525
--- /dev/null
+++ b/gmp/mpn/generic/popham.c
@@ -0,0 +1,114 @@
+/* mpn_popcount, mpn_hamdist -- mpn bit population count/hamming distance.
+
+Copyright 1994, 1996, 2000, 2001, 2002, 2005 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"
+
+#if OPERATION_popcount
+#define FNAME mpn_popcount
+#define POPHAM(u,v) u
+#endif
+
+#if OPERATION_hamdist
+#define FNAME mpn_hamdist
+#define POPHAM(u,v) u ^ v
+#endif
+
+unsigned long
+FNAME (mp_srcptr up,
+#if OPERATION_hamdist
+       mp_srcptr vp,
+#endif
+       mp_size_t n)
+{
+  unsigned long result = 0;
+  mp_limb_t p0, p1, p2, p3, x, p01, p23;
+  mp_size_t i;
+
+  ASSERT (n >= 1);             /* Actually, this code handles any n, but some
+                                  assembly implementations do not.  */
+
+  for (i = n >> 2; i != 0; i--)
+    {
+      p0 = POPHAM (up[0], vp[0]);
+      p0 -= (p0 >> 1) & MP_LIMB_T_MAX/3;                               /* 2 0-2 */
+      p0 = ((p0 >> 2) & MP_LIMB_T_MAX/5) + (p0 & MP_LIMB_T_MAX/5);     /* 4 0-4 */
+
+      p1 = POPHAM (up[1], vp[1]);
+      p1 -= (p1 >> 1) & MP_LIMB_T_MAX/3;                               /* 2 0-2 */
+      p1 = ((p1 >> 2) & MP_LIMB_T_MAX/5) + (p1 & MP_LIMB_T_MAX/5);     /* 4 0-4 */
+
+      p01 = p0 + p1;                                                   /* 8 0-8 */
+      p01 = ((p01 >> 4) & MP_LIMB_T_MAX/17) + (p01 & MP_LIMB_T_MAX/17);        /* 8 0-16 */
+
+      p2 = POPHAM (up[2], vp[2]);
+      p2 -= (p2 >> 1) & MP_LIMB_T_MAX/3;                               /* 2 0-2 */
+      p2 = ((p2 >> 2) & MP_LIMB_T_MAX/5) + (p2 & MP_LIMB_T_MAX/5);     /* 4 0-4 */
+
+      p3 = POPHAM (up[3], vp[3]);
+      p3 -= (p3 >> 1) & MP_LIMB_T_MAX/3;                               /* 2 0-2 */
+      p3 = ((p3 >> 2) & MP_LIMB_T_MAX/5) + (p3 & MP_LIMB_T_MAX/5);     /* 4 0-4 */
+
+      p23 = p2 + p3;                                                   /* 8 0-8 */
+      p23 = ((p23 >> 4) & MP_LIMB_T_MAX/17) + (p23 & MP_LIMB_T_MAX/17);        /* 8 0-16 */
+
+      x = p01 + p23;                                                   /* 8 0-32 */
+      x = (x >> 8) + x;                                                        /* 8 0-64 */
+      x = (x >> 16) + x;                                               /* 8 0-128 */
+#if GMP_LIMB_BITS > 32
+      x = ((x >> 32) & 0xff) + (x & 0xff);                             /* 8 0-256 */
+      result += x;
+#else
+      result += x & 0xff;
+#endif
+      up += 4;
+#if OPERATION_hamdist
+      vp += 4;
+#endif
+    }
+
+  n &= 3;
+  if (n != 0)
+    {
+      x = 0;
+      do
+       {
+         p0 = POPHAM (up[0], vp[0]);
+         p0 -= (p0 >> 1) & MP_LIMB_T_MAX/3;                            /* 2 0-2 */
+         p0 = ((p0 >> 2) & MP_LIMB_T_MAX/5) + (p0 & MP_LIMB_T_MAX/5);  /* 4 0-4 */
+         p0 = ((p0 >> 4) + p0) & MP_LIMB_T_MAX/17;                     /* 8 0-8 */
+
+         x += p0;
+         up += 1;
+#if OPERATION_hamdist
+         vp += 1;
+#endif
+       }
+      while (--n);
+
+      x = (x >> 8) + x;
+      x = (x >> 16) + x;
+#if GMP_LIMB_BITS > 32
+      x = (x >> 32) + x;
+#endif
+      result += x & 0xff;
+    }
+
+  return result;
+}