Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpz / kronzs.c

diff --git a/gmp/mpz/kronzs.c b/gmp/mpz/kronzs.c
new file mode 100644 (file)
index 0000000..045e556
--- /dev/null
+++ b/gmp/mpz/kronzs.c
@@ -0,0 +1,82 @@
+/* mpz_kronecker_si -- mpz+long Kronecker/Jacobi symbol.
+
+Copyright 1999, 2000, 2001, 2002 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"
+
+
+/* After the absolute value of b is established it's treated as an unsigned
+   long, because 0x80..00 doesn't fit in a signed long. */
+
+int
+mpz_kronecker_si (mpz_srcptr a, long b)
+{
+  mp_srcptr  a_ptr;
+  mp_size_t  a_size;
+  mp_limb_t  a_rem, b_limb;
+  int        result_bit1;
+
+  a_size = SIZ(a);
+  if (a_size == 0)
+    return JACOBI_0S (b);
+
+#if GMP_NUMB_BITS < BITS_PER_ULONG
+  if (b > GMP_NUMB_MAX || b < -GMP_NUMB_MAX)
+    {
+      mp_limb_t  blimbs[2];
+      mpz_t      bz;
+      ALLOC(bz) = numberof (blimbs);
+      PTR(bz) = blimbs;
+      mpz_set_si (bz, b);
+      return mpz_kronecker (a, bz);
+    }
+#endif
+
+  result_bit1 = JACOBI_BSGN_SS_BIT1 (a_size, b);
+  b_limb = (unsigned long) ABS (b);
+  a_ptr = PTR(a);
+
+  if ((b_limb & 1) == 0)
+    {
+      mp_limb_t  a_low = a_ptr[0];
+      int        twos;
+
+      if (b_limb == 0)
+        return JACOBI_LS0 (a_low, a_size);   /* (a/0) */
+
+      if (! (a_low & 1))
+        return 0;  /* (even/even)=0 */
+
+      /* (a/2)=(2/a) for a odd */
+      count_trailing_zeros (twos, b_limb);
+      b_limb >>= twos;
+      result_bit1 ^= JACOBI_TWOS_U_BIT1 (twos, a_low);
+    }
+
+  if (b_limb == 1)
+    return JACOBI_BIT1_TO_PN (result_bit1);  /* (a/1)=1 for any a */
+
+  result_bit1 ^= JACOBI_ASGN_SU_BIT1 (a_size, b_limb);
+  a_size = ABS(a_size);
+
+  /* (a/b) = (a mod b / b) */
+  JACOBI_MOD_OR_MODEXACT_1_ODD (result_bit1, a_rem, a_ptr, a_size, b_limb);
+  return mpn_jacobi_base (a_rem, b_limb, result_bit1);
+}