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-rw-r--r--gnu/lib/libgmp/mpz_sqrtrem.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/gnu/lib/libgmp/mpz_sqrtrem.c b/gnu/lib/libgmp/mpz_sqrtrem.c
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+/* mpz_sqrtrem(root,rem,x) -- Set ROOT to floor(sqrt(X)) and REM
+ to the remainder, i.e. X - ROOT**2.
+
+Copyright (C) 1991 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 General Public License as published by
+the Free Software Foundation; either version 2, 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with the GNU MP Library; see the file COPYING. If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+#ifndef BERKELEY_MP
+void
+#ifdef __STDC__
+mpz_sqrtrem (MP_INT *root, MP_INT *rem, const MP_INT *op)
+#else
+mpz_sqrtrem (root, rem, op)
+ MP_INT *root;
+ MP_INT *rem;
+ const MP_INT *op;
+#endif
+#else /* BERKELEY_MP */
+void
+#ifdef __STDC__
+msqrt (const MP_INT *op, MP_INT *root, MP_INT *rem)
+#else
+msqrt (op, root, rem)
+ const MP_INT *op;
+ MP_INT *root;
+ MP_INT *rem;
+#endif
+#endif /* BERKELEY_MP */
+{
+ mp_size op_size, root_size, rem_size;
+ mp_ptr root_ptr, op_ptr;
+ mp_ptr free_me = NULL;
+ mp_size free_me_size;
+
+ op_size = op->size;
+ if (op_size < 0)
+ op_size = 1 / (op_size > 0); /* Divide by zero for negative OP. */
+
+ if (rem->alloc < op_size)
+ _mpz_realloc (rem, op_size);
+
+ /* The size of the root is accurate after this simple calculation. */
+ root_size = (op_size + 1) / 2;
+
+ root_ptr = root->d;
+ op_ptr = op->d;
+
+ if (root->alloc < root_size)
+ {
+ if (root_ptr == op_ptr)
+ {
+ free_me = root_ptr;
+ free_me_size = root->alloc;
+ }
+ else
+ (*_mp_free_func) (root_ptr, root->alloc * BYTES_PER_MP_LIMB);
+
+ root->alloc = root_size;
+ root_ptr = (mp_ptr) (*_mp_allocate_func) (root_size * BYTES_PER_MP_LIMB);
+ root->d = root_ptr;
+ }
+ else
+ {
+ /* Make OP not overlap with ROOT. */
+ if (root_ptr == op_ptr)
+ {
+ /* ROOT and OP are identical. Allocate temporary space for OP. */
+ op_ptr = (mp_ptr) alloca (op_size * BYTES_PER_MP_LIMB);
+ /* Copy to the temporary space. Hack: Avoid temporary variable
+ by using ROOT_PTR. */
+ MPN_COPY (op_ptr, root_ptr, op_size);
+ }
+ }
+
+ rem_size = mpn_sqrt (root_ptr, rem->d, op_ptr, op_size);
+
+ root->size = root_size;
+
+ /* Write remainder size last, to enable us to define this function to
+ give only the square root remainder, if the user calles if with
+ ROOT == REM. */
+ rem->size = rem_size;
+
+ if (free_me != NULL)
+ (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);
+
+ alloca (0);
+}
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