MODULE: ZZ_limbs


Defines low-level access to the "limbs" of a ZZ.


#include <NTL/ZZ.h>

#ifdef NTL_GMP_LIP
#include <gmp.h>
// NOTE: unlike other NTL header files, this one needs access
// to GMP's header file, which means that C++ files that include
// this file will need to ensure that the compiler has the 
// right "include path" to get at GMP's header file.

typedef ... ZZ_limb_t;
// The type of a limb. 
// With GMP, this is mp_limb_t, wich is usually (but not always) 
// typedef'd to unsigned long.
// Without GMP, this is unisigned long (although that is subject to change).
// In any case, all that one should assume is that this is an 
// unisgned integral type.

#define NTL_BITS_PER_LIMB_T (...)
// Integral constant defining the number of bits of ZZ_limb_t.

const ZZ_limb_t * ZZ_limbs_get(const ZZ& a);
// Get a pointer to the limbs of a (possibly null).
// The number of limbs can be obtained by invoking a.size().

void ZZ_limbs_set(ZZ& x, const ZZ_limb_t *p, long n);
// Sets the limbs of x to p[0..n-1].
// An error is raised on n < 0 or p == NULL and n > 0.
// It will work correctly even if p points to a limb of x
// itself.