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/*
* Multiply-Add for 64-bit MSVC
* (C) 2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#ifndef BOTAN_MP_ASM_H__
#define BOTAN_MP_ASM_H__
#include <botan/mp_types.h>
#include <intrin.h>
#if (BOTAN_MP_WORD_BITS != 64)
#error The mp_amd64_msvc module requires that BOTAN_MP_WORD_BITS == 64
#endif
#pragma intrinsic(_umul128)
namespace Botan {
extern "C" {
/*
* Word Multiply
*/
inline word word_madd2(word a, word b, word* c)
{
word hi, lo;
lo = _umul128(a, b, &hi);
lo += *c;
hi += (lo < *c); // carry?
*c = hi;
return lo;
}
/*
* Word Multiply/Add
*/
inline word word_madd3(word a, word b, word c, word* d)
{
word hi, lo;
lo = _umul128(a, b, &hi);
lo += c;
hi += (lo < c); // carry?
lo += *d;
hi += (lo < *d); // carry?
*d = hi;
return lo;
}
}
}
#endif
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