/*

 * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.

 * Copyright 2014 Cryptography Research, Inc.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 *

 * Originally written by Mike Hamburg

 */

#ifndef OSSL_CRYPTO_EC_CURVE448_WORD_H

# define OSSL_CRYPTO_EC_CURVE448_WORD_H

# include <string.h>

# include <assert.h>

# include <stdlib.h>

# include <openssl/e_os2.h>

# include "arch_intrinsics.h"

# include "curve448utils.h"

# if (ARCH_WORD_BITS == 64)

typedef uint64_t word_t, mask_t;

typedef __uint128_t dword_t;

typedef int32_t hsword_t;

typedef int64_t sword_t;

typedef __int128_t dsword_t;

# elif (ARCH_WORD_BITS == 32)

typedef uint32_t word_t, mask_t;

typedef uint64_t dword_t;

typedef int16_t hsword_t;

typedef int32_t sword_t;

typedef int64_t dsword_t;

# else

#  error "For now, we only support 32- and 64-bit architectures."

# endif

/*

 * Scalar limbs are keyed off of the API word size instead of the arch word

 * size.

 */

# if C448_WORD_BITS == 64

#  define SC_LIMB(x) (x)

# elif C448_WORD_BITS == 32

#  define SC_LIMB(x) ((uint32_t)(x)),((x) >> 32)

# else

#  error "For now we only support 32- and 64-bit architectures."

# endif

/*

 * The plan on booleans: The external interface uses c448_bool_t, but this

 * might be a different size than our particular arch's word_t (and thus

 * mask_t).  Also, the caller isn't guaranteed to pass it as nonzero.  So

 * bool_to_mask converts word sizes and checks nonzero. On the flip side,

 * mask_t is always -1 or 0, but it might be a different size than

 * c448_bool_t. On the third hand, we have success vs boolean types, but

 * that's handled in common.h: it converts between c448_bool_t and

 * c448_error_t.

 */

static ossl_inline c448_bool_t mask_to_bool(mask_t m)

{

    return (c448_sword_t)(sword_t)m;

}

static ossl_inline mask_t bool_to_mask(c448_bool_t m)

{

    /* On most arches this will be optimized to a simple cast. */

    mask_t ret = 0;

    unsigned int i;

    unsigned int limit = sizeof(c448_bool_t) / sizeof(mask_t);

    if (limit < 1)

        limit = 1;

    for (i = 0; i < limit; i++)

        ret |= ~word_is_zero(m >> (i * 8 * sizeof(word_t)));

    return ret;

}

#endif                          /* OSSL_CRYPTO_EC_CURVE448_WORD_H */