ext-cryptopp/ppc_simd.h

// ppc_simd.h - written and placed in public domain by Jeffrey Walton

/// \file ppc_simd.h
/// \brief Support functions for PowerPC and vector operations
/// \details This header provides an agnostic interface into GCC and
///   IBM XL C/C++ compilers modulo their different built-in functions
///   for accessing vector intructions.
/// \details The abstractions are necesssary to support back to GCC 4.8.
///   GCC 4.8 and 4.9 are still popular, and they are the default
///   compiler for GCC112, GCC118 and others on the compile farm. Older
///   IBM XL C/C++ compilers also experience it due to lack of
///   <tt>vec_xl_be</tt> support on some platforms. Modern compilers
///   provide best support and don't need many of the little hacks below.
/// \details At Crypto++ 8.0 the various VectorFunc were renamed to
///   VecFunc. For example, VectorAnd was changed to VecAnd. The name change
///   helped consolidate two slightly different implementations.
/// \since Crypto++ 6.0

// Use __ALTIVEC__, _ARCH_PWR7 and _ARCH_PWR8. The preprocessor macros
// depend on compiler options like -maltivec (and not compiler versions).

#ifndef CRYPTOPP_PPC_CRYPTO_H
#define CRYPTOPP_PPC_CRYPTO_H

#include "config.h"
#include "misc.h"

#if defined(__ALTIVEC__)
# include <altivec.h>
# undef vector
# undef pixel
# undef bool
#endif

// VecLoad_ALTIVEC and VecStore_ALTIVEC are
// too noisy on modern compilers
#if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wdeprecated"
#endif

NAMESPACE_BEGIN(CryptoPP)

#if defined(__ALTIVEC__) || defined(CRYPTOPP_DOXYGEN_PROCESSING)

/// \brief Vector of 8-bit elements
typedef __vector unsigned char   uint8x16_p;
/// \brief Vector of 16-bit elements
typedef __vector unsigned short  uint16x8_p;
/// \brief Vector of 32-bit elements
typedef __vector unsigned int    uint32x4_p;

#if defined(_ARCH_PWR8) || defined(CRYPTOPP_DOXYGEN_PROCESSING)
/// \brief Vector of 64-bit elements
/// \details uint64x2_p is available on POWER8 and above
typedef __vector unsigned long long uint64x2_p;
#endif  // _ARCH_PWR8

/// \brief Reverse bytes in a vector
/// \tparam T vector type
/// \param src the vector
/// \returns vector
/// \details VecReverse() reverses the bytes in a vector
/// \since Crypto++ 6.0
template <class T>
inline T VecReverse(const T src)
{
    const uint8x16_p mask = {15,14,13,12, 11,10,9,8, 7,6,5,4, 3,2,1,0};
    return (T)vec_perm(src, src, mask);
}

//////////////////////// Loads ////////////////////////

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \details Loads a vector in native endian format from a byte array.
/// \details VecLoad_ALTIVEC() uses <tt>vec_ld</tt> if the effective address
///   of <tt>dest</tt> is aligned, and uses <tt>vec_lvsl</tt> and <tt>vec_perm</tt>
///   otherwise.
///   <tt>vec_lvsl</tt> and <tt>vec_perm</tt> are relatively expensive so you should
///   provide aligned memory adresses.
/// \details VecLoad_ALTIVEC() is used automatically when POWER7 or above
///   and unaligned loads is not available.
/// \note VecLoad does not require an aligned array.
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad_ALTIVEC(const byte src[16])
{
    if (IsAlignedOn(src, 16))
    {
        return (uint32x4_p)vec_ld(0, src);
    }
    else
    {
        // http://www.nxp.com/docs/en/reference-manual/ALTIVECPEM.pdf
        const uint8x16_p perm = vec_lvsl(0, src);
        const uint8x16_p low = vec_ld(0, src);
        const uint8x16_p high = vec_ld(15, src);
        return (uint32x4_p)vec_perm(low, high, perm);
    }
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \param off offset into the src byte array
/// \details Loads a vector in native endian format from a byte array.
/// \details VecLoad_ALTIVEC() uses <tt>vec_ld</tt> if the effective address
///   of <tt>dest</tt> is aligned, and uses <tt>vec_lvsl</tt> and <tt>vec_perm</tt>
///   otherwise.
///   <tt>vec_lvsl</tt> and <tt>vec_perm</tt> are relatively expensive so you should
///   provide aligned memory adresses.
/// \note VecLoad does not require an aligned array.
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad_ALTIVEC(int off, const byte src[16])
{
    if (IsAlignedOn(src, 16))
    {
        return (uint32x4_p)vec_ld(off, src);
    }
    else
    {
        // http://www.nxp.com/docs/en/reference-manual/ALTIVECPEM.pdf
        const uint8x16_p perm = vec_lvsl(off, src);
        const uint8x16_p low = vec_ld(off, src);
        const uint8x16_p high = vec_ld(15, src);
        return (uint32x4_p)vec_perm(low, high, perm);
    }
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \details VecLoad loads a vector in from a byte array.
/// \details VecLoad uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   an aligned memory address. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() is relatively expensive and
///   requires extra instructions to fix up unaligned effective memory
///   addresses.
/// \note VecLoad does not require an aligned array.
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad(const byte src[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (uint32x4_p)vec_xl(0, (byte*)src);
#  else
    return (uint32x4_p)vec_vsx_ld(0, (byte*)src);
#  endif
#else
    return VecLoad_ALTIVEC(src);
#endif
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \param off offset into the byte array
/// \details VecLoad loads a vector in from a byte array.
/// \details VecLoad uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   an aligned memory address. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() is relatively expensive and
///   requires extra instructions to fix up unaligned effective memory
///   addresses.
/// \note VecLoad does not require an aligned array.
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad(int off, const byte src[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (uint32x4_p)vec_xl(off, (byte*)src);
#  else
    return (uint32x4_p)vec_vsx_ld(off, (byte*)src);
#  endif
#else
    return VecLoad_ALTIVEC(off, src);
#endif
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \details VecLoad loads a vector in from a byte array.
/// \details VecLoad uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   an aligned memory address. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() is relatively expensive and
///   requires extra instructions to fix up unaligned effective memory
///   addresses.
/// \note VecLoad does not require an aligned array.
/// \since Crypto++ 8.0
inline uint32x4_p VecLoad(const word32 src[4])
{
    return VecLoad((const byte*)src);
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \param off offset into the byte array
/// \details VecLoad loads a vector in from a byte array.
/// \details VecLoad uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   an aligned memory address. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() is relatively expensive and
///   requires extra instructions to fix up unaligned effective memory
///   addresses.
/// \note VecLoad does not require an aligned array.
/// \since Crypto++ 8.0
inline uint32x4_p VecLoad(int off, const word32 src[4])
{
    return VecLoad(off, (const byte*)src);
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \details VecLoadBE loads a vector in from a byte array. VecLoadBE
///   will reverse all bytes in the arrya on a little endian system.
/// \details VecLoadBE uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   an aligned memory address. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() is relatively expensive and
///   requires extra instructions to fix up unaligned effective memory
///   addresses.
/// \note VecLoadBE does not require an aligned array.
/// \since Crypto++ 6.0
inline uint32x4_p VecLoadBE(const byte src[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
       return (uint32x4_p)vec_xl_be(0, (byte*)src);
#  else
#    if (CRYPTOPP_BIG_ENDIAN)
       return (uint32x4_p)vec_vsx_ld(0, (byte*)src);
#    else
       return (uint32x4_p)VecReverse(vec_vsx_ld(0, (byte*)src));
#    endif
#  endif
#else  // _ARCH_PWR7
#  if (CRYPTOPP_BIG_ENDIAN)
     return (uint32x4_p)VecLoad((const byte*)src);
#  else
     return (uint32x4_p)VecReverse(VecLoad((const byte*)src));
#  endif
#endif  // _ARCH_PWR7
}

/// \brief Loads a vector from a byte array
/// \param src the byte array
/// \param off offset into the src byte array
/// \details VecLoadBE loads a vector in from a byte array. VecLoadBE
///   will reverse all bytes in the arrya on a little endian system.
/// \details VecLoadBE uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   an aligned memory address. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() is relatively expensive and
///   requires extra instructions to fix up unaligned effective memory
///   addresses.
/// \note VecLoadBE does not require an aligned array.
/// \since Crypto++ 6.0
inline uint32x4_p VecLoadBE(int off, const byte src[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
       return (uint32x4_p)vec_xl_be(off, (byte*)src);
#  else
#    if (CRYPTOPP_BIG_ENDIAN)
       return (uint32x4_p)vec_vsx_ld(off, (byte*)src);
#    else
       return (uint32x4_p)VecReverse(vec_vsx_ld(off, (byte*)src));
#    endif
#  endif
#else  // _ARCH_PWR7
#  if (CRYPTOPP_BIG_ENDIAN)
     return (uint32x4_p)VecLoad(off, (const byte*)src);
#  else
     return (uint32x4_p)VecReverse(VecLoad(off, (const byte*)src));
#  endif
#endif  // _ARCH_PWR7
}

//////////////////////// Stores ////////////////////////

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param dest the byte array
/// \details Stores a vector in native endian format to a byte array.
/// \details VecStore_ALTIVEC() uses <tt>vec_st</tt> if the effective address
///   of <tt>dest</tt> is aligned, and uses <tt>vec_ste</tt> otherwise.
///   <tt>vec_ste</tt> is relatively expensive so you should provide aligned
///   memory adresses.
/// \details VecStore_ALTIVEC() is used automatically when POWER7 or above
///   and unaligned loads is not available.
/// \note VecStore does not require an aligned array.
/// \since Crypto++ 8.0
template<class T>
inline void VecStore_ALTIVEC(const T data, byte dest[16])
{
    if (IsAlignedOn(dest, 16))
    {
        vec_st((uint8x16_p)data, 0,  dest);
    }
    else
    {
        // http://www.nxp.com/docs/en/reference-manual/ALTIVECPEM.pdf
        uint8x16_p perm = (uint8x16_p)vec_perm(data, data, vec_lvsr(0, dest));
        vec_ste((uint8x16_p) perm,  0, (unsigned char*) dest);
        vec_ste((uint16x8_p) perm,  1, (unsigned short*)dest);
        vec_ste((uint32x4_p) perm,  3, (unsigned int*)  dest);
        vec_ste((uint32x4_p) perm,  4, (unsigned int*)  dest);
        vec_ste((uint32x4_p) perm,  8, (unsigned int*)  dest);
        vec_ste((uint32x4_p) perm, 12, (unsigned int*)  dest);
        vec_ste((uint16x8_p) perm, 14, (unsigned short*)dest);
        vec_ste((uint8x16_p) perm, 15, (unsigned char*) dest);
    }
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param off the byte offset into the array
/// \param dest the byte array
/// \details Stores a vector in native endian format to a byte array.
/// \details VecStore_ALTIVEC() uses <tt>vec_st</tt> if the effective address
///   of <tt>dest</tt> is aligned, and uses <tt>vec_ste</tt> otherwise.
///   <tt>vec_ste</tt> is relatively expensive so you should provide aligned
///   memory adresses.
/// \details VecStore_ALTIVEC() is used automatically when POWER7 or above
///   and unaligned loads is not available.
/// \note VecStore does not require an aligned array.
/// \since Crypto++ 8.0
template<class T>
inline void VecStore_ALTIVEC(const T data, int off, byte dest[16])
{
    if (IsAlignedOn(dest, 16))
    {
        vec_st((uint8x16_p)data, off,  dest);
    }
    else
    {
        // http://www.nxp.com/docs/en/reference-manual/ALTIVECPEM.pdf
        uint8x16_p perm = (uint8x16_p)vec_perm(data, data, vec_lvsr(off, dest));
        vec_ste((uint8x16_p) perm,  0, (unsigned char*) dest);
        vec_ste((uint16x8_p) perm,  1, (unsigned short*)dest);
        vec_ste((uint32x4_p) perm,  3, (unsigned int*)  dest);
        vec_ste((uint32x4_p) perm,  4, (unsigned int*)  dest);
        vec_ste((uint32x4_p) perm,  8, (unsigned int*)  dest);
        vec_ste((uint32x4_p) perm, 12, (unsigned int*)  dest);
        vec_ste((uint16x8_p) perm, 14, (unsigned short*)dest);
        vec_ste((uint8x16_p) perm, 15, (unsigned char*) dest);
    }
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param dest the byte array
/// \details Stores a vector in native endian format to a byte array.
/// \details VecStore uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   an aligned memory address.
/// \details VecStore_ALTIVEC() is used if POWER7 or above
///   is not available. VecStore_ALTIVEC() is relatively expensive.
/// \note VecStore does not require an aligned array.
/// \since Crypto++ 6.0
template<class T>
inline void VecStore(const T data, byte dest[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    vec_xst((uint8x16_p)data, 0, (byte*)dest);
#  else
    vec_vsx_st((uint8x16_p)data, 0, (byte*)dest);
#  endif
#else
    return VecStore_ALTIVEC(data, 0, dest);
#endif
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param off the byte offset into the array
/// \param dest the byte array
/// \details Stores a vector in native endian format to a byte array.
/// \details VecStore uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   an aligned memory address.
/// \details VecStore_ALTIVEC() is used if POWER7 or above
///   is not available. VecStore_ALTIVEC() is relatively expensive.
/// \note VecStore does not require an aligned array.
/// \since Crypto++ 6.0
template<class T>
inline void VecStore(const T data, int off, byte dest[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    vec_xst((uint8x16_p)data, off, (byte*)dest);
#  else
    vec_vsx_st((uint8x16_p)data, off, (byte*)dest);
#  endif
#else
    return VecStore_ALTIVEC(data, off, dest);
#endif
}

/// \brief Stores a vector to a word array
/// \tparam T vector type
/// \param data the vector
/// \param dest the byte array
/// \details Stores a vector in native endian format to a byte array.
/// \details VecStore uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   an aligned memory address.
/// \details VecStore_ALTIVEC() is used if POWER7 or above
///   is not available. VecStore_ALTIVEC() is relatively expensive.
/// \note VecStore does not require an aligned array.
/// \since Crypto++ 8.0
template<class T>
inline void VecStore(const T data, word32 dest[4])
{
    VecStore((uint8x16_p)data, 0, (byte*)dest);
}

/// \brief Stores a vector to a word array
/// \tparam T vector type
/// \param data the vector
/// \param off the byte offset into the array
/// \param dest the byte array
/// \details Stores a vector in native endian format to a byte array.
/// \details VecStore uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   an aligned memory address.
/// \details VecStore_ALTIVEC() is used if POWER7 or above
///   is not available. VecStore_ALTIVEC() is relatively expensive.
/// \note VecStore does not require an aligned array.
/// \since Crypto++ 8.0
template<class T>
inline void VecStore(const T data, int off, word32 dest[4])
{
    VecStore((uint8x16_p)data, off, (byte*)dest);
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param src the vector
/// \param dest the byte array
/// \details Stores a vector in big endian format to a byte array.
///   VecStoreBE will swap all bytes on little endian systems.
/// \details VecStoreBE uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   an aligned memory address.
/// \details VecStore_ALTIVEC() is used if POWER7 or above
///   is not available. VecStore_ALTIVEC() is relatively expensive.
/// \note VecStoreBE does not require an aligned array.
/// \since Crypto++ 6.0
template <class T>
inline void VecStoreBE(const T src, byte dest[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
     vec_xst_be((uint8x16_p)src, 0, (byte*)dest);
#  else
#    if (CRYPTOPP_BIG_ENDIAN)
       vec_vsx_st((uint8x16_p)src, 0, (byte*)dest);
#    else
       vec_vsx_st((uint8x16_p)VecReverse(src), 0, (byte*)dest);
#    endif
#  endif
#else  // _ARCH_PWR7
#  if (CRYPTOPP_BIG_ENDIAN)
     VecStore((uint8x16_p)src, (byte*)dest);
#  else
     VecStore((uint8x16_p)VecReverse(src), (byte*)dest);
#  endif
#endif  // _ARCH_PWR7
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param src the vector
/// \param off offset into the dest byte array
/// \param dest the byte array
/// \details Stores a vector in big endian format to a byte array.
///   VecStoreBE will swap all bytes on little endian systems.
/// \details VecStoreBE uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   an aligned memory address.
/// \details VecStore_ALTIVEC() is used if POWER7 or above
///   is not available. VecStore_ALTIVEC() is relatively expensive.
/// \note VecStoreBE does not require an aligned array.
/// \since Crypto++ 6.0
template <class T>
inline void VecStoreBE(const T src, int off, byte dest[16])
{
#if defined(_ARCH_PWR7)
#  if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
     vec_xst_be((uint8x16_p)src, off, (byte*)dest);
#  else
#    if (CRYPTOPP_BIG_ENDIAN)
       vec_vsx_st((uint8x16_p)src, off, (byte*)dest);
#    else
       vec_vsx_st((uint8x16_p)VecReverse(src), off, (byte*)dest);
#    endif
#  endif
#else  // _ARCH_PWR7
#  if (CRYPTOPP_BIG_ENDIAN)
     VecStore((uint8x16_p)src, off, (byte*)dest);
#  else
     VecStore((uint8x16_p)VecReverse(src), off, (byte*)dest);
#  endif
#endif  // _ARCH_PWR7
}

//////////////////////// Miscellaneous ////////////////////////

/// \brief Permutes a vector
/// \tparam T vector type
/// \param vec the vector
/// \param mask vector mask
/// \returns vector
/// \details VecPermute returns a new vector from vec based on
///   mask. mask is an uint8x16_p type vector. The return
///   vector is the same type as vec.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecPermute(const T1 vec, const T2 mask)
{
    return (T1)vec_perm(vec, vec, (uint8x16_p)mask);
}

/// \brief Permutes two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \param mask vector mask
/// \returns vector
/// \details VecPermute returns a new vector from vec1 and vec2
///   based on mask. mask is an uint8x16_p type vector. The return
///   vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecPermute(const T1 vec1, const T1 vec2, const T2 mask)
{
    return (T1)vec_perm(vec1, vec2, (uint8x16_p)mask);
}

/// \brief AND two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \details VecAnd returns a new vector from vec1 and vec2. The return
///   vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecAnd(const T1 vec1, const T2 vec2)
{
    return (T1)vec_and(vec1, (T1)vec2);
}

/// \brief OR two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \details VecOr returns a new vector from vec1 and vec2. The return
///   vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecOr(const T1 vec1, const T2 vec2)
{
    return (T1)vec_or(vec1, (T1)vec2);
}

/// \brief XOR two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \details VecXor returns a new vector from vec1 and vec2. The return
///   vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecXor(const T1 vec1, const T2 vec2)
{
    return (T1)vec_xor(vec1, (T1)vec2);
}

/// \brief Add two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \details VecAdd returns a new vector from vec1 and vec2.
///   vec2 is cast to the same type as vec1. The return vector
///   is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecAdd(const T1 vec1, const T2 vec2)
{
    return (T1)vec_add(vec1, (T1)vec2);
}

/// \brief Subtract two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \details VecSub returns a new vector from vec1 and vec2.
///   vec2 is cast to the same type as vec1. The return vector
///   is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecSub(const T1 vec1, const T2 vec2)
{
    return (T1)vec_sub(vec1, (T1)vec2);
}

/// \brief Add two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \details VecAdd64 returns a new vector from vec1 and vec2.
///   vec1 and vec2 are added as uint64x2_p quantities.
/// \since Crypto++ 8.0
inline uint32x4_p VecAdd64(const uint32x4_p& vec1, const uint32x4_p& vec2)
{
#if defined(_ARCH_PWR8)
    return (uint32x4_p)vec_add((uint64x2_p)vec1, (uint64x2_p)vec2);
#else
    // The carry mask selects carries from elements 1 and 3 and sets remaining
    // elements to 0. The mask also shifts the carried values left by 4 bytes
    // so the carries are added to elements 0 and 2.
    const uint8x16_p cmask = {4,5,6,7, 16,16,16,16, 12,13,14,15, 16,16,16,16};
    const uint32x4_p zero = {0, 0, 0, 0};

    uint32x4_p cy = vec_addc(vec1, vec2);
    cy = vec_perm(cy, zero, cmask);
    return vec_add(vec_add(vec1, vec2), cy);
#endif
}

/// \brief Shift a vector left
/// \tparam C shift byte count
/// \tparam T vector type
/// \param vec the vector
/// \returns vector
/// \details VecShiftLeftOctet() returns a new vector after shifting the
///   concatenation of the zero vector and the source vector by the specified
///   number of bytes. The return vector is the same type as vec.
/// \details On big endian machines VecShiftLeftOctet() is <tt>vec_sld(a, z,
///   c)</tt>. On little endian machines VecShiftLeftOctet() is translated to
///   <tt>vec_sld(z, a, 16-c)</tt>. You should always call the function as
///   if on a big endian machine as shown below.
/// <pre>
///    uint8x16_p x = VecLoad(ptr);
///    uint8x16_p y = VecShiftLeftOctet<12>(x);
/// </pre>
/// \sa <A HREF="https://stackoverflow.com/q/46341923/608639">Is vec_sld
///   endian sensitive?</A> on Stack Overflow
/// \since Crypto++ 6.0
template <unsigned int C, class T>
inline T VecShiftLeftOctet(const T vec)
{
    const T zero = {0};
    if (C >= 16)
    {
        // Out of range
        return zero;
    }
    else if (C == 0)
    {
        // Noop
        return vec;
    }
    else
    {
#if (CRYPTOPP_BIG_ENDIAN)
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, C);
#else
    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, 16-C);
#endif
    }
}

/// \brief Shift a vector right
/// \tparam C shift byte count
/// \tparam T vector type
/// \param vec the vector
/// \returns vector
/// \details VecShiftRightOctet() returns a new vector after shifting the
///   concatenation of the zero vector and the source vector by the specified
///   number of bytes. The return vector is the same type as vec.
/// \details On big endian machines VecShiftRightOctet() is <tt>vec_sld(a, z,
///   c)</tt>. On little endian machines VecShiftRightOctet() is translated to
///   <tt>vec_sld(z, a, 16-c)</tt>. You should always call the function as
///   if on a big endian machine as shown below.
/// <pre>
///    uint8x16_p x = VecLoad(ptr);
///    uint8x16_p y = VecShiftRightOctet<12>(y);
/// </pre>
/// \sa <A HREF="https://stackoverflow.com/q/46341923/608639">Is vec_sld
///   endian sensitive?</A> on Stack Overflow
/// \since Crypto++ 6.0
template <unsigned int C, class T>
inline T VecShiftRightOctet(const T vec)
{
    const T zero = {0};
    if (C >= 16)
    {
        // Out of range
        return zero;
    }
    else if (C == 0)
    {
        // Noop
        return vec;
    }
    else
    {
#if (CRYPTOPP_BIG_ENDIAN)
    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, 16-C);
#else
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, C);
#endif
    }
}

/// \brief Rotate a vector left
/// \tparam C shift byte count
/// \tparam T vector type
/// \param vec the vector
/// \returns vector
/// \details VecRotateLeftOctet() returns a new vector after rotating the
///   concatenation of the source vector with itself by the specified
///   number of bytes. The return vector is the same type as vec.
/// \sa <A HREF="https://stackoverflow.com/q/46341923/608639">Is vec_sld
///   endian sensitive?</A> on Stack Overflow
/// \since Crypto++ 6.0
template <unsigned int C, class T>
inline T VecRotateLeftOctet(const T vec)
{
    enum { R = C&0xf };
#if (CRYPTOPP_BIG_ENDIAN)
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
#else
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, 16-R);
#endif
}

/// \brief Rotate a vector right
/// \tparam C shift byte count
/// \tparam T vector type
/// \param vec the vector
/// \returns vector
/// \details VecRotateRightOctet() returns a new vector after rotating the
///   concatenation of the source vector with itself by the specified
///   number of bytes. The return vector is the same type as vec.
/// \sa <A HREF="https://stackoverflow.com/q/46341923/608639">Is vec_sld
///   endian sensitive?</A> on Stack Overflow
/// \since Crypto++ 6.0
template <unsigned int C, class T>
inline T VecRotateRightOctet(const T vec)
{
    enum { R = C&0xf };
#if (CRYPTOPP_BIG_ENDIAN)
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, 16-R);
#else
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
#endif
}

/// \brief Rotate a vector left
/// \tparam C shift bit count
/// \param vec the vector
/// \returns vector
/// \details VecRotateLeft rotates each element in a packed vector by bit count.
template<unsigned int C>
inline uint32x4_p VecRotateLeft(const uint32x4_p vec)
{
    const uint32x4_p m = {C, C, C, C};
    return vec_rl(vec, m);
}

/// \brief Rotate a vector right
/// \tparam C shift bit count
/// \param vec the vector
/// \returns vector
/// \details VecRotateRight rotates each element in a packed vector by bit count.
template<unsigned int C>
inline uint32x4_p VecRotateRight(const uint32x4_p vec)
{
    const uint32x4_p m = {32-C, 32-C, 32-C, 32-C};
    return vec_rl(vec, m);
}

/// \brief Exchange high and low double words
/// \tparam T vector type
/// \param vec the vector
/// \returns vector
/// \since Crypto++ 7.0
template <class T>
inline T VecSwapWords(const T vec)
{
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, 8);
}

/// \brief Extract a dword from a vector
/// \tparam T vector type
/// \param val the vector
/// \returns vector created from low dword
/// \details VecGetLow() extracts the low dword from a vector. The low dword
///   is composed of the least significant bits and occupies bytes 8 through 15
///   when viewed as a big endian array. The return vector is the same type as
///   the original vector and padded with 0's in the most significant bit positions.
template <class T>
inline T VecGetLow(const T val)
{
    //const T zero = {0};
    //const uint8x16_p mask = {16,16,16,16, 16,16,16,16, 8,9,10,11, 12,13,14,15 };
    //return (T)vec_perm(zero, val, mask);
    return VecShiftRightOctet<8>(VecShiftLeftOctet<8>(val));
}

/// \brief Extract a dword from a vector
/// \tparam T vector type
/// \param val the vector
/// \returns vector created from high dword
/// \details VecGetHigh() extracts the high dword from a vector. The high dword
///   is composed of the most significant bits and occupies bytes 0 through 7
///   when viewed as a big endian array. The return vector is the same type as
///   the original vector and padded with 0's in the most significant bit positions.
template <class T>
inline T VecGetHigh(const T val)
{
    //const T zero = {0};
    //const uint8x16_p mask = {16,16,16,16, 16,16,16,16, 0,1,2,3, 4,5,6,7 };
    //return (T)vec_perm(zero, val, mask);
    return VecShiftRightOctet<8>(val);
}

/// \brief Compare two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns true if vec1 equals vec2, false otherwise
template <class T1, class T2>
inline bool VecEqual(const T1 vec1, const T2 vec2)
{
    return 1 == vec_all_eq((uint32x4_p)vec1, (uint32x4_p)vec2);
}

/// \brief Compare two vectors
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns true if vec1 does not equal vec2, false otherwise
template <class T1, class T2>
inline bool VecNotEqual(const T1 vec1, const T2 vec2)
{
    return 0 == vec_all_eq((uint32x4_p)vec1, (uint32x4_p)vec2);
}

//////////////////////// Power8 Crypto ////////////////////////

#if defined(_ARCH_PWR8) || defined(CRYPTOPP_DOXYGEN_PROCESSING)

/// \brief One round of AES encryption
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param state the state vector
/// \param key the subkey vector
/// \details VecEncrypt performs one round of AES encryption of state
///   using subkey key. The return vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecEncrypt(const T1 state, const T2 key)
{
#if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (T1)__vcipher((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__GNUC__)
    return (T1)__builtin_crypto_vcipher((uint64x2_p)state, (uint64x2_p)key);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

/// \brief Final round of AES encryption
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param state the state vector
/// \param key the subkey vector
/// \details VecEncryptLast performs the final round of AES encryption
///   of state using subkey key. The return vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecEncryptLast(const T1 state, const T2 key)
{
#if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (T1)__vcipherlast((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__GNUC__)
    return (T1)__builtin_crypto_vcipherlast((uint64x2_p)state, (uint64x2_p)key);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

/// \brief One round of AES decryption
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param state the state vector
/// \param key the subkey vector
/// \details VecDecrypt performs one round of AES decryption of state
///   using subkey key. The return vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecDecrypt(const T1 state, const T2 key)
{
#if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (T1)__vncipher((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__GNUC__)
    return (T1)__builtin_crypto_vncipher((uint64x2_p)state, (uint64x2_p)key);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

/// \brief Final round of AES decryption
/// \tparam T1 vector type
/// \tparam T2 vector type
/// \param state the state vector
/// \param key the subkey vector
/// \details VecDecryptLast performs the final round of AES decryption
///   of state using subkey key. The return vector is the same type as vec1.
/// \since Crypto++ 6.0
template <class T1, class T2>
inline T1 VecDecryptLast(const T1 state, const T2 key)
{
#if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (T1)__vncipherlast((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__GNUC__)
    return (T1)__builtin_crypto_vncipherlast((uint64x2_p)state, (uint64x2_p)key);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

/// \brief SHA256 Sigma functions
/// \tparam func function
/// \tparam subfunc sub-function
/// \tparam T vector type
/// \param vec the block to transform
/// \details VecSHA256 selects sigma0, sigma1, Sigma0, Sigma1 based on
///   func and subfunc. The return vector is the same type as vec.
/// \since Crypto++ 6.0
template <int func, int subfunc, class T>
inline T VecSHA256(const T vec)
{
#if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (T)__vshasigmaw((uint32x4_p)vec, func, subfunc);
#elif defined(__GNUC__)
    return (T)__builtin_crypto_vshasigmaw((uint32x4_p)vec, func, subfunc);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

/// \brief SHA512 Sigma functions
/// \tparam func function
/// \tparam subfunc sub-function
/// \tparam T vector type
/// \param vec the block to transform
/// \details VecSHA512 selects sigma0, sigma1, Sigma0, Sigma1 based on
///   func and subfunc. The return vector is the same type as vec.
/// \since Crypto++ 6.0
template <int func, int subfunc, class T>
inline T VecSHA512(const T vec)
{
#if defined(__xlc__) || defined(__xlC__) || defined(__clang__)
    return (T)__vshasigmad((uint64x2_p)vec, func, subfunc);
#elif defined(__GNUC__)
    return (T)__builtin_crypto_vshasigmad((uint64x2_p)vec, func, subfunc);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

#endif  // _ARCH_PWR8

#endif  // _ALTIVEC_

NAMESPACE_END

#if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
# pragma GCC diagnostic pop
#endif

#endif  // CRYPTOPP_PPC_CRYPTO_H