/*
 * Compilation Copyright (c) 1995-2019 by Wei Dai.  All rights reserved.
 *	This copyright applies only to this software distribution package
 *	as a compilation, and does not imply a copyright on any particular
 *	file in the package.
 * 
 *	Boost Software License - Version 1.0 - August 17th, 2003
 *
 *	Permission is hereby granted, free of charge, to any person or organization
 *	obtaining a copy of the software and accompanying documentation covered by
 *	this license (the "Software") to use, reproduce, display, distribute,
 *	execute, and transmit the Software, and to prepare derivative works of the
 *	Software, and to permit third-parties to whom the Software is furnished to
 *	do so, all subject to the following:
 * 
 *	The copyright notices in the Software and this entire statement, including
 *	the above license grant, this restriction and the following disclaimer,
 *	must be included in all copies of the Software, in whole or in part, and
 *	all derivative works of the Software, unless such copies or derivative
 *	works are solely in the form of machine-executable object code generated by
 *	a source language processor.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 *	SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 *	FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 *	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 *	DEALINGS IN THE SOFTWARE.
 */

// 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 Clang, 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 and
///   XLC 11 and 12. 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</tt> and <tt>vec_xst</tt> support on some platforms. Modern
///   compilers provide best support and don't need many of the hacks
///   below.
/// \details The library is tested with the following PowerPC machines and
///   compilers. GCC110, GCC111, GCC112, GCC119 and GCC135 are provided by
///   the <A HREF="https://cfarm.tetaneutral.net/">GCC Compile Farm</A>
///   - PowerMac G5, OSX 10.5, POWER4, Apple GCC 4.0
///   - PowerMac G5, OSX 10.5, POWER4, Macports GCC 5.0
///   - GCC110, Linux, POWER7, GCC 4.8.5
///   - GCC110, Linux, POWER7, XLC 12.01
///   - GCC111, AIX, POWER7, GCC 4.8.1
///   - GCC111, AIX, POWER7, XLC 12.01
///   - GCC112, Linux, POWER8, GCC 4.8.5
///   - GCC112, Linux, POWER8, XLC 13.01
///   - GCC112, Linux, POWER8, Clang 7.0
///   - GCC119, AIX, POWER8, GCC 7.2.0
///   - GCC119, AIX, POWER8, XLC 13.01
///   - GCC135, Linux, POWER9, GCC 7.0
/// \details 12 machines are used for testing because the three compilers form
///   five profiles. The profiles are listed below.
///   - GCC (Linux GCC, Macports GCC, etc. Consistent across machines)
///   - XLC 13.0 and earlier (all IBM components)
///   - XLC 13.1 and later on Linux (LLVM front-end, no compatibility macros)
///   - XLC 13.1 and later on Linux (LLVM front-end, -qxlcompatmacros option)
///   - LLVM Clang (traditional Clang compiler)
/// \details The LLVM front-end makes it tricky to write portable code because
///   LLVM pretends to be other compilers but cannot consume other compiler's
///   builtins. When using XLC with -qxlcompatmacros the compiler pretends to
///   be GCC, Clang and XLC all at once but it can only consume it's variety
///   of builtins.
/// \details At Crypto++ 8.0 the various <tt>Vector{FuncName}</tt> were
///   renamed to <tt>Vec{FuncName}</tt>. For example, <tt>VectorAnd</tt> was
///   changed to <tt>VecAnd</tt>. The name change helped consolidate two
///   slightly different implementations.
/// \since Crypto++ 6.0, LLVM Clang compiler support since Crypto++ 8.0

// Use __ALTIVEC__, _ARCH_PWR7 and _ARCH_PWR8 when detecting actual
// availaibility of the feature for the source file being compiled. The
// preprocessor macros depend on compiler options like -maltivec; and
// not compiler versions.

// DO NOT USE this pattern in VecLoad and VecStore. We have to use the
// spaghetti code tangled in preprocessor macros because XLC 12 generates
// bad code in some places. To verify the bad code generation test on
// GCC111 with XLC 12.01 installed. XLC 13.01 on GCC112 and GCC119 are OK.
//
//   inline uint32x4_p VecLoad(const byte src[16])
//   {
//   #if defined(_ARCH_PWR8)
//       return (uint32x4_p) *(uint8x16_p*)((byte*)src);
//   #else
//       return VecLoad_ALTIVEC(src);
//   #endif
//   }

#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

// IBM XLC on AIX does not define __CRYPTO__ like it should with -qarch=pwr8.
// Crypto is available in XLC 13.1 and above. More LLVM front-end goodness.
#if defined(_AIX) && defined(_ARCH_PWR8) && (__xlC__ >= 0xd01)
# undef __CRYPTO__
# define __CRYPTO__ 1
#endif

// Hack to detect early XLC compilers. XLC compilers for POWER7 use
// vec_xlw4 and vec_xstw4 (and ld2 variants); not vec_xl and vec_st.
// Some XLC compilers for POWER7 and above use vec_xl and vec_xst.
// The way to tell the difference is, XLC compilers version 13.0 and
// earlier use vec_xlw4 and vec_xstw4. XLC compilers 13.1 and later
// are use vec_xl and vec_xst. The open question is, how to handle
// early Clang compilers for POWER7. We know the latest Clang
// compilers support vec_xl and vec_xst. Also see
// https://www-01.ibm.com/support/docview.wss?uid=swg21683541.

#if defined(__xlc__) && (__xlc__ < 0x0d01)
# define __early_xlc__ 1
#endif
#if defined(__xlC__) && (__xlC__ < 0x0d01)
# define __early_xlC__ 1
#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
/// \par Wraps
///   __vector unsigned char
/// \since Crypto++ 6.0
typedef __vector unsigned char   uint8x16_p;
/// \brief Vector of 16-bit elements
/// \par Wraps
///   __vector unsigned short
/// \since Crypto++ 6.0
typedef __vector unsigned short  uint16x8_p;
/// \brief Vector of 32-bit elements
/// \par Wraps
///   __vector unsigned int
/// \since Crypto++ 6.0
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 POWER7 and above. Some supporting
///   functions, like 64-bit <tt>vec_add</tt> (<tt>vaddudm</tt>), did not
///   arrive until POWER8.
/// \par Wraps
///   __vector unsigned long long
/// \since Crypto++ 6.0
typedef __vector unsigned long long uint64x2_p;
#endif  // _ARCH_PWR8

/// \brief The 0 vector
/// \returns a 32-bit vector of 0's
/// \since Crypto++ 8.0
inline uint32x4_p VecZero()
{
    const uint32x4_p v = {0,0,0,0};
    return v;
}

/// \brief The 1 vector
/// \returns a 32-bit vector of 1's
/// \since Crypto++ 8.0
inline uint32x4_p VecOne()
{
    const uint32x4_p v = {1,1,1,1};
    return v;
}

/// \brief Reverse bytes in a vector
/// \tparam T vector type
/// \param data the vector
/// \returns vector
/// \details VecReverse() reverses the bytes in a vector
/// \par Wraps
///   vec_perm
/// \since Crypto++ 6.0
template <class T>
inline T VecReverse(const T data)
{
#if (_ARCH_PWR9)
    return (T)vec_revb((uint8x16_p)data);
#else
    const uint8x16_p mask = {15,14,13,12, 11,10,9,8, 7,6,5,4, 3,2,1,0};
    return (T)vec_perm(data, data, mask);
#endif
}

/// \name LOAD OPERATIONS
//@{

/// \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>src</tt> is aligned. If unaligned it uses <tt>vec_lvsl</tt>,
///   <tt>vec_ld</tt>, <tt>vec_perm</tt> and <tt>src</tt>. The fixups using
///   <tt>vec_lvsl</tt> and <tt>vec_perm</tt> are relatively expensive so
///   you should provide aligned memory adresses.
/// \par Wraps
///   vec_ld, vec_lvsl, vec_perm
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad_ALTIVEC(const byte src[16])
{
    // Avoid IsAlignedOn for convenience.
    uintptr_t eff = reinterpret_cast<uintptr_t>(src)+0;
    if (eff % 16 == 0)
    {
        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>src</tt> is aligned. If unaligned it uses <tt>vec_lvsl</tt>,
///   <tt>vec_ld</tt>, <tt>vec_perm</tt> and <tt>src</tt>.
/// \details The fixups using <tt>vec_lvsl</tt> and <tt>vec_perm</tt> are
///   relatively expensive so you should provide aligned memory adresses.
/// \par Wraps
///   vec_ld, vec_lvsl, vec_perm
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad_ALTIVEC(int off, const byte src[16])
{
    // Avoid IsAlignedOn for convenience.
    uintptr_t eff = reinterpret_cast<uintptr_t>(src)+off;
    if (eff % 16 == 0)
    {
        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
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad(const byte src[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
    return (uint32x4_p)vec_xlw4(0, (byte*)src);
#  elif 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
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 6.0
inline uint32x4_p VecLoad(int off, const byte src[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
    return (uint32x4_p)vec_xlw4(off, (byte*)src);
#  elif 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 word array
/// \param src the word array
/// \details VecLoad() loads a vector in from a word array.
/// \details VecLoad() uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 8.0
inline uint32x4_p VecLoad(const word32 src[4])
{
    return VecLoad((const byte*)src);
}

/// \brief Loads a vector from a word array
/// \param src the word array
/// \param off offset into the word array
/// \details VecLoad() loads a vector in from a word array.
/// \details VecLoad() uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 8.0
inline uint32x4_p VecLoad(int off, const word32 src[4])
{
    return VecLoad(off, (const byte*)src);
}

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

/// \brief Loads a vector from a word array
/// \param src the word array
/// \details VecLoad() loads a vector in from a word array.
/// \details VecLoad() uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \details VecLoad() with 64-bit elements is available on POWER7 and above.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 8.0
inline uint64x2_p VecLoad(const word64 src[2])
{
    return (uint64x2_p)VecLoad((const byte*)src);
}

/// \brief Loads a vector from a word array
/// \param src the word array
/// \param off offset into the word array
/// \details VecLoad() loads a vector in from a word array.
/// \details VecLoad() uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \details VecLoad() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 8.0
inline uint64x2_p VecLoad(int off, const word64 src[2])
{
    return (uint64x2_p)VecLoad(off, (const byte*)src);
}

#endif  // _ARCH_PWR8

/// \brief Loads a vector from an aligned byte array
/// \param src the byte array
/// \details VecLoadAligned() loads a vector in from an aligned byte array.
/// \details VecLoadAligned() uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   aligned effective memory addresses. Altivec's <tt>vec_ld</tt> is used
///   if POWER7 is not available. The effective address of <tt>src</tt> must
///   be aligned.
/// \par Wraps
///   vec_ld, vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld
/// \since Crypto++ 8.0
inline uint32x4_p VecLoadAligned(const byte src[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
    return (uint32x4_p)vec_xlw4(0, (byte*)src);
#  elif 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  // _ARCH_PWR8
    CRYPTOPP_ASSERT(((uintptr_t)src) % 16 == 0);
    return (uint32x4_p)vec_ld(0, (byte*)src);
#endif  // _ARCH_PWR8
}

/// \brief Loads a vector from an aligned byte array
/// \param src the byte array
/// \param off offset into the byte array
/// \details VecLoadAligned() loads a vector in from an aligned byte array.
/// \details VecLoadAligned() uses POWER7's <tt>vec_xl</tt> or
///   <tt>vec_vsx_ld</tt> if available. The instructions do not require
///   aligned effective memory addresses. Altivec's <tt>vec_ld</tt> is used
///   if POWER7 is not available. The effective address of <tt>src</tt> must
///   be aligned.
/// \par Wraps
///   vec_ld, vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld
/// \since Crypto++ 8.0
inline uint32x4_p VecLoadAligned(int off, const byte src[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
    return (uint32x4_p)vec_xlw4(off, (byte*)src);
#  elif 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  // _ARCH_PWR8
    CRYPTOPP_ASSERT((((uintptr_t)src)+off) % 16 == 0);
    return (uint32x4_p)vec_ld(off, (byte*)src);
#endif  // _ARCH_PWR8
}

/// \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 array 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
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 6.0
inline uint32x4_p VecLoadBE(const byte src[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
#    if (CRYPTOPP_BIG_ENDIAN)
       return (uint32x4_p)vec_xlw4(0, (byte*)src);
#    else
       return (uint32x4_p)VecReverse(vec_xlw4(0, (byte*)src));
#    endif
#  elif 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_PWR8
#  if (CRYPTOPP_BIG_ENDIAN)
     return (uint32x4_p)VecLoad((const byte*)src);
#  else
     return (uint32x4_p)VecReverse(VecLoad((const byte*)src));
#  endif
#endif  // _ARCH_PWR8
}

/// \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 array 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
///   aligned effective memory addresses. VecLoad_ALTIVEC() is used if POWER7
///   is not available. VecLoad_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xlw4, vec_xld2, vec_xl, vec_vsx_ld (and Altivec load)
/// \since Crypto++ 6.0
inline uint32x4_p VecLoadBE(int off, const byte src[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
#    if (CRYPTOPP_BIG_ENDIAN)
       return (uint32x4_p)vec_xlw4(off, (byte*)src);
#    else
       return (uint32x4_p)VecReverse(vec_xlw4(off, (byte*)src));
#    endif
#  elif 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_PWR8
#  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_PWR8
}

//@}

/// \name STORE OPERATIONS
//@{

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param dest the byte array
/// \details VecStore_ALTIVEC() stores a vector 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.
/// \par Wraps
///   vec_st, vec_ste, vec_lvsr, vec_perm
/// \since Crypto++ 8.0
template<class T>
inline void VecStore_ALTIVEC(const T data, byte dest[16])
{
    // Avoid IsAlignedOn for convenience.
    uintptr_t eff = reinterpret_cast<uintptr_t>(dest)+0;
    if (eff % 16 == 0)
    {
        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 VecStore_ALTIVEC() stores a vector 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.
/// \par Wraps
///   vec_st, vec_ste, vec_lvsr, vec_perm
/// \since Crypto++ 8.0
template<class T>
inline void VecStore_ALTIVEC(const T data, int off, byte dest[16])
{
    // Avoid IsAlignedOn for convenience.
    uintptr_t eff = reinterpret_cast<uintptr_t>(dest)+off;
    if (eff % 16 == 0)
    {
        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 VecStore() stores a vector 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
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 6.0
template<class T>
inline void VecStore(const T data, byte dest[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
    vec_xstw4((uint8x16_p)data, 0, (byte*)dest);
#  elif 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
    VecStore_ALTIVEC((uint8x16_p)data, 0, (byte*)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 VecStore() stores a vector 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
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 6.0
template<class T>
inline void VecStore(const T data, int off, byte dest[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
    vec_xstw4((uint8x16_p)data, off, (byte*)dest);
#  elif 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
    VecStore_ALTIVEC((uint8x16_p)data, off, (byte*)dest);
#endif
}

/// \brief Stores a vector to a word array
/// \tparam T vector type
/// \param data the vector
/// \param dest the word array
/// \details VecStore() stores a vector to a word array.
/// \details VecStore() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \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 word array
/// \details VecStore() stores a vector to a word array.
/// \details VecStore() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \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 word array
/// \tparam T vector type
/// \param data the vector
/// \param dest the word array
/// \details VecStore() stores a vector to a word array.
/// \details VecStore() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \details VecStore() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 8.0
template<class T>
inline void VecStore(const T data, word64 dest[2])
{
    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 word array
/// \details VecStore() stores a vector to a word array.
/// \details VecStore() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \details VecStore() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 8.0
template<class T>
inline void VecStore(const T data, int off, word64 dest[2])
{
    VecStore((uint8x16_p)data, off, (byte*)dest);
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param dest the byte array
/// \details VecStoreBE() stores a vector to a byte array. VecStoreBE
///   will reverse all bytes in the array on a little endian system.
/// \details VecStoreBE() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 6.0
template <class T>
inline void VecStoreBE(const T data, byte dest[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
#    if (CRYPTOPP_BIG_ENDIAN)
       vec_xstw4((uint8x16_p)data, 0, (byte*)dest);
#    else
       vec_xstw4((uint8x16_p)VecReverse(data), 0, (byte*)dest);
#    endif
#  elif defined(__xlc__) || defined(__xlC__) || defined(__clang__)
       vec_xst_be((uint8x16_p)data, 0, (byte*)dest);
#  else
#    if (CRYPTOPP_BIG_ENDIAN)
       vec_vsx_st((uint8x16_p)data, 0, (byte*)dest);
#    else
       vec_vsx_st((uint8x16_p)VecReverse(data), 0, (byte*)dest);
#    endif
#  endif
#else  // _ARCH_PWR8
#  if (CRYPTOPP_BIG_ENDIAN)
     VecStore_ALTIVEC((uint8x16_p)data, 0, (byte*)dest);
#  else
     VecStore_ALTIVEC((uint8x16_p)VecReverse(data), 0, (byte*)dest);
#  endif
#endif  // _ARCH_PWR8
}

/// \brief Stores a vector to a byte array
/// \tparam T vector type
/// \param data the vector
/// \param off offset into the dest byte array
/// \param dest the byte array
/// \details VecStoreBE() stores a vector to a byte array. VecStoreBE
///   will reverse all bytes in the array on a little endian system.
/// \details VecStoreBE() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 6.0
template <class T>
inline void VecStoreBE(const T data, int off, byte dest[16])
{
#if defined(_ARCH_PWR8)
#  if defined(__early_xlc__) || defined(__early_xlC__)
#    if (CRYPTOPP_BIG_ENDIAN)
       vec_xstw4((uint8x16_p)data, off, (byte*)dest);
#    else
       vec_xstw4((uint8x16_p)VecReverse(data), off, (byte*)dest);
#    endif
#  elif defined(__xlc__) || defined(__xlC__) || defined(__clang__)
     vec_xst_be((uint8x16_p)data, off, (byte*)dest);
#  else
#    if (CRYPTOPP_BIG_ENDIAN)
       vec_vsx_st((uint8x16_p)data, off, (byte*)dest);
#    else
       vec_vsx_st((uint8x16_p)VecReverse(data), off, (byte*)dest);
#    endif
#  endif
#else  // _ARCH_PWR8
#  if (CRYPTOPP_BIG_ENDIAN)
     VecStore_ALTIVEC((uint8x16_p)data, off, (byte*)dest);
#  else
     VecStore_ALTIVEC((uint8x16_p)VecReverse(data), off, (byte*)dest);
#  endif
#endif  // _ARCH_PWR8
}

/// \brief Stores a vector to a word array
/// \tparam T vector type
/// \param data the vector
/// \param dest the word array
/// \details VecStoreBE() stores a vector to a word array. VecStoreBE
///   will reverse all bytes in the array on a little endian system.
/// \details VecStoreBE() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 8.0
template <class T>
inline void VecStoreBE(const T data, word32 dest[4])
{
    return VecStoreBE((uint8x16_p)data, (byte*)dest);
}

/// \brief Stores a vector to a word array
/// \tparam T vector type
/// \param data the vector
/// \param off offset into the dest word array
/// \param dest the word array
/// \details VecStoreBE() stores a vector to a word array. VecStoreBE
///   will reverse all words in the array on a little endian system.
/// \details VecStoreBE() uses POWER7's <tt>vec_xst</tt> or
///   <tt>vec_vsx_st</tt> if available. The instructions do not require
///   aligned effective memory addresses. VecStore_ALTIVEC() is used if POWER7
///   is not available. VecStore_ALTIVEC() can be relatively expensive if
///   extra instructions are required to fix up unaligned memory
///   addresses.
/// \par Wraps
///   vec_xstw4, vec_xstld2, vec_xst, vec_vsx_st (and Altivec store)
/// \since Crypto++ 8.0
template <class T>
inline void VecStoreBE(const T data, int off, word32 dest[4])
{
    return VecStoreBE((uint8x16_p)data, off, (byte*)dest);
}

//@}

/// \name LOGICAL OPERATIONS
//@{

/// \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.
/// \par Wraps
///   vec_and
/// \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.
/// \par Wraps
///   vec_or
/// \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.
/// \par Wraps
///   vec_xor
/// \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);
}

//@}

/// \name ARITHMETIC OPERATIONS
//@{

/// \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.
/// \par Wraps
///   vec_add
/// \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.
/// \par Wraps
///   vec_sub
/// \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 if uint64x2_p vectors. On POWER7
///   and below VecAdd64() manages the carries from two elements in
///   a uint32x4_p vector.
/// \par Wraps
///   vec_add for POWER8, vec_addc, vec_perm, vec_add for Altivec
/// \since Crypto++ 8.0
inline uint32x4_p VecAdd64(const uint32x4_p& vec1, const uint32x4_p& vec2)
{
    // 64-bit elements available at POWER7, but addudm requires POWER8
#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
}

//@}

/// \name OTHER OPERATIONS
//@{

/// \brief Permutes a vector
/// \tparam T1 vector type
/// \tparam T2 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.
/// \par Wraps
///   vec_perm
/// \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.
/// \par Wraps
///   vec_perm
/// \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, (T1)vec2, (uint8x16_p)mask);
}

/// \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>
/// \par Wraps
///   vec_sld
/// \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)
    enum { R=C&0xf };
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, R);
#else
    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, R);
#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>
/// \par Wraps
///   vec_sld
/// \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)
    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, R);
#else
    enum { R=C&0xf };
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, R);
#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.
/// \par Wraps
///   vec_sld
/// \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)
{
#if (CRYPTOPP_BIG_ENDIAN)
    enum { R = C&0xf };
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
#else
    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, 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.
/// \par Wraps
///   vec_sld
/// \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)
{
#if (CRYPTOPP_BIG_ENDIAN)
    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
#else
    enum { R = C&0xf };
    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
#endif
}

/// \brief Rotate a packed 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.
/// \par Wraps
///   vec_rl
/// \since Crypto++ 7.0
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 Shift a packed vector left
/// \tparam C shift bit count
/// \param vec the vector
/// \returns vector
/// \details VecShiftLeft() rotates each element in a packed vector by bit count.
/// \par Wraps
///   vec_sl
/// \since Crypto++ 8.1
template<unsigned int C>
inline uint32x4_p VecShiftLeft(const uint32x4_p vec)
{
    const uint32x4_p m = {C, C, C, C};
    return vec_sl(vec, m);
}

/// \brief Merge two vectors
/// \tparam T vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \par Wraps
///   vec_mergeh
/// \since Crypto++ 8.1
template <class T>
inline T VecMergeHigh(const T vec1, const T vec2)
{
    return vec_mergeh(vec1, vec2);
}

/// \brief Merge two vectors
/// \tparam T vector type
/// \param vec1 the first vector
/// \param vec2 the second vector
/// \returns vector
/// \par Wraps
///   vec_mergel
/// \since Crypto++ 8.1
template <class T>
inline T VecMergeLow(const T vec1, const T vec2)
{
    return vec_mergel(vec1, vec2);
}

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

/// \brief Rotate a packed 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.
/// \details VecRotateLeft() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_rl
/// \since Crypto++ 8.0
template<unsigned int C>
inline uint64x2_p VecRotateLeft(const uint64x2_p vec)
{
    const uint64x2_p m = {C, C};
    return vec_rl(vec, m);
}

/// \brief Shift a packed vector left
/// \tparam C shift bit count
/// \param vec the vector
/// \returns vector
/// \details VecShiftLeft() rotates each element in a packed vector by bit count.
/// \details VecShiftLeft() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_sl
/// \since Crypto++ 8.1
template<unsigned int C>
inline uint64x2_p VecShiftLeft(const uint64x2_p vec)
{
    const uint64x2_p m = {C, C};
    return vec_sl(vec, m);
}

#endif

/// \brief Rotate a packed 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.
/// \par Wraps
///   vec_rl
/// \since Crypto++ 7.0
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 Shift a packed vector right
/// \tparam C shift bit count
/// \param vec the vector
/// \returns vector
/// \details VecShiftRight() rotates each element in a packed vector by bit count.
/// \par Wraps
///   vec_rl
/// \since Crypto++ 8.1
template<unsigned int C>
inline uint32x4_p VecShiftRight(const uint32x4_p vec)
{
    const uint32x4_p m = {C, C, C, C};
    return vec_sr(vec, m);
}

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

/// \brief Rotate a packed 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.
/// \details VecRotateRight() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_rl
/// \since Crypto++ 8.0
template<unsigned int C>
inline uint64x2_p VecRotateRight(const uint64x2_p vec)
{
    const uint64x2_p m = {64-C, 64-C};
    return vec_rl(vec, m);
}

/// \brief Shift a packed vector right
/// \tparam C shift bit count
/// \param vec the vector
/// \returns vector
/// \details VecShiftRight() rotates each element in a packed vector by bit count.
/// \details VecShiftRight() with 64-bit elements is available on POWER8 and above.
/// \par Wraps
///   vec_sr
/// \since Crypto++ 8.1
template<unsigned int C>
inline uint64x2_p VecShiftRight(const uint64x2_p vec)
{
    const uint64x2_p m = {C, C};
    return vec_sr(vec, m);
}

#endif

/// \brief Exchange high and low double words
/// \tparam T vector type
/// \param vec the vector
/// \returns vector
/// \par Wraps
///   vec_sld
/// \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.
/// \par Wraps
///   vec_sld
/// \since Crypto++ 7.0
template <class T>
inline T VecGetLow(const T val)
{
#if (CRYPTOPP_BIG_ENDIAN) && (_ARCH_PWR8)
    const T zero = {0};
    return (T)VecMergeLow((uint64x2_p)zero, (uint64x2_p)val);
#else
    return VecShiftRightOctet<8>(VecShiftLeftOctet<8>(val));
#endif
}

/// \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.
/// \par Wraps
///   vec_sld
/// \since Crypto++ 7.0
template <class T>
inline T VecGetHigh(const T val)
{
#if (CRYPTOPP_BIG_ENDIAN) && (_ARCH_PWR8)
    const T zero = {0};
    return (T)VecMergeHigh((uint64x2_p)zero, (uint64x2_p)val);
#else
    return VecShiftRightOctet<8>(val);
#endif
}

/// \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
/// \details VecEqual() performs a bitwise compare. The vector element types do
///  not matter.
/// \par Wraps
///   vec_all_eq
/// \since Crypto++ 8.0
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
/// \details VecNotEqual() performs a bitwise compare. The vector element types do
///  not matter.
/// \par Wraps
///   vec_all_eq
/// \since Crypto++ 8.0
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(__CRYPTO__) || defined(CRYPTOPP_DOXYGEN_PROCESSING)

/// \name POLYNOMIAL MULTIPLICATION
//@{

/// \brief Polynomial multiplication
/// \param a the first term
/// \param b the second term
/// \returns vector product
/// \details VecPolyMultiply() performs polynomial multiplication. POWER8
///   polynomial multiplication multiplies the high and low terms, and then
///   XOR's the high and low products. That is, the result is <tt>ah*bh XOR
///   al*bl</tt>. It is different behavior than Intel polynomial
///   multiplication. To obtain a single product without the XOR, then set
///   one of the high or low terms to 0. For example, setting <tt>ah=0</tt>
///   results in <tt>0*bh XOR al*bl = al*bl</tt>.
/// \par Wraps
///   __vpmsumw, __builtin_altivec_crypto_vpmsumw and __builtin_crypto_vpmsumw.
/// \since Crypto++ 8.1
inline uint32x4_p VecPolyMultiply(const uint32x4_p& a, const uint32x4_p& b)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return __vpmsumw (a, b);
#elif defined(__clang__)
    return __builtin_altivec_crypto_vpmsumw (a, b);
#else
    return __builtin_crypto_vpmsumw (a, b);
#endif
}

/// \brief Polynomial multiplication
/// \param a the first term
/// \param b the second term
/// \returns vector product
/// \details VecPolyMultiply() performs polynomial multiplication. POWER8
///   polynomial multiplication multiplies the high and low terms, and then
///   XOR's the high and low products. That is, the result is <tt>ah*bh XOR
///   al*bl</tt>. It is different behavior than Intel polynomial
///   multiplication. To obtain a single product without the XOR, then set
///   one of the high or low terms to 0. For example, setting <tt>ah=0</tt>
///   results in <tt>0*bh XOR al*bl = al*bl</tt>.
/// \par Wraps
///   __vpmsumd, __builtin_altivec_crypto_vpmsumd and __builtin_crypto_vpmsumd.
/// \since Crypto++ 8.1
inline uint64x2_p VecPolyMultiply(const uint64x2_p& a, const uint64x2_p& b)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return __vpmsumd (a, b);
#elif defined(__clang__)
    return __builtin_altivec_crypto_vpmsumd (a, b);
#else
    return __builtin_crypto_vpmsumd (a, b);
#endif
}

/// \brief Polynomial multiplication
/// \param a the first term
/// \param b the second term
/// \returns vector product
/// \details VecPolyMultiply00LE() performs polynomial multiplication and presents
///  the result like Intel's <tt>c = _mm_clmulepi64_si128(a, b, 0x00)</tt>.
///  The <tt>0x00</tt> indicates the low 64-bits of <tt>a</tt> and <tt>b</tt>
///  are multiplied.
/// \note An Intel XMM register is composed of 128-bits. The leftmost bit
///  is MSB and numbered 127, while the the rightmost bit is LSB and numbered 0.
/// \par Wraps
///   __vpmsumd, __builtin_altivec_crypto_vpmsumd and __builtin_crypto_vpmsumd.
/// \since Crypto++ 8.0
inline uint64x2_p VecPolyMultiply00LE(const uint64x2_p& a, const uint64x2_p& b)
{
#if (CRYPTOPP_BIG_ENDIAN)
    return VecSwapWords(VecPolyMultiply(VecGetHigh(a), VecGetHigh(b)));
#else
    return VecPolyMultiply(VecGetHigh(a), VecGetHigh(b));
#endif
}

/// \brief Polynomial multiplication
/// \param a the first term
/// \param b the second term
/// \returns vector product
/// \details VecPolyMultiply01LE performs() polynomial multiplication and presents
///  the result like Intel's <tt>c = _mm_clmulepi64_si128(a, b, 0x01)</tt>.
///  The <tt>0x01</tt> indicates the low 64-bits of <tt>a</tt> and high
///  64-bits of <tt>b</tt> are multiplied.
/// \note An Intel XMM register is composed of 128-bits. The leftmost bit
///  is MSB and numbered 127, while the the rightmost bit is LSB and numbered 0.
/// \par Wraps
///   __vpmsumd, __builtin_altivec_crypto_vpmsumd and __builtin_crypto_vpmsumd.
/// \since Crypto++ 8.0
inline uint64x2_p VecPolyMultiply01LE(const uint64x2_p& a, const uint64x2_p& b)
{
#if (CRYPTOPP_BIG_ENDIAN)
    return VecSwapWords(VecPolyMultiply(a, VecGetHigh(b)));
#else
    return VecPolyMultiply(a, VecGetHigh(b));
#endif
}

/// \brief Polynomial multiplication
/// \param a the first term
/// \param b the second term
/// \returns vector product
/// \details VecPolyMultiply10LE() performs polynomial multiplication and presents
///  the result like Intel's <tt>c = _mm_clmulepi64_si128(a, b, 0x10)</tt>.
///  The <tt>0x10</tt> indicates the high 64-bits of <tt>a</tt> and low
///  64-bits of <tt>b</tt> are multiplied.
/// \note An Intel XMM register is composed of 128-bits. The leftmost bit
///  is MSB and numbered 127, while the the rightmost bit is LSB and numbered 0.
/// \par Wraps
///   __vpmsumd, __builtin_altivec_crypto_vpmsumd and __builtin_crypto_vpmsumd.
/// \since Crypto++ 8.0
inline uint64x2_p VecPolyMultiply10LE(const uint64x2_p& a, const uint64x2_p& b)
{
#if (CRYPTOPP_BIG_ENDIAN)
    return VecSwapWords(VecPolyMultiply(VecGetHigh(a), b));
#else
    return VecPolyMultiply(VecGetHigh(a), b);
#endif
}

/// \brief Polynomial multiplication
/// \param a the first term
/// \param b the second term
/// \returns vector product
/// \details VecPolyMultiply11LE() performs polynomial multiplication and presents
///  the result like Intel's <tt>c = _mm_clmulepi64_si128(a, b, 0x11)</tt>.
///  The <tt>0x11</tt> indicates the high 64-bits of <tt>a</tt> and <tt>b</tt>
///  are multiplied.
/// \note An Intel XMM register is composed of 128-bits. The leftmost bit
///  is MSB and numbered 127, while the the rightmost bit is LSB and numbered 0.
/// \par Wraps
///   __vpmsumd, __builtin_altivec_crypto_vpmsumd and __builtin_crypto_vpmsumd.
/// \since Crypto++ 8.0
inline uint64x2_p VecPolyMultiply11LE(const uint64x2_p& a, const uint64x2_p& b)
{
#if (CRYPTOPP_BIG_ENDIAN)
    return VecSwapWords(VecPolyMultiply(VecGetLow(a), b));
#else
    return VecPolyMultiply(VecGetLow(a), b);
#endif
}

//@}

/// \name AES ENCRYPTION
//@{

/// \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.
/// \details VecEncrypt() is available on POWER8 and above.
/// \par Wraps
///   __vcipher, __builtin_altivec_crypto_vcipher, __builtin_crypto_vcipher
/// \since GCC and XLC since Crypto++ 6.0, LLVM Clang since Crypto++ 8.0
template <class T1, class T2>
inline T1 VecEncrypt(const T1 state, const T2 key)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return (T1)__vcipher((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__clang__)
    return (T1)__builtin_altivec_crypto_vcipher((uint64x2_p)state, (uint64x2_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.
/// \details VecEncryptLast() is available on POWER8 and above.
/// \par Wraps
///   __vcipherlast, __builtin_altivec_crypto_vcipherlast, __builtin_crypto_vcipherlast
/// \since GCC and XLC since Crypto++ 6.0, LLVM Clang since Crypto++ 8.0
template <class T1, class T2>
inline T1 VecEncryptLast(const T1 state, const T2 key)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return (T1)__vcipherlast((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__clang__)
    return (T1)__builtin_altivec_crypto_vcipherlast((uint64x2_p)state, (uint64x2_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.
/// \details VecDecrypt() is available on POWER8 and above.
/// \par Wraps
///   __vncipher, __builtin_altivec_crypto_vncipher, __builtin_crypto_vncipher
/// \since GCC and XLC since Crypto++ 6.0, LLVM Clang since Crypto++ 8.0
template <class T1, class T2>
inline T1 VecDecrypt(const T1 state, const T2 key)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return (T1)__vncipher((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__clang__)
    return (T1)__builtin_altivec_crypto_vncipher((uint64x2_p)state, (uint64x2_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.
/// \details VecDecryptLast() is available on POWER8 and above.
/// \par Wraps
///   __vncipherlast, __builtin_altivec_crypto_vncipherlast, __builtin_crypto_vncipherlast
/// \since GCC and XLC since Crypto++ 6.0, LLVM Clang since Crypto++ 8.0
template <class T1, class T2>
inline T1 VecDecryptLast(const T1 state, const T2 key)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return (T1)__vncipherlast((uint8x16_p)state, (uint8x16_p)key);
#elif defined(__clang__)
    return (T1)__builtin_altivec_crypto_vncipherlast((uint64x2_p)state, (uint64x2_p)key);
#elif defined(__GNUC__)
    return (T1)__builtin_crypto_vncipherlast((uint64x2_p)state, (uint64x2_p)key);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

//@}

/// \name SHA DIGESTS
//@{

/// \brief SHA256 Sigma functions
/// \tparam func function
/// \tparam fmask function mask
/// \tparam T vector type
/// \param vec the block to transform
/// \details VecSHA256() selects sigma0, sigma1, Sigma0, Sigma1 based on
///   func and fmask. The return vector is the same type as vec.
/// \details VecSHA256() is available on POWER8 and above.
/// \par Wraps
///   __vshasigmaw, __builtin_altivec_crypto_vshasigmaw, __builtin_crypto_vshasigmaw
/// \since GCC and XLC since Crypto++ 6.0, LLVM Clang since Crypto++ 8.0
template <int func, int fmask, class T>
inline T VecSHA256(const T vec)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return (T)__vshasigmaw((uint32x4_p)vec, func, fmask);
#elif defined(__clang__)
    return (T)__builtin_altivec_crypto_vshasigmaw((uint32x4_p)vec, func, fmask);
#elif defined(__GNUC__)
    return (T)__builtin_crypto_vshasigmaw((uint32x4_p)vec, func, fmask);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

/// \brief SHA512 Sigma functions
/// \tparam func function
/// \tparam fmask function mask
/// \tparam T vector type
/// \param vec the block to transform
/// \details VecSHA512() selects sigma0, sigma1, Sigma0, Sigma1 based on
///   func and fmask. The return vector is the same type as vec.
/// \details VecSHA512() is available on POWER8 and above.
/// \par Wraps
///   __vshasigmad, __builtin_altivec_crypto_vshasigmad, __builtin_crypto_vshasigmad
/// \since GCC and XLC since Crypto++ 6.0, LLVM Clang since Crypto++ 8.0
template <int func, int fmask, class T>
inline T VecSHA512(const T vec)
{
#if defined(__ibmxl__) || (defined(_AIX) && defined(__xlC__))
    return (T)__vshasigmad((uint64x2_p)vec, func, fmask);
#elif defined(__clang__)
    return (T)__builtin_altivec_crypto_vshasigmad((uint64x2_p)vec, func, fmask);
#elif defined(__GNUC__)
    return (T)__builtin_crypto_vshasigmad((uint64x2_p)vec, func, fmask);
#else
    CRYPTOPP_ASSERT(0);
#endif
}

//@}

#endif  // __CRYPTO__

#endif  // _ALTIVEC_

NAMESPACE_END

#if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
# pragma GCC diagnostic pop
#endif

#endif  // CRYPTOPP_PPC_CRYPTO_H
