Refactor LoadT() and StoreT(). Add separate ReverseT() for little endian machines

The refactoring has no effect on little endian machines. However, on big endian GCC119 using GCC 7.1 the performance improved by 2.5x for ECB and CTR modes:

BEFORE:

<TR><TH>AES/CTR (128-bit key)<TD>2723<TD>1.4<TD>0.163<TD>670
<TR><TH>AES/CTR (192-bit key)<TD>2560<TD>1.5<TD>0.175<TD>719
<TR><TH>AES/CTR (256-bit key)<TD>2728<TD>1.4<TD>0.183<TD>749
<TR><TH>AES/CBC (128-bit key)<TD>1204<TD>3.2<TD>0.135<TD>554
<TR><TH>AES/CBC (192-bit key)<TD>1066<TD>3.7<TD>0.148<TD>605
<TR><TH>AES/CBC (256-bit key)<TD>948<TD>4.1<TD>0.155<TD>635
<TR><TH>AES/OFB (128-bit key)<TD>1019<TD>3.8<TD>0.158<TD>648
<TR><TH>AES/CFB (128-bit key)<TD>949<TD>4.1<TD>0.192<TD>787
<TR><TH>AES/ECB (128-bit key)<TD>3564<TD>1.1<TD>0.082<TD>337

AFTER:

<TR><TH>AES/CTR (128-bit key)<TD>6484<TD>0.6<TD>0.163<TD>677
<TR><TH>AES/CTR (192-bit key)<TD>5641<TD>0.7<TD>0.176<TD>728
<TR><TH>AES/CTR (256-bit key)<TD>5005<TD>0.8<TD>0.183<TD>761
<TR><TH>AES/CBC (128-bit key)<TD>1223<TD>3.2<TD>0.135<TD>559
<TR><TH>AES/CBC (192-bit key)<TD>1080<TD>3.7<TD>0.147<TD>611
<TR><TH>AES/CBC (256-bit key)<TD>966<TD>4.1<TD>0.155<TD>642
<TR><TH>AES/OFB (128-bit key)<TD>1057<TD>3.7<TD>0.158<TD>656
<TR><TH>AES/CFB (128-bit key)<TD>1217<TD>3.3<TD>0.186<TD>774
<TR><TH>AES/ECB (128-bit key)<TD>7289<TD>0.5<TD>0.082<TD>342

1 files changed, 2 insertions, 2 deletions

diff --git a/rijndael.cpp b/rijndael.cpp
index 43c7fa80..94085ac1 100644
--- a/rijndael.cpp
+++ b/rijndael.cpp
@@ -251,7 +251,7 @@ extern size_t Rijndael_Dec_AdvancedProcessBlocks_ARMV8(const word32 *subkeys, si
 #endif

 

 #if (CRYPTOPP_POWER8_AES_AVAILABLE)

-extern void ByteReverseArrayLE(byte src[16]);

+extern void ByteReverseArray(byte src[16]);

 

 extern size_t Rijndael_Enc_AdvancedProcessBlocks_POWER8(const word32 *subkeys, size_t rounds,

         const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags);

@@ -329,7 +329,7 @@ void Rijndael::Base::UncheckedSetKey(const byte *userKey, unsigned int keyLen, c
 		// reversed on little-endian systems to ensure it loads properly.

 		byte * ptr = reinterpret_cast<byte*>(rk);

 		for (unsigned int i=0; i<=m_rounds; i++)

-			ByteReverseArrayLE(ptr+i*16);

+			ByteReverseArray(ptr+i*16);

 #endif  // IS_LITTLE_ENDIAN

 

 		return;