Use pre-splatted key table for LEA NEON and Aarch64

2 files changed, 20 insertions, 5 deletions

diff --git a/lea-simd.cpp b/lea-simd.cpp
index a43b719a..8dacdf56 100644
--- a/lea-simd.cpp
+++ b/lea-simd.cpp
@@ -140,7 +140,7 @@ uint32x4_t UnpackHigh64(uint32x4_t a, uint32x4_t b)
 template <unsigned int IDX>

 inline uint32x4_t LoadKey(const word32 rkey[])

 {

-    return vdupq_n_u32(rkey[IDX]);

+    return vld1q_u32(&rkey[IDX*4]);

 }

 

 template <unsigned int IDX>

@@ -1012,6 +1012,16 @@ size_t LEA_Dec_AdvancedProcessBlocks_SSSE3(const word32* subKeys, size_t rounds,
 #endif // CRYPTOPP_SSSE3_AVAILABLE

 

 #if defined(CRYPTOPP_ARM_NEON_AVAILABLE)

+void LEA_SplatKeys_NEON(SecBlock<word32>& rkeys)

+{

+    SecBlock<word32> temp(rkeys.size() * 4);

+    for (size_t i=0, j=0; i<rkeys.size(); i++, j+=4)

+    {

+		vst1q_u32(&temp[j], vdupq_n_u32(rkeys[i]));

+    }

+    std::swap(rkeys, temp);

+}

+

 size_t LEA_Enc_AdvancedProcessBlocks_NEON(const word32* subKeys, size_t rounds,

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

 {

diff --git a/lea.cpp b/lea.cpp
index 35149157..122313da 100644
--- a/lea.cpp
+++ b/lea.cpp
@@ -567,6 +567,8 @@ extern size_t LEA_Dec_AdvancedProcessBlocks_SSSE3(const word32* subKeys, size_t
 # endif

 

 # if (CRYPTOPP_ARM_NEON_AVAILABLE)

+extern void LEA_SplatKeys_NEON(SecBlock<word32>& rkeys);

+

 extern size_t LEA_Enc_AdvancedProcessBlocks_NEON(const word32* subKeys, size_t rounds,

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

 

@@ -606,13 +608,16 @@ void LEA::Base::UncheckedSetKey(const byte *userKey, unsigned int keyLength, con
         CRYPTOPP_ASSERT(0);;

     }

 

+    // If we pre-splat the round keys at setup then we avoid a shuffle

+    // at runtime for each subkey used during encryption and decryption.

+    // Pre-splatting saves about 0.7 to 1.0 cpb at the cost of 4x storage.

 #if (CRYPTOPP_LEA_ADVANCED_PROCESS_BLOCKS) && (CRYPTOPP_SSSE3_AVAILABLE)

     if (HasSSSE3())

-    {

-        // If we pre-splat the round keys at setup then we avoid a shuffle

-        // at runtime for each subkey used during encryption and decryption.

         LEA_SplatKeys_SSSE3(m_rkey);

-    }

+#endif

+#if (CRYPTOPP_LEA_ADVANCED_PROCESS_BLOCKS) && (CRYPTOPP_ARM_NEON_AVAILABLE)

+    if (HasNEON())

+        LEA_SplatKeys_NEON(m_rkey);

 #endif

 }