AES: Improve XOR routines

calamity-inc · Dec 1, 2024 · d61175d · d61175d
1 parent bed1296
commit d61175d
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/soup/aes.cpp b/soup/aes.cpp
@@ -875,9 +875,15 @@ NAMESPACE_SOUP
 
 	void aes::xorBlocks(uint8_t a[16], const uint8_t b[16]) noexcept
 	{
-#if SOUP_BITS == 64
+#if SOUP_BITS >= 64
+		// Could use _mm_xor_si128 if target supports SSE2
 		reinterpret_cast<uint64_t*>(a)[0] ^= reinterpret_cast<const uint64_t*>(b)[0];
 		reinterpret_cast<uint64_t*>(a)[1] ^= reinterpret_cast<const uint64_t*>(b)[1];
+#elif SOUP_BITS >= 32
+		reinterpret_cast<uint32_t*>(a)[0] ^= reinterpret_cast<const uint32_t*>(b)[0];
+		reinterpret_cast<uint32_t*>(a)[1] ^= reinterpret_cast<const uint32_t*>(b)[1];
+		reinterpret_cast<uint32_t*>(a)[2] ^= reinterpret_cast<const uint32_t*>(b)[2];
+		reinterpret_cast<uint32_t*>(a)[3] ^= reinterpret_cast<const uint32_t*>(b)[3];
 #else
 		for (unsigned int i = 0; i != 16; ++i)
 		{

diff --git a/soup/aes.hpp b/soup/aes.hpp
@@ -51,7 +51,7 @@ NAMESPACE_SOUP
 		static void encryptBlock(const uint8_t in[16], uint8_t out[16], const uint8_t roundKeys[240], const int Nr) noexcept;
 		static void decryptBlock(const uint8_t in[16], uint8_t out[16], const uint8_t roundKeys[240], const int Nr) noexcept;
 		static SOUP_FORCEINLINE void xorBlocks(uint8_t a[16], const uint8_t b[16]) noexcept;
-		static void xorBlocks(uint8_t a[], const uint8_t b[], unsigned int len) noexcept;
+		static SOUP_FORCEINLINE void xorBlocks(uint8_t a[], const uint8_t b[], unsigned int len) noexcept;
 
 		static void ghash(uint8_t res[16], const uint8_t h[16], const std::vector<uint8_t>& x) noexcept;
 		static void calcH(uint8_t h[16], uint8_t roundKeys[240], const int Nr) noexcept;