From bbf13b77e795c50c133816907af1f783f6999e69 Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Thu, 19 Jan 2017 06:22:38 -0500
Subject: [PATCH] Switch to vext and remove unnecessary casts

---
 gcm.cpp | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/gcm.cpp b/gcm.cpp
index 882f10c9..b36e6c9e 100644
--- a/gcm.cpp
+++ b/gcm.cpp
@@ -368,8 +368,7 @@ void GCM_Base::SetKeyWithoutResync(const byte *userKey, size_t keylength, const
 	{
 		const uint64x2_t r = s_clmulConstants[0];
 		const uint64x2_t t = vld1q_u64((const uint64_t *)hashKey);
-		const uint64x2_t h0 = vreinterpretq_u64_u8(vrev64q_u8(
-				vreinterpretq_u8_u64(vcombine_u64(vget_high_u64(t), vget_low_u64(t)))));
+		const uint64x2_t h0 = vrev64q_u8(vextq_u64(t, t, 1));
 
 		uint64x2_t h = h0;
 		for (i=0; i<tableSize-32; i+=32)
@@ -505,8 +504,8 @@ inline void GCM_Base::ReverseHashBufferIfNeeded()
 	{
 		if (GetNativeByteOrder() != BIG_ENDIAN_ORDER)
 		{
-			const uint64x2_t x = vreinterpretq_u64_u8(vrev64q_u8(vld1q_u8(HashBuffer())));
-			vst1q_u8(HashBuffer(), vreinterpretq_u8_u64(vcombine_u64(vget_high_u64(x), vget_low_u64(x))));
+			const uint8x16_t x = vld1q_u8(HashBuffer());
+			vst1q_u8(HashBuffer(), vrev64q_u8(vextq_u8(x, x, 8)));
 		}
 	}
 #endif
@@ -674,16 +673,17 @@ size_t GCM_Base::AuthenticateBlocks(const byte *data, size_t len)
 				if (++i == s)
 				{
 					const uint64x2_t t1 = vld1q_u64((const uint64_t *)data);
-					d1 = veorq_u64(vreinterpretq_u64_u8(vrev64q_u8(vreinterpretq_u8_u64(vcombine_u64(vget_high_u64(t1), vget_low_u64(t1))))), x);
+					d1 = veorq_u64(vrev64q_u8(vextq_u64(t1, t1, 1)), x);
 					c0 = veorq_u64(c0, PMULL_00(d1, h0));
 					c2 = veorq_u64(c2, PMULL_10(d1, h1));
-					d1 = veorq_u64(d1, (uint64x2_t)vcombine_u32(vget_high_u32(vreinterpretq_u32_u64(d1)), vget_low_u32(vreinterpretq_u32_u64(d1))));
+					d1 = veorq_u64(d1, (uint64x2_t)vcombine_u32(vget_high_u32(vreinterpretq_u32_u64(d1)),
+                                                                vget_low_u32(vreinterpretq_u32_u64(d1))));
 					c1 = veorq_u64(c1, PMULL_00(d1, h2));
 
 					break;
 				}
 
-				d1 = vreinterpretq_u64_u8(vrev64q_u8(vreinterpretq_u8_u64(vld1q_u64((const uint64_t *)(data+(s-i)*16-8)))));
+				d1 = vreinterpretq_u64_u8(vrev64q_u8(vld1q_u8(data+(s-i)*16-8)));
 				c0 = veorq_u64(c0, PMULL_10(d2, h0));
 				c2 = veorq_u64(c2, PMULL_10(d1, h1));
 				d2 = veorq_u64(d2, d1);
@@ -692,17 +692,18 @@ size_t GCM_Base::AuthenticateBlocks(const byte *data, size_t len)
 				if (++i == s)
 				{
 					const uint64x2_t t2 = vld1q_u64((const uint64_t *)data);
-					d1 = veorq_u64((uint64x2_t)vrev64q_u8(vreinterpretq_u8_u64(vcombine_u64(vget_high_u64(t2), vget_low_u64(t2)))), x);
+					d1 = veorq_u64(vrev64q_u8(vextq_u64(t2, t2, 1)), x);
 					c0 = veorq_u64(c0, PMULL_01(d1, h0));
 					c2 = veorq_u64(c2, PMULL_11(d1, h1));
-					d1 = veorq_u64(d1, (uint64x2_t)vcombine_u32(vget_high_u32(vreinterpretq_u32_u64(d1)), vget_low_u32(vreinterpretq_u32_u64(d1))));
+					d1 = veorq_u64(d1, (uint64x2_t)vcombine_u32(vget_high_u32(vreinterpretq_u32_u64(d1)),
+                                                                vget_low_u32(vreinterpretq_u32_u64(d1))));
 					c1 = veorq_u64(c1, PMULL_01(d1, h2));
 
 					break;
 				}
 
 				const uint64x2_t t3 = vld1q_u64((uint64_t *)(data+(s-i)*16-8));
-				d2 = vreinterpretq_u64_u8(vrev64q_u8(vreinterpretq_u8_u64(vcombine_u64(vget_high_u64(t3), vget_low_u64(t3)))));
+				d2 = vrev64q_u8(vextq_u64(t3, t3, 1));
 				c0 = veorq_u64(c0, PMULL_01(d1, h0));
 				c2 = veorq_u64(c2, PMULL_01(d2, h1));
 				d1 = veorq_u64(d1, d2);