diff --git a/cpu.h b/cpu.h
index c0b0122e..36d26dd2 100644
--- a/cpu.h
+++ b/cpu.h
@@ -278,6 +278,21 @@ inline int GetCacheLineSize()
 #define IF0(y)
 #define IF1(y) y
 
+// Should be confined to GCC, but its used to help manage Clang 3.4 compiler error.
+//   Also see LLVM Bug 24232, http://llvm.org/bugs/show_bug.cgi?id=24232 .
+#ifndef INTEL_PREFIX
+	#define INTEL_PREFIX
+#endif
+#ifndef INTEL_NOPREFIX
+	#define INTEL_NOPREFIX
+#endif
+#ifndef ATT_PREFIX
+	#define ATT_PREFIX
+#endif
+#ifndef ATT_NOPREFIX
+	#define ATT_NOPREFIX
+#endif
+
 #ifdef CRYPTOPP_GENERATE_X64_MASM
 #define ASM_MOD(x, y) ((x) MOD (y))
 #define XMMWORD_PTR XMMWORD PTR
diff --git a/gcm.cpp b/gcm.cpp
index dd28c25f..e74c7408 100644
--- a/gcm.cpp
+++ b/gcm.cpp
@@ -735,7 +735,9 @@ size_t GCM_Base::AuthenticateBlocks(const byte *data, size_t len)
 
 		AS2(	add		WORD_REG(cx), 16				)
 		AS2(	sub		WORD_REG(dx), 1					)
+		ATT_NOPREFIX
 		ASJ(	jnz,	0, b							)
+		INTEL_NOPREFIX
 		AS2(	movdqa	[WORD_REG(si)], xmm0			)
 
 		#if CRYPTOPP_BOOL_X32
@@ -820,7 +822,9 @@ size_t GCM_Base::AuthenticateBlocks(const byte *data, size_t len)
 
 		AS2(	add	WORD_REG(cx), 16		)
 		AS2(	sub	WORD_REG(dx), 1			)
+		ATT_NOPREFIX
 		ASJ(	jnz,	1, b				)
+		INTEL_NOPREFIX
 		AS2(	movdqa	[WORD_REG(si)], xmm0		)
 
 		#ifdef __GNUC__
diff --git a/panama.h b/panama.h
index f3b86501..b7db323a 100644
--- a/panama.h
+++ b/panama.h
@@ -10,8 +10,8 @@
 #include "iterhash.h"
 #include "secblock.h"
 
-// Clang 3.3 integrated assembler crash on Linux
-#if CRYPTOPP_BOOL_X32 || (defined(CRYPTOPP_CLANG_VERSION) && (CRYPTOPP_CLANG_VERSION < 30400))
+// Clang 3.3 integrated assembler crash on Linux. Clang 3.4 due to compiler error with .intel_syntax
+#if CRYPTOPP_BOOL_X32 || (defined(CRYPTOPP_CLANG_VERSION) && (CRYPTOPP_CLANG_VERSION < 30500))
 # define CRYPTOPP_DISABLE_PANAMA_ASM
 #endif
 
diff --git a/rijndael.cpp b/rijndael.cpp
index 934b6884..0b6d1581 100644
--- a/rijndael.cpp
+++ b/rijndael.cpp
@@ -651,7 +651,9 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 	AS2(	movdqa	XMMWORD_PTR [L_SUBKEYS+WORD_REG(si)], xmm0)
 	AS2(	add		WORD_REG(si), 16)
 	AS2(	cmp		WORD_REG(si), 16*12)
+	ATT_NOPREFIX
 	ASJ(	jl,		0, b)
+	INTEL_NOPREFIX
 
 	// read subkeys 0, 1 and last
 	AS2(	movdqa	xmm4, [WORD_REG(ax)+WORD_REG(si)])	// last subkey
@@ -673,11 +675,15 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 	AS2(	mov		esi, [AS_REG_7+WORD_REG(ax)])
 	AS2(	add		WORD_REG(ax), WORD_REG(di))
 	AS2(	cmp		WORD_REG(ax), 2048)
+	ATT_NOPREFIX
 	ASJ(	jl,		9, b)
+	INTEL_NOPREFIX
 	AS1(	lfence)
 
 	AS2(	test	DWORD PTR [L_LENGTH], 1)
+	ATT_NOPREFIX
 	ASJ(	jz,		8, f)
+	INTEL_NOPREFIX
 
 	// counter mode one-time setup
 	AS2(	mov		WORD_REG(si), [L_INBLOCKS])
@@ -751,8 +757,9 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 	AS2(	mov		[L_SAVED_X+0*4], eax)
 	AS2(	mov		[L_SAVED_X+1*4], ebx)
 	AS2(	mov		[L_SAVED_X+2*4], edi)
+	ATT_NOPREFIX
 	ASJ(	jmp,	5, f)
-
+	INTEL_NOPREFIX
 	ASL(3)
 	// non-counter mode per-block setup
 	AS2(	MOVD	MM(1), [L_KEY12+0*4])	// 0,1,2,3
@@ -802,8 +809,9 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 
 	AS2(	add		L_REG, [L_KEYS_BEGIN])
 	AS2(	add		L_REG, 4*16)
+	ATT_NOPREFIX
 	ASJ(	jmp,	2, f)
-
+	INTEL_NOPREFIX
 	ASL(1)
 	// counter-mode per-block setup
 	AS2(	MOVD	ecx, MM(2))
@@ -830,7 +838,9 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 
 	AS2(	add		L_REG, [L_KEYS_BEGIN])
 	AS2(	add		L_REG, 3*16)
+	ATT_NOPREFIX
 	ASJ(	jmp,	4, f)
+	INTEL_NOPREFIX
 
 // in: eax(0,1,2,3), ebx(4,5,6,7), ecx(8,9,10,11), edx(12,13,14,15)
 // out: eax, ebx, edi, mm0
@@ -877,7 +887,9 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 
 	AS2(	add		L_REG, 32)
 	AS2(	test	L_REG, 255)
+	ATT_NOPREFIX
 	ASJ(	jnz,	2, b)
+	INTEL_NOPREFIX
 	AS2(	sub		L_REG, 16*16)
 
 #define LAST(a, b, c)												\
@@ -923,16 +935,22 @@ CRYPTOPP_NAKED void CRYPTOPP_FASTCALL Rijndael_Enc_AdvancedProcessBlocks(void *l
 	AS2(	pxor	xmm2, [L_LASTROUND])
 	AS2(	movdqu	[WORD_REG(bx)], xmm2)
 
+	ATT_NOPREFIX
 	ASJ(	jle,	7, f)
+	INTEL_NOPREFIX
 	AS2(	mov		[L_LENGTH], WORD_REG(cx))
 	AS2(	test	WORD_REG(cx), 1)
+	ATT_NOPREFIX
 	ASJ(	jnz,	1, b)
+	INTEL_NOPREFIX
 #if CRYPTOPP_BOOL_X64
 	AS2(	movdqa	xmm0, [L_INCREMENTS])
 	AS2(	paddq	xmm0, [L_INBLOCKS])
 	AS2(	movdqa	[L_INBLOCKS], xmm0)
 #endif
+	ATT_NOPREFIX
 	ASJ(	jmp,	3, b)
+	INTEL_NOPREFIX
 
 	ASL(7)
 	// erase keys on stack
diff --git a/sha.cpp b/sha.cpp
index 78ba88f5..bdd87df7 100644
--- a/sha.cpp
+++ b/sha.cpp
@@ -371,7 +371,9 @@ static void CRYPTOPP_FASTCALL X86_SHA256_HashBlocks(word32 *state, const word32
 	ROUND(14, 1, eax, ecx, edi, edx)
 	ROUND(15, 1, ecx, eax, edx, edi)
 	AS2(	cmp		WORD_REG(si), K_END)
+	ATT_NOPREFIX
 	ASJ(	jb,		1, b)
+	INTEL_NOPREFIX
 
 	AS2(	mov		WORD_REG(dx), DATA_SAVE)
 	AS2(	add		WORD_REG(dx), 64)
@@ -390,7 +392,9 @@ static void CRYPTOPP_FASTCALL X86_SHA256_HashBlocks(word32 *state, const word32
 	AS2(	movdqa	[AS_REG_7+1*16], xmm1)
 	AS2(	movdqa	[AS_REG_7+0*16], xmm0)
 	AS2(	cmp		WORD_REG(dx), DATA_END)
+	ATT_NOPREFIX
 	ASJ(	jb,		0, b)
+	INTEL_NOPREFIX
 #endif
 
 #if CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32