From 41a80fce20a9d22279c5c5ee4f296c24beab17a9 Mon Sep 17 00:00:00 2001
From: Gregory Hainaut <gregory.hainaut@gmail.com>
Date: Sun, 17 Jan 2016 17:02:38 +0100
Subject: [PATCH] x86emitter: finally support 64 bits instructions

Note: a couple of instructions don't support REX prefix. Some
exception ought to be implemented later
---
 common/include/x86emitter/internal.h | 15 ++++++++++-----
 common/src/x86emitter/simd.cpp       |  3 +++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/common/include/x86emitter/internal.h b/common/include/x86emitter/internal.h
index ef6eadc2e3..f24d660f27 100644
--- a/common/include/x86emitter/internal.h
+++ b/common/include/x86emitter/internal.h
@@ -50,10 +50,10 @@ namespace x86Emitter {
 	template< typename T1, typename T2 > __emitinline
 		void xOpWrite( u8 prefix, u8 opcode, const T1& param1, const T2& param2 )
 	{
-		if( prefix != 0 )
-			xWrite16( (opcode<<8) | prefix );
-		else
-			xWrite8( opcode );
+		if( prefix != 0 ) xWrite8( prefix );
+		EmitRex( param1, param2 );
+
+		xWrite8( opcode );
 
 		EmitSibMagic( param1, param2 );
 	}
@@ -62,6 +62,7 @@ namespace x86Emitter {
 		void xOpAccWrite( u8 prefix, u8 opcode, const T1& param1, const T2& param2 )
 	{
 		if( prefix != 0 ) xWrite8( prefix );
+		EmitRex( param1, param2 );
 
 		xWrite8( opcode );
 	}
@@ -80,7 +81,11 @@ namespace x86Emitter {
 	template< typename T1, typename T2 > __emitinline
 		void xOpWrite0F( u8 prefix, u16 opcode, const T1& param1, const T2& param2 )
 	{
-		SimdPrefix( prefix, opcode );
+		if( prefix != 0 ) xWrite8( prefix );
+		EmitRex( param1, param2 );
+
+		SimdPrefix( 0, opcode );
+
 		EmitSibMagic( param1, param2 );
 	}
 
diff --git a/common/src/x86emitter/simd.cpp b/common/src/x86emitter/simd.cpp
index 2ea553539d..00af27f0f3 100644
--- a/common/src/x86emitter/simd.cpp
+++ b/common/src/x86emitter/simd.cpp
@@ -90,6 +90,9 @@ namespace x86Emitter {
 //
 __emitinline void SimdPrefix( u8 prefix, u16 opcode )
 {
+#ifdef __x86_64__
+	pxAssertMsg(prefix == 0, "REX prefix must be just before the opcode");
+#endif
 	const bool is16BitOpcode = ((opcode & 0xff) == 0x38) || ((opcode & 0xff) == 0x3a);
 
 	// If the lower byte is not a valid prefix and the upper byte is non-zero it