From 9e0af6d2b513ed7ee2f6221bbdf85a8e54e00fc1 Mon Sep 17 00:00:00 2001
From: Michael Matz <matz@suse.de>
Date: Mon, 8 Aug 2016 20:28:21 +0200
Subject: [PATCH] x86-64-asm: Implement cmpxchg16b

---
 tests/asmtest.S | 3 +++
 x86_64-asm.h    | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/tests/asmtest.S b/tests/asmtest.S
index dbc6c15a..c19db064 100644
--- a/tests/asmtest.S
+++ b/tests/asmtest.S
@@ -535,6 +535,9 @@ cmpxchgw %ax, 0x1000
 cmpxchgl %eax, 0x1000
 invlpg 0x1000
 cmpxchg8b 0x1002
+#ifdef __x86_64__
+cmpxchg16b (%rax)
+#endif
 
 fcmovb %st(5), %st
 fcmove %st(5), %st
diff --git a/x86_64-asm.h b/x86_64-asm.h
index 4db32687..675e7df8 100644
--- a/x86_64-asm.h
+++ b/x86_64-asm.h
@@ -394,6 +394,9 @@ ALT(DEF_ASM_OP2(cmpxchgb, 0x0fb0, 0, OPC_MODRM | OPC_BWLX, OPT_REG, OPT_REG | OP
     /* pentium */
     DEF_ASM_OP1(cmpxchg8b, 0x0fc7, 1, OPC_MODRM, OPT_EA )
 
+    /* AMD 64 */
+    DEF_ASM_OP1(cmpxchg16b, 0x480fc7, 1, OPC_MODRM, OPT_EA )
+
     /* pentium pro */
 ALT(DEF_ASM_OP2(cmovo, 0x0f40, 0, OPC_MODRM | OPC_TEST | OPC_WLX, OPT_REGW | OPT_EA, OPT_REGW))