cmpxchg8b fix - added cmpxchg16b

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4522 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/target-i386/helper.c b/target-i386/helper.c
index 0317f9c..4562a16 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1879,8 +1879,8 @@
 
     eflags = cc_table[CC_OP].compute_all();
     d = ldq(a0);
-    if (d == (((uint64_t)EDX << 32) | EAX)) {
-        stq(a0, ((uint64_t)ECX << 32) | EBX);
+    if (d == (((uint64_t)EDX << 32) | (uint32_t)EAX)) {
+        stq(a0, ((uint64_t)ECX << 32) | (uint32_t)EBX);
         eflags |= CC_Z;
     } else {
         EDX = (uint32_t)(d >> 32);
@@ -1890,6 +1890,28 @@
     CC_SRC = eflags;
 }
 
+#ifdef TARGET_X86_64
+void helper_cmpxchg16b(target_ulong a0)
+{
+    uint64_t d0, d1;
+    int eflags;
+
+    eflags = cc_table[CC_OP].compute_all();
+    d0 = ldq(a0);
+    d1 = ldq(a0 + 8);
+    if (d0 == EAX && d1 == EDX) {
+        stq(a0, EBX);
+        stq(a0 + 8, ECX);
+        eflags |= CC_Z;
+    } else {
+        EDX = d1;
+        EAX = d0;
+        eflags &= ~CC_Z;
+    }
+    CC_SRC = eflags;
+}
+#endif
+
 void helper_single_step(void)
 {
     env->dr[6] |= 0x4000;
diff --git a/target-i386/helper.h b/target-i386/helper.h
index 9df198a..9bbf4fc 100644
--- a/target-i386/helper.h
+++ b/target-i386/helper.h
@@ -75,6 +75,9 @@
 void helper_rsm(void);
 void helper_into(int next_eip_addend);
 void helper_cmpxchg8b(target_ulong a0);
+#ifdef TARGET_X86_64
+void helper_cmpxchg16b(target_ulong a0);
+#endif
 void helper_single_step(void);
 void helper_cpuid(void);
 void helper_rdtsc(void);
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 85b3d6d..6e55930 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -4333,11 +4333,26 @@
         mod = (modrm >> 6) & 3;
         if ((mod == 3) || ((modrm & 0x38) != 0x8))
             goto illegal_op;
-        gen_jmp_im(pc_start - s->cs_base);
-        if (s->cc_op != CC_OP_DYNAMIC)
-            gen_op_set_cc_op(s->cc_op);
-        gen_lea_modrm(s, modrm, &reg_addr, &offset_addr);
-        tcg_gen_helper_0_1(helper_cmpxchg8b, cpu_A0);
+#ifdef TARGET_X86_64
+        if (dflag == 2) {
+            if (!(s->cpuid_ext_features & CPUID_EXT_CX16))
+                goto illegal_op;
+            gen_jmp_im(pc_start - s->cs_base);
+            if (s->cc_op != CC_OP_DYNAMIC)
+                gen_op_set_cc_op(s->cc_op);
+            gen_lea_modrm(s, modrm, &reg_addr, &offset_addr);
+            tcg_gen_helper_0_1(helper_cmpxchg16b, cpu_A0);
+        } else
+#endif        
+        {
+            if (!(s->cpuid_features & CPUID_CX8))
+                goto illegal_op;
+            gen_jmp_im(pc_start - s->cs_base);
+            if (s->cc_op != CC_OP_DYNAMIC)
+                gen_op_set_cc_op(s->cc_op);
+            gen_lea_modrm(s, modrm, &reg_addr, &offset_addr);
+            tcg_gen_helper_0_1(helper_cmpxchg8b, cpu_A0);
+        }
         s->cc_op = CC_OP_EFLAGS;
         break;