From aa22db534b2a69bcfb6a141afe05d3827a94529d Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Wed, 6 Mar 2019 17:38:15 -0500
Subject: [PATCH] A64: Implement AXFlag and XAFlag

---
 src/CMakeLists.txt                            |  1 +
 src/frontend/A64/decoder/a64.inc              |  4 +-
 .../A64/translate/impl/system_flag_format.cpp | 47 +++++++++++++++++++
 3 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 src/frontend/A64/translate/impl/system_flag_format.cpp

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index da59d6f5..9fd65fe5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -175,6 +175,7 @@ add_library(dynarmic
     frontend/A64/translate/impl/simd_vector_x_indexed_element.cpp
     frontend/A64/translate/impl/sys_dc.cpp
     frontend/A64/translate/impl/system.cpp
+    frontend/A64/translate/impl/system_flag_format.cpp
     frontend/A64/translate/impl/system_flag_manipulation.cpp
     frontend/A64/translate/translate.cpp
     frontend/A64/translate/translate.h
diff --git a/src/frontend/A64/decoder/a64.inc b/src/frontend/A64/decoder/a64.inc
index 078e97db..d1d3fbf2 100644
--- a/src/frontend/A64/decoder/a64.inc
+++ b/src/frontend/A64/decoder/a64.inc
@@ -87,8 +87,8 @@ INST(RMIF,                   "RMIF",                                      "10111
 //INST(SETF16,                 "SETF16",                                    "0011101000000000010010nnnnn01101") // ARMv8.4
 
 // System - Flag format instructions
-//INST(XAFlag,                 "XAFlag",                                    "11010101000000000100000000111111") // ARMv8.5
-//INST(AXFlag,                 "AXFlag",                                    "11010101000000000100000001011111") // ARMv8.5
+INST(XAFlag,                 "XAFlag",                                    "11010101000000000100000000111111") // ARMv8.5
+INST(AXFlag,                 "AXFlag",                                    "11010101000000000100000001011111") // ARMv8.5
 
 // SYS: Data Cache
 INST(DC_IVAC,                "DC IVAC",                                   "110101010000100001110110001ttttt")
diff --git a/src/frontend/A64/translate/impl/system_flag_format.cpp b/src/frontend/A64/translate/impl/system_flag_format.cpp
new file mode 100644
index 00000000..c7fc56d9
--- /dev/null
+++ b/src/frontend/A64/translate/impl/system_flag_format.cpp
@@ -0,0 +1,47 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2019 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#include "frontend/A64/translate/impl/impl.h"
+
+namespace Dynarmic::A64 {
+
+bool TranslatorVisitor::AXFlag() {
+    const IR::U32 nzcv = ir.GetNZCVRaw();
+
+    const IR::U32 z = ir.And(nzcv, ir.Imm32(0x40000000));
+    const IR::U32 c = ir.And(nzcv, ir.Imm32(0x20000000));
+    const IR::U32 v = ir.And(nzcv, ir.Imm32(0x10000000));
+
+    const IR::U32 new_z = ir.Or(ir.LogicalShiftLeft(v, ir.Imm8(2)), z);
+    const IR::U32 new_c = ir.And(ir.And(c, ir.Not(ir.LogicalShiftLeft(v, ir.Imm8(1)))), ir.Imm32(0x20000000));
+
+    ir.SetNZCVRaw(ir.Or(new_z, new_c));
+    return true;
+}
+
+bool TranslatorVisitor::XAFlag() {
+    const IR::U32 nzcv = ir.GetNZCVRaw();
+
+    const IR::U32 z = ir.And(nzcv, ir.Imm32(0x40000000));
+    const IR::U32 c = ir.And(nzcv, ir.Imm32(0x20000000));
+
+    const IR::U32 not_z = ir.And(ir.Not(z), ir.Imm32(0x40000000));
+    const IR::U32 not_c = ir.And(ir.Not(c), ir.Imm32(0x20000000));
+
+    const IR::U32 new_n = ir.And(ir.LogicalShiftLeft(not_c, ir.Imm8(2)),
+                                 ir.LogicalShiftLeft(not_z, ir.Imm8(1)));
+    const IR::U32 new_z = ir.And(z, ir.LogicalShiftLeft(c, ir.Imm8(1)));
+    const IR::U32 new_c = ir.Or(c, ir.LogicalShiftRight(z, ir.Imm8(1)));
+    const IR::U32 new_v = ir.And(ir.LogicalShiftRight(not_c, ir.Imm8(1)),
+                                 ir.LogicalShiftRight(z, ir.Imm8(2)));
+
+    const IR::U32 result = ir.Or(ir.Or(ir.Or(new_n, new_z), new_c), new_v);
+
+    ir.SetNZCVRaw(result);
+    return true;
+}
+
+} // namespace Dynarmic::A64