From f876e4afa28fa14446bdd3f09284935265f913be Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Mon, 16 Jul 2018 13:48:13 +0100
Subject: [PATCH] fp: Implement FPProcessNaN

---
 src/CMakeLists.txt            |  2 ++
 src/common/fp/process_nan.cpp | 40 +++++++++++++++++++++++++++++++++++
 src/common/fp/process_nan.h   | 20 ++++++++++++++++++
 3 files changed, 62 insertions(+)
 create mode 100644 src/common/fp/process_nan.cpp
 create mode 100644 src/common/fp/process_nan.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index f1abb1cc..b7b88d6c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -24,6 +24,8 @@ add_library(dynarmic
     common/fp/op/FPToFixed.h
     common/fp/process_exception.cpp
     common/fp/process_exception.h
+    common/fp/process_nan.cpp
+    common/fp/process_nan.h
     common/fp/rounding_mode.h
     common/fp/unpacked.cpp
     common/fp/unpacked.h
diff --git a/src/common/fp/process_nan.cpp b/src/common/fp/process_nan.cpp
new file mode 100644
index 00000000..cd4f7f25
--- /dev/null
+++ b/src/common/fp/process_nan.cpp
@@ -0,0 +1,40 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2018 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 "common/assert.h"
+#include "common/bit_util.h"
+#include "common/fp/fpsr.h"
+#include "common/fp/info.h"
+#include "common/fp/process_exception.h"
+#include "common/fp/process_nan.h"
+#include "frontend/A64/FPCR.h"
+
+namespace Dynarmic::FP {
+
+template<typename FPT>
+FPT FPProcessNaN(FPType type, FPT op, FPCR fpcr, FPSR& fpsr) {
+    ASSERT(type == FPType::QNaN || type == FPType::SNaN);
+
+    constexpr size_t topfrac = FPInfo<FPT>::explicit_mantissa_width - 1;
+
+    FPT result = op;
+
+    if (type == FPType::SNaN) {
+        result = Common::ModifyBit<topfrac>(op, true);
+        FPProcessException(FPExc::InvalidOp, fpcr, fpsr);
+    }
+
+    if (fpcr.DN()) {
+        result = FPInfo<FPT>::DefaultNaN();
+    }
+
+    return result;
+}
+
+template u32 FPProcessNaN<u32>(FPType type, u32 op, FPCR fpcr, FPSR& fpsr);
+template u64 FPProcessNaN<u64>(FPType type, u64 op, FPCR fpcr, FPSR& fpsr);
+
+} // namespace Dynarmic::FP 
diff --git a/src/common/fp/process_nan.h b/src/common/fp/process_nan.h
new file mode 100644
index 00000000..50f7cf68
--- /dev/null
+++ b/src/common/fp/process_nan.h
@@ -0,0 +1,20 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2018 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#pragma once
+
+#include "common/fp/fpsr.h"
+#include "common/fp/unpacked.h"
+#include "frontend/A64/FPCR.h"
+
+namespace Dynarmic::FP {
+
+using FPCR = A64::FPCR;
+
+template<typename FPT>
+FPT FPProcessNaN(FPType type, FPT op, FPCR fpcr, FPSR& fpsr);
+
+} // namespace Dynarmic::FP