From 66381352f376df1fab2337cf42e95b7b378ee824 Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Sat, 14 Jul 2018 09:41:36 +0100
Subject: [PATCH] fp: Add FPInfo

Provides information about floating-point format for various bit sizes
---
 src/CMakeLists.txt   |  1 +
 src/common/fp/info.h | 58 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 src/common/fp/info.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5807525a..f3c59dfa 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -17,6 +17,7 @@ add_library(dynarmic
     common/crc32.cpp
     common/crc32.h
     common/fp_util.h
+    common/fp/info.h
     common/fp/rounding_mode.h
     common/intrusive_list.h
     common/iterator_util.h
diff --git a/src/common/fp/info.h b/src/common/fp/info.h
new file mode 100644
index 00000000..1c4032e0
--- /dev/null
+++ b/src/common/fp/info.h
@@ -0,0 +1,58 @@
+/* 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/common_types.h"
+
+namespace Dynarmic::FP {
+
+template<typename FPT>
+struct FPInfo {};
+
+template<>
+struct FPInfo<u32> {
+    static constexpr size_t total_width = 32;
+    static constexpr size_t exponent_width = 8;
+    static constexpr size_t explicit_mantissa_width = 23;
+    static constexpr size_t mantissa_width = explicit_mantissa_width + 1;
+
+    static constexpr u32 implicit_leading_bit = u32(1) << explicit_mantissa_width;
+    static constexpr u32 sign_mask = 0x80000000;
+    static constexpr u32 exponent_mask = 0x7F800000;
+    static constexpr u32 mantissa_mask = 0x007FFFFF;
+
+    static constexpr int exponent_min = -126;
+    static constexpr int exponent_max = 127;
+    static constexpr int exponent_bias = 127;
+
+    static constexpr u32 Zero(bool sign) { return sign ? sign_mask : 0; }
+    static constexpr u32 Infinity(bool sign) { return exponent_mask | Zero(sign); }
+    static constexpr u32 MaxNormal(bool sign) { return (exponent_mask - 1) | Zero(sign); }
+};
+
+template<>
+struct FPInfo<u64> {
+    static constexpr size_t total_width = 64;
+    static constexpr size_t exponent_width = 11;
+    static constexpr size_t explicit_mantissa_width = 52;
+    static constexpr size_t mantissa_width = explicit_mantissa_width + 1;
+
+    static constexpr u64 implicit_leading_bit = u64(1) << explicit_mantissa_width;
+    static constexpr u64 sign_mask = 0x8000'0000'0000'0000;
+    static constexpr u64 exponent_mask = 0x7FF0'0000'0000'0000;
+    static constexpr u64 mantissa_mask = 0x000F'FFFF'FFFF'FFFF;
+
+    static constexpr int exponent_min = -1022;
+    static constexpr int exponent_max = 1023;
+    static constexpr int exponent_bias = 1023;
+
+    static constexpr u64 Zero(bool sign) { return sign ? sign_mask : 0; }
+    static constexpr u64 Infinity(bool sign) { return exponent_mask | Zero(sign); }
+    static constexpr u64 MaxNormal(bool sign) { return (exponent_mask - 1) | Zero(sign); }
+};
+
+} // namespace Dynarmic::FP