From 474e210cd585cb40f8ff8f647f1e011329b584c6 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Mon, 2 Dec 2019 23:36:13 -0500
Subject: [PATCH] PPCCache: Make arrays constexpr where applicable

Two of these arrays were stored within the save state when the exact
same data is constructed all the time.

We can just build this into the binary rather than the save state,
shrinking a little bit of the save state's overall size.
---
 Source/Core/Core/PowerPC/PPCCache.cpp | 103 ++++++++++++++++----------
 Source/Core/Core/PowerPC/PPCCache.h   |   3 -
 Source/Core/Core/State.cpp            |   2 +-
 3 files changed, 65 insertions(+), 43 deletions(-)

diff --git a/Source/Core/Core/PowerPC/PPCCache.cpp b/Source/Core/Core/PowerPC/PPCCache.cpp
index f914c0e36a..80e74f5a5c 100644
--- a/Source/Core/Core/PowerPC/PPCCache.cpp
+++ b/Source/Core/Core/PowerPC/PPCCache.cpp
@@ -23,45 +23,72 @@ constexpr std::array<u32, 8> s_plru_mask{
 constexpr std::array<u32, 8> s_plru_value{
     11, 3, 17, 1, 36, 4, 64, 0,
 };
+
+constexpr std::array<u32, 255> s_way_from_valid = [] {
+  std::array<u32, 255> data{};
+  for (size_t m = 0; m < data.size(); m++)
+  {
+    u32 w = 0;
+    while ((m & (size_t{1} << w)) != 0)
+      w++;
+    data[m] = w;
+  }
+  return data;
+}();
+
+constexpr std::array<u32, 128> s_way_from_plru = [] {
+  std::array<u32, 128> data{};
+
+  for (size_t m = 0; m < data.size(); m++)
+  {
+    std::array<u32, 7> b{};
+    for (size_t i = 0; i < b.size(); i++)
+      b[i] = u32(m & (size_t{1} << i));
+
+    u32 w = 0;
+    if (b[0] != 0)
+    {
+      if (b[2] != 0)
+      {
+        if (b[6] != 0)
+          w = 7;
+        else
+          w = 6;
+      }
+      else if (b[5] != 0)
+      {
+        w = 5;
+      }
+      else
+      {
+        w = 4;
+      }
+    }
+    else if (b[1] != 0)
+    {
+      if (b[4] != 0)
+        w = 3;
+      else
+        w = 2;
+    }
+    else if (b[3] != 0)
+    {
+      w = 1;
+    }
+    else
+    {
+      w = 0;
+    }
+
+    data[m] = w;
+  }
+
+  return data;
+}();
 }  // Anonymous namespace
 
 InstructionCache::InstructionCache()
 {
-  for (u32 m = 0; m < 0xff; m++)
-  {
-    u32 w = 0;
-    while (m & (1 << w))
-      w++;
-    way_from_valid[m] = w;
-  }
-
-  for (u32 m = 0; m < 128; m++)
-  {
-    u32 b[7];
-    for (int i = 0; i < 7; i++)
-      b[i] = m & (1 << i);
-    u32 w;
-    if (b[0])
-      if (b[2])
-        if (b[6])
-          w = 7;
-        else
-          w = 6;
-      else if (b[5])
-        w = 5;
-      else
-        w = 4;
-    else if (b[1])
-      if (b[4])
-        w = 3;
-      else
-        w = 2;
-    else if (b[3])
-      w = 1;
-    else
-      w = 0;
-    way_from_plru[m] = w;
-  }
 }
 
 void InstructionCache::Reset()
@@ -131,9 +158,9 @@ u32 InstructionCache::ReadInstruction(u32 addr)
       return Memory::Read_U32(addr);
     // select a way
     if (valid[set] != 0xff)
-      t = way_from_valid[valid[set]];
+      t = s_way_from_valid[valid[set]];
     else
-      t = way_from_plru[plru[set]];
+      t = s_way_from_plru[plru[set]];
     // load
     Memory::CopyFromEmu(reinterpret_cast<u8*>(data[set][t].data()), (addr & ~0x1f), 32);
     if (valid[set] & (1 << t))
@@ -174,8 +201,6 @@ void InstructionCache::DoState(PointerWrap& p)
   p.DoArray(tags);
   p.DoArray(plru);
   p.DoArray(valid);
-  p.DoArray(way_from_valid);
-  p.DoArray(way_from_plru);
   p.DoArray(lookup_table);
   p.DoArray(lookup_table_ex);
   p.DoArray(lookup_table_vmem);
diff --git a/Source/Core/Core/PowerPC/PPCCache.h b/Source/Core/Core/PowerPC/PPCCache.h
index 0298523131..d5220dbde3 100644
--- a/Source/Core/Core/PowerPC/PPCCache.h
+++ b/Source/Core/Core/PowerPC/PPCCache.h
@@ -27,9 +27,6 @@ struct InstructionCache
   std::array<u32, ICACHE_SETS> plru;
   std::array<u32, ICACHE_SETS> valid;
 
-  std::array<u32, 255> way_from_valid;
-  std::array<u32, 128> way_from_plru;
-
   std::array<u8, 1 << 20> lookup_table;
   std::array<u8, 1 << 21> lookup_table_ex;
   std::array<u8, 1 << 20> lookup_table_vmem;
diff --git a/Source/Core/Core/State.cpp b/Source/Core/Core/State.cpp
index 329c1052da..93f0b33318 100644
--- a/Source/Core/Core/State.cpp
+++ b/Source/Core/Core/State.cpp
@@ -73,7 +73,7 @@ static Common::Event g_compressAndDumpStateSyncEvent;
 static std::thread g_save_thread;
 
 // Don't forget to increase this after doing changes on the savestate system
-static const u32 STATE_VERSION = 112;  // Last changed in PR 8444
+constexpr u32 STATE_VERSION = 113;  // Last changed in PR 8506
 
 // Maps savestate versions to Dolphin versions.
 // Versions after 42 don't need to be added to this list,