From a27473cbc2462f5acbc2268bd5287b4a121fe69e Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 13 Jul 2020 20:23:00 +0200
Subject: [PATCH] UserspaceEmulator+LibX86: Turn on -O3 optimization for
 emulation code

Since this code is performance-sensitive, let's have the compiler do
whatever it can to help us with the most important files.

This yields a ~8% speedup.
---
 DevTools/UserspaceEmulator/Emulator.cpp | 7 ++++++-
 DevTools/UserspaceEmulator/SoftCPU.cpp  | 4 ++++
 Libraries/LibX86/Instruction.cpp        | 4 ++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/DevTools/UserspaceEmulator/Emulator.cpp b/DevTools/UserspaceEmulator/Emulator.cpp
index 961d08533f..a0ad483b50 100644
--- a/DevTools/UserspaceEmulator/Emulator.cpp
+++ b/DevTools/UserspaceEmulator/Emulator.cpp
@@ -38,6 +38,10 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+#if defined(__GNUC__) && !defined(__clang__)
+#    pragma GCC optimize("O3")
+#endif
+
 //#define DEBUG_SPAM
 
 namespace UserspaceEmulator {
@@ -171,7 +175,8 @@ void Emulator::dump_backtrace()
         if (!ret_ptr)
             return;
         symbol = m_elf->symbolicate(ret_ptr, &offset);
-        printf("> %#08x  %s +%#x\n", ret_ptr, symbol.characters(), offset);
+        if (!symbol.is_null())
+            printf("> %#08x  %s +%#x\n", ret_ptr, symbol.characters(), offset);
 
         frame_ptr = m_mmu.read32({ 0x20, frame_ptr });
     }
diff --git a/DevTools/UserspaceEmulator/SoftCPU.cpp b/DevTools/UserspaceEmulator/SoftCPU.cpp
index 980ce3bb83..1c6459f20b 100644
--- a/DevTools/UserspaceEmulator/SoftCPU.cpp
+++ b/DevTools/UserspaceEmulator/SoftCPU.cpp
@@ -30,6 +30,10 @@
 #include <stdio.h>
 #include <string.h>
 
+#if defined(__GNUC__) && !defined(__clang__)
+#    pragma GCC optimize("O3")
+#endif
+
 //#define MEMORY_DEBUG
 
 namespace UserspaceEmulator {
diff --git a/Libraries/LibX86/Instruction.cpp b/Libraries/LibX86/Instruction.cpp
index 6d59beccec..54f878b3e3 100644
--- a/Libraries/LibX86/Instruction.cpp
+++ b/Libraries/LibX86/Instruction.cpp
@@ -29,6 +29,10 @@
 #include <LibX86/Interpreter.h>
 #include <stdio.h>
 
+#if defined(__GNUC__) && !defined(__clang__)
+#    pragma GCC optimize("O3")
+#endif
+
 namespace X86 {
 
 enum IsLockPrefixAllowed {