CMake: Add DISABLE_SSE4 option

NOT recommended. Only if you ABSOLUTELY need it.

The SSE2/legacy build will be a separate download option, and
warn you if you try to run it on a CPU that supports SSE4.

CMakeModules/DuckStationBuildOptions.cmake

@@ -5,6 +5,7 @@ option(BUILD_NOGUI_FRONTEND "Build the NoGUI frontend" OFF)
 option(BUILD_QT_FRONTEND "Build the Qt frontend" ON)
 option(BUILD_REGTEST "Build regression test runner" OFF)
 option(BUILD_TESTS "Build unit tests" OFF)
+option(DISABLE_SSE4 "Build with SSE4 instructions disabled, reduces performance" OFF)
 
 if(LINUX OR BSD)
   option(ENABLE_X11 "Support X11 window system" ON)

CMakeModules/DuckStationBuildSummary.cmake

@@ -38,8 +38,7 @@ It does **not** use the LSB subdirectories of bin, share, etc, so you should dis
 endif()
 
 if(NOT IS_SUPPORTED_COMPILER)
-  message(WARNING "
-*************** UNSUPPORTED CONFIGURATION ***************
+  message(WARNING "*************** UNSUPPORTED CONFIGURATION ***************
 You are not compiling DuckStation with a supported compiler.
 It may not even build successfully.
 DuckStation only supports the Clang and MSVC compilers.
@@ -48,11 +47,18 @@ No support will be provided, continue at your own risk.
 endif()
 
 if(WIN32)
-  message(WARNING "
-*************** UNSUPPORTED CONFIGURATION ***************
+  message(WARNING "*************** UNSUPPORTED CONFIGURATION ***************
 You are compiling DuckStation with CMake on Windows.
 It may not even build successfully.
 DuckStation only supports MSBuild on Windows.
 No support will be provided, continue at your own risk.
 *********************************************************")
 endif()
+
+if(CPU_ARCH_X64 AND DISABLE_SSE4)
+  message(WARNING "*********************** WARNING ***********************
+SSE4 instructions are disabled. This will result in
+reduced performance. You should not enable this option
+unless you have a pre-2008 CPU.
+*******************************************************")
+endif()

CMakeModules/DuckStationUtils.cmake

@@ -69,7 +69,7 @@ function(detect_architecture)
          CMAKE_SIZEOF_VOID_P EQUAL 8)
     message(STATUS "Building x86_64 binaries.")
     set(CPU_ARCH_X64 TRUE PARENT_SCOPE)
-    if(NOT MSVC OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    if(NOT MSVC OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND NOT DISABLE_SSE4)
       set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -msse4.1" PARENT_SCOPE)
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -msse4.1" PARENT_SCOPE)
     endif()

src/core/system.cpp

@@ -357,17 +357,19 @@ bool System::Internal::PerformEarlyHardwareChecks(Error* error)
 #ifdef CPU_ARCH_SSE41
   if (!cpuinfo_has_x86_sse4_1())
   {
-    Error::SetStringFmt(error, "Your CPU does not support the SSE4.1 instruction set, which is required for this "
-                               "version of DuckStation.\nPlease download and switch to the legacy SSE2 version.\nYou "
-                               "can download this from https://www.duckstation.org/ under \"Other Platforms\".");
+    Error::SetStringFmt(
+      error, "<h3>Your CPU does not support the SSE4.1 instruction set.</h3><p>SSE4.1 is required for this version of "
+             "DuckStation. Please download and switch to the legacy SSE2 version.</p><p>You can download this from <a "
+             "href=\"https://www.duckstation.org/\">www.duckstation.org</a> under \"Other Platforms\".");
     return false;
   }
 #else
   if (cpuinfo_has_x86_sse4_1())
   {
-    Error::SetStringFmt(error, "You are running the legacy SSE2 DuckStation executable on a CPU that supports the "
-                               "SSE4.1 instruction set.\nPlease download and switch the regular, non-SSE2 "
-                               "version.\nYou can download this from https://www.duckstation.org/.");
+    Error::SetStringFmt(
+      error, "You are running the <strong>legacy SSE2 DuckStation executable</strong> on a CPU that supports the "
+             "SSE4.1 instruction set.\nPlease download and switch to the regular, non-SSE2 version.\nYou can download "
+             "this from <a href=\"https://www.duckstation.org/\">www.duckstation.org</a>.");
   }
 #endif
 #endif

src/duckstation-qt/qthost.cpp

@@ -2550,13 +2550,14 @@ int main(int argc, char* argv[])
   CrashHandler::Install(&Bus::CleanupMemoryMap);
 
   QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
-  QtHost::RegisterTypes();
 
   QApplication app(argc, argv);
-
   if (!QtHost::PerformEarlyHardwareChecks())
     return EXIT_FAILURE;
 
+  // Type registration has to happen after hardware checks, clang emits ptest instructions otherwise.
+  QtHost::RegisterTypes();
+
   std::shared_ptr<SystemBootParameters> autoboot;
   if (!QtHost::ParseCommandLineParametersAndInitializeConfig(app, autoboot))
     return EXIT_FAILURE;