Option cleanup (WIP)

cpu: Make it clear this does nothing since there's no backends other than x64.
native_2x_msaa: Disabling this only makes performance worse, and idiots think this disables anti-aliasing for some reason.

src/xenia/cpu/cpu_flags.cc

@@ -9,7 +9,7 @@
 
 #include "xenia/cpu/cpu_flags.h"
 
-DEFINE_string(cpu, "any", "CPU backend [any, x64].", "CPU");
+DEFINE_string(cpu, "any", "Does nothing. CPU backend [any, x64].", "CPU");
 
 DEFINE_string(
     load_module_map, "",
@@ -31,6 +31,7 @@ DEFINE_bool(trace_function_data, false,
             "Generate tracing for function result data.", "CPU");
 
 DEFINE_bool(validate_hir, false,
+            "Only does anything on debug builds. "
             "Perform validation checks on the HIR during compilation.", "CPU");
 
 DEFINE_uint64(

src/xenia/cpu/ppc/ppc_translator.cc

@@ -45,7 +45,12 @@ PPCTranslator::PPCTranslator(PPCFrontend* frontend) : frontend_(frontend) {
   assembler_ = backend->CreateAssembler();
   assembler_->Initialize();
 
-  bool validate = cvars::validate_hir;
+  bool validate =
+    #ifdef DEBUG
+    cvars::validate_hir;
+    #else
+    0;
+    #endif
 
   // Merge blocks early. This will let us use more context in other passes.
   // The CFG is required for simplification and dirtied by it.

src/xenia/gpu/d3d12/d3d12_render_target_cache.cc

@@ -447,7 +447,9 @@ bool D3D12RenderTargetCache::Initialize() {
   // Using the cvar on emulator initialization so used pipelines are consistent
   // across different titles launched in one emulator instance.
   use_stencil_reference_output_ =
+      #ifdef DEBUG
       cvars::native_stencil_value_output &&
+      #endif
       provider.IsPSSpecifiedStencilReferenceSupported() &&
       (cvars::native_stencil_value_output_d3d12_intel ||
        provider.GetAdapterVendorID() !=
@@ -464,6 +466,7 @@ bool D3D12RenderTargetCache::Initialize() {
 
     // Check if 2x MSAA is supported or needs to be emulated with 4x MSAA
     // instead.
+    #ifdef DEBUG
     if (cvars::native_2x_msaa) {
       msaa_2x_supported_ = true;
       static const DXGI_FORMAT kRenderTargetDXGIFormats[] = {
@@ -502,6 +505,42 @@ bool D3D12RenderTargetCache::Initialize() {
     } else {
       msaa_2x_supported_ = false;
     }
+    #else // DEBUG
+    msaa_2x_supported_ = true;
+    static const DXGI_FORMAT kRenderTargetDXGIFormats[] = {
+        DXGI_FORMAT_R16G16B16A16_FLOAT,
+        DXGI_FORMAT_R16G16B16A16_SNORM,
+        DXGI_FORMAT_R32G32_FLOAT,
+        DXGI_FORMAT_D32_FLOAT_S8X24_UINT,
+        DXGI_FORMAT_R10G10B10A2_UNORM,
+        DXGI_FORMAT_R8G8B8A8_UNORM,
+        DXGI_FORMAT_R16G16_FLOAT,
+        DXGI_FORMAT_R16G16_SNORM,
+        DXGI_FORMAT_R32_FLOAT,
+        DXGI_FORMAT_D24_UNORM_S8_UINT,
+        // For ownership transfer.
+        DXGI_FORMAT_R16G16B16A16_UINT,
+        DXGI_FORMAT_R32G32_UINT,
+        DXGI_FORMAT_R16G16_UINT,
+        DXGI_FORMAT_R32_UINT,
+    };
+    D3D12_FEATURE_DATA_MULTISAMPLE_QUALITY_LEVELS multisample_quality_levels;
+    multisample_quality_levels.SampleCount = 2;
+    multisample_quality_levels.Flags =
+        D3D12_MULTISAMPLE_QUALITY_LEVELS_FLAG_NONE;
+    for (size_t i = 0; i < xe::countof(kRenderTargetDXGIFormats); ++i) {
+      multisample_quality_levels.Format = kRenderTargetDXGIFormats[i];
+      multisample_quality_levels.NumQualityLevels = 0;
+      if (FAILED(device->CheckFeatureSupport(
+              D3D12_FEATURE_MULTISAMPLE_QUALITY_LEVELS,
+              &multisample_quality_levels,
+              sizeof(multisample_quality_levels))) ||
+          !multisample_quality_levels.NumQualityLevels) {
+        msaa_2x_supported_ = false;
+        break;
+      }
+    }
+    #endif // DEBUG
     if (!msaa_2x_supported_) {
       XELOGW(
           "2x MSAA is not supported, emulated via top-left and bottom-right "

src/xenia/gpu/render_target_cache.cc

@@ -172,6 +172,7 @@ DEFINE_bool(
     "GPU");
 DEFINE_bool(
     native_2x_msaa, true,
+    "Only does anything in debug builds."
     "Use host 2x MSAA when available. Can be disabled for scalability testing "
     "on host GPU APIs where 2x is not mandatory, in this case, 2 samples of 4x "
     "MSAA will be used instead (with similar or worse quality and higher "
@@ -179,6 +180,7 @@ DEFINE_bool(
     "GPU");
 DEFINE_bool(
     native_stencil_value_output, true,
+    "Only does anything in debug builds."
     "Use pixel shader stencil reference output where available for purposes "
     "like copying between render targets. Can be disabled for scalability "
     "testing, in this case, much more expensive drawing of 8 quads will be "