From c8135b3c1864726d855beacd97bc2b099d2ceed0 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Fri, 14 Aug 2020 08:20:40 -0400
Subject: [PATCH] gl_shader_disk_cache: Make use of std::nullopt where
 applicable

Allows the compiler to avoid unnecessarily zeroing out the internal
buffer of std::optional on some implementations.
---
 .../renderer_opengl/gl_shader_disk_cache.cpp  | 23 ++++++++++---------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/video_core/renderer_opengl/gl_shader_disk_cache.cpp b/src/video_core/renderer_opengl/gl_shader_disk_cache.cpp
index 2dcc2b0eb..4f3c47c41 100644
--- a/src/video_core/renderer_opengl/gl_shader_disk_cache.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_disk_cache.cpp
@@ -214,20 +214,20 @@ std::optional<std::vector<ShaderDiskCacheEntry>> ShaderDiskCacheOpenGL::LoadTran
     // Skip games without title id
     const bool has_title_id = system.CurrentProcess()->GetTitleID() != 0;
     if (!Settings::values.use_disk_shader_cache.GetValue() || !has_title_id) {
-        return {};
+        return std::nullopt;
     }
 
     FileUtil::IOFile file(GetTransferablePath(), "rb");
     if (!file.IsOpen()) {
         LOG_INFO(Render_OpenGL, "No transferable shader cache found");
         is_usable = true;
-        return {};
+        return std::nullopt;
     }
 
     u32 version{};
     if (file.ReadBytes(&version, sizeof(version)) != sizeof(version)) {
         LOG_ERROR(Render_OpenGL, "Failed to get transferable cache version, skipping it");
-        return {};
+        return std::nullopt;
     }
 
     if (version < NativeVersion) {
@@ -235,12 +235,12 @@ std::optional<std::vector<ShaderDiskCacheEntry>> ShaderDiskCacheOpenGL::LoadTran
         file.Close();
         InvalidateTransferable();
         is_usable = true;
-        return {};
+        return std::nullopt;
     }
     if (version > NativeVersion) {
         LOG_WARNING(Render_OpenGL, "Transferable shader cache was generated with a newer version "
                                    "of the emulator, skipping");
-        return {};
+        return std::nullopt;
     }
 
     // Version is valid, load the shaders
@@ -249,7 +249,7 @@ std::optional<std::vector<ShaderDiskCacheEntry>> ShaderDiskCacheOpenGL::LoadTran
         ShaderDiskCacheEntry& entry = entries.emplace_back();
         if (!entry.Load(file)) {
             LOG_ERROR(Render_OpenGL, "Failed to load transferable raw entry, skipping");
-            return {};
+            return std::nullopt;
         }
     }
 
@@ -290,12 +290,12 @@ std::optional<std::vector<ShaderDiskCachePrecompiled>> ShaderDiskCacheOpenGL::Lo
     ShaderCacheVersionHash file_hash{};
     if (!LoadArrayFromPrecompiled(file_hash.data(), file_hash.size())) {
         precompiled_cache_virtual_file_offset = 0;
-        return {};
+        return std::nullopt;
     }
     if (GetShaderCacheVersionHash() != file_hash) {
         LOG_INFO(Render_OpenGL, "Precompiled cache is from another version of the emulator");
         precompiled_cache_virtual_file_offset = 0;
-        return {};
+        return std::nullopt;
     }
 
     std::vector<ShaderDiskCachePrecompiled> entries;
@@ -305,15 +305,16 @@ std::optional<std::vector<ShaderDiskCachePrecompiled>> ShaderDiskCacheOpenGL::Lo
         if (!LoadObjectFromPrecompiled(entry.unique_identifier) ||
             !LoadObjectFromPrecompiled(entry.binary_format) ||
             !LoadObjectFromPrecompiled(binary_size)) {
-            return {};
+            return std::nullopt;
         }
 
         entry.binary.resize(binary_size);
         if (!LoadArrayFromPrecompiled(entry.binary.data(), entry.binary.size())) {
-            return {};
+            return std::nullopt;
         }
     }
-    return entries;
+
+    return std::move(entries);
 }
 
 void ShaderDiskCacheOpenGL::InvalidateTransferable() {