[common/cpu_detect] Remove SSE/SSE2/FMA4/AVX_VNNI detection (#3979)

Removes Eden's own feature detection for SSE, SSE2, FMA4 and AVX_VNNI, in order to clean up code and make the function slightly lighter. They are all unused and I have specific reasons for their removal:
- SSE/SSE2 are always true for x64
- FMA4 is a deprecated AMD exclusive extension, replaced by the regular FMA and was logged here as "FMA" for no reason
- AVX_VNNI simply does not seem applicable for Eden (but can still be checked for through Xbyak's feature detection if necessary)

Co-authored-by: RedBlackAka <140876408+RedBlackAka@users.noreply.github.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3979
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

src/common/x64/cpu_detect.cpp

@@ -106,8 +106,6 @@ static CPUCaps Detect() {
     // Detect family and other miscellaneous features
     if (max_std_fn >= 1) {
         __cpuid(cpu_id, 0x00000001);
-        caps.sse = Common::Bit<25>(cpu_id[3]);
-        caps.sse2 = Common::Bit<26>(cpu_id[3]);
         caps.sse3 = Common::Bit<0>(cpu_id[2]);
         caps.pclmulqdq = Common::Bit<1>(cpu_id[2]);
         caps.ssse3 = Common::Bit<9>(cpu_id[2]);
@@ -150,9 +148,6 @@ static CPUCaps Detect() {
 
             caps.waitpkg = Common::Bit<5>(cpu_id[2]);
             caps.gfni = Common::Bit<8>(cpu_id[2]);
-
-            __cpuidex(cpu_id, 0x00000007, 0x00000001);
-            caps.avx_vnni = caps.avx && Common::Bit<4>(cpu_id[0]);
         }
     }
 
@@ -170,7 +165,6 @@ static CPUCaps Detect() {
         // Check for more features
         __cpuid(cpu_id, 0x80000001);
         caps.lzcnt = Common::Bit<5>(cpu_id[2]);
-        caps.fma4 = Common::Bit<16>(cpu_id[2]);
         caps.monitorx = Common::Bit<29>(cpu_id[2]);
     }
 

src/common/x64/cpu_detect.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-FileCopyrightText: Copyright 2013 Dolphin Emulator Project / 2015 Citra Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
@@ -36,15 +39,12 @@ struct CPUCaps {
     u32 crystal_frequency;
     u64 tsc_frequency; // Derived from the above three values
 
-    bool sse : 1;
-    bool sse2 : 1;
     bool sse3 : 1;
     bool ssse3 : 1;
     bool sse4_1 : 1;
     bool sse4_2 : 1;
 
     bool avx : 1;
-    bool avx_vnni : 1;
     bool avx2 : 1;
     bool avx512f : 1;
     bool avx512dq : 1;
@@ -59,7 +59,6 @@ struct CPUCaps {
     bool bmi2 : 1;
     bool f16c : 1;
     bool fma : 1;
-    bool fma4 : 1;
     bool gfni : 1;
     bool invariant_tsc : 1;
     bool lzcnt : 1;

src/qt_common/qt_common.cpp

@@ -223,7 +223,7 @@ void Init(QWidget* root) {
         } else if (caps.avx2) {
             cpu_string += '2';
         }
-        if (caps.fma || caps.fma4) {
+        if (caps.fma) {
             cpu_string += " | FMA";
         }
     }

src/yuzu/main_window.cpp

@@ -3120,7 +3120,7 @@ void MainWindow::OnMenuReportCompatibility() {
 
     // #if defined(ARCHITECTURE_x86_64) && !defined(__APPLE__)
     //     const auto& caps = Common::GetCPUCaps();
-    //     const bool has_fma = caps.fma || caps.fma4;
+    //     const bool has_fma = caps.fma;
     //     const auto processor_count = std::thread::hardware_concurrency();
     //     const bool has_4threads = processor_count == 0 || processor_count >= 4;
     //     const bool has_8gb_ram = Common::GetMemInfo().TotalPhysicalMemory >= 8_GiB;