Common: Cleanup CPU capability detection code.

1 files changed, 89 insertions, 131 deletions

diff --git a/src/common/x64/cpu_detect.cpp b/src/common/x64/cpu_detect.cpp
index 72c8297a3..d9c430c67 100644
--- a/src/common/x64/cpu_detect.cpp
+++ b/src/common/x64/cpu_detect.cpp
@@ -1,23 +1,25 @@
-// Copyright 2008 Dolphin Emulator Project
-// Licensed under GPLv2+
+// Copyright 2013 Dolphin Emulator Project / 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
 #include <cstring>
 #include <string>
+#include <thread>
 
 #include "common/common_types.h"
 
 #include "cpu_detect.h"
 
-#ifndef _WIN32
+namespace Common {
+
+#ifndef _MSC_VER
 
 #ifdef __FreeBSD__
 #include <sys/types.h>
 #include <machine/cpufunc.h>
 #endif
 
-static inline void __cpuidex(int info[4], int function_id, int subfunction_id)
-{
+static inline void __cpuidex(int info[4], int function_id, int subfunction_id) {
 #ifdef __FreeBSD__
     // Despite the name, this is just do_cpuid() with ECX as second input.
     cpuid_count((u_int)function_id, (u_int)subfunction_id, (u_int*)info);
@@ -36,96 +38,67 @@ static inline void __cpuidex(int info[4], int function_id, int subfunction_id)
 #endif
 }
 
-static inline void __cpuid(int info[4], int function_id)
-{
+static inline void __cpuid(int info[4], int function_id) {
     return __cpuidex(info, function_id, 0);
 }
 
 #define _XCR_XFEATURE_ENABLED_MASK 0
-static u64 _xgetbv(u32 index)
-{
+static u64 _xgetbv(u32 index) {
     u32 eax, edx;
     __asm__ __volatile__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(index));
     return ((u64)edx << 32) | eax;
 }
 
-#endif // ifndef _WIN32
-
-namespace Common {
-
-CPUInfo cpu_info;
-
-CPUInfo::CPUInfo() {
-    Detect();
-}
+#endif // ifndef _MSC_VER
 
 // Detects the various CPU features
-void CPUInfo::Detect() {
-    memset(this, 0, sizeof(*this));
-#ifdef ARCHITECTURE_X64
-    Mode64bit = true;
-    OS64bit = true;
-#endif
-    num_cores = 1;
+static CPUCaps Detect() {
+    CPUCaps caps = {};
 
-    // Set obvious defaults, for extra safety
-    if (Mode64bit) {
-        bSSE = true;
-        bSSE2 = true;
-        bLongMode = true;
-    }
+    caps.num_cores = std::thread::hardware_concurrency();
+
+    // Assumes the CPU supports the CPUID instruction. Those that don't would likely not support
+    // Citra at all anyway
 
-    // Assume CPU supports the CPUID instruction. Those that don't can barely
-    // boot modern OS:es anyway.
     int cpu_id[4];
-    memset(brand_string, 0, sizeof(brand_string));
+    memset(caps.brand_string, 0, sizeof(caps.brand_string));
 
-    // Detect CPU's CPUID capabilities, and grab CPU string
+    // Detect CPU's CPUID capabilities and grab CPU string
     __cpuid(cpu_id, 0x00000000);
-    u32 max_std_fn = cpu_id[0];  // EAX
-    *((int *)brand_string) = cpu_id[1];
-    *((int *)(brand_string + 4)) = cpu_id[3];
-    *((int *)(brand_string + 8)) = cpu_id[2];
+    u32 max_std_fn = cpu_id[0]; // EAX
+
+    std::memcpy(&caps.brand_string[0], &cpu_id[1], sizeof(int));
+    std::memcpy(&caps.brand_string[4], &cpu_id[3], sizeof(int));
+    std::memcpy(&caps.brand_string[8], &cpu_id[2], sizeof(int));
+
     __cpuid(cpu_id, 0x80000000);
+
     u32 max_ex_fn = cpu_id[0];
-    if (!strcmp(brand_string, "GenuineIntel"))
-        vendor = VENDOR_INTEL;
-    else if (!strcmp(brand_string, "AuthenticAMD"))
-        vendor = VENDOR_AMD;
+    if (!strcmp(caps.brand_string, "GenuineIntel"))
+        caps.vendor = CPUVendor::INTEL;
+    else if (!strcmp(caps.brand_string, "AuthenticAMD"))
+        caps.vendor = CPUVendor::AMD;
     else
-        vendor = VENDOR_OTHER;
+        caps.vendor = CPUVendor::OTHER;
 
-    // Set reasonable default brand string even if brand string not available.
-    strcpy(cpu_string, brand_string);
+    // Set reasonable default brand string even if brand string not available
+    strcpy(caps.cpu_string, caps.brand_string);
 
-    // Detect family and other misc stuff.
-    bool ht = false;
-    HTT = ht;
-    logical_cpu_count = 1;
+    // Detect family and other miscellaneous features
     if (max_std_fn >= 1) {
         __cpuid(cpu_id, 0x00000001);
-        int family = ((cpu_id[0] >> 8) & 0xf) + ((cpu_id[0] >> 20) & 0xff);
-        int model = ((cpu_id[0] >> 4) & 0xf) + ((cpu_id[0] >> 12) & 0xf0);
-        // Detect people unfortunate enough to be running Dolphin on an Atom
-        if (family == 6 && (model == 0x1C || model == 0x26 || model == 0x27 || model == 0x35 || model == 0x36 ||
-            model == 0x37 || model == 0x4A || model == 0x4D || model == 0x5A || model == 0x5D))
-            bAtom = true;
-        logical_cpu_count = (cpu_id[1] >> 16) & 0xFF;
-        ht = (cpu_id[3] >> 28) & 1;
-
-        if ((cpu_id[3] >> 25) & 1) bSSE = true;
-        if ((cpu_id[3] >> 26) & 1) bSSE2 = true;
-        if ((cpu_id[2]) & 1) bSSE3 = true;
-        if ((cpu_id[2] >> 9) & 1) bSSSE3 = true;
-        if ((cpu_id[2] >> 19) & 1) bSSE4_1 = true;
-        if ((cpu_id[2] >> 20) & 1) bSSE4_2 = true;
-        if ((cpu_id[2] >> 22) & 1) bMOVBE = true;
-        if ((cpu_id[2] >> 25) & 1) bAES = true;
-
-        if ((cpu_id[3] >> 24) & 1)
-        {
-            // We can use FXSAVE.
-            bFXSR = true;
+
+        if ((cpu_id[3] >> 25) & 1) caps.sse = true;
+        if ((cpu_id[3] >> 26) & 1) caps.sse2 = true;
+        if ((cpu_id[2]) & 1) caps.sse3 = true;
+        if ((cpu_id[2] >> 9) & 1) caps.ssse3 = true;
+        if ((cpu_id[2] >> 19) & 1) caps.sse4_1 = true;
+        if ((cpu_id[2] >> 20) & 1) caps.sse4_2 = true;
+        if ((cpu_id[2] >> 22) & 1) caps.movbe = true;
+        if ((cpu_id[2] >> 25) & 1) caps.aes = true;
+
+        if ((cpu_id[3] >> 24) & 1) {
+            caps.fxsave_fxrstor = true;
         }
 
         // AVX support requires 3 separate checks:
@@ -134,95 +107,80 @@ void CPUInfo::Detect() {
         //  - XGETBV result has the XCR bit set.
         if (((cpu_id[2] >> 28) & 1) && ((cpu_id[2] >> 27) & 1)) {
             if ((_xgetbv(_XCR_XFEATURE_ENABLED_MASK) & 0x6) == 0x6) {
-                bAVX = true;
+                caps.avx = true;
                 if ((cpu_id[2] >> 12) & 1)
-                    bFMA = true;
+                    caps.fma = true;
             }
         }
 
         if (max_std_fn >= 7) {
             __cpuidex(cpu_id, 0x00000007, 0x00000000);
-            // careful; we can't enable AVX2 unless the XSAVE/XGETBV checks above passed
+            // Can't enable AVX2 unless the XSAVE/XGETBV checks above passed
             if ((cpu_id[1] >> 5) & 1)
-                bAVX2 = bAVX;
+                caps.avx2 = caps.avx;
             if ((cpu_id[1] >> 3) & 1)
-                bBMI1 = true;
+                caps.bmi1 = true;
             if ((cpu_id[1] >> 8) & 1)
-                bBMI2 = true;
+                caps.bmi2 = true;
         }
     }
 
-    bFlushToZero = bSSE;
+    caps.flush_to_zero = caps.sse;
 
     if (max_ex_fn >= 0x80000004) {
         // Extract CPU model string
         __cpuid(cpu_id, 0x80000002);
-        memcpy(cpu_string, cpu_id, sizeof(cpu_id));
+        std::memcpy(caps.cpu_string, cpu_id, sizeof(cpu_id));
         __cpuid(cpu_id, 0x80000003);
-        memcpy(cpu_string + 16, cpu_id, sizeof(cpu_id));
+        std::memcpy(caps.cpu_string + 16, cpu_id, sizeof(cpu_id));
         __cpuid(cpu_id, 0x80000004);
-        memcpy(cpu_string + 32, cpu_id, sizeof(cpu_id));
+        std::memcpy(caps.cpu_string + 32, cpu_id, sizeof(cpu_id));
     }
+
     if (max_ex_fn >= 0x80000001) {
-        // Check for more features.
+        // Check for more features
         __cpuid(cpu_id, 0x80000001);
-        if (cpu_id[2] & 1) bLAHFSAHF64 = true;
-        if ((cpu_id[2] >> 5) & 1) bLZCNT = true;
-        if ((cpu_id[2] >> 16) & 1) bFMA4 = true;
-        if ((cpu_id[3] >> 29) & 1) bLongMode = true;
+        if (cpu_id[2] & 1) caps.lahf_sahf_64 = true;
+        if ((cpu_id[2] >> 5) & 1) caps.lzcnt = true;
+        if ((cpu_id[2] >> 16) & 1) caps.fma4 = true;
+        if ((cpu_id[3] >> 29) & 1) caps.long_mode = true;
     }
 
-    num_cores = (logical_cpu_count == 0) ? 1 : logical_cpu_count;
-
-    if (max_ex_fn >= 0x80000008) {
-        // Get number of cores. This is a bit complicated. Following AMD manual here.
-        __cpuid(cpu_id, 0x80000008);
-        int apic_id_core_id_size = (cpu_id[2] >> 12) & 0xF;
-        if (apic_id_core_id_size == 0) {
-            if (ht) {
-                // New mechanism for modern Intel CPUs.
-                if (vendor == VENDOR_INTEL) {
-                    __cpuidex(cpu_id, 0x00000004, 0x00000000);
-                    int cores_x_package = ((cpu_id[0] >> 26) & 0x3F) + 1;
-                    HTT = (cores_x_package < logical_cpu_count);
-                    cores_x_package = ((logical_cpu_count % cores_x_package) == 0) ? cores_x_package : 1;
-                    num_cores = (cores_x_package > 1) ? cores_x_package : num_cores;
-                    logical_cpu_count /= cores_x_package;
-                }
-            }
-        } else {
-            // Use AMD's new method.
-            num_cores = (cpu_id[2] & 0xFF) + 1;
-        }
-    }
+    return caps;
 }
 
-// Turn the CPU info into a string we can show
-std::string CPUInfo::Summarize() {
-    std::string sum(cpu_string);
+const CPUCaps& GetCPUCaps() {
+    static CPUCaps caps = Detect();
+    return caps;
+}
+
+std::string GetCPUCapsString() {
+    auto caps = GetCPUCaps();
+
+    std::string sum(caps.cpu_string);
     sum += " (";
-    sum += brand_string;
+    sum += caps.brand_string;
     sum += ")";
 
-    if (bSSE) sum += ", SSE";
-    if (bSSE2) {
+    if (caps.sse) sum += ", SSE";
+    if (caps.sse2) {
         sum += ", SSE2";
-        if (!bFlushToZero)
-            sum += " (but not DAZ!)";
+        if (!caps.flush_to_zero) sum += " (without DAZ)";
     }
-    if (bSSE3) sum += ", SSE3";
-    if (bSSSE3) sum += ", SSSE3";
-    if (bSSE4_1) sum += ", SSE4.1";
-    if (bSSE4_2) sum += ", SSE4.2";
-    if (HTT) sum += ", HTT";
-    if (bAVX) sum += ", AVX";
-    if (bAVX2) sum += ", AVX2";
-    if (bBMI1) sum += ", BMI1";
-    if (bBMI2) sum += ", BMI2";
-    if (bFMA) sum += ", FMA";
-    if (bAES) sum += ", AES";
-    if (bMOVBE) sum += ", MOVBE";
-    if (bLongMode) sum += ", 64-bit support";
+
+    if (caps.sse3) sum += ", SSE3";
+    if (caps.ssse3) sum += ", SSSE3";
+    if (caps.sse4_1) sum += ", SSE4.1";
+    if (caps.sse4_2) sum += ", SSE4.2";
+    if (caps.avx) sum += ", AVX";
+    if (caps.avx2) sum += ", AVX2";
+    if (caps.bmi1) sum += ", BMI1";
+    if (caps.bmi2) sum += ", BMI2";
+    if (caps.fma) sum += ", FMA";
+    if (caps.aes) sum += ", AES";
+    if (caps.movbe) sum += ", MOVBE";
+    if (caps.long_mode) sum += ", 64-bit support";
+
     return sum;
 }