Move CPUCapFlags and FillCPUCaps to their own source

1 files changed, 147 insertions, 0 deletions

diff --git a/alc/cpu_caps.cpp b/alc/cpu_caps.cpp
new file mode 100644
index 00000000..9470d7a0
--- /dev/null
+++ b/alc/cpu_caps.cpp
@@ -0,0 +1,147 @@
+
+#include "config.h"
+
+#include "cpu_caps.h"
+
+#ifdef HAVE_INTRIN_H
+#include <intrin.h>
+#endif
+#ifdef HAVE_CPUID_H
+#include <cpuid.h>
+#endif
+
+#include <cctype>
+#include <fstream>
+#include <string>
+
+#include "logging.h"
+
+
+int CPUCapFlags{0};
+
+namespace {
+
+#if defined(HAVE_GCC_GET_CPUID) \
+    && (defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64))
+using reg_type = unsigned int;
+inline void get_cpuid(unsigned int f, reg_type *regs)
+{ __get_cpuid(f, &regs[0], &regs[1], &regs[2], &regs[3]); }
+#define CAN_GET_CPUID
+#elif defined(HAVE_CPUID_INTRINSIC) \
+    && (defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64))
+using reg_type = int;
+inline void get_cpuid(unsigned int f, reg_type *regs)
+{ (__cpuid)(regs, f); }
+#define CAN_GET_CPUID
+#endif
+
+} // namespace
+
+
+void FillCPUCaps(int capfilter)
+{
+    int caps{0};
+
+/* FIXME: We really should get this for all available CPUs in case different
+ * CPUs have different caps (is that possible on one machine?).
+ */
+#ifdef CAN_GET_CPUID
+    union {
+        reg_type regs[4];
+        char str[sizeof(reg_type[4])];
+    } cpuinf[3]{};
+
+    get_cpuid(0, cpuinf[0].regs);
+    if(cpuinf[0].regs[0] == 0)
+        ERR("Failed to get CPUID\n");
+    else
+    {
+        const reg_type maxfunc{cpuinf[0].regs[0]};
+
+        get_cpuid(0x80000000, cpuinf[0].regs);
+        const reg_type maxextfunc{cpuinf[0].regs[0]};
+
+        TRACE("Detected max CPUID function: 0x%x (ext. 0x%x)\n", maxfunc, maxextfunc);
+
+        TRACE("Vendor ID: \"%.4s%.4s%.4s\"\n", cpuinf[0].str+4, cpuinf[0].str+12, cpuinf[0].str+8);
+        if(maxextfunc >= 0x80000004)
+        {
+            get_cpuid(0x80000002, cpuinf[0].regs);
+            get_cpuid(0x80000003, cpuinf[1].regs);
+            get_cpuid(0x80000004, cpuinf[2].regs);
+            TRACE("Name: \"%.16s%.16s%.16s\"\n", cpuinf[0].str, cpuinf[1].str, cpuinf[2].str);
+        }
+
+        if(maxfunc >= 1)
+        {
+            get_cpuid(1, cpuinf[0].regs);
+            if((cpuinf[0].regs[3]&(1<<25)))
+                caps |= CPU_CAP_SSE;
+            if((caps&CPU_CAP_SSE) && (cpuinf[0].regs[3]&(1<<26)))
+                caps |= CPU_CAP_SSE2;
+            if((caps&CPU_CAP_SSE2) && (cpuinf[0].regs[2]&(1<<0)))
+                caps |= CPU_CAP_SSE3;
+            if((caps&CPU_CAP_SSE3) && (cpuinf[0].regs[2]&(1<<19)))
+                caps |= CPU_CAP_SSE4_1;
+        }
+    }
+#else
+    /* Assume support for whatever's supported if we can't check for it */
+#if defined(HAVE_SSE4_1)
+#warning "Assuming SSE 4.1 run-time support!"
+    caps |= CPU_CAP_SSE | CPU_CAP_SSE2 | CPU_CAP_SSE3 | CPU_CAP_SSE4_1;
+#elif defined(HAVE_SSE3)
+#warning "Assuming SSE 3 run-time support!"
+    caps |= CPU_CAP_SSE | CPU_CAP_SSE2 | CPU_CAP_SSE3;
+#elif defined(HAVE_SSE2)
+#warning "Assuming SSE 2 run-time support!"
+    caps |= CPU_CAP_SSE | CPU_CAP_SSE2;
+#elif defined(HAVE_SSE)
+#warning "Assuming SSE run-time support!"
+    caps |= CPU_CAP_SSE;
+#endif
+#endif
+#ifdef HAVE_NEON
+    al::ifstream file{"/proc/cpuinfo"};
+    if(!file.is_open())
+        ERR("Failed to open /proc/cpuinfo, cannot check for NEON support\n");
+    else
+    {
+        std::string features;
+
+        auto getline = [](std::istream &f, std::string &output) -> bool
+        {
+            while(f.good() && f.peek() == '\n')
+                f.ignore();
+            return std::getline(f, output) && !output.empty();
+        };
+        while(getline(file, features))
+        {
+            if(features.compare(0, 10, "Features\t:", 10) == 0)
+                break;
+        }
+        file.close();
+
+        size_t extpos{9};
+        while((extpos=features.find("neon", extpos+1)) != std::string::npos)
+        {
+            if((extpos == 0 || std::isspace(features[extpos-1])) &&
+                (extpos+4 == features.length() || std::isspace(features[extpos+4])))
+            {
+                caps |= CPU_CAP_NEON;
+                break;
+            }
+        }
+    }
+#endif
+
+    TRACE("Extensions:%s%s%s%s%s%s\n",
+        ((capfilter&CPU_CAP_SSE)    ? ((caps&CPU_CAP_SSE)    ? " +SSE"    : " -SSE")    : ""),
+        ((capfilter&CPU_CAP_SSE2)   ? ((caps&CPU_CAP_SSE2)   ? " +SSE2"   : " -SSE2")   : ""),
+        ((capfilter&CPU_CAP_SSE3)   ? ((caps&CPU_CAP_SSE3)   ? " +SSE3"   : " -SSE3")   : ""),
+        ((capfilter&CPU_CAP_SSE4_1) ? ((caps&CPU_CAP_SSE4_1) ? " +SSE4.1" : " -SSE4.1") : ""),
+        ((capfilter&CPU_CAP_NEON)   ? ((caps&CPU_CAP_NEON)   ? " +NEON"   : " -NEON")   : ""),
+        ((!capfilter) ? " -none-" : "")
+    );
+    CPUCapFlags = caps & capfilter;
+}