From 74c8de6372bc84916551a6685f337e69017eb239 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Mon, 11 Aug 2014 14:19:15 -0700
Subject: [PATCH] Try the __cpuid intrinsic if GCC's __get_cpuid isn't
 available

---
 Alc/helpers.c  | 52 ++++++++++++++++++++++++++++++++++++++++++----------
 CMakeLists.txt | 11 +++++++++++
 config.h.in    |  6 ++++++
 3 files changed, 59 insertions(+), 10 deletions(-)

diff --git a/Alc/helpers.c b/Alc/helpers.c
index 22e99d7e..90419c17 100644
--- a/Alc/helpers.c
+++ b/Alc/helpers.c
@@ -66,6 +66,9 @@ DEFINE_DEVPROPKEY(DEVPKEY_Device_FriendlyName, 0xa45c254e, 0xdf1c, 0x4efd, 0x80,
 #ifdef HAVE_DLFCN_H
 #include <dlfcn.h>
 #endif
+#ifdef HAVE_INTRIN_H
+#include <intrin.h>
+#endif
 #ifdef HAVE_CPUID_H
 #include <cpuid.h>
 #endif
@@ -147,19 +150,48 @@ void FillCPUCaps(ALuint capfilter)
             }
         }
     }
-#elif defined(HAVE_WINDOWS_H)
-    HMODULE k32 = GetModuleHandleA("kernel32.dll");
-    BOOL (WINAPI*IsProcessorFeaturePresent)(DWORD ProcessorFeature);
-    IsProcessorFeaturePresent = (BOOL(WINAPI*)(DWORD))GetProcAddress(k32, "IsProcessorFeaturePresent");
-    if(!IsProcessorFeaturePresent)
-        ERR("IsProcessorFeaturePresent not available; CPU caps not detected\n");
+#elif defined(HAVE_CPUID_INTRINSIC) && (defined(__i386__) || defined(__x86_64__) || \
+                                        defined(_M_IX86) || defined(_M_X64))
+    union {
+        int regs[4];
+        char str[sizeof(int[4])];
+    } cpuinf[3];
+
+    (__cpuid)(cpuinf[0].regs, 0);
+    if(cpuinf[0].regs[0] == 0)
+        ERR("Failed to get CPUID\n");
     else
     {
-        if(IsProcessorFeaturePresent(PF_XMMI_INSTRUCTIONS_AVAILABLE))
+        unsigned int maxfunc = cpuinf[0].regs[0];
+        unsigned int maxextfunc;
+
+        (__cpuid)(cpuinf[0].regs, 0x80000000);
+        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)
         {
-            caps |= CPU_CAP_SSE;
-            if(IsProcessorFeaturePresent(PF_XMMI64_INSTRUCTIONS_AVAILABLE))
-                caps |= CPU_CAP_SSE2;
+            (__cpuid)(cpuinf[0].regs, 0x80000002);
+            (__cpuid)(cpuinf[1].regs, 0x80000003);
+            (__cpuid)(cpuinf[2].regs, 0x80000004);
+            TRACE("Name: \"%.16s%.16s%.16s\"\n", cpuinf[0].str, cpuinf[1].str, cpuinf[2].str);
+        }
+
+        if(maxfunc >= 1)
+        {
+            (__cpuid)(cpuinf[0].regs, 1);
+            if((cpuinf[0].regs[3]&(1<<25)))
+            {
+                caps |= CPU_CAP_SSE;
+                if((cpuinf[0].regs[3]&(1<<26)))
+                {
+                    caps |= CPU_CAP_SSE2;
+                    if((cpuinf[0].regs[2]&(1<<19)))
+                        caps |= CPU_CAP_SSE4_1;
+                }
+            }
         }
     }
 #endif
diff --git a/CMakeLists.txt b/CMakeLists.txt
index cbb6844b..f1de92d6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -351,6 +351,7 @@ CHECK_INCLUDE_FILE(ftw.h HAVE_FTW_H)
 CHECK_INCLUDE_FILE(io.h HAVE_IO_H)
 CHECK_INCLUDE_FILE(strings.h HAVE_STRINGS_H)
 CHECK_INCLUDE_FILE(cpuid.h HAVE_CPUID_H)
+CHECK_INCLUDE_FILE(intrin.h HAVE_INTRIN_H)
 CHECK_INCLUDE_FILE(sys/sysconf.h HAVE_SYS_SYSCONF_H)
 CHECK_INCLUDE_FILE(fenv.h HAVE_FENV_H)
 CHECK_INCLUDE_FILE(float.h HAVE_FLOAT_H)
@@ -369,6 +370,16 @@ IF(HAVE_CPUID_H)
         }" HAVE_GCC_GET_CPUID)
 ENDIF()
 
+IF(HAVE_INTRIN_H)
+    CHECK_C_SOURCE_COMPILES("#include <intrin.h>
+        int main()
+        {
+            int regs[4];
+            __cpuid(regs, 0);
+            return regs[0];
+        }" HAVE_CPUID_INTRINSIC)
+ENDIF()
+
 # Some systems need libm for some of the following math functions to work
 CHECK_LIBRARY_EXISTS(m pow "" HAVE_LIBM)
 IF(HAVE_LIBM)
diff --git a/config.h.in b/config.h.in
index 27184824..af0d8bfd 100644
--- a/config.h.in
+++ b/config.h.in
@@ -148,6 +148,9 @@
 /* Define if we have cpuid.h */
 #cmakedefine HAVE_CPUID_H
 
+/* Define if we have intrin.h */
+#cmakedefine HAVE_INTRIN_H
+
 /* Define if we have sys/sysconf.h */
 #cmakedefine HAVE_SYS_SYSCONF_H
 
@@ -169,6 +172,9 @@
 /* Define if we have GCC's __get_cpuid() */
 #cmakedefine HAVE_GCC_GET_CPUID
 
+/* Define if we have the __cpuid() intrinsic */
+#cmakedefine HAVE_CPUID_INTRINSIC
+
 /* Define if we have _controlfp() */
 #cmakedefine HAVE__CONTROLFP
 
-- 
2.11.4.GIT