Runtime detection of SSE support for raytracing. Also enabled rayoptimization

by default now on all platforms since it shouldn't crash anymore if SSE is
not there. If this breaks compilation on some platforms, please let me know.

1 files changed, 52 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/cpu.c b/source/blender/blenlib/intern/cpu.c
new file mode 100644
index 00000000000..490e1c3f02a
--- /dev/null
+++ b/source/blender/blenlib/intern/cpu.c
@@ -0,0 +1,52 @@
+/**
+ *
+ * $Id$
+ *
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version. 
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#include "BLI_cpu.h"
+
+int BLI_cpu_support_sse2(void)
+{
+#if defined(__x86_64__) || defined(_M_X64)
+	/* x86_64 always has SSE2 instructions */
+	return 1;
+#elif defined(__GNUC__) && defined(i386)
+	/* for GCC x86 we check cpuid */
+	unsigned int a, b, c, d;
+	__asm__("cpuid": "=a"(a), "=b"(b), "=c"(c), "=d"(d): "a"(1));
+	return (d & 0x04000000) != 0;
+#elif (defined(_MSC_VER) && defined(_M_IX86))
+	/* also check cpuid for MSVC x86 */
+	unsigned int d;
+	__asm {
+		xor     eax, eax
+		inc     eax
+		push    ebx
+		cpuid
+		pop     ebx
+		mov     d, edx
+	}
+	return (d & 0x04000000) != 0;
+#endif
+
+	return 0;
+}
+