Fix cpuid on AMD64 (Jon Burgess, newer ffmpeg).

1 files changed, 11 insertions, 2 deletions

diff --git a/dxr3cpu.c b/dxr3cpu.c
index 41f2435..e4035ef 100644
--- a/dxr3cpu.c
+++ b/dxr3cpu.c
@@ -126,10 +126,19 @@ bool cDxr3CPU::CheckCPUIDPresence()
 bool cDxr3CPU::Cpuid(unsigned long function, unsigned long& out_eax, unsigned long& out_ebx, unsigned long& out_ecx, unsigned long& out_edx)
 {
 	// This works with PIC/non-PIC, from ffmpeg (libavcodec/i386/cputest.c)
+
+#ifdef __x86_64__
+#  define REG_b "rbx"
+#  define REG_S "rsi"
+#else
+#  define REG_b "ebx"
+#  define REG_S "esi"
+#endif
+
 	__asm __volatile					\
-	  ("movl %%ebx, %%esi\n\t"				\
+	  ("mov %%"REG_b", %%"REG_S"\n\t"			\
 	   "cpuid\n\t"						\
-	   "xchgl %%ebx, %%esi"					\
+	   "xchg %%"REG_b", %%"REG_S				\
 	   : "=a" (out_eax), "=S" (out_ebx),			\
 	     "=c" (out_ecx), "=d" (out_edx)			\
 	   : "0" (function));