diff mbox

dxr3plugin fix for AMD64 cpuid segv

Message ID 4272D936.6020606@uklinux.net
State New
Headers

Commit Message

Jon Burgess April 30, 2005, 1:02 a.m. UTC 
  The current vdr-dxr3-0-2 branch of dxr3plugin segv's when run on an 
AMD64 system due to a problem with the cpuid code. The patch attached 
syncs the code with a recent ffmpeg/libavcodec/i386/cputest.c and it 
works for me.

I have not had the chance to test it on a regular 32 bit x86 system.

	Jon

Comments

Ville Skyttä April 30, 2005, 11:42 a.m. UTC | #1 
On Sat, 2005-04-30 at 02:02 +0100, Jon Burgess wrote:
> The current vdr-dxr3-0-2 branch of dxr3plugin segv's when run on an 
> AMD64 system due to a problem with the cpuid code. The patch attached 
> syncs the code with a recent ffmpeg/libavcodec/i386/cputest.c and it 
> works for me.

Applied, thanks.

> I have not had the chance to test it on a regular 32 bit x86 system.

Still works fine here.

(On the other hand, as far as I'm concerned, the whole optimized memcpy
and related stuff is on its way out: it is being used in only one place
in the whole plugin and I'm told that the performance of memcpy doesn't
really matter even there.  If someone has something against it being
removed, now would be a good time to yell... :)
Jan Wagner April 30, 2005, 12:14 p.m. UTC | #2 
> (On the other hand, as far as I'm concerned, the whole optimized memcpy
> and related stuff is on its way out: it is being used in only one place
> in the whole plugin and I'm told that the performance of memcpy doesn't
> really matter even there.  If someone has something against it being
> removed, now would be a good time to yell... :)

Interesting that you mention that now. Over the last days I have
experimented with dxr3 on my via eden board with a c3 processor.
memcpy_mmx makes the plugin segfault any time you start it with "unknown
machine code". This is caused by the assembler code in dxr3memcpy.c in
function mmx_memcpy. I removed the function from
cDxr3MemCpyBench::cDxr3MemCpyBench and it worked. Strange thing is, that
I remember it working before ...

Jan
diff mbox

Patch

--- dxr3/dxr3cpu.c.~1.1.2.9.~	2005-04-19 19:19:37.000000000 +0100
+++ dxr3/dxr3cpu.c	2005-04-30 01:29:39.000000000 +0100
@@ -128,10 +128,19 @@ 
 		     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));