--- //depot/vendor/freebsd/src/sys/amd64/amd64/fpu.c	2006/06/19 22:39:16
+++ //depot/user/jhb/acpipci/amd64/amd64/fpu.c	2009/01/26 21:47:49
@@ -391,6 +391,7 @@
 {
 	struct pcb *pcb;
 	register_t s;
+	u_short control;
 
 	if (PCPU_GET(fpcurthread) == curthread) {
 		printf("fpudna: fpcurthread == curthread %d times\n",
@@ -421,6 +422,10 @@
 		 * explicitly load sanitized registers.
 		 */
 		fxrstor(&fpu_cleanstate);
+		if (pcb->pcb_flags & PCB_32BIT) {
+			control = __INITIAL_FPUCW_I386__;
+			fldcw(&control);
+		}
 		pcb->pcb_flags |= PCB_FPUINITDONE;
 	} else
 		fxrstor(&pcb->pcb_save);
--- //depot/vendor/freebsd/src/sys/amd64/include/fpu.h	2004/04/05 21:30:47
+++ //depot/user/jhb/acpipci/amd64/include/fpu.h	2009/01/26 21:47:49
@@ -92,6 +92,7 @@
  * SSE2 based math.  For FreeBSD/amd64, we go with the default settings.
  */
 #define	__INITIAL_FPUCW__	0x037F
+#define	__INITIAL_FPUCW_I386__	0x127F
 #define	__INITIAL_MXCSR__	0x1F80
 #define	__INITIAL_MXCSR_MASK__	0xFFBF