From 40310f021dcc3d82235e0dd9debb9a50d2ddf1fe Mon Sep 17 00:00:00 2001
From: David Xu <davidxu@FreeBSD.org>
Date: Sun, 28 May 2006 04:40:45 +0000
Subject: [PATCH] If parent thread never used FPU, the only work is to clear
 flag PCB_NPXINITDONE for new thread and let trap code initialize it.

---
 sys/i386/isa/npx.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sys/i386/isa/npx.c b/sys/i386/isa/npx.c
index 7b7f3a5c670d..129a853f20ed 100644
--- a/sys/i386/isa/npx.c
+++ b/sys/i386/isa/npx.c
@@ -952,9 +952,14 @@ npx_fork_thread(struct thread *td, struct thread *newtd)
 	u_int32_t	mxcsr;
 	u_int32_t	cw;
 
+	if (!(td->td_pcb->pcb_flags & PCB_NPXINITDONE)) {
+		newtd->td_pcb->pcb_flags &= ~PCB_NPXINITDONE;
+		return;
+	}
+		
 	state = &newtd->td_pcb->pcb_save;
 	/* get control word */
-	if (npxgetregs(td, &newtd->td_pcb->pcb_save))
+	if (npxgetregs(td, state))
 		return;
 	if (cpu_fxsr) {
 		mxcsr = state->sv_xmm.sv_env.en_mxcsr;