From 88ddd9e832bb23dc8e03c0aa33ea1e3a3d034322 Mon Sep 17 00:00:00 2001
From: David Schultz <das@FreeBSD.org>
Date: Thu, 6 May 2004 09:35:57 +0000
Subject: [PATCH] Don't clear the exception flags after we finish emulating a
 floating-point instruction in the kernel.  The flags are supposed to be
 cumulative.

Thanks to marcel for helping me test this.
---
 sys/alpha/alpha/fp_emulate.c | 2 +-
 sys/alpha/include/fpu.h      | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/alpha/alpha/fp_emulate.c b/sys/alpha/alpha/fp_emulate.c
index e24ce889573..243c1727346 100644
--- a/sys/alpha/alpha/fp_emulate.c
+++ b/sys/alpha/alpha/fp_emulate.c
@@ -296,7 +296,7 @@ static int fp_emulate(union alpha_instruction ins, struct thread *td)
 		td->td_pcb->pcb_fp_control = control;
 
 		/* Regenerate the control register */
-		fpcr = fpregs->fpr_cr & FPCR_DYN_MASK;
+		fpcr = fpregs->fpr_cr & (FPCR_DYN_MASK | FPCR_STATUS_MASK);
 		fpcr |= ((control & IEEE_STATUS_MASK)
 			 << IEEE_STATUS_TO_FPCR_SHIFT);
 		if (!(control & IEEE_TRAP_ENABLE_INV))
diff --git a/sys/alpha/include/fpu.h b/sys/alpha/include/fpu.h
index 9f4800feeea..ad539e90451 100644
--- a/sys/alpha/include/fpu.h
+++ b/sys/alpha/include/fpu.h
@@ -56,6 +56,8 @@
 #define FPCR_INED	(1LL << 62)	/* Inexact Disable */
 #define FPCR_SUM	(1LL << 63)	/* Summary Bit */
 #define FPCR_MASK	(~0LL << 49)
+#define	FPCR_STATUS_MASK	(FPCR_INV | FPCR_DZE | FPCR_OVF | \
+				 FPCR_UNF | FPCR_INE | FPCR_IOV)
 
 /*
  * Exception summary bits.