From 13c86772e981cb947f7264a1a65f3e7ad6dd14d9 Mon Sep 17 00:00:00 2001
From: ad <ad@NetBSD.org>
Date: Wed, 28 Nov 2007 16:59:09 +0000
Subject: [PATCH] Memory barrier in respect of the CAS isn't necessary.

---
 common/lib/libc/atomic/atomic_add_32_cas.c    | 5 +----
 common/lib/libc/atomic/atomic_add_32_nv_cas.c | 5 +----
 common/lib/libc/atomic/atomic_add_64_cas.c    | 5 +----
 common/lib/libc/atomic/atomic_add_64_nv_cas.c | 5 +----
 common/lib/libc/atomic/atomic_and_32_cas.c    | 5 +----
 common/lib/libc/atomic/atomic_and_32_nv_cas.c | 5 +----
 common/lib/libc/atomic/atomic_and_64_cas.c    | 5 +----
 common/lib/libc/atomic/atomic_and_64_nv_cas.c | 5 +----
 common/lib/libc/atomic/atomic_or_32_cas.c     | 5 +----
 common/lib/libc/atomic/atomic_or_32_nv_cas.c  | 5 +----
 common/lib/libc/atomic/atomic_or_64_cas.c     | 5 +----
 common/lib/libc/atomic/atomic_or_64_nv_cas.c  | 5 +----
 common/lib/libc/atomic/atomic_swap_32_cas.c   | 4 +---
 common/lib/libc/atomic/atomic_swap_64_cas.c   | 4 +---
 14 files changed, 14 insertions(+), 54 deletions(-)

diff --git a/common/lib/libc/atomic/atomic_add_32_cas.c b/common/lib/libc/atomic/atomic_add_32_cas.c
index 0d108930bab8..7a6bb46096e0 100644
--- a/common/lib/libc/atomic/atomic_add_32_cas.c
+++ b/common/lib/libc/atomic/atomic_add_32_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_add_32_cas.c,v 1.2 2007/11/28 16:54:58 ad Exp $	*/
+/*	$NetBSD: atomic_add_32_cas.c,v 1.3 2007/11/28 16:59:09 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 void
 atomic_add_32(volatile uint32_t *addr, int32_t val)
@@ -47,9 +46,7 @@ atomic_add_32(volatile uint32_t *addr, int32_t val)
 	uint32_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old + val;
 	} while (atomic_cas_32(addr, old, new) != old);
 }
diff --git a/common/lib/libc/atomic/atomic_add_32_nv_cas.c b/common/lib/libc/atomic/atomic_add_32_nv_cas.c
index c48c77149f3e..0d71f0a6e957 100644
--- a/common/lib/libc/atomic/atomic_add_32_nv_cas.c
+++ b/common/lib/libc/atomic/atomic_add_32_nv_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_add_32_nv_cas.c,v 1.2 2007/11/28 16:54:58 ad Exp $	*/
+/*	$NetBSD: atomic_add_32_nv_cas.c,v 1.3 2007/11/28 16:59:09 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint32_t
 atomic_add_32_nv(volatile uint32_t *addr, int32_t val)
@@ -47,9 +46,7 @@ atomic_add_32_nv(volatile uint32_t *addr, int32_t val)
 	uint32_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old + val;
 	} while (atomic_cas_32(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_add_64_cas.c b/common/lib/libc/atomic/atomic_add_64_cas.c
index 7427da5f36b0..d60da4536e6b 100644
--- a/common/lib/libc/atomic/atomic_add_64_cas.c
+++ b/common/lib/libc/atomic/atomic_add_64_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_add_64_cas.c,v 1.2 2007/11/28 16:54:59 ad Exp $	*/
+/*	$NetBSD: atomic_add_64_cas.c,v 1.3 2007/11/28 16:59:09 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 void
 atomic_add_64(volatile uint64_t *addr, int64_t val)
@@ -47,9 +46,7 @@ atomic_add_64(volatile uint64_t *addr, int64_t val)
 	uint64_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old + val;
 	} while (atomic_cas_64(addr, old, new) != old);
 }
diff --git a/common/lib/libc/atomic/atomic_add_64_nv_cas.c b/common/lib/libc/atomic/atomic_add_64_nv_cas.c
index 8b200ad87b69..cb121d5ba5e1 100644
--- a/common/lib/libc/atomic/atomic_add_64_nv_cas.c
+++ b/common/lib/libc/atomic/atomic_add_64_nv_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_add_64_nv_cas.c,v 1.2 2007/11/28 16:54:59 ad Exp $	*/
+/*	$NetBSD: atomic_add_64_nv_cas.c,v 1.3 2007/11/28 16:59:09 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint64_t
 atomic_add_64_nv(volatile uint64_t *addr, int64_t val)
@@ -47,9 +46,7 @@ atomic_add_64_nv(volatile uint64_t *addr, int64_t val)
 	uint64_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old + val;
 	} while (atomic_cas_64(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_and_32_cas.c b/common/lib/libc/atomic/atomic_and_32_cas.c
index ecbe9077cd85..6df7713303dc 100644
--- a/common/lib/libc/atomic/atomic_and_32_cas.c
+++ b/common/lib/libc/atomic/atomic_and_32_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_and_32_cas.c,v 1.2 2007/11/28 16:55:00 ad Exp $	*/
+/*	$NetBSD: atomic_and_32_cas.c,v 1.3 2007/11/28 16:59:09 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 void
 atomic_and_32(volatile uint32_t *addr, uint32_t val)
@@ -47,9 +46,7 @@ atomic_and_32(volatile uint32_t *addr, uint32_t val)
 	uint32_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old & val;
 	} while (atomic_cas_32(addr, old, new) != old);
 }
diff --git a/common/lib/libc/atomic/atomic_and_32_nv_cas.c b/common/lib/libc/atomic/atomic_and_32_nv_cas.c
index 39ef96e02423..1bbbeb7ab28d 100644
--- a/common/lib/libc/atomic/atomic_and_32_nv_cas.c
+++ b/common/lib/libc/atomic/atomic_and_32_nv_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_and_32_nv_cas.c,v 1.2 2007/11/28 16:55:00 ad Exp $	*/
+/*	$NetBSD: atomic_and_32_nv_cas.c,v 1.3 2007/11/28 16:59:09 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint32_t
 atomic_and_32_nv(volatile uint32_t *addr, uint32_t val)
@@ -47,9 +46,7 @@ atomic_and_32_nv(volatile uint32_t *addr, uint32_t val)
 	uint32_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old & val;
 	} while (atomic_cas_32(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_and_64_cas.c b/common/lib/libc/atomic/atomic_and_64_cas.c
index 896f2ac95973..4c08515881fe 100644
--- a/common/lib/libc/atomic/atomic_and_64_cas.c
+++ b/common/lib/libc/atomic/atomic_and_64_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_and_64_cas.c,v 1.2 2007/11/28 16:55:01 ad Exp $	*/
+/*	$NetBSD: atomic_and_64_cas.c,v 1.3 2007/11/28 16:59:10 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 void
 atomic_and_64(volatile uint64_t *addr, uint64_t val)
@@ -47,9 +46,7 @@ atomic_and_64(volatile uint64_t *addr, uint64_t val)
 	uint64_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old & val;
 	} while (atomic_cas_64(addr, old, new) != old);
 }
diff --git a/common/lib/libc/atomic/atomic_and_64_nv_cas.c b/common/lib/libc/atomic/atomic_and_64_nv_cas.c
index 182a5c256d44..34f85bd7cad9 100644
--- a/common/lib/libc/atomic/atomic_and_64_nv_cas.c
+++ b/common/lib/libc/atomic/atomic_and_64_nv_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_and_64_nv_cas.c,v 1.2 2007/11/28 16:55:01 ad Exp $	*/
+/*	$NetBSD: atomic_and_64_nv_cas.c,v 1.3 2007/11/28 16:59:10 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint64_t
 atomic_and_64_nv(volatile uint64_t *addr, uint64_t val)
@@ -47,9 +46,7 @@ atomic_and_64_nv(volatile uint64_t *addr, uint64_t val)
 	uint64_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old & val;
 	} while (atomic_cas_64(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_or_32_cas.c b/common/lib/libc/atomic/atomic_or_32_cas.c
index d16af05c8609..492e8d53c716 100644
--- a/common/lib/libc/atomic/atomic_or_32_cas.c
+++ b/common/lib/libc/atomic/atomic_or_32_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_or_32_cas.c,v 1.2 2007/11/28 16:55:08 ad Exp $	*/
+/*	$NetBSD: atomic_or_32_cas.c,v 1.3 2007/11/28 16:59:10 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 void
 atomic_or_32(volatile uint32_t *addr, uint32_t val)
@@ -47,9 +46,7 @@ atomic_or_32(volatile uint32_t *addr, uint32_t val)
 	uint32_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old | val;
 	} while (atomic_cas_32(addr, old, new) != old);
 }
diff --git a/common/lib/libc/atomic/atomic_or_32_nv_cas.c b/common/lib/libc/atomic/atomic_or_32_nv_cas.c
index e1a1bfa8d214..d8cdffaa452e 100644
--- a/common/lib/libc/atomic/atomic_or_32_nv_cas.c
+++ b/common/lib/libc/atomic/atomic_or_32_nv_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_or_32_nv_cas.c,v 1.2 2007/11/28 16:55:09 ad Exp $	*/
+/*	$NetBSD: atomic_or_32_nv_cas.c,v 1.3 2007/11/28 16:59:10 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint32_t
 atomic_or_32_nv(volatile uint32_t *addr, uint32_t val)
@@ -47,9 +46,7 @@ atomic_or_32_nv(volatile uint32_t *addr, uint32_t val)
 	uint32_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old | val;
 	} while (atomic_cas_32(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_or_64_cas.c b/common/lib/libc/atomic/atomic_or_64_cas.c
index ccc249bca8f6..4f7480d9cb3a 100644
--- a/common/lib/libc/atomic/atomic_or_64_cas.c
+++ b/common/lib/libc/atomic/atomic_or_64_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_or_64_cas.c,v 1.2 2007/11/28 16:55:09 ad Exp $	*/
+/*	$NetBSD: atomic_or_64_cas.c,v 1.3 2007/11/28 16:59:10 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 void
 atomic_or_64(volatile uint64_t *addr, uint64_t val)
@@ -47,9 +46,7 @@ atomic_or_64(volatile uint64_t *addr, uint64_t val)
 	uint64_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old | val;
 	} while (atomic_cas_64(addr, old, new) != old);
 }
diff --git a/common/lib/libc/atomic/atomic_or_64_nv_cas.c b/common/lib/libc/atomic/atomic_or_64_nv_cas.c
index 78a2cbcf429a..77a91e797b50 100644
--- a/common/lib/libc/atomic/atomic_or_64_nv_cas.c
+++ b/common/lib/libc/atomic/atomic_or_64_nv_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_or_64_nv_cas.c,v 1.2 2007/11/28 16:55:10 ad Exp $	*/
+/*	$NetBSD: atomic_or_64_nv_cas.c,v 1.3 2007/11/28 16:59:11 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint64_t
 atomic_or_64_nv(volatile uint64_t *addr, uint64_t val)
@@ -47,9 +46,7 @@ atomic_or_64_nv(volatile uint64_t *addr, uint64_t val)
 	uint64_t old, new;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
-
 		new = old | val;
 	} while (atomic_cas_64(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_swap_32_cas.c b/common/lib/libc/atomic/atomic_swap_32_cas.c
index 4b0b79b04ff3..b886e578f74b 100644
--- a/common/lib/libc/atomic/atomic_swap_32_cas.c
+++ b/common/lib/libc/atomic/atomic_swap_32_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_swap_32_cas.c,v 1.2 2007/11/28 16:55:11 ad Exp $	*/
+/*	$NetBSD: atomic_swap_32_cas.c,v 1.3 2007/11/28 16:59:11 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint32_t
 atomic_swap_32(volatile uint32_t *addr, uint32_t new)
@@ -47,7 +46,6 @@ atomic_swap_32(volatile uint32_t *addr, uint32_t new)
 	uint32_t old;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
 	} while (atomic_cas_32(addr, old, new) != old);
 
diff --git a/common/lib/libc/atomic/atomic_swap_64_cas.c b/common/lib/libc/atomic/atomic_swap_64_cas.c
index f3c7c4f89c04..39cd9dd5999e 100644
--- a/common/lib/libc/atomic/atomic_swap_64_cas.c
+++ b/common/lib/libc/atomic/atomic_swap_64_cas.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: atomic_swap_64_cas.c,v 1.2 2007/11/28 16:55:11 ad Exp $	*/
+/*	$NetBSD: atomic_swap_64_cas.c,v 1.3 2007/11/28 16:59:11 ad Exp $	*/
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -39,7 +39,6 @@
 #include "atomic_op_namespace.h"
 
 #include <sys/atomic.h>
-#include "atomic_op_cas_impl.h"
 
 uint64_t
 atomic_swap_64(volatile uint64_t *addr, uint64_t new)
@@ -47,7 +46,6 @@ atomic_swap_64(volatile uint64_t *addr, uint64_t new)
 	uint64_t old;
 
 	do {
-		OP_READ_BARRIER;
 		old = *addr;
 	} while (atomic_cas_64(addr, old, new) != old);