sync/atomic: use cas64 to implement {Load,Store,Add}{Uint,Int}64 on Linux/ARM

        Now with GOARM=5 our all.bash should pass on ARMv5 systems.
        Fixes #3331.

R=golang-dev, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/6210071

diff --git a/src/pkg/sync/atomic/64bit_linux_arm.go b/src/pkg/sync/atomic/64bit_linux_arm.go
new file mode 100644 (file)
index 0000000..f070e78
--- /dev/null
+++ b/src/pkg/sync/atomic/64bit_linux_arm.go
@@ -0,0 +1,36 @@
+// Copyright 2012 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package atomic
+
+func loadUint64(addr *uint64) (val uint64) {
+       for {
+               val = *addr
+               if CompareAndSwapUint64(addr, val, val) {
+                       break
+               }
+       }
+       return
+}
+
+func storeUint64(addr *uint64, val uint64) {
+       for {
+               old := *addr
+               if CompareAndSwapUint64(addr, old, val) {
+                       break
+               }
+       }
+       return
+}
+
+func addUint64(val *uint64, delta uint64) (new uint64) {
+       for {
+               old := *val
+               new = old + delta
+               if CompareAndSwapUint64(val, old, new) {
+                       break
+               }
+       }
+       return
+}

diff --git a/src/pkg/sync/atomic/asm_linux_arm.s b/src/pkg/sync/atomic/asm_linux_arm.s
index f03ea66301f8a060c61cbf477ae630ec6cb745c2..4619c234334fa815408263b3f877fc02155610d8 100644 (file)
--- a/src/pkg/sync/atomic/asm_linux_arm.s
+++ b/src/pkg/sync/atomic/asm_linux_arm.s
@@ -121,20 +121,20 @@ TEXT setupAndCallCAS64<>(SB),7,$-4
        MOVW    R1, armCAS64(SB)
        MOVW    R1, PC
 
-TEXT ·CompareAndSwapInt64(SB),7,$-4
+TEXT ·CompareAndSwapInt64(SB),7,$0
+       B       ·CompareAndSwapUint64(SB)
+
+TEXT ·CompareAndSwapUint64(SB),7,$-4
        MOVW    armCAS64(SB), R0
        CMP     $0, R0
        MOVW.NE R0, PC
        B               setupAndCallCAS64<>(SB)
 
-TEXT ·CompareAndSwapUint64(SB),7,$0
-       B       ·CompareAndSwapInt64(SB)
-
 TEXT ·AddInt64(SB),7,$0
-       B       ·armAddUint64(SB)
+       B       ·addUint64(SB)
 
 TEXT ·AddUint64(SB),7,$0
-       B       ·armAddUint64(SB)
+       B       ·addUint64(SB)
 
 TEXT ·LoadInt32(SB),7,$0
        B       ·LoadUint32(SB)
@@ -150,10 +150,10 @@ loadloop1:
        RET
 
 TEXT ·LoadInt64(SB),7,$0
-       B       ·armLoadUint64(SB)
+       B       ·loadUint64(SB)
 
 TEXT ·LoadUint64(SB),7,$0
-       B       ·armLoadUint64(SB)
+       B       ·loadUint64(SB)
 
 TEXT ·LoadUintptr(SB),7,$0
        B       ·LoadUint32(SB)
@@ -174,10 +174,10 @@ storeloop1:
        RET
 
 TEXT ·StoreInt64(SB),7,$0
-       B       ·armStoreUint64(SB)
+       B       ·storeUint64(SB)
 
 TEXT ·StoreUint64(SB),7,$0
-       B       ·armStoreUint64(SB)
+       B       ·storeUint64(SB)
 
 TEXT ·StoreUintptr(SB),7,$0
        B       ·StoreUint32(SB)