cmd/compile,cmd/go,cmd/internal,runtime: remove dynamic checks for atomics for ARM64 targets that support LSE

Remove dynamic checks for atomic instructions for ARM64 targets that support LSE extension.

For #66131

Change-Id: I0ec1b183a3f4ea4c8a537430646e6bc4b4f64271
Reviewed-on: https://go-review.googlesource.com/c/go/+/569536
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Fannie Zhang <Fannie.Zhang@arm.com>
Reviewed-by: Shu-Chun Weng <scw@google.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/test/codegen/atomics.go b/test/codegen/atomics.go
new file mode 100644
index 0000000000..feaa31b9c1
--- /dev/null
+++ b/test/codegen/atomics.go
@@ -0,0 +1,27 @@
+// asmcheck
+
+// Copyright 2024 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.
+
+// These tests check that atomic instructions without dynamic checks are
+// generated for architectures that support them
+
+package codegen
+
+import "sync/atomic"
+
+type Counter struct {
+	count int32
+}
+
+func (c *Counter) Increment() {
+	// Check that ARm64 v8.0 has both atomic instruction (LDADDALW) and a dynamic check
+	// (for arm64HasATOMICS), while ARM64 v8.1 has only atomic and no dynamic check.
+	// arm64/v8.0:"LDADDALW"
+	// arm64/v8.1:"LDADDALW"
+	// arm64/v8.0:".*arm64HasATOMICS"
+	// arm64/v8.1:-".*arm64HasATOMICS"
+	atomic.AddInt32(&c.count, 1)
+}
+