cmd/compile: support pointers to arrays in arrayClear

Fixes #52635

Change-Id: I85f182931e30292983ef86c55a0ab6e01282395c
Reviewed-on: https://go-review.googlesource.com/c/go/+/403337
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/test/codegen/issue52635.go b/test/codegen/issue52635.go
new file mode 100644
index 0000000000..0e4d169081
--- /dev/null
+++ b/test/codegen/issue52635.go
@@ -0,0 +1,36 @@
+// asmcheck
+
+// Copyright 2022 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.
+
+// Test that optimized range memclr works with pointers to arrays.
+
+package codegen
+
+type T struct {
+	a *[10]int
+	b [10]int
+}
+
+func (t *T) f() {
+	// amd64:".*runtime.memclrNoHeapPointers"
+	for i := range t.a {
+		t.a[i] = 0
+	}
+
+	// amd64:".*runtime.memclrNoHeapPointers"
+	for i := range *t.a {
+		t.a[i] = 0
+	}
+
+	// amd64:".*runtime.memclrNoHeapPointers"
+	for i := range t.a {
+		(*t.a)[i] = 0
+	}
+
+	// amd64:".*runtime.memclrNoHeapPointers"
+	for i := range *t.a {
+		(*t.a)[i] = 0
+	}
+}