diff --git a/src/cmd/compile/internal/gc/cgen.go b/src/cmd/compile/internal/gc/cgen.go
index 4160ae9d40..b6a3e5bbeb 100644
--- a/src/cmd/compile/internal/gc/cgen.go
+++ b/src/cmd/compile/internal/gc/cgen.go
@@ -2018,11 +2018,11 @@ func bgenx(n, res *Node, wantTrue bool, likely int, to *obj.Prog) {
 		Regalloc(&n2, nr.Type, nil)
 		Cgen(nr, &n2)
 		nr = &n2
-		Regfree(&n2)
 
 		Regalloc(&n1, nl.Type, nil)
 		Cgen(&tmp, &n1)
 		Regfree(&n1)
+		Regfree(&n2)
 	} else {
 		var n1 Node
 		if !nl.Addable && Ctxt.Arch.Thechar == '8' {
diff --git a/test/fixedbugs/issue12226.go b/test/fixedbugs/issue12226.go
new file mode 100644
index 0000000000..22467116c1
--- /dev/null
+++ b/test/fixedbugs/issue12226.go
@@ -0,0 +1,15 @@
+// run
+
+// Copyright 2015 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 main
+
+import "fmt"
+
+func main() {
+	if []byte("foo")[0] == []byte("b")[0] {
+		fmt.Println("BUG: \"foo\" and \"b\" appear to have the same first byte")
+	}
+}