diff --git a/src/cmd/compile/internal/ssa/deadstore.go b/src/cmd/compile/internal/ssa/deadstore.go
index 31d3f62d4e7..d694133ec3b 100644
--- a/src/cmd/compile/internal/ssa/deadstore.go
+++ b/src/cmd/compile/internal/ssa/deadstore.go
@@ -201,8 +201,9 @@ func elimDeadAutosGeneric(f *Func) {
 			panic("unhandled op with sym effect")
 		}
 
-		if v.Uses == 0 && v.Op != OpNilCheck || len(args) == 0 {
+		if v.Uses == 0 && v.Op != OpNilCheck && !v.Op.IsCall() && !v.Op.HasSideEffects() || len(args) == 0 {
 			// Nil check has no use, but we need to keep it.
+			// Also keep calls and values that have side effects.
 			return
 		}
 
diff --git a/test/fixedbugs/issue45693.go b/test/fixedbugs/issue45693.go
new file mode 100644
index 00000000000..20a0cec8ffa
--- /dev/null
+++ b/test/fixedbugs/issue45693.go
@@ -0,0 +1,16 @@
+// compile
+
+// Copyright 2021 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.
+
+// Issue 45693: ICE with register args.
+
+package p
+
+func f() {
+	var s string
+	s = s + "" + s + "" + s + ""
+	for {
+	}
+}