if base.Debug.MergeLocals != 0 {
		mls = liveness.MergeLocals(fn, f)
		if base.Debug.MergeLocalsTrace > 0 && mls != nil {
			savedNP, savedP := mls.EstSavings()
			fmt.Fprintf(os.Stderr, "%s: %d bytes of stack space saved via stack slot merging (%d nonpointer %d pointer)\n", ir.FuncName(fn), savedNP+savedP, savedNP, savedP)
			if base.Debug.MergeLocalsTrace > 1 {
				fmt.Fprintf(os.Stderr, "=-= merge locals state for %v:\n%v",
					fn, mls)
			}

	src := filepath.Join("testdata", "mergelocals", "integration.go")
	obj := filepath.Join(tmpdir, "p.a")
	out, err := testenv.Command(t, testenv.GoToolPath(t), "tool", "compile",
		"-p=p", "-c", "1", "-o", obj, "-d=mergelocalstrace=2,mergelocals=1",
		src).CombinedOutput()
	if err != nil {
		t.Fatalf("failed to compile: %v\n%s", err, out)
	}
	vars := make(map[string]string)
	lines := strings.Split(string(out), "\n")
	prolog := true