"reflect"
	"testing"
)

// initOverlay resets the overlay state to reflect the config.
// config should be a text archive string. The comment is the overlay config
// json, and the files, in the archive are laid out in a temp directory
// that cwd is set to.
func initOverlay(t *testing.T, config string) {
	t.Helper()

	// Create a temporary directory and chdir to it.
	prevwd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}

	// Note: We expect that for one reason or another it may happen
	// that repeating an action produces a different output hash
	// (for example, if the output contains a time stamp or temp dir name).
	// While not ideal, this is also not a correctness problem, so we
	// don't make a big deal about it. In particular, we leave the action
	// cache entries writable specifically so that they can be overwritten.
	//

		init.Append(typecheck.Stmt(nif))

		t = types.NewArray(t.Elem(), i) // [r]T
		var_ := typecheck.TempAt(base.Pos, ir.CurFunc, t)
		appendWalkStmt(init, ir.NewAssignStmt(base.Pos, var_, nil))  // zero temp
		r := ir.NewSliceExpr(base.Pos, ir.OSLICE, var_, nil, l, nil) // arr[:l]
		// The conv is necessary in case n.Type is named.
		return walkExpr(typecheck.Expr(typecheck.Conv(r, n.Type())), init)
	}

		p.Reg = v.Args[0].Reg()
	case ssa.OpS390XDIVD, ssa.OpS390XDIVW,
		ssa.OpS390XDIVDU, ssa.OpS390XDIVWU,
		ssa.OpS390XMODD, ssa.OpS390XMODW,
		ssa.OpS390XMODDU, ssa.OpS390XMODWU:

		// TODO(mundaym): use the temp registers every time like x86 does with AX?
		dividend := v.Args[0].Reg()
		divisor := v.Args[1].Reg()

		// CPU faults upon signed overflow, which occurs when most
		// negative int is divided by -1.

				inputs:   []regMask{buildReg("R20")},
				clobbers: buildReg("R20"),
			},
			clobberFlags:   true,
			typ:            "Mem",
			faultOnNilArg0: true,
			unsafePoint:    true,
		},

		// R31 is temp register
		// Loop code:
		//	MOVD len/32,R31		set up loop ctr
		//	MOVD R31,CTR
		//	MOVD $16,R31		index register
		// loop:
		//	LXVD2X (R0)(R4),VS32
		//	LXVD2X (R31)(R4),VS33