return true
	}
	if p.To.Type == obj.TYPE_MEM && (isR15(p.To.Reg) || isR15(p.To.Index)) {
		return true
	}
	if f3 := p.GetFrom3(); f3 != nil && f3.Type == obj.TYPE_MEM && (isR15(f3.Reg) || isR15(f3.Index)) {
		return true
	}
	return false
}

// progWritesR15 reports whether p writes the register R15.
func progWritesR15(p *obj.Prog) bool {