auto ir = new AluInstruction(op, dest[chan], i & 1 ? ip.j : ip.i,
                                    PValue(new InlineConstValue(ALU_SRC_PARAM_BASE + io.lds_pos(), 0)),
                                    i == 0  ? EmitInstruction::write : EmitInstruction::last);
+      dest.pin_to_channel(chan);
+
       ir->set_bank_swizzle(alu_vec_210);
       emit_instruction(ir);
    }
    for (unsigned i = 0; i < 4 ; ++i) {
       ir = new AluInstruction(op, dest[i], i & 1 ? ip.j : ip.i, PValue(new InlineConstValue(ALU_SRC_PARAM_BASE + io.lds_pos(), 0)),
                               (writemask & (1 << i)) ? EmitInstruction::write : EmitInstruction::empty);
+      dest.pin_to_channel(i);
       ir->set_bank_swizzle(alu_vec_210);
       emit_instruction(ir);
    }
                                    PValue(new InlineConstValue(ALU_SRC_PARAM_BASE + io.lds_pos(), 0)),
                                    i == comp ? EmitInstruction::write : EmitInstruction::empty);
       ir->set_bank_swizzle(alu_vec_210);
+      dest.pin_to_channel(i);
       emit_instruction(ir);
    }
    ir->set_flag(alu_last_instr);
 
    m_elms[i] = reg;
 }
 
+void GPRVector::pin_to_channel(int i)
+{
+   auto& v = static_cast<GPRValue&>(*m_elms[i]);
+   v.pin_to_channel();
+}
+
 void GPRVector::do_print(std::ostream& os) const
 {
    os << "R" << sel() << ".";
 
    PValue operator [] (int i) const {return m_elms[i];}
    PValue& operator [] (int i) {return m_elms[i];}
 
+   void pin_to_channel(int i);
 
    PValue x() const {return m_elms[0];}
    PValue y() const {return m_elms[1];}