library ieee; use ieee.std_logic_1164.all; use ieee.numeric_std.all; library work; use work.decode_types.all; use work.common.all; use work.helpers.all; use work.insn_helpers.all; entity decode2 is port ( clk : in std_ulogic; rst : in std_ulogic; complete_in : in std_ulogic; stall_out : out std_ulogic; stopped_out : out std_ulogic; flush_in: in std_ulogic; d_in : in Decode1ToDecode2Type; e_out : out Decode2ToExecute1Type; m_out : out Decode2ToMultiplyType; d_out : out Decode2ToDividerType; l_out : out Decode2ToLoadstore1Type; r_in : in RegisterFileToDecode2Type; r_out : out Decode2ToRegisterFileType; c_in : in CrFileToDecode2Type; c_out : out Decode2ToCrFileType ); end entity decode2; architecture behaviour of decode2 is type reg_type is record e : Decode2ToExecute1Type; m : Decode2ToMultiplyType; d : Decode2ToDividerType; l : Decode2ToLoadstore1Type; end record; signal r, rin : reg_type; type decode_input_reg_t is record reg_valid : std_ulogic; reg : std_ulogic_vector(4 downto 0); data : std_ulogic_vector(63 downto 0); end record; function decode_input_reg_a (t : input_reg_a_t; insn_in : std_ulogic_vector(31 downto 0); reg_data : std_ulogic_vector(63 downto 0)) return decode_input_reg_t is variable is_reg : std_ulogic; begin is_reg := '0' when insn_ra(insn_in) = "00000" else '1'; if t = RA or (t = RA_OR_ZERO and insn_ra(insn_in) /= "00000") then --return (is_reg, insn_ra(insn_in), reg_data); return ('1', insn_ra(insn_in), reg_data); else return ('0', (others => '0'), (others => '0')); end if; end; function decode_input_reg_b (t : input_reg_b_t; insn_in : std_ulogic_vector(31 downto 0); reg_data : std_ulogic_vector(63 downto 0)) return decode_input_reg_t is begin case t is when RB => return ('1', insn_rb(insn_in), reg_data); when CONST_UI => return ('0', (others => '0'), std_ulogic_vector(resize(unsigned(insn_ui(insn_in)), 64))); when CONST_SI => return ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_si(insn_in)), 64))); when CONST_SI_HI => return ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_si(insn_in)) & x"0000", 64))); when CONST_UI_HI => return ('0', (others => '0'), std_ulogic_vector(resize(unsigned(insn_si(insn_in)) & x"0000", 64))); when CONST_LI => return ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_li(insn_in)) & "00", 64))); when CONST_BD => return ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_bd(insn_in)) & "00", 64))); when CONST_DS => return ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_ds(insn_in)) & "00", 64))); when CONST_M1 => return ('0', (others => '0'), x"FFFFFFFFFFFFFFFF"); when CONST_SH => return ('0', (others => '0'), x"00000000000000" & "00" & insn_in(1) & insn_in(15 downto 11)); when CONST_SH32 => return ('0', (others => '0'), x"00000000000000" & "000" & insn_in(15 downto 11)); when NONE => return ('0', (others => '0'), (others => '0')); end case; end; function decode_input_reg_c (t : input_reg_c_t; insn_in : std_ulogic_vector(31 downto 0); reg_data : std_ulogic_vector(63 downto 0)) return decode_input_reg_t is begin case t is when RS => return ('1', insn_rs(insn_in), reg_data); when NONE => return ('0', (others => '0'), (others => '0')); end case; end; function decode_output_reg (t : output_reg_a_t; insn_in : std_ulogic_vector(31 downto 0)) return std_ulogic_vector is begin case t is when RT => return insn_rt(insn_in); when RA => return insn_ra(insn_in); when NONE => return "00000"; end case; end; function decode_rc (t : rc_t; insn_in : std_ulogic_vector(31 downto 0)) return std_ulogic is begin case t is when RC => return insn_rc(insn_in); when ONE => return '1'; when NONE => return '0'; end case; end; -- For now, use "rc" in the decode table to decide whether oe exists. -- This is not entirely correct architecturally: For mulhd and -- mulhdu, the OE field is reserved. It remains to be seen what an -- actual POWER9 does if we set it on those instructions, for now we -- test that further down when assigning to the multiplier oe input. -- function decode_oe (t : rc_t; insn_in : std_ulogic_vector(31 downto 0)) return std_ulogic is begin case t is when RC => return insn_oe(insn_in); when OTHERS => return '0'; end case; end; -- issue control signals signal control_valid_in : std_ulogic; signal control_valid_out : std_ulogic; signal control_sgl_pipe : std_logic; signal gpr_write_valid : std_ulogic; signal gpr_write : std_ulogic_vector(4 downto 0); signal gpr_a_read_valid : std_ulogic; signal gpr_a_read : std_ulogic_vector(4 downto 0); signal gpr_b_read_valid : std_ulogic; signal gpr_b_read : std_ulogic_vector(4 downto 0); signal gpr_c_read_valid : std_ulogic; signal gpr_c_read : std_ulogic_vector(4 downto 0); signal cr_write_valid : std_ulogic; begin control_0: entity work.control generic map ( PIPELINE_DEPTH => 1 ) port map ( clk => clk, rst => rst, complete_in => complete_in, valid_in => control_valid_in, flush_in => flush_in, sgl_pipe_in => control_sgl_pipe, stop_mark_in => d_in.stop_mark, gpr_write_valid_in => gpr_write_valid, gpr_write_in => gpr_write, gpr_a_read_valid_in => gpr_a_read_valid, gpr_a_read_in => gpr_a_read, gpr_b_read_valid_in => gpr_b_read_valid, gpr_b_read_in => gpr_b_read, gpr_c_read_valid_in => gpr_c_read_valid, gpr_c_read_in => gpr_c_read, cr_read_in => d_in.decode.input_cr, cr_write_in => cr_write_valid, valid_out => control_valid_out, stall_out => stall_out, stopped_out => stopped_out ); decode2_0: process(clk) begin if rising_edge(clk) then if rin.e.valid = '1' or rin.l.valid = '1' or rin.m.valid = '1' or rin.d.valid = '1' then report "execute " & to_hstring(rin.e.nia); end if; r <= rin; end if; end process; r_out.read1_reg <= insn_ra(d_in.insn); r_out.read2_reg <= insn_rb(d_in.insn); r_out.read3_reg <= insn_rs(d_in.insn); c_out.read <= d_in.decode.input_cr; decode2_1: process(all) variable v : reg_type; variable mul_a : std_ulogic_vector(63 downto 0); variable mul_b : std_ulogic_vector(63 downto 0); variable decoded_reg_a : decode_input_reg_t; variable decoded_reg_b : decode_input_reg_t; variable decoded_reg_c : decode_input_reg_t; variable signed_division: std_ulogic; variable length : std_ulogic_vector(3 downto 0); begin v := r; v.e := Decode2ToExecute1Init; v.l := Decode2ToLoadStore1Init; v.m := Decode2ToMultiplyInit; v.d := Decode2ToDividerInit; mul_a := (others => '0'); mul_b := (others => '0'); --v.e.input_cr := d_in.decode.input_cr; --v.m.input_cr := d_in.decode.input_cr; --v.e.output_cr := d_in.decode.output_cr; decoded_reg_a := decode_input_reg_a (d_in.decode.input_reg_a, d_in.insn, r_in.read1_data); decoded_reg_b := decode_input_reg_b (d_in.decode.input_reg_b, d_in.insn, r_in.read2_data); decoded_reg_c := decode_input_reg_c (d_in.decode.input_reg_c, d_in.insn, r_in.read3_data); r_out.read1_enable <= decoded_reg_a.reg_valid; r_out.read2_enable <= decoded_reg_b.reg_valid; r_out.read3_enable <= decoded_reg_c.reg_valid; case d_in.decode.length is when is1B => length := "0001"; when is2B => length := "0010"; when is4B => length := "0100"; when is8B => length := "1000"; when NONE => length := "0000"; end case; -- execute unit v.e.nia := d_in.nia; v.e.insn_type := d_in.decode.insn_type; v.e.read_reg1 := decoded_reg_a.reg; v.e.read_data1 := decoded_reg_a.data; v.e.read_reg2 := decoded_reg_b.reg; v.e.read_data2 := decoded_reg_b.data; v.e.read_data3 := decoded_reg_c.data; v.e.write_reg := decode_output_reg(d_in.decode.output_reg_a, d_in.insn); v.e.rc := decode_rc(d_in.decode.rc, d_in.insn); v.e.oe := decode_oe(d_in.decode.rc, d_in.insn); v.e.cr := c_in.read_cr_data; v.e.xerc := c_in.read_xerc_data; v.e.invert_a := d_in.decode.invert_a; v.e.invert_out := d_in.decode.invert_out; v.e.input_carry := d_in.decode.input_carry; v.e.output_carry := d_in.decode.output_carry; v.e.is_32bit := d_in.decode.is_32bit; v.e.is_signed := d_in.decode.is_signed; if d_in.decode.lr = '1' then v.e.lr := insn_lk(d_in.insn); end if; v.e.insn := d_in.insn; v.e.data_len := length; -- multiply unit v.m.insn_type := d_in.decode.insn_type; mul_a := decoded_reg_a.data; mul_b := decoded_reg_b.data; v.m.write_reg := decode_output_reg(d_in.decode.output_reg_a, d_in.insn); v.m.rc := decode_rc(d_in.decode.rc, d_in.insn); v.m.xerc := c_in.read_xerc_data; if v.m.insn_type = OP_MUL_L64 then v.m.oe := decode_oe(d_in.decode.rc, d_in.insn); end if; v.m.is_32bit := d_in.decode.is_32bit; if d_in.decode.is_32bit = '1' then if d_in.decode.is_signed = '1' then v.m.data1 := (others => mul_a(31)); v.m.data1(31 downto 0) := mul_a(31 downto 0); v.m.data2 := (others => mul_b(31)); v.m.data2(31 downto 0) := mul_b(31 downto 0); else v.m.data1 := '0' & x"00000000" & mul_a(31 downto 0); v.m.data2 := '0' & x"00000000" & mul_b(31 downto 0); end if; else if d_in.decode.is_signed = '1' then v.m.data1 := mul_a(63) & mul_a; v.m.data2 := mul_b(63) & mul_b; else v.m.data1 := '0' & mul_a; v.m.data2 := '0' & mul_b; end if; end if; -- divide unit -- PPC divide and modulus instruction words have these bits in -- the bottom 11 bits: o1dns 010t1 r -- where o = OE for div instrs, signedness for mod instrs -- d = 1 for div*, 0 for mod* -- n = 1 for normal, 0 for extended (dividend << 32/64) -- s = 1 for signed, 0 for unsigned (for div*) -- t = 1 for 32-bit, 0 for 64-bit -- r = RC bit (record condition code) v.d.write_reg := decode_output_reg(d_in.decode.output_reg_a, d_in.insn); v.d.is_modulus := not d_in.insn(8); v.d.is_32bit := d_in.insn(2); if d_in.insn(8) = '1' then signed_division := d_in.insn(6); else signed_division := d_in.insn(10); end if; v.d.is_signed := signed_division; if d_in.insn(2) = '0' then -- 64-bit forms if d_in.insn(8) = '1' and d_in.insn(7) = '0' then v.d.is_extended := '1'; end if; v.d.dividend := decoded_reg_a.data; v.d.divisor := decoded_reg_b.data; else -- 32-bit forms if d_in.insn(8) = '1' and d_in.insn(7) = '0' then -- extended forms v.d.dividend := decoded_reg_a.data(31 downto 0) & x"00000000"; elsif signed_division = '1' and decoded_reg_a.data(31) = '1' then -- sign extend to 64 bits v.d.dividend := x"ffffffff" & decoded_reg_a.data(31 downto 0); else v.d.dividend := x"00000000" & decoded_reg_a.data(31 downto 0); end if; if signed_division = '1' and decoded_reg_b.data(31) = '1' then v.d.divisor := x"ffffffff" & decoded_reg_b.data(31 downto 0); else v.d.divisor := x"00000000" & decoded_reg_b.data(31 downto 0); end if; end if; v.d.rc := decode_rc(d_in.decode.rc, d_in.insn); v.d.xerc := c_in.read_xerc_data; v.d.oe := decode_oe(d_in.decode.rc, d_in.insn); -- load/store unit v.l.update_reg := decoded_reg_a.reg; v.l.addr1 := decoded_reg_a.data; v.l.addr2 := decoded_reg_b.data; v.l.data := decoded_reg_c.data; v.l.write_reg := decode_output_reg(d_in.decode.output_reg_a, d_in.insn); if d_in.decode.insn_type = OP_LOAD then v.l.load := '1'; else v.l.load := '0'; end if; v.l.length := length; v.l.byte_reverse := d_in.decode.byte_reverse; v.l.sign_extend := d_in.decode.sign_extend; v.l.update := d_in.decode.update; v.l.xerc := c_in.read_xerc_data; -- issue control control_valid_in <= d_in.valid; control_sgl_pipe <= d_in.decode.sgl_pipe; gpr_write_valid <= '1' when d_in.decode.output_reg_a /= NONE else '0'; gpr_write <= decode_output_reg(d_in.decode.output_reg_a, d_in.insn); gpr_a_read_valid <= decoded_reg_a.reg_valid; gpr_a_read <= decoded_reg_a.reg; gpr_b_read_valid <= decoded_reg_b.reg_valid; gpr_b_read <= decoded_reg_b.reg; gpr_c_read_valid <= decoded_reg_c.reg_valid; gpr_c_read <= decoded_reg_c.reg; cr_write_valid <= d_in.decode.output_cr or decode_rc(d_in.decode.rc, d_in.insn); v.e.valid := '0'; v.m.valid := '0'; v.d.valid := '0'; v.l.valid := '0'; case d_in.decode.unit is when ALU => v.e.valid := control_valid_out; when LDST => v.l.valid := control_valid_out; when MUL => v.m.valid := control_valid_out; when DIV => v.d.valid := control_valid_out; when NONE => v.e.valid := control_valid_out; v.e.insn_type := OP_ILLEGAL; end case; if rst = '1' then v.e := Decode2ToExecute1Init; v.l := Decode2ToLoadStore1Init; v.m := Decode2ToMultiplyInit; v.d := Decode2ToDividerInit; end if; -- Update registers rin <= v; -- Update outputs e_out <= r.e; l_out <= r.l; m_out <= r.m; d_out <= r.d; end process; end architecture behaviour;