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 generic ( EX1_BYPASS : boolean := true ); port ( clk : in std_ulogic; rst : in std_ulogic; complete_in : in std_ulogic; stall_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; 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; end record; signal r, rin : reg_type; type decode_input_reg_t is record reg_valid : std_ulogic; reg : gspr_index_t; data : std_ulogic_vector(63 downto 0); end record; type decode_output_reg_t is record reg_valid : std_ulogic; reg : gspr_index_t; 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); ispr : gspr_index_t; instr_addr : std_ulogic_vector(63 downto 0)) return decode_input_reg_t is begin if t = RA or (t = RA_OR_ZERO and insn_ra(insn_in) /= "00000") then assert is_fast_spr(ispr) = '0' report "Decode A says GPR but ISPR says SPR:" & to_hstring(ispr) severity failure; return ('1', gpr_to_gspr(insn_ra(insn_in)), reg_data); elsif t = SPR then -- ISPR must be either a valid fast SPR number or all 0 for a slow SPR. -- If it's all 0, we don't treat it as a dependency as slow SPRs -- operations are single issue. -- assert is_fast_spr(ispr) = '1' or ispr = "000000" report "Decode A says SPR but ISPR is invalid:" & to_hstring(ispr) severity failure; return (is_fast_spr(ispr), ispr, reg_data); elsif t = CIA then return ('0', (others => '0'), instr_addr); 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); ispr : gspr_index_t) return decode_input_reg_t is variable ret : decode_input_reg_t; begin case t is when RB => assert is_fast_spr(ispr) = '0' report "Decode B says GPR but ISPR says SPR:" & to_hstring(ispr) severity failure; ret := ('1', gpr_to_gspr(insn_rb(insn_in)), reg_data); when CONST_UI => ret := ('0', (others => '0'), std_ulogic_vector(resize(unsigned(insn_ui(insn_in)), 64))); when CONST_SI => ret := ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_si(insn_in)), 64))); when CONST_SI_HI => ret := ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_si(insn_in)) & x"0000", 64))); when CONST_UI_HI => ret := ('0', (others => '0'), std_ulogic_vector(resize(unsigned(insn_si(insn_in)) & x"0000", 64))); when CONST_LI => ret := ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_li(insn_in)) & "00", 64))); when CONST_BD => ret := ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_bd(insn_in)) & "00", 64))); when CONST_DS => ret := ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_ds(insn_in)) & "00", 64))); when CONST_DXHI4 => ret := ('0', (others => '0'), std_ulogic_vector(resize(signed(insn_dx(insn_in)) & x"0004", 64))); when CONST_M1 => ret := ('0', (others => '0'), x"FFFFFFFFFFFFFFFF"); when CONST_SH => ret := ('0', (others => '0'), x"00000000000000" & "00" & insn_in(1) & insn_in(15 downto 11)); when CONST_SH32 => ret := ('0', (others => '0'), x"00000000000000" & "000" & insn_in(15 downto 11)); when SPR => -- ISPR must be either a valid fast SPR number or all 0 for a slow SPR. -- If it's all 0, we don't treat it as a dependency as slow SPRs -- operations are single issue. assert is_fast_spr(ispr) = '1' or ispr = "000000" report "Decode B says SPR but ISPR is invalid:" & to_hstring(ispr) severity failure; ret := (is_fast_spr(ispr), ispr, reg_data); when NONE => ret := ('0', (others => '0'), (others => '0')); end case; return ret; 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', gpr_to_gspr(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); ispr : gspr_index_t) return decode_output_reg_t is begin case t is when RT => return ('1', gpr_to_gspr(insn_rt(insn_in))); when RA => return ('1', gpr_to_gspr(insn_ra(insn_in))); when SPR => -- ISPR must be either a valid fast SPR number or all 0 for a slow SPR. -- If it's all 0, we don't treat it as a dependency as slow SPRs -- operations are single issue. assert is_fast_spr(ispr) = '1' or ispr = "000000" report "Decode B says SPR but ISPR is invalid:" & to_hstring(ispr) severity failure; return (is_fast_spr(ispr), ispr); when NONE => return ('0', "000000"); 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 : gspr_index_t; signal gpr_bypassable : std_ulogic; signal gpr_a_read_valid : std_ulogic; signal gpr_a_read :gspr_index_t; signal gpr_a_bypass : std_ulogic; signal gpr_b_read_valid : std_ulogic; signal gpr_b_read : gspr_index_t; signal gpr_b_bypass : std_ulogic; signal gpr_c_read_valid : std_ulogic; signal gpr_c_read : gpr_index_t; signal gpr_c_bypass : std_ulogic; 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, stall_in => stall_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_bypassable => gpr_bypassable, 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, gpr_bypass_a => gpr_a_bypass, gpr_bypass_b => gpr_b_bypass, gpr_bypass_c => gpr_c_bypass ); decode2_0: process(clk) begin if rising_edge(clk) then if rin.e.valid = '1' then report "execute " & to_hstring(rin.e.nia); end if; r <= rin; end if; end process; r_out.read1_reg <= gpr_or_spr_to_gspr(insn_ra(d_in.insn), d_in.ispr1); r_out.read2_reg <= gpr_or_spr_to_gspr(insn_rb(d_in.insn), d_in.ispr2); 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 decoded_reg_o : decode_output_reg_t; variable length : std_ulogic_vector(3 downto 0); begin v := r; v.e := Decode2ToExecute1Init; mul_a := (others => '0'); mul_b := (others => '0'); --v.e.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, d_in.ispr1, d_in.nia); decoded_reg_b := decode_input_reg_b (d_in.decode.input_reg_b, d_in.insn, r_in.read2_data, d_in.ispr2); decoded_reg_c := decode_input_reg_c (d_in.decode.input_reg_c, d_in.insn, r_in.read3_data); decoded_reg_o := decode_output_reg (d_in.decode.output_reg_a, d_in.insn, d_in.ispr1); r_out.read1_enable <= decoded_reg_a.reg_valid and d_in.valid; r_out.read2_enable <= decoded_reg_b.reg_valid and d_in.valid; r_out.read3_enable <= decoded_reg_c.reg_valid and d_in.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.unit := d_in.decode.unit; 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.bypass_data1 := gpr_a_bypass; v.e.read_reg2 := decoded_reg_b.reg; v.e.read_data2 := decoded_reg_b.data; v.e.bypass_data2 := gpr_b_bypass; v.e.read_data3 := decoded_reg_c.data; v.e.bypass_data3 := gpr_c_bypass; v.e.write_reg := decoded_reg_o.reg; v.e.rc := decode_rc(d_in.decode.rc, d_in.insn); if not (d_in.decode.insn_type = OP_MUL_H32 or d_in.decode.insn_type = OP_MUL_H64) then v.e.oe := decode_oe(d_in.decode.rc, d_in.insn); end if; 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; v.e.byte_reverse := d_in.decode.byte_reverse; v.e.sign_extend := d_in.decode.sign_extend; v.e.update := d_in.decode.update; v.e.reserve := d_in.decode.reserve; -- issue control control_valid_in <= d_in.valid; control_sgl_pipe <= d_in.decode.sgl_pipe; gpr_write_valid <= decoded_reg_o.reg_valid; gpr_write <= decoded_reg_o.reg; gpr_bypassable <= '0'; if EX1_BYPASS and d_in.decode.unit = ALU then gpr_bypassable <= '1'; end if; 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 <= gspr_to_gpr(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 := control_valid_out; if d_in.decode.unit = NONE then v.e.insn_type := OP_ILLEGAL; end if; if rst = '1' then v.e := Decode2ToExecute1Init; end if; -- Update registers rin <= v; -- Update outputs e_out <= r.e; end process; end architecture behaviour;