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.crhelpers.all; use work.insn_helpers.all; use work.ppc_fx_insns.all; entity execute1 is generic ( SIM : boolean := false; EX1_BYPASS : boolean := true; HAS_FPU : boolean := true; HAS_SHORT_MULT : boolean := false; -- Non-zero to enable log data collection LOG_LENGTH : natural := 0 ); port ( clk : in std_ulogic; rst : in std_ulogic; -- asynchronous flush_in : in std_ulogic; busy_out : out std_ulogic; e_in : in Decode2ToExecute1Type; l_in : in Loadstore1ToExecute1Type; fp_in : in FPUToExecute1Type; ext_irq_in : std_ulogic; interrupt_in : WritebackToExecute1Type; -- asynchronous l_out : out Execute1ToLoadstore1Type; fp_out : out Execute1ToFPUType; e_out : out Execute1ToWritebackType; bypass_data : out bypass_data_t; bypass_cr_data : out cr_bypass_data_t; bypass2_data : out bypass_data_t; bypass2_cr_data : out cr_bypass_data_t; dbg_ctrl_out : out ctrl_t; icache_inval : out std_ulogic; terminate_out : out std_ulogic; -- PMU event buses wb_events : in WritebackEventType; ls_events : in Loadstore1EventType; dc_events : in DcacheEventType; ic_events : in IcacheEventType; -- Access to SPRs from core_debug module dbg_spr_req : in std_ulogic; dbg_spr_ack : out std_ulogic; dbg_spr_addr : in std_ulogic_vector(7 downto 0); dbg_spr_data : out std_ulogic_vector(63 downto 0); -- debug sim_dump : in std_ulogic; sim_dump_done : out std_ulogic; log_out : out std_ulogic_vector(14 downto 0); log_rd_addr : out std_ulogic_vector(31 downto 0); log_rd_data : in std_ulogic_vector(63 downto 0); log_wr_addr : in std_ulogic_vector(31 downto 0) ); end entity execute1; architecture behaviour of execute1 is type side_effect_type is record terminate : std_ulogic; icache_inval : std_ulogic; write_msr : std_ulogic; write_xerlow : std_ulogic; write_dec : std_ulogic; write_cfar : std_ulogic; write_loga : std_ulogic; inc_loga : std_ulogic; write_pmuspr : std_ulogic; ramspr_write_even : std_ulogic; ramspr_write_odd : std_ulogic; end record; constant side_effect_init : side_effect_type := (others => '0'); type actions_type is record e : Execute1ToWritebackType; se : side_effect_type; complete : std_ulogic; exception : std_ulogic; trap : std_ulogic; advance_nia : std_ulogic; new_msr : std_ulogic_vector(63 downto 0); take_branch : std_ulogic; direct_branch : std_ulogic; start_mul : std_ulogic; start_div : std_ulogic; do_trace : std_ulogic; fp_intr : std_ulogic; res2_sel : std_ulogic_vector(1 downto 0); bypass_valid : std_ulogic; ramspr_odd_data : std_ulogic_vector(63 downto 0); end record; constant actions_type_init : actions_type := (e => Execute1ToWritebackInit, se => side_effect_init, new_msr => (others => '0'), res2_sel => "00", ramspr_odd_data => 64x"0", others => '0'); type reg_stage1_type is record e : Execute1ToWritebackType; se : side_effect_type; busy: std_ulogic; fp_exception_next : std_ulogic; trace_next : std_ulogic; prev_op : insn_type_t; oe : std_ulogic; mul_select : std_ulogic_vector(1 downto 0); res2_sel : std_ulogic_vector(1 downto 0); spr_select : spr_id; pmu_spr_num : std_ulogic_vector(4 downto 0); mul_in_progress : std_ulogic; mul_finish : std_ulogic; div_in_progress : std_ulogic; no_instr_avail : std_ulogic; instr_dispatch : std_ulogic; ext_interrupt : std_ulogic; taken_branch_event : std_ulogic; br_mispredict : std_ulogic; msr : std_ulogic_vector(63 downto 0); xerc : xer_common_t; xerc_valid : std_ulogic; ramspr_wraddr : ramspr_index; ramspr_odd_data : std_ulogic_vector(63 downto 0); end record; constant reg_stage1_type_init : reg_stage1_type := (e => Execute1ToWritebackInit, se => side_effect_init, busy => '0', fp_exception_next => '0', trace_next => '0', prev_op => OP_ILLEGAL, oe => '0', mul_select => "00", res2_sel => "00", spr_select => spr_id_init, pmu_spr_num => 5x"0", mul_in_progress => '0', mul_finish => '0', div_in_progress => '0', no_instr_avail => '0', instr_dispatch => '0', ext_interrupt => '0', taken_branch_event => '0', br_mispredict => '0', msr => 64x"0", xerc => xerc_init, xerc_valid => '0', ramspr_wraddr => (others => '0'), ramspr_odd_data => 64x"0"); type reg_stage2_type is record e : Execute1ToWritebackType; se : side_effect_type; ext_interrupt : std_ulogic; taken_branch_event : std_ulogic; br_mispredict : std_ulogic; log_addr_spr : std_ulogic_vector(31 downto 0); end record; constant reg_stage2_type_init : reg_stage2_type := (e => Execute1ToWritebackInit, se => side_effect_init, log_addr_spr => 32x"0", others => '0'); signal ex1, ex1in : reg_stage1_type; signal ex2, ex2in : reg_stage2_type; signal actions : actions_type; signal a_in, b_in, c_in : std_ulogic_vector(63 downto 0); signal cr_in : std_ulogic_vector(31 downto 0); signal xerc_in : xer_common_t; signal mshort_p : std_ulogic_vector(31 downto 0) := (others => '0'); signal valid_in : std_ulogic; signal ctrl: ctrl_t := ctrl_t_init; signal ctrl_tmp: ctrl_t := ctrl_t_init; signal right_shift, rot_clear_left, rot_clear_right: std_ulogic; signal rot_sign_ext: std_ulogic; signal rotator_result: std_ulogic_vector(63 downto 0); signal rotator_carry: std_ulogic; signal logical_result: std_ulogic_vector(63 downto 0); signal do_popcnt: std_ulogic; signal countbits_result: std_ulogic_vector(63 downto 0); signal alu_result: std_ulogic_vector(63 downto 0); signal adder_result: std_ulogic_vector(63 downto 0); signal misc_result: std_ulogic_vector(63 downto 0); signal muldiv_result: std_ulogic_vector(63 downto 0); signal shortmul_result: std_ulogic_vector(63 downto 0); signal spr_result: std_ulogic_vector(63 downto 0); signal next_nia : std_ulogic_vector(63 downto 0); signal s1_sel : std_ulogic_vector(2 downto 0); signal carry_32 : std_ulogic; signal carry_64 : std_ulogic; signal overflow_32 : std_ulogic; signal overflow_64 : std_ulogic; signal trapval : std_ulogic_vector(4 downto 0); signal write_cr_mask : std_ulogic_vector(7 downto 0); signal write_cr_data : std_ulogic_vector(31 downto 0); -- multiply signals signal x_to_multiply: MultiplyInputType; signal multiply_to_x: MultiplyOutputType; -- divider signals signal x_to_divider: Execute1ToDividerType; signal divider_to_x: DividerToExecute1Type := DividerToExecute1Init; -- random number generator signals signal random_raw : std_ulogic_vector(63 downto 0); signal random_cond : std_ulogic_vector(63 downto 0); signal random_err : std_ulogic; -- PMU signals signal x_to_pmu : Execute1ToPMUType; signal pmu_to_x : PMUToExecute1Type; -- signals for logging signal exception_log : std_ulogic; signal irq_valid_log : std_ulogic; -- SPR-related signals type ramspr_half_t is array(ramspr_index_range) of std_ulogic_vector(63 downto 0); signal even_sprs : ramspr_half_t := (others => (others => '0')); signal odd_sprs : ramspr_half_t := (others => (others => '0')); signal ramspr_even : std_ulogic_vector(63 downto 0); signal ramspr_odd : std_ulogic_vector(63 downto 0); signal ramspr_result : std_ulogic_vector(63 downto 0); signal ramspr_rd_odd : std_ulogic; signal ramspr_wr_addr : ramspr_index; signal ramspr_even_wr_data : std_ulogic_vector(63 downto 0); signal ramspr_even_wr_enab : std_ulogic; signal ramspr_odd_wr_data : std_ulogic_vector(63 downto 0); signal ramspr_odd_wr_enab : std_ulogic; signal stage2_stall : std_ulogic; type privilege_level is (USER, SUPER); type op_privilege_array is array(insn_type_t) of privilege_level; constant op_privilege: op_privilege_array := ( OP_ATTN => SUPER, OP_MFMSR => SUPER, OP_MTMSRD => SUPER, OP_RFID => SUPER, OP_TLBIE => SUPER, others => USER ); function instr_is_privileged(op: insn_type_t; insn: std_ulogic_vector(31 downto 0)) return boolean is begin if op_privilege(op) = SUPER then return true; elsif op = OP_MFSPR or op = OP_MTSPR then return insn(20) = '1'; else return false; end if; end; procedure set_carry(e: inout Execute1ToWritebackType; carry32 : in std_ulogic; carry : in std_ulogic) is begin e.xerc.ca32 := carry32; e.xerc.ca := carry; end; procedure set_ov(e: inout Execute1ToWritebackType; ov : in std_ulogic; ov32 : in std_ulogic) is begin e.xerc.ov32 := ov32; e.xerc.ov := ov; if ov = '1' then e.xerc.so := '1'; end if; end; function calc_ov(msb_a : std_ulogic; msb_b: std_ulogic; ca: std_ulogic; msb_r: std_ulogic) return std_ulogic is begin return (ca xor msb_r) and not (msb_a xor msb_b); end; function decode_input_carry(ic : carry_in_t; xerc : xer_common_t) return std_ulogic is begin case ic is when ZERO => return '0'; when CA => return xerc.ca; when OV => return xerc.ov; when ONE => return '1'; end case; end; function msr_copy(msr: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is variable msr_out: std_ulogic_vector(63 downto 0); begin -- ISA says this: -- Defined MSR bits are classified as either full func- -- tion or partial function. Full function MSR bits are -- saved in SRR1 or HSRR1 when an interrupt other -- than a System Call Vectored interrupt occurs and -- restored by rfscv, rfid, or hrfid, while partial func- -- tion MSR bits are not saved or restored. -- Full function MSR bits lie in the range 0:32, 37:41, and -- 48:63, and partial function MSR bits lie in the range -- 33:36 and 42:47. (Note this is IBM bit numbering). msr_out := (others => '0'); msr_out(63 downto 31) := msr(63 downto 31); msr_out(26 downto 22) := msr(26 downto 22); msr_out(15 downto 0) := msr(15 downto 0); return msr_out; end; function intr_srr1(msr: std_ulogic_vector; flags: std_ulogic_vector) return std_ulogic_vector is variable srr1: std_ulogic_vector(63 downto 0); begin srr1(63 downto 31) := msr(63 downto 31); srr1(30 downto 27) := flags(14 downto 11); srr1(26 downto 22) := msr(26 downto 22); srr1(21 downto 16) := flags(5 downto 0); srr1(15 downto 0) := msr(15 downto 0); return srr1; end; -- Work out whether a signed value fits into n bits, -- that is, see if it is in the range -2^(n-1) .. 2^(n-1) - 1 function fits_in_n_bits(val: std_ulogic_vector; n: integer) return boolean is variable x, xp1: std_ulogic_vector(val'left downto val'right); begin x := val; if val(val'left) = '0' then x := not val; end if; xp1 := bit_reverse(std_ulogic_vector(unsigned(bit_reverse(x)) + 1)); x := x and not xp1; -- For positive inputs, x has ones at the positions -- to the left of the leftmost 1 bit in val. -- For negative inputs, x has ones to the left of -- the leftmost 0 bit in val. return x(n - 1) = '1'; end; function assemble_xer(xerc: xer_common_t; xer_low: std_ulogic_vector) return std_ulogic_vector is begin return 32x"0" & xerc.so & xerc.ov & xerc.ca & "000000000" & xerc.ov32 & xerc.ca32 & xer_low(17 downto 0); end; -- Tell vivado to keep the hierarchy for the random module so that the -- net names in the xdc file match. attribute keep_hierarchy : string; attribute keep_hierarchy of random_0 : label is "yes"; begin rotator_0: entity work.rotator port map ( rs => c_in, ra => a_in, shift => b_in(6 downto 0), insn => e_in.insn, is_32bit => e_in.is_32bit, right_shift => right_shift, arith => e_in.is_signed, clear_left => rot_clear_left, clear_right => rot_clear_right, sign_ext_rs => rot_sign_ext, result => rotator_result, carry_out => rotator_carry ); logical_0: entity work.logical port map ( rs => c_in, rb => b_in, op => e_in.insn_type, invert_in => e_in.invert_a, invert_out => e_in.invert_out, result => logical_result, datalen => e_in.data_len ); countbits_0: entity work.bit_counter port map ( clk => clk, rs => c_in, stall => stage2_stall, count_right => e_in.insn(10), is_32bit => e_in.is_32bit, do_popcnt => do_popcnt, datalen => e_in.data_len, result => countbits_result ); multiply_0: entity work.multiply port map ( clk => clk, m_in => x_to_multiply, m_out => multiply_to_x ); divider_0: if not HAS_FPU generate div_0: entity work.divider port map ( clk => clk, rst => rst, d_in => x_to_divider, d_out => divider_to_x ); end generate; random_0: entity work.random port map ( clk => clk, data => random_cond, raw => random_raw, err => random_err ); pmu_0: entity work.pmu port map ( clk => clk, rst => rst, p_in => x_to_pmu, p_out => pmu_to_x ); short_mult_0: if HAS_SHORT_MULT generate begin short_mult: entity work.short_multiply port map ( clk => clk, a_in => a_in(15 downto 0), b_in => b_in(15 downto 0), m_out => mshort_p ); end generate; dbg_ctrl_out <= ctrl; log_rd_addr <= ex2.log_addr_spr; a_in <= e_in.read_data1; b_in <= e_in.read_data2; c_in <= e_in.read_data3; cr_in <= e_in.cr; x_to_pmu.occur <= (instr_complete => wb_events.instr_complete, fp_complete => wb_events.fp_complete, ld_complete => ls_events.load_complete, st_complete => ls_events.store_complete, itlb_miss => ls_events.itlb_miss, dc_load_miss => dc_events.load_miss, dc_ld_miss_resolved => dc_events.dcache_refill, dc_store_miss => dc_events.store_miss, dtlb_miss => dc_events.dtlb_miss, dtlb_miss_resolved => dc_events.dtlb_miss_resolved, icache_miss => ic_events.icache_miss, itlb_miss_resolved => ic_events.itlb_miss_resolved, no_instr_avail => ex1.no_instr_avail, dispatch => ex1.instr_dispatch, ext_interrupt => ex2.ext_interrupt, br_taken_complete => ex2.taken_branch_event, br_mispredict => ex2.br_mispredict, others => '0'); x_to_pmu.nia <= e_in.nia; x_to_pmu.addr <= (others => '0'); x_to_pmu.addr_v <= '0'; x_to_pmu.spr_num <= ex1.pmu_spr_num; x_to_pmu.spr_val <= ex1.e.write_data; x_to_pmu.run <= '1'; -- XER forwarding. The CA and CA32 bits are only modified by instructions -- that are handled here, so for them we can just use the result most -- recently sent to writeback, unless a pipeline flush has happened in the -- meantime. -- Hazards for SO/OV/OV32 are handled by control.vhdl as there may be other -- units writing to them. No forwarding is done because performance of -- instructions that alter them is not considered significant. xerc_in.so <= e_in.xerc.so; xerc_in.ov <= e_in.xerc.ov; xerc_in.ov32 <= e_in.xerc.ov32; xerc_in.ca <= ex1.xerc.ca when ex1.xerc_valid = '1' else e_in.xerc.ca; xerc_in.ca32 <= ex1.xerc.ca32 when ex1.xerc_valid = '1' else e_in.xerc.ca32; -- N.B. the busy signal from each source includes the -- stage2 stall from that source in it. busy_out <= l_in.busy or ex1.busy or fp_in.busy; valid_in <= e_in.valid and not (busy_out or flush_in or ex1.e.redirect or ex1.e.interrupt); -- SPRs stored in two small RAM arrays (two so that we can read and write -- two SPRs in each cycle). ramspr_read: process(all) variable even_rd_data, odd_rd_data : std_ulogic_vector(63 downto 0); variable wr_addr : ramspr_index; variable even_wr_enab, odd_wr_enab : std_ulogic; variable even_wr_data, odd_wr_data : std_ulogic_vector(63 downto 0); variable doit : std_ulogic; begin -- Read address mux and async RAM reading if is_X(e_in.ramspr_even_rdaddr) then even_rd_data := (others => 'X'); else even_rd_data := even_sprs(to_integer(e_in.ramspr_even_rdaddr)); end if; if is_X(e_in.ramspr_even_rdaddr) then odd_rd_data := (others => 'X'); else odd_rd_data := odd_sprs(to_integer(e_in.ramspr_odd_rdaddr)); end if; -- Write address and data muxes doit := ex1.e.valid and not stage2_stall and not flush_in; even_wr_enab := (ex1.se.ramspr_write_even and doit) or interrupt_in.intr; odd_wr_enab := (ex1.se.ramspr_write_odd and doit) or interrupt_in.intr; if interrupt_in.intr = '1' then wr_addr := RAMSPR_SRR0; else wr_addr := ex1.ramspr_wraddr; end if; if interrupt_in.intr = '1' then even_wr_data := ex2.e.last_nia; odd_wr_data := intr_srr1(ctrl.msr, interrupt_in.srr1); else even_wr_data := ex1.e.write_data; odd_wr_data := ex1.ramspr_odd_data; end if; ramspr_wr_addr <= wr_addr; ramspr_even_wr_data <= even_wr_data; ramspr_even_wr_enab <= even_wr_enab; ramspr_odd_wr_data <= odd_wr_data; ramspr_odd_wr_enab <= odd_wr_enab; -- SPR RAM read with write data bypass -- We assume no instruction executes in the cycle immediately following -- an interrupt, so we don't need to bypass interrupt data if ex1.se.ramspr_write_even = '1' and e_in.ramspr_even_rdaddr = ex1.ramspr_wraddr then ramspr_even <= ex1.e.write_data; else ramspr_even <= even_rd_data; end if; if ex1.se.ramspr_write_odd = '1' and e_in.ramspr_odd_rdaddr = ex1.ramspr_wraddr then ramspr_odd <= ex1.ramspr_odd_data; else ramspr_odd <= odd_rd_data; end if; if e_in.ramspr_rd_odd = '0' then ramspr_result <= ramspr_even; else ramspr_result <= ramspr_odd; end if; end process; ramspr_write: process(clk) begin if rising_edge(clk) then if ramspr_even_wr_enab = '1' then assert not is_X(ramspr_wr_addr) report "Writing to unknown address" severity FAILURE; even_sprs(to_integer(ramspr_wr_addr)) <= ramspr_even_wr_data; report "writing even spr " & integer'image(to_integer(ramspr_wr_addr)) & " data=" & to_hstring(ramspr_even_wr_data); end if; if ramspr_odd_wr_enab = '1' then assert not is_X(ramspr_wr_addr) report "Writing to unknown address" severity FAILURE; odd_sprs(to_integer(ramspr_wr_addr)) <= ramspr_odd_wr_data; report "writing odd spr " & integer'image(to_integer(ramspr_wr_addr)) & " data=" & to_hstring(ramspr_odd_wr_data); end if; end if; end process; -- First stage result mux s1_sel <= e_in.result_sel when ex1.busy = '0' else "100"; with s1_sel select alu_result <= adder_result when "000", logical_result when "001", rotator_result when "010", shortmul_result when "011", muldiv_result when "100", ramspr_result when "101", next_nia when "110", misc_result when others; execute1_0: process(clk) begin if rising_edge(clk) then if rst = '1' then ex1 <= reg_stage1_type_init; ex2 <= reg_stage2_type_init; ctrl <= ctrl_t_init; ctrl.msr <= (MSR_SF => '1', MSR_LE => '1', others => '0'); ex1.msr <= (MSR_SF => '1', MSR_LE => '1', others => '0'); else ex1 <= ex1in; ex2 <= ex2in; ctrl <= ctrl_tmp; if valid_in = '1' then report "execute " & to_hstring(e_in.nia) & " op=" & insn_type_t'image(e_in.insn_type) & " wr=" & to_hstring(ex1in.e.write_reg) & " we=" & std_ulogic'image(ex1in.e.write_enable) & " tag=" & integer'image(ex1in.e.instr_tag.tag) & std_ulogic'image(ex1in.e.instr_tag.valid); end if; -- We mustn't get stalled on a cycle where execute2 is -- completing an instruction or generating an interrupt if ex2.e.valid = '1' or ex2.e.interrupt = '1' then assert stage2_stall = '0' severity failure; end if; end if; end if; end process; ex_dbg_spr: process(clk) begin if rising_edge(clk) then if rst = '0' and dbg_spr_req = '1' then if e_in.dbg_spr_access = '1' and dbg_spr_ack = '0' then if dbg_spr_addr(7) = '1' then dbg_spr_data <= ramspr_result; else dbg_spr_data <= assemble_xer(xerc_in, ctrl.xer_low); end if; dbg_spr_ack <= '1'; end if; else dbg_spr_ack <= '0'; end if; end if; end process; -- Data path for integer instructions (first execute stage) execute1_dp: process(all) variable a_inv : std_ulogic_vector(63 downto 0); variable sum_with_carry : std_ulogic_vector(64 downto 0); variable sign1, sign2 : std_ulogic; variable abs1, abs2 : signed(63 downto 0); variable addend : std_ulogic_vector(127 downto 0); variable addg6s : std_ulogic_vector(63 downto 0); variable crbit : integer range 0 to 31; variable isel_result : std_ulogic_vector(63 downto 0); variable darn : std_ulogic_vector(63 downto 0); variable setb_result : std_ulogic_vector(63 downto 0); variable mfcr_result : std_ulogic_vector(63 downto 0); variable lo, hi : integer; variable l : std_ulogic; variable zerohi, zerolo : std_ulogic; variable msb_a, msb_b : std_ulogic; variable a_lt : std_ulogic; variable a_lt_lo : std_ulogic; variable a_lt_hi : std_ulogic; variable newcrf : std_ulogic_vector(3 downto 0); variable bf, bfa : std_ulogic_vector(2 downto 0); variable crnum : crnum_t; variable scrnum : crnum_t; variable cr_operands : std_ulogic_vector(1 downto 0); variable crresult : std_ulogic; variable bt, ba, bb : std_ulogic_vector(4 downto 0); variable btnum : integer range 0 to 3; variable banum, bbnum : integer range 0 to 31; variable j : integer; begin -- Main adder if e_in.invert_a = '0' then a_inv := a_in; else a_inv := not a_in; end if; sum_with_carry := ppc_adde(a_inv, b_in, decode_input_carry(e_in.input_carry, xerc_in)); adder_result <= sum_with_carry(63 downto 0); carry_32 <= sum_with_carry(32) xor a_inv(32) xor b_in(32); carry_64 <= sum_with_carry(64); overflow_32 <= calc_ov(a_inv(31), b_in(31), carry_32, sum_with_carry(31)); overflow_64 <= calc_ov(a_inv(63), b_in(63), carry_64, sum_with_carry(63)); -- signals to multiply and divide units sign1 := '0'; sign2 := '0'; if e_in.is_signed = '1' then if e_in.is_32bit = '1' then sign1 := a_in(31); sign2 := b_in(31); else sign1 := a_in(63); sign2 := b_in(63); end if; end if; -- take absolute values if sign1 = '0' then abs1 := signed(a_in); else abs1 := - signed(a_in); end if; if sign2 = '0' then abs2 := signed(b_in); else abs2 := - signed(b_in); end if; -- Interface to multiply and divide units x_to_divider.is_signed <= e_in.is_signed; x_to_divider.is_32bit <= e_in.is_32bit; x_to_divider.is_extended <= '0'; x_to_divider.is_modulus <= '0'; if e_in.insn_type = OP_MOD then x_to_divider.is_modulus <= '1'; end if; x_to_divider.flush <= flush_in; addend := (others => '0'); if e_in.insn(26) = '0' then -- integer multiply-add, major op 4 (if it is a multiply) addend(63 downto 0) := c_in; if e_in.is_signed = '1' then addend(127 downto 64) := (others => c_in(63)); end if; end if; if (sign1 xor sign2) = '1' then addend := not addend; end if; x_to_multiply.is_32bit <= e_in.is_32bit; x_to_multiply.not_result <= sign1 xor sign2; x_to_multiply.addend <= addend; x_to_divider.neg_result <= sign1 xor (sign2 and not x_to_divider.is_modulus); if e_in.is_32bit = '0' then -- 64-bit forms x_to_multiply.data1 <= std_ulogic_vector(abs1); x_to_multiply.data2 <= std_ulogic_vector(abs2); if e_in.insn_type = OP_DIVE then x_to_divider.is_extended <= '1'; end if; x_to_divider.dividend <= std_ulogic_vector(abs1); x_to_divider.divisor <= std_ulogic_vector(abs2); else -- 32-bit forms x_to_multiply.data1 <= x"00000000" & std_ulogic_vector(abs1(31 downto 0)); x_to_multiply.data2 <= x"00000000" & std_ulogic_vector(abs2(31 downto 0)); x_to_divider.is_extended <= '0'; if e_in.insn_type = OP_DIVE then -- extended forms x_to_divider.dividend <= std_ulogic_vector(abs1(31 downto 0)) & x"00000000"; else x_to_divider.dividend <= x"00000000" & std_ulogic_vector(abs1(31 downto 0)); end if; x_to_divider.divisor <= x"00000000" & std_ulogic_vector(abs2(31 downto 0)); end if; shortmul_result <= std_ulogic_vector(resize(signed(mshort_p), 64)); case ex1.mul_select is when "00" => muldiv_result <= multiply_to_x.result(63 downto 0); when "01" => muldiv_result <= multiply_to_x.result(127 downto 64); when "10" => muldiv_result <= multiply_to_x.result(63 downto 32) & multiply_to_x.result(63 downto 32); when others => muldiv_result <= divider_to_x.write_reg_data; end case; -- Compute misc_result case e_in.sub_select is when "000" => misc_result <= (others => '0'); when "001" => -- addg6s addg6s := (others => '0'); for i in 0 to 14 loop lo := i * 4; hi := (i + 1) * 4; if (a_in(hi) xor b_in(hi) xor sum_with_carry(hi)) = '0' then addg6s(lo + 3 downto lo) := "0110"; end if; end loop; if sum_with_carry(64) = '0' then addg6s(63 downto 60) := "0110"; end if; misc_result <= addg6s; when "010" => -- isel crbit := to_integer(unsigned(insn_bc(e_in.insn))); if cr_in(31-crbit) = '1' then isel_result := a_in; else isel_result := b_in; end if; misc_result <= isel_result; when "011" => -- darn darn := (others => '1'); if random_err = '0' then case e_in.insn(17 downto 16) is when "00" => darn := x"00000000" & random_cond(31 downto 0); when "10" => darn := random_raw; when others => darn := random_cond; end case; end if; misc_result <= darn; when "100" => -- mfmsr misc_result <= ex1.msr; when "101" => if e_in.insn(20) = '0' then -- mfcr mfcr_result := x"00000000" & cr_in; else -- mfocrf crnum := fxm_to_num(insn_fxm(e_in.insn)); mfcr_result := (others => '0'); for i in 0 to 7 loop lo := (7-i)*4; hi := lo + 3; if crnum = i then mfcr_result(hi downto lo) := cr_in(hi downto lo); end if; end loop; end if; misc_result <= mfcr_result; when "110" => -- setb bfa := insn_bfa(e_in.insn); crbit := to_integer(unsigned(bfa)) * 4; setb_result := (others => '0'); if cr_in(31 - crbit) = '1' then setb_result := (others => '1'); elsif cr_in(30 - crbit) = '1' then setb_result(0) := '1'; end if; misc_result <= setb_result; when others => misc_result <= (others => '0'); end case; -- compute comparison results -- Note, we have done RB - RA, not RA - RB if e_in.insn_type = OP_CMP then l := insn_l(e_in.insn); else l := not e_in.is_32bit; end if; zerolo := not (or (a_in(31 downto 0) xor b_in(31 downto 0))); zerohi := not (or (a_in(63 downto 32) xor b_in(63 downto 32))); if zerolo = '1' and (l = '0' or zerohi = '1') then -- values are equal trapval <= "00100"; else a_lt_lo := '0'; a_lt_hi := '0'; if unsigned(a_in(30 downto 0)) < unsigned(b_in(30 downto 0)) then a_lt_lo := '1'; end if; if unsigned(a_in(62 downto 31)) < unsigned(b_in(62 downto 31)) then a_lt_hi := '1'; end if; if l = '1' then -- 64-bit comparison msb_a := a_in(63); msb_b := b_in(63); a_lt := a_lt_hi or (zerohi and (a_in(31) xnor b_in(31)) and a_lt_lo); else -- 32-bit comparison msb_a := a_in(31); msb_b := b_in(31); a_lt := a_lt_lo; end if; if msb_a /= msb_b then -- Comparison is clear from MSB difference. -- for signed, 0 is greater; for unsigned, 1 is greater trapval <= msb_a & msb_b & '0' & msb_b & msb_a; else -- MSBs are equal, so signed and unsigned comparisons give the -- same answer. trapval <= a_lt & not a_lt & '0' & a_lt & not a_lt; end if; end if; -- CR result mux bf := insn_bf(e_in.insn); crnum := to_integer(unsigned(bf)); newcrf := (others => '0'); case e_in.sub_select is when "000" => -- CMP and CMPL instructions if e_in.is_signed = '1' then newcrf := trapval(4 downto 2) & xerc_in.so; else newcrf := trapval(1 downto 0) & trapval(2) & xerc_in.so; end if; when "001" => newcrf := ppc_cmprb(a_in, b_in, insn_l(e_in.insn)); when "010" => newcrf := ppc_cmpeqb(a_in, b_in); when "011" => if e_in.insn(1) = '1' then -- CR logical instructions j := (7 - crnum) * 4; newcrf := cr_in(j + 3 downto j); bt := insn_bt(e_in.insn); ba := insn_ba(e_in.insn); bb := insn_bb(e_in.insn); btnum := 3 - to_integer(unsigned(bt(1 downto 0))); banum := 31 - to_integer(unsigned(ba)); bbnum := 31 - to_integer(unsigned(bb)); -- Bits 6-9 of the instruction word give the truth table -- of the requested logical operation cr_operands := cr_in(banum) & cr_in(bbnum); crresult := e_in.insn(6 + to_integer(unsigned(cr_operands))); for i in 0 to 3 loop if i = btnum then newcrf(i) := crresult; end if; end loop; else -- MCRF bfa := insn_bfa(e_in.insn); scrnum := to_integer(unsigned(bfa)); j := (7 - scrnum) * 4; newcrf := cr_in(j + 3 downto j); end if; when "100" => -- MCRXRX newcrf := xerc_in.ov & xerc_in.ov32 & xerc_in.ca & xerc_in.ca32; when others => end case; if e_in.insn_type = OP_MTCRF then if e_in.insn(20) = '0' then -- mtcrf write_cr_mask <= insn_fxm(e_in.insn); else -- mtocrf: We require one hot priority encoding here crnum := fxm_to_num(insn_fxm(e_in.insn)); write_cr_mask <= num_to_fxm(crnum); end if; elsif e_in.output_cr = '1' then write_cr_mask <= num_to_fxm(crnum); else write_cr_mask <= (others => '0'); end if; for i in 0 to 7 loop if write_cr_mask(i) = '0' then write_cr_data(i*4 + 3 downto i*4) <= cr_in(i*4 + 3 downto i*4); elsif e_in.insn_type = OP_MTCRF then write_cr_data(i*4 + 3 downto i*4) <= c_in(i*4 + 3 downto i*4); else write_cr_data(i*4 + 3 downto i*4) <= newcrf; end if; end loop; end process; execute1_actions: process(all) variable v: actions_type; variable bo, bi : std_ulogic_vector(4 downto 0); variable illegal : std_ulogic; variable privileged : std_ulogic; variable slow_op : std_ulogic; variable owait : std_ulogic; variable srr1 : std_ulogic_vector(63 downto 0); begin v := actions_type_init; v.e.write_data := alu_result; v.e.write_reg := e_in.write_reg; v.e.write_enable := e_in.write_reg_enable; v.e.rc := e_in.rc; v.e.write_cr_data := write_cr_data; v.e.write_cr_mask := write_cr_mask; v.e.write_cr_enable := e_in.output_cr; v.e.write_xerc_enable := e_in.output_xer; v.e.xerc := xerc_in; v.new_msr := ex1.msr; v.e.redir_mode := ex1.msr(MSR_IR) & not ex1.msr(MSR_PR) & not ex1.msr(MSR_LE) & not ex1.msr(MSR_SF); v.e.intr_vec := 16#700#; v.e.mode_32bit := not ex1.msr(MSR_SF); v.e.instr_tag := e_in.instr_tag; v.e.last_nia := e_in.nia; v.e.br_offset := 64x"4"; v.se.ramspr_write_even := e_in.ramspr_write_even; v.se.ramspr_write_odd := e_in.ramspr_write_odd; v.ramspr_odd_data := c_in; if e_in.dec_ctr = '1' then v.ramspr_odd_data := std_ulogic_vector(unsigned(ramspr_odd) - 1); end if; -- Note the difference between v.exception and v.trap: -- v.exception signals a condition that prevents execution of the -- instruction, and hence shouldn't depend on operand data, so as to -- avoid timing chains through both data and control paths. -- v.trap also means we want to generate an interrupt, but doesn't -- cancel instruction execution (hence we need to avoid setting any -- side-effect flags or write enables when generating a trap). -- With v.trap = 1 we will assert both ex1.e.valid and ex1.e.interrupt -- to writeback, and it will complete the instruction and take -- and interrupt. It is OK for v.trap to depend on operand data. illegal := '0'; privileged := '0'; slow_op := '0'; owait := '0'; if ex1.msr(MSR_PR) = '1' and instr_is_privileged(e_in.insn_type, e_in.insn) then privileged := '1'; end if; if (not HAS_FPU and e_in.fac = FPU) or e_in.unit = NONE then -- make lfd/stfd/lfs/stfs etc. illegal in no-FPU implementations illegal := '1'; end if; v.do_trace := ex1.msr(MSR_SE); case_0: case e_in.insn_type is when OP_ILLEGAL => illegal := '1'; when OP_SC => -- check bit 1 of the instruction is 1 so we know this is sc; -- 0 would mean scv, so generate an illegal instruction interrupt if e_in.insn(1) = '1' then v.trap := '1'; v.advance_nia := '1'; v.e.intr_vec := 16#C00#; if e_in.valid = '1' then report "sc"; end if; else illegal := '1'; end if; when OP_ATTN => -- check bits 1-10 of the instruction to make sure it's attn -- if not then it is illegal if e_in.insn(10 downto 1) = "0100000000" then v.se.terminate := '1'; if e_in.valid = '1' then report "ATTN"; end if; else illegal := '1'; end if; when OP_NOP | OP_DCBF | OP_DCBST | OP_DCBT | OP_DCBTST | OP_ICBT => -- Do nothing when OP_ADD => if e_in.output_carry = '1' then if e_in.input_carry /= OV then set_carry(v.e, carry_32, carry_64); else v.e.xerc.ov := carry_64; v.e.xerc.ov32 := carry_32; end if; end if; if e_in.oe = '1' then set_ov(v.e, overflow_64, overflow_32); end if; when OP_CMP => when OP_TRAP => -- trap instructions (tw, twi, td, tdi) v.e.intr_vec := 16#700#; -- set bit 46 to say trap occurred v.e.srr1(47 - 46) := '1'; if or (trapval and insn_to(e_in.insn)) = '1' then -- generate trap-type program interrupt v.trap := '1'; if e_in.valid = '1' then report "trap"; end if; end if; when OP_ADDG6S => when OP_CMPRB => when OP_CMPEQB => when OP_AND | OP_OR | OP_XOR | OP_PRTY | OP_CMPB | OP_EXTS | OP_BPERM | OP_BCD => when OP_B => v.take_branch := '1'; v.direct_branch := '1'; v.e.br_last := '1'; v.e.br_taken := '1'; v.e.br_offset := b_in; v.e.abs_br := insn_aa(e_in.insn); if e_in.br_pred = '0' then -- should never happen v.e.redirect := '1'; end if; if ex1.msr(MSR_BE) = '1' then v.do_trace := '1'; end if; v.se.write_cfar := '1'; when OP_BC => -- If CTR is being decremented, it is in ramspr_odd. bo := insn_bo(e_in.insn); bi := insn_bi(e_in.insn); v.take_branch := ppc_bc_taken(bo, bi, cr_in, ramspr_odd); if v.take_branch = '1' then v.e.br_offset := b_in; v.e.abs_br := insn_aa(e_in.insn); end if; -- Mispredicted branches cause a redirect if v.take_branch /= e_in.br_pred then v.e.redirect := '1'; end if; v.direct_branch := '1'; v.e.br_last := '1'; v.e.br_taken := v.take_branch; if ex1.msr(MSR_BE) = '1' then v.do_trace := '1'; end if; v.se.write_cfar := v.take_branch; when OP_BCREG => -- If CTR is being decremented, it is in ramspr_odd. -- The target address is in ramspr_result (LR, CTR or TAR). bo := insn_bo(e_in.insn); bi := insn_bi(e_in.insn); v.take_branch := ppc_bc_taken(bo, bi, cr_in, ramspr_odd); if v.take_branch = '1' then v.e.br_offset := ramspr_result; v.e.abs_br := '1'; end if; -- Indirect branches are never predicted taken v.e.redirect := v.take_branch; v.e.br_taken := v.take_branch; if ex1.msr(MSR_BE) = '1' then v.do_trace := '1'; end if; v.se.write_cfar := v.take_branch; when OP_RFID => srr1 := ramspr_odd; v.e.redir_mode := (srr1(MSR_IR) or srr1(MSR_PR)) & not srr1(MSR_PR) & not srr1(MSR_LE) & not srr1(MSR_SF); -- Can't use msr_copy here because the partial function MSR -- bits should be left unchanged, not zeroed. v.new_msr(63 downto 31) := srr1(63 downto 31); v.new_msr(26 downto 22) := srr1(26 downto 22); v.new_msr(15 downto 0) := srr1(15 downto 0); if srr1(MSR_PR) = '1' then v.new_msr(MSR_EE) := '1'; v.new_msr(MSR_IR) := '1'; v.new_msr(MSR_DR) := '1'; end if; v.se.write_msr := '1'; v.e.br_offset := ramspr_result; v.e.abs_br := '1'; v.e.redirect := '1'; v.se.write_cfar := '1'; if HAS_FPU then v.fp_intr := fp_in.exception and (srr1(MSR_FE0) or srr1(MSR_FE1)); end if; v.do_trace := '0'; when OP_CNTZ | OP_POPCNT => v.res2_sel := "01"; slow_op := '1'; when OP_ISEL => when OP_CROP => when OP_MCRXRX => when OP_DARN => when OP_MFMSR => when OP_MFSPR => if e_in.spr_is_ram = '1' then if e_in.valid = '1' and not is_X(e_in.insn) then report "MFSPR to SPR " & integer'image(decode_spr_num(e_in.insn)) & "=" & to_hstring(alu_result); end if; elsif e_in.spr_select.valid = '1' then if e_in.valid = '1' and not is_X(e_in.insn) then report "MFSPR to slow SPR " & integer'image(decode_spr_num(e_in.insn)); end if; slow_op := '1'; if e_in.spr_select.ispmu = '0' then case e_in.spr_select.sel is when SPRSEL_LOGD => v.se.inc_loga := '1'; when others => end case; v.res2_sel := "10"; else v.res2_sel := "11"; end if; else -- mfspr from unimplemented SPRs should be a nop in -- supervisor mode and a program interrupt for user mode if e_in.valid = '1' and not is_X(e_in.insn) then report "MFSPR to SPR " & integer'image(decode_spr_num(e_in.insn)) & " invalid"; end if; if ex1.msr(MSR_PR) = '1' then illegal := '1'; end if; end if; when OP_MFCR => when OP_MTCRF => when OP_MTMSRD => v.se.write_msr := '1'; if e_in.insn(16) = '1' then -- just update EE and RI v.new_msr(MSR_EE) := c_in(MSR_EE); v.new_msr(MSR_RI) := c_in(MSR_RI); else -- Architecture says to leave out bits 3 (HV), 51 (ME) -- and 63 (LE) (IBM bit numbering) if e_in.is_32bit = '0' then v.new_msr(63 downto 61) := c_in(63 downto 61); v.new_msr(59 downto 32) := c_in(59 downto 32); end if; v.new_msr(31 downto 13) := c_in(31 downto 13); v.new_msr(11 downto 1) := c_in(11 downto 1); if c_in(MSR_PR) = '1' then v.new_msr(MSR_EE) := '1'; v.new_msr(MSR_IR) := '1'; v.new_msr(MSR_DR) := '1'; end if; if HAS_FPU then v.fp_intr := fp_in.exception and (c_in(MSR_FE0) or c_in(MSR_FE1)); end if; end if; when OP_MTSPR => if e_in.valid = '1' and not is_X(e_in.insn) then report "MTSPR to SPR " & integer'image(decode_spr_num(e_in.insn)) & "=" & to_hstring(c_in); end if; v.se.write_pmuspr := e_in.spr_select.ispmu; if e_in.spr_select.valid = '1' and e_in.spr_select.ispmu = '0' then case e_in.spr_select.sel is when SPRSEL_XER => v.e.xerc.so := c_in(63-32); v.e.xerc.ov := c_in(63-33); v.e.xerc.ca := c_in(63-34); v.e.xerc.ov32 := c_in(63-44); v.e.xerc.ca32 := c_in(63-45); v.se.write_xerlow := '1'; when SPRSEL_DEC => v.se.write_dec := '1'; when SPRSEL_LOGA => v.se.write_loga := '1'; when others => end case; end if; if e_in.spr_select.valid = '0' and e_in.spr_is_ram = '0' then -- mtspr to unimplemented SPRs should be a nop in -- supervisor mode and a program interrupt for user mode if ex1.msr(MSR_PR) = '1' then illegal := '1'; end if; end if; when OP_RLC | OP_RLCL | OP_RLCR | OP_SHL | OP_SHR | OP_EXTSWSLI => if e_in.output_carry = '1' then set_carry(v.e, rotator_carry, rotator_carry); end if; when OP_SETB => when OP_ISYNC => v.e.redirect := '1'; when OP_ICBI => v.se.icache_inval := '1'; when OP_MUL_L64 => if HAS_SHORT_MULT and e_in.insn(26) = '1' and fits_in_n_bits(a_in, 16) and fits_in_n_bits(b_in, 16) then -- Operands fit into 16 bits, so use short multiplier if e_in.oe = '1' then -- Note 16x16 multiply can't overflow, even for mullwo set_ov(v.e, '0', '0'); end if; else -- Use standard multiplier v.start_mul := '1'; slow_op := '1'; owait := '1'; end if; when OP_MUL_H64 | OP_MUL_H32 => v.start_mul := '1'; slow_op := '1'; owait := '1'; when OP_DIV | OP_DIVE | OP_MOD => if not HAS_FPU then v.start_div := '1'; slow_op := '1'; owait := '1'; end if; when OP_FETCH_FAILED => -- Handling an ITLB miss doesn't count as having executed an instruction v.do_trace := '0'; when others => if e_in.valid = '1' and e_in.unit = ALU then report "unhandled insn_type " & insn_type_t'image(e_in.insn_type); end if; end case; if privileged = '1' then -- generate a program interrupt v.exception := '1'; -- set bit 45 to indicate privileged instruction type interrupt v.e.srr1(47 - 45) := '1'; if e_in.valid = '1' then report "privileged instruction"; end if; elsif illegal = '1' then v.exception := '1'; -- Since we aren't doing Hypervisor emulation assist (0xe40) we -- set bit 44 to indicate we have an illegal v.e.srr1(47 - 44) := '1'; if e_in.valid = '1' then report "illegal instruction"; end if; elsif HAS_FPU and ex1.msr(MSR_FP) = '0' and e_in.fac = FPU then -- generate a floating-point unavailable interrupt v.exception := '1'; v.e.intr_vec := 16#800#; if e_in.valid = '1' then report "FP unavailable interrupt"; end if; end if; if e_in.unit = ALU then v.complete := e_in.valid and not v.exception and not owait; v.bypass_valid := e_in.valid and not v.exception and not slow_op; end if; actions <= v; end process; -- First execute stage execute1_1: process(all) variable v : reg_stage1_type; variable overflow : std_ulogic; variable lv : Execute1ToLoadstore1Type; variable irq_valid : std_ulogic; variable exception : std_ulogic; variable fv : Execute1ToFPUType; variable go : std_ulogic; variable bypass_valid : std_ulogic; begin v := ex1; if (ex1.busy or l_in.busy or fp_in.busy) = '0' then v.e := actions.e; v.e.valid := '0'; v.oe := e_in.oe; v.spr_select := e_in.spr_select; v.pmu_spr_num := e_in.insn(20 downto 16); v.mul_select := e_in.sub_select(1 downto 0); v.se := side_effect_init; v.ramspr_wraddr := e_in.ramspr_wraddr; v.ramspr_odd_data := actions.ramspr_odd_data; end if; lv := Execute1ToLoadstore1Init; fv := Execute1ToFPUInit; x_to_multiply.valid <= '0'; x_to_divider.valid <= '0'; v.ext_interrupt := '0'; v.taken_branch_event := '0'; v.br_mispredict := '0'; v.busy := '0'; bypass_valid := '0'; irq_valid := ex1.msr(MSR_EE) and (pmu_to_x.intr or ctrl.dec(63) or ext_irq_in); -- Next insn adder used in a couple of places next_nia <= std_ulogic_vector(unsigned(e_in.nia) + 4); -- rotator control signals right_shift <= '1' when e_in.insn_type = OP_SHR else '0'; rot_clear_left <= '1' when e_in.insn_type = OP_RLC or e_in.insn_type = OP_RLCL else '0'; rot_clear_right <= '1' when e_in.insn_type = OP_RLC or e_in.insn_type = OP_RLCR else '0'; rot_sign_ext <= '1' when e_in.insn_type = OP_EXTSWSLI else '0'; do_popcnt <= '1' when e_in.insn_type = OP_POPCNT else '0'; if valid_in = '1' then v.prev_op := e_in.insn_type; end if; -- Determine if there is any interrupt to be taken -- before/instead of executing this instruction exception := valid_in and actions.exception; if valid_in = '1' and e_in.second = '0' then if HAS_FPU and ex1.fp_exception_next = '1' then -- This is used for FP-type program interrupts that -- become pending due to MSR[FE0,FE1] changing from 00 to non-zero. exception := '1'; v.e.intr_vec := 16#700#; v.e.srr1 := (others => '0'); v.e.srr1(47 - 43) := '1'; v.e.srr1(47 - 47) := '1'; elsif ex1.trace_next = '1' then -- Generate a trace interrupt rather than executing the next instruction -- or taking any asynchronous interrupt exception := '1'; v.e.intr_vec := 16#d00#; v.e.srr1 := (others => '0'); v.e.srr1(47 - 33) := '1'; if ex1.prev_op = OP_LOAD or ex1.prev_op = OP_ICBI or ex1.prev_op = OP_ICBT or ex1.prev_op = OP_DCBT or ex1.prev_op = OP_DCBST or ex1.prev_op = OP_DCBF then v.e.srr1(47 - 35) := '1'; elsif ex1.prev_op = OP_STORE or ex1.prev_op = OP_DCBZ or ex1.prev_op = OP_DCBTST then v.e.srr1(47 - 36) := '1'; end if; elsif irq_valid = '1' then -- Don't deliver the interrupt until we have a valid instruction -- coming in, so we have a valid NIA to put in SRR0. if pmu_to_x.intr = '1' then v.e.intr_vec := 16#f00#; report "IRQ valid: PMU"; elsif ctrl.dec(63) = '1' then v.e.intr_vec := 16#900#; report "IRQ valid: DEC"; elsif ext_irq_in = '1' then v.e.intr_vec := 16#500#; report "IRQ valid: External"; v.ext_interrupt := '1'; end if; v.e.srr1 := (others => '0'); exception := '1'; end if; end if; v.no_instr_avail := not (e_in.valid or l_in.busy or ex1.busy or fp_in.busy); go := valid_in and not exception; v.instr_dispatch := go; if go = '1' then v.se := actions.se; v.e.valid := actions.complete; bypass_valid := actions.bypass_valid; v.taken_branch_event := actions.take_branch; v.trace_next := actions.do_trace; v.fp_exception_next := actions.fp_intr; v.res2_sel := actions.res2_sel; v.msr := actions.new_msr; x_to_multiply.valid <= actions.start_mul; v.mul_in_progress := actions.start_mul; x_to_divider.valid <= actions.start_div; v.div_in_progress := actions.start_div; v.br_mispredict := v.e.redirect and actions.direct_branch; exception := actions.trap; if actions.advance_nia = '1' then v.e.last_nia := next_nia; end if; -- Go busy while division is happening because the -- divider is not pipelined. Also go busy while a -- multiply is happening in order to stop following -- instructions from using the wrong XER value -- (and for simplicity in the OE=0 case). v.busy := actions.start_div or actions.start_mul; -- instruction for other units, i.e. LDST if e_in.unit = LDST then lv.valid := '1'; end if; if HAS_FPU and e_in.unit = FPU then fv.valid := '1'; end if; end if; if ex1.div_in_progress = '1' then v.div_in_progress := not divider_to_x.valid; v.busy := not divider_to_x.valid; if divider_to_x.valid = '1' and ex1.oe = '1' then v.e.xerc.ov := divider_to_x.overflow; v.e.xerc.ov32 := divider_to_x.overflow; if divider_to_x.overflow = '1' then v.e.xerc.so := '1'; end if; end if; v.e.valid := divider_to_x.valid; v.e.write_data := alu_result; bypass_valid := v.e.valid; end if; if ex1.mul_in_progress = '1' then v.mul_in_progress := not multiply_to_x.valid; v.mul_finish := multiply_to_x.valid and ex1.oe; v.e.valid := multiply_to_x.valid and not ex1.oe; v.busy := not v.e.valid; v.e.write_data := alu_result; bypass_valid := v.e.valid; end if; if ex1.mul_finish = '1' then v.mul_finish := '0'; v.e.xerc.ov := multiply_to_x.overflow; v.e.xerc.ov32 := multiply_to_x.overflow; if multiply_to_x.overflow = '1' then v.e.xerc.so := '1'; end if; v.e.valid := '1'; end if; if v.e.write_xerc_enable = '1' and v.e.valid = '1' then v.xerc := v.e.xerc; v.xerc_valid := '1'; end if; if (ex1.busy or l_in.busy or fp_in.busy) = '0' then v.e.interrupt := exception; end if; if v.e.valid = '0' then v.e.redirect := '0'; v.e.br_last := '0'; end if; if flush_in = '1' then v.e.valid := '0'; v.e.interrupt := '0'; v.e.redirect := '0'; v.e.br_last := '0'; v.busy := '0'; v.div_in_progress := '0'; v.mul_in_progress := '0'; v.mul_finish := '0'; v.xerc_valid := '0'; end if; if flush_in = '1' or interrupt_in.intr = '1' then v.msr := ctrl_tmp.msr; end if; if interrupt_in.intr = '1' then v.trace_next := '0'; v.fp_exception_next := '0'; end if; bypass_data.tag.valid <= v.e.write_enable and bypass_valid; bypass_data.tag.tag <= v.e.instr_tag.tag; bypass_data.data <= alu_result; bypass_cr_data.tag.valid <= v.e.write_cr_enable and bypass_valid; bypass_cr_data.tag.tag <= v.e.instr_tag.tag; bypass_cr_data.data <= v.e.write_cr_data; -- Outputs to loadstore1 (async) lv.op := e_in.insn_type; lv.nia := e_in.nia; lv.instr_tag := e_in.instr_tag; lv.addr1 := a_in; lv.addr2 := b_in; lv.data := c_in; lv.write_reg := e_in.write_reg; lv.length := e_in.data_len; lv.byte_reverse := e_in.byte_reverse xnor ex1.msr(MSR_LE); lv.sign_extend := e_in.sign_extend; lv.update := e_in.update; lv.xerc := xerc_in; lv.reserve := e_in.reserve; lv.rc := e_in.rc; lv.insn := e_in.insn; -- decode l*cix and st*cix instructions here if e_in.insn(31 downto 26) = "011111" and e_in.insn(10 downto 9) = "11" and e_in.insn(5 downto 1) = "10101" then lv.ci := '1'; end if; lv.virt_mode := ex1.msr(MSR_DR); lv.priv_mode := not ex1.msr(MSR_PR); lv.mode_32bit := not ex1.msr(MSR_SF); lv.is_32bit := e_in.is_32bit; lv.repeat := e_in.repeat; lv.second := e_in.second; lv.e2stall := fp_in.f2stall; -- Outputs to FPU fv.op := e_in.insn_type; fv.insn := e_in.insn; fv.itag := e_in.instr_tag; fv.single := e_in.is_32bit; fv.is_signed := e_in.is_signed; fv.fe_mode := ex1.msr(MSR_FE0) & ex1.msr(MSR_FE1); fv.fra := a_in; fv.frb := b_in; fv.frc := c_in; fv.frt := e_in.write_reg; fv.rc := e_in.rc; fv.out_cr := e_in.output_cr; fv.m32b := not ex1.msr(MSR_SF); fv.oe := e_in.oe; fv.xerc := xerc_in; fv.stall := l_in.l2stall; -- Update registers ex1in <= v; -- update outputs l_out <= lv; fp_out <= fv; irq_valid_log <= irq_valid; end process; -- Slow SPR read mux with ex1.spr_select.sel select spr_result <= ctrl.tb when SPRSEL_TB, 32x"0" & ctrl.tb(63 downto 32) when SPRSEL_TBU, ctrl.dec when SPRSEL_DEC, 32x"0" & PVR_MICROWATT when SPRSEL_PVR, log_wr_addr & ex2.log_addr_spr when SPRSEL_LOGA, log_rd_data when SPRSEL_LOGD, ctrl.cfar when SPRSEL_CFAR, assemble_xer(ex1.e.xerc, ctrl.xer_low) when others; stage2_stall <= l_in.l2stall or fp_in.f2stall; -- Second execute stage control execute2_1: process(all) variable v : reg_stage2_type; variable overflow : std_ulogic; variable lv : Execute1ToLoadstore1Type; variable fv : Execute1ToFPUType; variable k : integer; variable go : std_ulogic; variable bypass_valid : std_ulogic; variable rcresult : std_ulogic_vector(63 downto 0); variable sprres : std_ulogic_vector(63 downto 0); variable ex_result : std_ulogic_vector(63 downto 0); variable cr_res : std_ulogic_vector(31 downto 0); variable cr_mask : std_ulogic_vector(7 downto 0); variable sign, zero : std_ulogic; variable rcnz_hi, rcnz_lo : std_ulogic; begin v := ex2; if stage2_stall = '0' then v.e := ex1.e; v.se := ex1.se; v.ext_interrupt := ex1.ext_interrupt; v.taken_branch_event := ex1.taken_branch_event; v.br_mispredict := ex1.br_mispredict; end if; ctrl_tmp <= ctrl; -- FIXME: run at 512MHz not core freq ctrl_tmp.tb <= std_ulogic_vector(unsigned(ctrl.tb) + 1); ctrl_tmp.dec <= std_ulogic_vector(unsigned(ctrl.dec) - 1); x_to_pmu.mfspr <= '0'; x_to_pmu.mtspr <= '0'; x_to_pmu.tbbits(3) <= ctrl.tb(63 - 47); x_to_pmu.tbbits(2) <= ctrl.tb(63 - 51); x_to_pmu.tbbits(1) <= ctrl.tb(63 - 55); x_to_pmu.tbbits(0) <= ctrl.tb(63 - 63); x_to_pmu.pmm_msr <= ctrl.msr(MSR_PMM); x_to_pmu.pr_msr <= ctrl.msr(MSR_PR); if v.e.valid = '0' or flush_in = '1' then v.e.write_enable := '0'; v.e.write_cr_enable := '0'; v.e.write_xerc_enable := '0'; v.e.redirect := '0'; v.e.br_last := '0'; v.se := side_effect_init; v.taken_branch_event := '0'; v.br_mispredict := '0'; end if; if flush_in = '1' then v.e.valid := '0'; v.e.interrupt := '0'; v.ext_interrupt := '0'; end if; -- This is split like this because mfspr doesn't have an Rc bit, -- and we don't want the zero-detect logic to be after the -- SPR mux for timing reasons. if ex1.res2_sel(0) = '0' then rcresult := ex1.e.write_data; sprres := spr_result; else rcresult := countbits_result; sprres := pmu_to_x.spr_val; end if; if ex1.res2_sel(1) = '0' then ex_result := rcresult; else ex_result := sprres; end if; cr_res := ex1.e.write_cr_data; cr_mask := ex1.e.write_cr_mask; if ex1.e.rc = '1' and ex1.e.write_enable = '1' then rcnz_lo := or (rcresult(31 downto 0)); if ex1.e.mode_32bit = '0' then rcnz_hi := or (rcresult(63 downto 32)); zero := not (rcnz_hi or rcnz_lo); sign := ex_result(63); else zero := not rcnz_lo; sign := ex_result(31); end if; cr_res(31) := sign; cr_res(30) := not (sign or zero); cr_res(29) := zero; cr_res(28) := ex1.e.xerc.so; cr_mask(7) := '1'; end if; if stage2_stall = '0' then v.e.write_data := ex_result; v.e.write_cr_data := cr_res; v.e.write_cr_mask := cr_mask; if ex1.e.rc = '1' and ex1.e.write_enable = '1' and v.e.valid = '1' then v.e.write_cr_enable := '1'; end if; if ex1.se.write_msr = '1' then ctrl_tmp.msr <= ex1.msr; end if; if ex1.se.write_xerlow = '1' then ctrl_tmp.xer_low <= ex1.e.write_data(17 downto 0); end if; if ex1.se.write_dec = '1' then ctrl_tmp.dec <= ex1.e.write_data; end if; if ex1.se.write_cfar = '1' then ctrl_tmp.cfar <= ex1.e.last_nia; end if; if ex1.se.write_loga = '1' then v.log_addr_spr := ex1.e.write_data(31 downto 0); elsif ex1.se.inc_loga = '1' then v.log_addr_spr := std_ulogic_vector(unsigned(ex2.log_addr_spr) + 1); end if; x_to_pmu.mtspr <= ex1.se.write_pmuspr; end if; if interrupt_in.intr = '1' then ctrl_tmp.msr(MSR_SF) <= '1'; ctrl_tmp.msr(MSR_EE) <= '0'; ctrl_tmp.msr(MSR_PR) <= '0'; ctrl_tmp.msr(MSR_SE) <= '0'; ctrl_tmp.msr(MSR_BE) <= '0'; ctrl_tmp.msr(MSR_FP) <= '0'; ctrl_tmp.msr(MSR_FE0) <= '0'; ctrl_tmp.msr(MSR_FE1) <= '0'; ctrl_tmp.msr(MSR_IR) <= '0'; ctrl_tmp.msr(MSR_DR) <= '0'; ctrl_tmp.msr(MSR_RI) <= '0'; ctrl_tmp.msr(MSR_LE) <= '1'; end if; bypass_valid := ex1.e.valid; if stage2_stall = '1' and ex1.res2_sel(1) = '1' then bypass_valid := '0'; end if; bypass2_data.tag.valid <= ex1.e.write_enable and bypass_valid; bypass2_data.tag.tag <= ex1.e.instr_tag.tag; bypass2_data.data <= ex_result; bypass2_cr_data.tag.valid <= (ex1.e.write_cr_enable or (ex1.e.rc and ex1.e.write_enable)) and bypass_valid; bypass2_cr_data.tag.tag <= ex1.e.instr_tag.tag; bypass2_cr_data.data <= cr_res; -- Update registers ex2in <= v; -- update outputs e_out <= ex2.e; e_out.msr <= msr_copy(ctrl.msr); terminate_out <= ex2.se.terminate; icache_inval <= ex2.se.icache_inval; exception_log <= v.e.interrupt; end process; sim_dump_test: if SIM generate dump_exregs: process(all) variable xer : std_ulogic_vector(63 downto 0); begin if sim_dump = '1' then report "LR " & to_hstring(even_sprs(to_integer(RAMSPR_LR))); report "CTR " & to_hstring(odd_sprs(to_integer(RAMSPR_CTR))); sim_dump_done <= '1'; else sim_dump_done <= '0'; end if; end process; end generate; -- Keep GHDL synthesis happy sim_dump_test_synth: if not SIM generate sim_dump_done <= '0'; end generate; e1_log: if LOG_LENGTH > 0 generate signal log_data : std_ulogic_vector(14 downto 0); begin ex1_log : process(clk) begin if rising_edge(clk) then log_data <= ctrl.msr(MSR_EE) & ctrl.msr(MSR_PR) & ctrl.msr(MSR_IR) & ctrl.msr(MSR_DR) & exception_log & irq_valid_log & interrupt_in.intr & "000" & ex2.e.write_enable & ex2.e.valid & (ex2.e.redirect or ex2.e.interrupt) & ex1.busy & flush_in; end if; end process; log_out <= log_data; end generate; end architecture behaviour;