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1597 lines
58 KiB
VHDL
1597 lines
58 KiB
VHDL
library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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library work;
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use work.decode_types.all;
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use work.common.all;
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use work.helpers.all;
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use work.crhelpers.all;
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use work.insn_helpers.all;
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use work.ppc_fx_insns.all;
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entity execute1 is
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generic (
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EX1_BYPASS : boolean := true;
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HAS_FPU : boolean := true;
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HAS_SHORT_MULT : boolean := false;
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-- Non-zero to enable log data collection
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LOG_LENGTH : natural := 0
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);
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port (
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clk : in std_ulogic;
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rst : in std_ulogic;
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-- asynchronous
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flush_in : in std_ulogic;
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busy_out : out std_ulogic;
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e_in : in Decode2ToExecute1Type;
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l_in : in Loadstore1ToExecute1Type;
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fp_in : in FPUToExecute1Type;
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ext_irq_in : std_ulogic;
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interrupt_in : std_ulogic;
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-- asynchronous
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l_out : out Execute1ToLoadstore1Type;
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fp_out : out Execute1ToFPUType;
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e_out : out Execute1ToWritebackType;
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bypass_data : out bypass_data_t;
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bypass_cr_data : out cr_bypass_data_t;
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dbg_ctrl_out : out ctrl_t;
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icache_inval : out std_ulogic;
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terminate_out : out std_ulogic;
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-- PMU event buses
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wb_events : in WritebackEventType;
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ls_events : in Loadstore1EventType;
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dc_events : in DcacheEventType;
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ic_events : in IcacheEventType;
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log_out : out std_ulogic_vector(14 downto 0);
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log_rd_addr : out std_ulogic_vector(31 downto 0);
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log_rd_data : in std_ulogic_vector(63 downto 0);
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log_wr_addr : in std_ulogic_vector(31 downto 0)
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);
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end entity execute1;
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architecture behaviour of execute1 is
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type side_effect_type is record
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terminate : std_ulogic;
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icache_inval : std_ulogic;
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write_msr : std_ulogic;
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write_xerlow : std_ulogic;
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write_dec : std_ulogic;
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write_cfar : std_ulogic;
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write_loga : std_ulogic;
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inc_loga : std_ulogic;
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write_pmuspr : std_ulogic;
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end record;
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constant side_effect_init : side_effect_type := (others => '0');
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type actions_type is record
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e : Execute1ToWritebackType;
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se : side_effect_type;
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complete : std_ulogic;
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exception : std_ulogic;
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trap : std_ulogic;
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new_msr : std_ulogic_vector(63 downto 0);
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take_branch : std_ulogic;
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direct_branch : std_ulogic;
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start_mul : std_ulogic;
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start_div : std_ulogic;
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do_trace : std_ulogic;
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fp_intr : std_ulogic;
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res2_sel : std_ulogic_vector(1 downto 0);
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bypass_valid : std_ulogic;
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end record;
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constant actions_type_init : actions_type :=
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(e => Execute1ToWritebackInit, se => side_effect_init,
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new_msr => (others => '0'), res2_sel => "00", others => '0');
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type reg_stage1_type is record
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e : Execute1ToWritebackType;
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se : side_effect_type;
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busy: std_ulogic;
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fp_exception_next : std_ulogic;
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trace_next : std_ulogic;
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prev_op : insn_type_t;
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br_taken : std_ulogic;
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oe : std_ulogic;
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mul_select : std_ulogic_vector(1 downto 0);
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res2_sel : std_ulogic_vector(1 downto 0);
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spr_select : spr_id;
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pmu_spr_num : std_ulogic_vector(4 downto 0);
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mul_in_progress : std_ulogic;
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mul_finish : std_ulogic;
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div_in_progress : std_ulogic;
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no_instr_avail : std_ulogic;
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instr_dispatch : std_ulogic;
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ext_interrupt : std_ulogic;
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taken_branch_event : std_ulogic;
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br_mispredict : std_ulogic;
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msr : std_ulogic_vector(63 downto 0);
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xerc : xer_common_t;
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xerc_valid : std_ulogic;
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end record;
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constant reg_stage1_type_init : reg_stage1_type :=
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(e => Execute1ToWritebackInit, se => side_effect_init,
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busy => '0',
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fp_exception_next => '0', trace_next => '0', prev_op => OP_ILLEGAL, br_taken => '0',
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oe => '0', mul_select => "00", res2_sel => "00",
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spr_select => spr_id_init, pmu_spr_num => 5x"0",
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mul_in_progress => '0', mul_finish => '0', div_in_progress => '0',
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no_instr_avail => '0', instr_dispatch => '0', ext_interrupt => '0',
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taken_branch_event => '0', br_mispredict => '0',
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msr => 64x"0",
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xerc => xerc_init, xerc_valid => '0');
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type reg_stage2_type is record
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e : Execute1ToWritebackType;
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se : side_effect_type;
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ext_interrupt : std_ulogic;
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taken_branch_event : std_ulogic;
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br_mispredict : std_ulogic;
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log_addr_spr : std_ulogic_vector(31 downto 0);
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end record;
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constant reg_stage2_type_init : reg_stage2_type :=
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(e => Execute1ToWritebackInit, se => side_effect_init,
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log_addr_spr => 32x"0", others => '0');
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signal ex1, ex1in : reg_stage1_type;
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signal ex2, ex2in : reg_stage2_type;
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signal actions : actions_type;
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signal a_in, b_in, c_in : std_ulogic_vector(63 downto 0);
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signal cr_in : std_ulogic_vector(31 downto 0);
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signal xerc_in : xer_common_t;
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signal mshort_p : std_ulogic_vector(31 downto 0) := (others => '0');
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signal valid_in : std_ulogic;
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signal ctrl: ctrl_t := ctrl_t_init;
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signal ctrl_tmp: ctrl_t := ctrl_t_init;
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signal right_shift, rot_clear_left, rot_clear_right: std_ulogic;
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signal rot_sign_ext: std_ulogic;
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signal rotator_result: std_ulogic_vector(63 downto 0);
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signal rotator_carry: std_ulogic;
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signal logical_result: std_ulogic_vector(63 downto 0);
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signal do_popcnt: std_ulogic;
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signal countbits_result: std_ulogic_vector(63 downto 0);
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signal alu_result: std_ulogic_vector(63 downto 0);
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signal adder_result: std_ulogic_vector(63 downto 0);
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signal misc_result: std_ulogic_vector(63 downto 0);
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signal muldiv_result: std_ulogic_vector(63 downto 0);
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signal shortmul_result: std_ulogic_vector(63 downto 0);
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signal spr_result: std_ulogic_vector(63 downto 0);
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signal ex_result: std_ulogic_vector(63 downto 0);
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signal next_nia : std_ulogic_vector(63 downto 0);
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signal s1_sel : std_ulogic_vector(2 downto 0);
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signal carry_32 : std_ulogic;
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signal carry_64 : std_ulogic;
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signal overflow_32 : std_ulogic;
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signal overflow_64 : std_ulogic;
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signal trapval : std_ulogic_vector(4 downto 0);
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signal write_cr_mask : std_ulogic_vector(7 downto 0);
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signal write_cr_data : std_ulogic_vector(31 downto 0);
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-- multiply signals
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signal x_to_multiply: MultiplyInputType;
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signal multiply_to_x: MultiplyOutputType;
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-- divider signals
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signal x_to_divider: Execute1ToDividerType;
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signal divider_to_x: DividerToExecute1Type;
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-- random number generator signals
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signal random_raw : std_ulogic_vector(63 downto 0);
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signal random_cond : std_ulogic_vector(63 downto 0);
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signal random_err : std_ulogic;
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-- PMU signals
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signal x_to_pmu : Execute1ToPMUType;
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signal pmu_to_x : PMUToExecute1Type;
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-- signals for logging
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signal exception_log : std_ulogic;
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signal irq_valid_log : std_ulogic;
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type privilege_level is (USER, SUPER);
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type op_privilege_array is array(insn_type_t) of privilege_level;
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constant op_privilege: op_privilege_array := (
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OP_ATTN => SUPER,
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OP_MFMSR => SUPER,
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OP_MTMSRD => SUPER,
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OP_RFID => SUPER,
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OP_TLBIE => SUPER,
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others => USER
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);
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function instr_is_privileged(op: insn_type_t; insn: std_ulogic_vector(31 downto 0))
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return boolean is
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begin
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if op_privilege(op) = SUPER then
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return true;
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elsif op = OP_MFSPR or op = OP_MTSPR then
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return insn(20) = '1';
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else
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return false;
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end if;
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end;
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procedure set_carry(e: inout Execute1ToWritebackType;
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carry32 : in std_ulogic;
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carry : in std_ulogic) is
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begin
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e.xerc.ca32 := carry32;
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e.xerc.ca := carry;
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end;
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procedure set_ov(e: inout Execute1ToWritebackType;
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ov : in std_ulogic;
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ov32 : in std_ulogic) is
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begin
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e.xerc.ov32 := ov32;
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e.xerc.ov := ov;
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if ov = '1' then
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e.xerc.so := '1';
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end if;
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end;
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function calc_ov(msb_a : std_ulogic; msb_b: std_ulogic;
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ca: std_ulogic; msb_r: std_ulogic) return std_ulogic is
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begin
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return (ca xor msb_r) and not (msb_a xor msb_b);
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end;
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function decode_input_carry(ic : carry_in_t;
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xerc : xer_common_t) return std_ulogic is
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begin
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case ic is
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when ZERO =>
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return '0';
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when CA =>
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return xerc.ca;
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when OV =>
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return xerc.ov;
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when ONE =>
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return '1';
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end case;
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end;
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function msr_copy(msr: std_ulogic_vector(63 downto 0))
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return std_ulogic_vector is
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variable msr_out: std_ulogic_vector(63 downto 0);
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begin
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-- ISA says this:
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-- Defined MSR bits are classified as either full func-
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-- tion or partial function. Full function MSR bits are
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-- saved in SRR1 or HSRR1 when an interrupt other
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-- than a System Call Vectored interrupt occurs and
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-- restored by rfscv, rfid, or hrfid, while partial func-
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-- tion MSR bits are not saved or restored.
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-- Full function MSR bits lie in the range 0:32, 37:41, and
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-- 48:63, and partial function MSR bits lie in the range
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-- 33:36 and 42:47. (Note this is IBM bit numbering).
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msr_out := (others => '0');
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msr_out(63 downto 31) := msr(63 downto 31);
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msr_out(26 downto 22) := msr(26 downto 22);
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msr_out(15 downto 0) := msr(15 downto 0);
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return msr_out;
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end;
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-- Work out whether a signed value fits into n bits,
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-- that is, see if it is in the range -2^(n-1) .. 2^(n-1) - 1
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function fits_in_n_bits(val: std_ulogic_vector; n: integer) return boolean is
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variable x, xp1: std_ulogic_vector(val'left downto val'right);
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begin
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x := val;
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if val(val'left) = '0' then
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x := not val;
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end if;
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xp1 := bit_reverse(std_ulogic_vector(unsigned(bit_reverse(x)) + 1));
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x := x and not xp1;
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-- For positive inputs, x has ones at the positions
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-- to the left of the leftmost 1 bit in val.
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-- For negative inputs, x has ones to the left of
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-- the leftmost 0 bit in val.
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return x(n - 1) = '1';
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end;
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function assemble_xer(xerc: xer_common_t; xer_low: std_ulogic_vector)
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return std_ulogic_vector is
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begin
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return 32x"0" & xerc.so & xerc.ov & xerc.ca & "000000000" &
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xerc.ov32 & xerc.ca32 & xer_low(17 downto 0);
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end;
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-- Tell vivado to keep the hierarchy for the random module so that the
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-- net names in the xdc file match.
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attribute keep_hierarchy : string;
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attribute keep_hierarchy of random_0 : label is "yes";
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begin
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rotator_0: entity work.rotator
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port map (
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rs => c_in,
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ra => a_in,
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shift => b_in(6 downto 0),
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insn => e_in.insn,
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is_32bit => e_in.is_32bit,
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right_shift => right_shift,
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arith => e_in.is_signed,
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clear_left => rot_clear_left,
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clear_right => rot_clear_right,
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sign_ext_rs => rot_sign_ext,
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result => rotator_result,
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carry_out => rotator_carry
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);
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logical_0: entity work.logical
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port map (
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rs => c_in,
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rb => b_in,
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op => e_in.insn_type,
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invert_in => e_in.invert_a,
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invert_out => e_in.invert_out,
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result => logical_result,
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datalen => e_in.data_len
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);
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countbits_0: entity work.bit_counter
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port map (
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clk => clk,
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rs => c_in,
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count_right => e_in.insn(10),
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is_32bit => e_in.is_32bit,
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do_popcnt => do_popcnt,
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datalen => e_in.data_len,
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result => countbits_result
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);
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multiply_0: entity work.multiply
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port map (
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clk => clk,
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m_in => x_to_multiply,
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m_out => multiply_to_x
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);
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divider_0: entity work.divider
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port map (
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clk => clk,
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rst => rst,
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d_in => x_to_divider,
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d_out => divider_to_x
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);
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random_0: entity work.random
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port map (
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clk => clk,
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data => random_cond,
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raw => random_raw,
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err => random_err
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);
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pmu_0: entity work.pmu
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port map (
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clk => clk,
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rst => rst,
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p_in => x_to_pmu,
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p_out => pmu_to_x
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);
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short_mult_0: if HAS_SHORT_MULT generate
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begin
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short_mult: entity work.short_multiply
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port map (
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clk => clk,
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a_in => a_in(15 downto 0),
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b_in => b_in(15 downto 0),
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m_out => mshort_p
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);
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end generate;
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dbg_ctrl_out <= ctrl;
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log_rd_addr <= ex2.log_addr_spr;
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a_in <= e_in.read_data1;
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b_in <= e_in.read_data2;
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c_in <= e_in.read_data3;
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cr_in <= e_in.cr;
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x_to_pmu.occur <= (instr_complete => wb_events.instr_complete,
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fp_complete => wb_events.fp_complete,
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ld_complete => ls_events.load_complete,
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st_complete => ls_events.store_complete,
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itlb_miss => ls_events.itlb_miss,
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dc_load_miss => dc_events.load_miss,
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dc_ld_miss_resolved => dc_events.dcache_refill,
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dc_store_miss => dc_events.store_miss,
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dtlb_miss => dc_events.dtlb_miss,
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dtlb_miss_resolved => dc_events.dtlb_miss_resolved,
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icache_miss => ic_events.icache_miss,
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itlb_miss_resolved => ic_events.itlb_miss_resolved,
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no_instr_avail => ex1.no_instr_avail,
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dispatch => ex1.instr_dispatch,
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ext_interrupt => ex2.ext_interrupt,
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br_taken_complete => ex2.taken_branch_event,
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br_mispredict => ex2.br_mispredict,
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others => '0');
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x_to_pmu.nia <= e_in.nia;
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x_to_pmu.addr <= (others => '0');
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x_to_pmu.addr_v <= '0';
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x_to_pmu.spr_num <= ex1.pmu_spr_num;
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x_to_pmu.spr_val <= ex1.e.write_data;
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x_to_pmu.run <= '1';
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-- XER forwarding. To avoid having to track XER hazards, we use
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-- the previously latched value. Since the XER common bits
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-- (SO, OV[32] and CA[32]) are only modified by instructions that are
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-- handled here, we can just forward the result being sent to
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-- writeback.
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xerc_in <= ex1.xerc when ex1.xerc_valid = '1' else e_in.xerc;
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with e_in.unit select busy_out <=
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l_in.busy or ex1.e.valid or ex1.busy or fp_in.busy when LDST,
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l_in.busy or l_in.in_progress or ex1.e.valid or ex1.busy or fp_in.busy when FPU,
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l_in.busy or l_in.in_progress or ex1.busy or fp_in.busy when others;
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valid_in <= e_in.valid and not (busy_out or flush_in or ex1.e.redirect or ex1.e.interrupt);
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-- First stage result mux
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s1_sel <= e_in.result_sel when ex1.busy = '0' else "100";
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with s1_sel select alu_result <=
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adder_result when "000",
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logical_result when "001",
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rotator_result when "010",
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shortmul_result when "011",
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muldiv_result when "100",
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next_nia when "110",
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misc_result when others;
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|
|
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 (l_in.busy or fp_in.busy) = '0'
|
|
severity failure;
|
|
end if;
|
|
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 b_or_m1 : 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;
|
|
if e_in.addm1 = '0' then
|
|
b_or_m1 := b_in;
|
|
else
|
|
b_or_m1 := (others => '1');
|
|
end if;
|
|
sum_with_carry := ppc_adde(a_inv, b_or_m1,
|
|
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;
|
|
else
|
|
write_cr_mask <= num_to_fxm(crnum);
|
|
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;
|
|
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";
|
|
|
|
-- 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.e.intr_vec := 16#C00#;
|
|
v.e.last_nia := next_nia;
|
|
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 =>
|
|
-- read_data1 is CTR
|
|
-- If this instruction updates both CTR and LR, then it is
|
|
-- doubled; the first instruction decrements CTR and determines
|
|
-- whether the branch is taken, and the second does the
|
|
-- redirect and the LR update.
|
|
bo := insn_bo(e_in.insn);
|
|
bi := insn_bi(e_in.insn);
|
|
if e_in.second = '0' then
|
|
v.take_branch := ppc_bc_taken(bo, bi, cr_in, a_in);
|
|
else
|
|
v.take_branch := ex1.br_taken;
|
|
end if;
|
|
if v.take_branch = '1' then
|
|
v.e.br_offset := b_in;
|
|
v.e.abs_br := insn_aa(e_in.insn);
|
|
end if;
|
|
if e_in.repeat = '0' or e_in.second = '1' then
|
|
-- 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;
|
|
end if;
|
|
when OP_BCREG =>
|
|
-- read_data1 is CTR, read_data2 is target register (CTR, LR or TAR)
|
|
-- If this instruction updates both CTR and LR, then it is
|
|
-- doubled; the first instruction decrements CTR and determines
|
|
-- whether the branch is taken, and the second does the
|
|
-- redirect and the LR update.
|
|
bo := insn_bo(e_in.insn);
|
|
bi := insn_bi(e_in.insn);
|
|
if e_in.second = '0' then
|
|
v.take_branch := ppc_bc_taken(bo, bi, cr_in, a_in);
|
|
else
|
|
v.take_branch := ex1.br_taken;
|
|
end if;
|
|
if v.take_branch = '1' then
|
|
v.e.br_offset := b_in;
|
|
v.e.abs_br := '1';
|
|
end if;
|
|
if e_in.repeat = '0' or e_in.second = '1' then
|
|
-- 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;
|
|
end if;
|
|
|
|
when OP_RFID =>
|
|
v.e.redir_mode := (a_in(MSR_IR) or a_in(MSR_PR)) & not a_in(MSR_PR) &
|
|
not a_in(MSR_LE) & not a_in(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) := a_in(63 downto 31);
|
|
v.new_msr(26 downto 22) := a_in(26 downto 22);
|
|
v.new_msr(15 downto 0) := a_in(15 downto 0);
|
|
if a_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;
|
|
v.se.write_msr := '1';
|
|
v.e.br_offset := b_in;
|
|
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
|
|
(a_in(MSR_FE0) or a_in(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 is_fast_spr(e_in.read_reg1) = '1' then
|
|
if e_in.valid = '1' then
|
|
report "MFSPR to SPR " & integer'image(decode_spr_num(e_in.insn)) &
|
|
"=" & to_hstring(a_in);
|
|
end if;
|
|
elsif e_in.spr_select.valid = '1' then
|
|
if e_in.valid = '1' 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' 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' 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;
|
|
elsif is_fast_spr(e_in.write_reg) = '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 =>
|
|
v.start_div := '1';
|
|
slow_op := '1';
|
|
owait := '1';
|
|
|
|
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;
|
|
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 l_in.in_progress 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.br_taken := 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;
|
|
|
|
-- 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 = '1' then
|
|
v.msr := ctrl_tmp.msr;
|
|
end if;
|
|
if interrupt_in = '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;
|
|
|
|
-- Outputs to FPU
|
|
fv.op := e_in.insn_type;
|
|
fv.nia := e_in.nia;
|
|
fv.insn := e_in.insn;
|
|
fv.itag := e_in.instr_tag;
|
|
fv.single := e_in.is_32bit;
|
|
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;
|
|
|
|
-- 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;
|
|
|
|
-- Second stage result mux
|
|
with ex1.res2_sel select ex_result <=
|
|
countbits_result when "01",
|
|
spr_result when "10",
|
|
pmu_to_x.spr_val when "11",
|
|
ex1.e.write_data when others;
|
|
|
|
-- 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;
|
|
begin
|
|
v := ex2;
|
|
if (l_in.busy or fp_in.busy) = '0' then
|
|
v.e := ex1.e;
|
|
v.se := ex1.se;
|
|
v.e.write_data := ex_result;
|
|
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;
|
|
|
|
if (l_in.busy or fp_in.busy) = '0' then
|
|
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 = '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;
|
|
|
|
-- 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;
|
|
|
|
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 &
|
|
"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;
|