Files
kernels/hw/rtl/VX_issue.v
2020-07-19 05:03:47 -04:00

87 lines
3.8 KiB
Verilog

`include "VX_define.vh"
module VX_issue #(
parameter CORE_ID = 0
) (
input wire clk,
input wire reset,
VX_decode_if decode_if,
VX_wb_if writeback_if,
VX_execute_if execute_if,
output wire is_empty
);
localparam CTVW = `CLOG2(`NUM_WARPS * 32 + 1);
reg [31:0][`NUM_THREADS-1:0] rename_table[`NUM_WARPS-1:0];
reg [CTVW-1:0] count_valid;
wire rs1_rename = (rename_table[decode_if.warp_num][decode_if.rs1] != 0);
wire rs2_rename = (rename_table[decode_if.warp_num][decode_if.rs2] != 0);
wire rd_rename = (rename_table[decode_if.warp_num][decode_if.rd ] != 0);
wire rs1_rename_qual = (rs1_rename) && (decode_if.use_rs1);
wire rs2_rename_qual = (rs2_rename) && (decode_if.use_rs2);
wire rd_rename_qual = (rd_rename) && (decode_if.wb != 0);
wire rename_valid = (| decode_if.valid) && (rs1_rename_qual || rs2_rename_qual || rd_rename_qual);
wire ex_stalled = (| decode_if.valid)
&& ((!execute_if.alu_ready && (decode_if.ex_type == `EX_ALU))
|| (!execute_if.br_ready && (decode_if.ex_type == `EX_BR))
|| (!execute_if.lsu_ready && (decode_if.ex_type == `EX_LSU))
|| (!execute_if.csr_ready && (decode_if.ex_type == `EX_CSR))
|| (!execute_if.mul_ready && (decode_if.ex_type == `EX_MUL))
|| (!execute_if.gpu_ready && (decode_if.ex_type == `EX_GPU)));
wire stall = rename_valid || ex_stalled;
wire acquire_rd = (| decode_if.valid) && (decode_if.wb != 0) && (decode_if.rd != 0) && ~stall;
wire release_rd = (| writeback_if.valid) && (writeback_if.wb != 0) && (writeback_if.rd != 0);
wire [`NUM_THREADS-1:0] valid_wb_new_mask = rename_table[writeback_if.warp_num][writeback_if.rd] & ~writeback_if.valid;
reg [CTVW-1:0] count_valid_next = (acquire_rd && !(release_rd && (0 == valid_wb_new_mask))) ? (count_valid + 1) :
(~acquire_rd && (release_rd && (0 == valid_wb_new_mask))) ? (count_valid - 1) :
count_valid;
integer i, w;
always @(posedge clk) begin
if (reset) begin
for (w = 0; w < `NUM_WARPS; w++) begin
for (i = 0; i < 32; i++) begin
rename_table[w][i] <= 0;
end
end
count_valid <= 0;
end else begin
if (acquire_rd) begin
rename_table[decode_if.warp_num][decode_if.rd] <= decode_if.valid;
end
if (release_rd) begin
assert(rename_table[writeback_if.warp_num][writeback_if.rd] != 0);
rename_table[writeback_if.warp_num][writeback_if.rd] <= valid_wb_new_mask;
end
count_valid <= count_valid_next;
end
end
VX_generic_register #(
.N(`NUM_THREADS + `NW_BITS + 32 + 32 + `NR_BITS + `NR_BITS + `NR_BITS + 32 + 1 + 1 + `EX_BITS + `OP_BITS + `WB_BITS),
) schedule_reg (
.clk (clk),
.reset (reset),
.stall (stall),
.flush (0),
.in ({decode_if.valid, decode_if.warp_num, decode_if.curr_PC, decode_if.next_PC, decode_if.rd, decode_if.rs1, decode_if.rs2, decode_if.imm, decode_if.rs1_is_PC, decode_if.rs2_is_imm, decode_if.ex_type, decode_if.instr_op, decode_if.wb}),
.out ({execute_if.valid, execute_if.warp_num, execute_if.curr_PC, execute_if.next_PC, execute_if.rd, execute_if.rs1, execute_if.rs2, execute_if.imm, execute_if.rs1_is_PC, execute_if.rs2_is_imm, execute_if.ex_type, execute_if.instr_op, execute_if.wb})
);
assign decode_if.ready = ~stall;
assign is_empty = (0 == count_valid);
endmodule