Files
kernels/hw/rtl/VX_scheduler.v
2020-07-02 19:31:55 -07:00

83 lines
3.4 KiB
Verilog

`include "VX_define.vh"
module VX_scheduler (
input wire clk,
input wire reset,
input wire memory_delay,
input wire exec_delay,
input wire gpr_stage_delay,
VX_backend_req_if bckE_req_if,
VX_wb_if writeback_if,
output wire schedule_delay,
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 is_store = (bckE_req_if.mem_write != `BYTE_EN_NO);
wire is_load = (bckE_req_if.mem_read != `BYTE_EN_NO);
wire is_mem = (is_store || is_load);
wire is_gpu = (bckE_req_if.is_wspawn || bckE_req_if.is_tmc || bckE_req_if.is_barrier || bckE_req_if.is_split);
wire is_csr = bckE_req_if.is_csr;
wire is_exec = !is_mem && !is_gpu && !is_csr;
wire using_rs2 = is_store
|| (bckE_req_if.rs2_src == `RS2_REG)
|| bckE_req_if.is_barrier
|| bckE_req_if.is_wspawn;
wire rs1_rename = (rename_table[bckE_req_if.warp_num][bckE_req_if.rs1] != 0);
wire rs2_rename = (rename_table[bckE_req_if.warp_num][bckE_req_if.rs2] != 0);
wire rd_rename = (rename_table[bckE_req_if.warp_num][bckE_req_if.rd ] != 0);
wire rs1_rename_qual = (rs1_rename) && (bckE_req_if.rs1 != 0);
wire rs2_rename_qual = (rs2_rename) && (bckE_req_if.rs2 != 0 && using_rs2);
wire rd_rename_qual = (rd_rename) && (bckE_req_if.rd != 0);
wire rename_valid = rs1_rename_qual || rs2_rename_qual || rd_rename_qual;
assign schedule_delay = (| bckE_req_if.valid)
&& ((rename_valid)
|| (memory_delay && is_mem)
|| (gpr_stage_delay && (is_mem || is_exec))
|| (exec_delay && is_exec));
assign is_empty = (count_valid == 0);
integer i, w;
wire acquire_rd = (| bckE_req_if.valid) && (bckE_req_if.wb != 0) && (bckE_req_if.rd != 0) && !schedule_delay;
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;
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[bckE_req_if.warp_num][bckE_req_if.rd] <= bckE_req_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
endmodule