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Remote unuse fast mul code.

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colin.liang 2023-01-12 17:04:17 +08:00
parent 9adf1c0029
commit 92b7265264
1 changed files with 0 additions and 91 deletions
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picorv32.v
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@ -1599,97 +1599,6 @@ module picorv32_pcpi_mul #(
end
endmodule
module picorv32_pcpi_fast_mul #(
parameter EXTRA_MUL_FFS = 0,
parameter EXTRA_INSN_FFS = 0,
parameter MUL_CLKGATE = 0
) (
input clk, resetn,
input pcpi_valid,
input [31:0] pcpi_insn,
input [31:0] pcpi_rs1,
input [31:0] pcpi_rs2,
output pcpi_wr,
output [31:0] pcpi_rd,
output pcpi_wait,
output pcpi_ready
);
reg instr_mul, instr_mulh, instr_mulhsu, instr_mulhu;
wire instr_any_mul = |{instr_mul, instr_mulh, instr_mulhsu, instr_mulhu};
wire instr_any_mulh = |{instr_mulh, instr_mulhsu, instr_mulhu};
wire instr_rs1_signed = |{instr_mulh, instr_mulhsu};
wire instr_rs2_signed = |{instr_mulh};
reg shift_out;
reg [3:0] active;
reg [32:0] rs1, rs2, rs1_q, rs2_q;
reg [63:0] rd, rd_q;
wire pcpi_insn_valid = pcpi_valid && pcpi_insn[6:0] == 7'b0110011 && pcpi_insn[31:25] == 7'b0000001;
reg pcpi_insn_valid_q;
always @* begin
instr_mul = 0;
instr_mulh = 0;
instr_mulhsu = 0;
instr_mulhu = 0;
if (resetn && (EXTRA_INSN_FFS ? pcpi_insn_valid_q : pcpi_insn_valid)) begin
case (pcpi_insn[14:12])
3'b000: instr_mul = 1;
3'b001: instr_mulh = 1;
3'b010: instr_mulhsu = 1;
3'b011: instr_mulhu = 1;
endcase
end
end
always @(posedge clk) begin
pcpi_insn_valid_q <= pcpi_insn_valid;
if (!MUL_CLKGATE || active[0]) begin
rs1_q <= rs1;
rs2_q <= rs2;
end
if (!MUL_CLKGATE || active[1]) begin
rd <= $signed(EXTRA_MUL_FFS ? rs1_q : rs1) * $signed(EXTRA_MUL_FFS ? rs2_q : rs2);
end
if (!MUL_CLKGATE || active[2]) begin
rd_q <= rd;
end
end
always @(posedge clk) begin
if (instr_any_mul && !(EXTRA_MUL_FFS ? active[3:0] : active[1:0])) begin
if (instr_rs1_signed)
rs1 <= $signed(pcpi_rs1);
else
rs1 <= $unsigned(pcpi_rs1);
if (instr_rs2_signed)
rs2 <= $signed(pcpi_rs2);
else
rs2 <= $unsigned(pcpi_rs2);
active[0] <= 1;
end else begin
active[0] <= 0;
end
active[3:1] <= active;
shift_out <= instr_any_mulh;
if (!resetn)
active <= 0;
end
assign pcpi_wr = active[EXTRA_MUL_FFS ? 3 : 1];
assign pcpi_wait = 0;
assign pcpi_ready = active[EXTRA_MUL_FFS ? 3 : 1];
assign pcpi_rd = shift_out ? (EXTRA_MUL_FFS ? rd_q : rd) >> 32 : (EXTRA_MUL_FFS ? rd_q : rd);
endmodule
/***************************************************************
* picorv32_pcpi_div
***************************************************************/