Yosys ABC error/segmentation fault in SymbiFlow

[regymm]

Hope this is the place for yosys issue in SymbiFlow as well.

Steps to reproduce the issue

I'm using SymbiFlow for xc7z010 following this installation and Makefile same as in the SymbiFlow examples, symbiflow_synth -t ${TOP} -v ${VERILOG} -d ${BITSTREAM_DEVICE} -p ${PARTNAME} -x ${XDC}.

Symbiflow_synth reported segmentation fault or similar errors for this piece of code, which is trimmed to as short as I can from a CPU cache design that can be run in Vivado with no problem:

`timescale 1ns / 1ps

module cache_cpu
    (
        input clk,

        input [31:0]a,
        input [31:0]d,
        input we,
    output ready
    );

    localparam IDLE = 1;
    localparam LOAD = 3;
    reg [3:0]state = IDLE;

    assign ready = !(we) & (state == IDLE);

    reg way_en;
    reg way_tag_we;
    always @ (*) begin
        way_en = 0;
        way_tag_we = 0;
        case (state)
            IDLE: begin
                if (way_tag_out) begin
                    way_tag_we = 1;
                end
            end
            LOAD: begin
                way_en = 1;
                way_tag_we = 1;
            end
        endcase
    end

    always @ (posedge clk) begin
        case(state)
            IDLE: begin
                if (way_tag_out) begin
                    state <= LOAD;
                end
            end
            LOAD: begin
                state <= IDLE;
            end
        endcase
    end

    wire [31:0]way_tag_out;

    cacheway way_gen (
        .clk(clk),
        .en(way_en),
        .tag_we(way_tag_we),
        .tag_out(way_tag_out),
    );

endmodule
module cacheway
    (
        input clk,
        input en,
        input tag_we,
        output [31:0]tag_out
    );

    reg [31:0]tags[31:0];

    reg state = 0;
    reg [9:0]count = 0;
    always @ (posedge clk) begin
        if (state == 0) begin
            count <= count + 1;
            if (count == 10) state <= 1;
            tags[count] <= 0;
        end else
            if (en & tag_we) tags[0] <= 23;
            //if (tag_we) tags[0] <= 23; // and remove all en
    end
    assign tag_out = tags[0];

endmodule

The whole compile output is here.

The yosys version is managed by SymbiFlow installer so I'm not sure it's git master or not.

[Ravenslofty]

The yosys version is managed by SymbiFlow installer so I'm not sure it's git master or not.

Yosys 0.9+3962 is 5d0cc54f from way back in February, and there have been multiple ABC9 bug fixes since then.

I can't reproduce this with 707d98b0.

[regymm]

Oh, seems my SymbiFlow toolchain is too old. After bumping to latest this is solved.