How can I use multiple IP cores that both contain modules with the same names with Yosys

Question

Consider a design with two IP cores ip1.v and ip2.v that each declare a (different) module with the same name.

For example, the contents of ip1.v:

module ip1 (input A, B, C, output X);
  wire T;
  mygate gate_0 (.I0(A), .I1(B), .O(T));
  mygate gate_1 (.I0(T), .I1(C), .O(X));
endmodule

module mygate (input I0, I1, output O);
  assign O = I0 & I1;
endmodule

And the contents of ip2.v:

module ip2 (input A, B, C, output X);
  wire T;
  mygate gate_0 (.I0(A), .I1(B), .O(T));
  mygate gate_1 (.I0(T), .I1(C), .O(X));
endmodule

module mygate (input I0, I1, output O);
  assign O = I0 | I1;
endmodule

And then a top module that uses both IP cores (top.v):

module top (input A, B, C, output X, Y);
  ip1 ip1_inst (.A(A), .B(B), .C(C), .X(X));
  ip2 ip2_inst (.A(A), .B(B), .C(C), .X(Y));
endmodule

How can I process a design like that so that each IP cores sees it's own version of mygate?

Answer 1

For situations like this it is necessary to read and elaborate the two IP cores as separate designs and then link it all together by "importing" the two designs for the individual IP cores into the top-level design:

# Read IP core 1
read_verilog ip1.v
hierarchy -top ip1
design -stash ip1

# Read IP core 2
read_verilog ip2.v
hierarchy -top ip2
design -stash ip2

# Read top level and link design
read_verilog top.v
design -import ip1
design -import ip2
synth -top top

The command design -import ip1 will import the modules ip1 and mygate from the ip1 design, but it will rename mygate into ip1.mygate. Similarly design -import ip1 will rename mygate from ip2 to ip2.mygate.