diff --git a/techlibs/xilinx/lut_map.v b/techlibs/xilinx/lut_map.v index d07c59dee..fa2a005b1 100644 --- a/techlibs/xilinx/lut_map.v +++ b/techlibs/xilinx/lut_map.v @@ -29,58 +29,84 @@ module \$lut (A, Y); input [WIDTH-1:0] A; output Y; + // Need to swap input ordering, and fix init accordingly, + // to match ABC's expectation of LUT inputs in non-decreasing + // delay order + localparam P_WIDTH = WIDTH < 4 ? 4 : WIDTH; + function [P_WIDTH-1:0] permute_index; + input [P_WIDTH-1:0] i; + integer j; + begin + permute_index = 0; + for (j = 0; j < P_WIDTH; j = j + 1) + permute_index[P_WIDTH-1 - j] = i[j]; + end + endfunction + + function [2**P_WIDTH-1:0] permute_init; + input [2**P_WIDTH-1:0] orig; + integer i; + begin + permute_init = 0; + for (i = 0; i < 2**P_WIDTH; i = i + 1) + permute_init[i] = orig[permute_index(i)]; + end + endfunction + + parameter [2**P_WIDTH-1:0] P_LUT = permute_init(LUT); + generate if (WIDTH == 1) begin - LUT1 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), + LUT1 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), .I0(A[0])); end else if (WIDTH == 2) begin - LUT2 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), - .I0(A[0]), .I1(A[1])); + LUT2 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[1]), .I1(A[0])); end else if (WIDTH == 3) begin - LUT3 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), - .I0(A[0]), .I1(A[1]), .I2(A[2])); + LUT3 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[2]), .I1(A[1]), .I2(A[0])); end else if (WIDTH == 4) begin - LUT4 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3])); + LUT4 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[3]), .I1(A[2]), .I2(A[1]), + .I3(A[0])); end else if (WIDTH == 5) begin - LUT5 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4])); + LUT5 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[4]), .I1(A[3]), .I2(A[2]), + .I3(A[1]), .I4(A[0])); end else if (WIDTH == 6) begin - LUT6 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); + LUT6 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); end else if (WIDTH == 7) begin wire T0, T1; - LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); - LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); + LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); + LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[6])); end else if (WIDTH == 8) begin wire T0, T1, T2, T3, T4, T5; - LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); - LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); - LUT6 #(.INIT(LUT[191:128])) fpga_lut_2 (.O(T2), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); - LUT6 #(.INIT(LUT[255:192])) fpga_lut_3 (.O(T3), - .I0(A[0]), .I1(A[1]), .I2(A[2]), - .I3(A[3]), .I4(A[4]), .I5(A[5])); + LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); + LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); + LUT6 #(.INIT(P_LUT[191:128])) fpga_lut_2 (.O(T2), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); + LUT6 #(.INIT(P_LUT[255:192])) fpga_lut_3 (.O(T3), + .I0(A[5]), .I1(A[4]), .I2(A[3]), + .I3(A[2]), .I4(A[1]), .I5(A[0])); MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[6])); MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[6])); MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[7]));