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-rw-r--r--techlibs/xilinx/lut_map.v97
1 files changed, 61 insertions, 36 deletions
diff --git a/techlibs/xilinx/lut_map.v b/techlibs/xilinx/lut_map.v
index d07c59dee..13d3c3268 100644
--- a/techlibs/xilinx/lut_map.v
+++ b/techlibs/xilinx/lut_map.v
@@ -29,61 +29,86 @@ 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
+ function [WIDTH-1:0] permute_index;
+ input [WIDTH-1:0] i;
+ integer j;
+ begin
+ permute_index = 0;
+ for (j = 0; j < WIDTH; j = j + 1)
+ permute_index[WIDTH-1 - j] = i[j];
+ end
+ endfunction
+
+ function [2**WIDTH-1:0] permute_init;
+ input [2**WIDTH-1:0] orig;
+ integer i;
+ begin
+ permute_init = 0;
+ for (i = 0; i < 2**WIDTH; i = i + 1)
+ permute_init[i] = orig[permute_index(i)];
+ end
+ endfunction
+
+ parameter [2**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]));
- MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[6]));
+ LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0),
+ .I0(A[6]), .I1(A[5]), .I2(A[4]),
+ .I3(A[3]), .I4(A[2]), .I5(A[1]));
+ LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1),
+ .I0(A[6]), .I1(A[5]), .I2(A[4]),
+ .I3(A[3]), .I4(A[2]), .I5(A[1]));
+ MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[0]));
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]));
- 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]));
+ LUT6 #(.INIT(P_LUT[63:0])) fpga_lut_0 (.O(T0),
+ .I0(A[7]), .I1(A[6]), .I2(A[5]),
+ .I3(A[4]), .I4(A[3]), .I5(A[2]));
+ LUT6 #(.INIT(P_LUT[127:64])) fpga_lut_1 (.O(T1),
+ .I0(A[7]), .I1(A[6]), .I2(A[5]),
+ .I3(A[4]), .I4(A[3]), .I5(A[2]));
+ LUT6 #(.INIT(P_LUT[191:128])) fpga_lut_2 (.O(T2),
+ .I0(A[7]), .I1(A[6]), .I2(A[5]),
+ .I3(A[4]), .I4(A[3]), .I5(A[2]));
+ LUT6 #(.INIT(P_LUT[255:192])) fpga_lut_3 (.O(T3),
+ .I0(A[7]), .I1(A[6]), .I2(A[5]),
+ .I3(A[4]), .I4(A[3]), .I5(A[2]));
+ MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[1]));
+ MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[1]));
+ MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[0]));
end else begin
wire _TECHMAP_FAIL_ = 1;
end