fabulous: Add support for LUT6s

Signed-off-by: gatecat <gatecat@ds0.me>

2 files changed, 38 insertions, 1 deletions

diff --git a/techlibs/fabulous/cells_map.v b/techlibs/fabulous/cells_map.v
index eadd18b6f..e33e641a8 100644
--- a/techlibs/fabulous/cells_map.v
+++ b/techlibs/fabulous/cells_map.v
@@ -16,10 +16,15 @@ module \$lut (A, Y);
     end else
     if (WIDTH == 3) begin
       LUT3 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y), .I0(A[0]), .I1(A[1]), .I2(A[2]));
-
     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]));
+    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]));
+    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]));
     end else begin
       wire _TECHMAP_FAIL_ = 1;
     end
diff --git a/techlibs/fabulous/prims.v b/techlibs/fabulous/prims.v
index fe3e8536a..21dc5223d 100644
--- a/techlibs/fabulous/prims.v
+++ b/techlibs/fabulous/prims.v
@@ -38,6 +38,38 @@ module LUT4_HA(output O, Co, input I0, I1, I2, I3, Ci);
   assign Co = (Ci & I1) | (Ci & I2) | (I1 & I2);
 endmodule
 
+module LUT5(output O, input I0, I1, I2, I3, I4);
+  parameter [31:0] INIT = 0;
+  wire [15: 0] s4 = I4 ? INIT[31:16] : INIT[15: 0];
+  wire [ 7: 0] s3 = I3 ?   s4[15: 8] :   s4[ 7: 0];
+  wire [ 3: 0] s2 = I2 ?   s3[ 7: 4] :   s3[ 3: 0];
+  wire [ 1: 0] s1 = I1 ?   s2[ 3: 2] :   s2[ 1: 0];
+  assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module LUT6(output O, input I0, I1, I2, I3, I4, I5);
+  parameter [63:0] INIT = 0;
+  wire [31: 0] s5 = I5 ? INIT[63:32] : INIT[31: 0];
+  wire [15: 0] s4 = I4 ?   s5[31:16] :   s5[15: 0];
+  wire [ 7: 0] s3 = I3 ?   s4[15: 8] :   s4[ 7: 0];
+  wire [ 3: 0] s2 = I2 ?   s3[ 7: 4] :   s3[ 3: 0];
+  wire [ 1: 0] s1 = I1 ?   s2[ 3: 2] :   s2[ 1: 0];
+  assign O = I0 ? s1[1] : s1[0];
+endmodule
+
+module LUT55_FCY (output O, Co, input I0, I1, I2, I3, I4, Ci);
+  parameter [63:0] INIT = 0;
+
+  wire comb1, comb2;
+
+  LUT5 #(.INIT(INIT[31: 0])) l5_1 (.I0(I0), .I1(I1), .I2(I2), .I3(I3), .I4(I4), .O(comb1));
+  LUT5 #(.INIT(INIT[63:32])) l5_2 (.I0(I0), .I1(I1), .I2(I2), .I3(I3), .I4(I4), .O(comb2));
+
+  assign O = comb1 ^ Ci;
+  assign Co = comb1 ? Ci : comb2;
+endmodule
+
+
 module LUTFF(input CLK, D, output reg O);
   initial O = 1'b0;
   always @ (posedge CLK) begin