Merge remote-tracking branch 'origin/master' into xc7srl

1 files changed, 275 insertions, 7 deletions

diff --git a/techlibs/xilinx/arith_map.v b/techlibs/xilinx/arith_map.v
index 03719659b..09a5f07e8 100644
--- a/techlibs/xilinx/arith_map.v
+++ b/techlibs/xilinx/arith_map.v
@@ -17,6 +17,9 @@
  *
  */
 
+// ============================================================================
+// LCU
+
 (* techmap_celltype = "$lcu" *)
 module _80_xilinx_lcu (P, G, CI, CO);
 	parameter WIDTH = 2;
@@ -28,10 +31,78 @@ module _80_xilinx_lcu (P, G, CI, CO);
 
 	wire _TECHMAP_FAIL_ = WIDTH <= 2;
 
+	genvar i;
+
+`ifdef _CLB_CARRY
+
+	localparam CARRY4_COUNT = (WIDTH + 3) / 4;
+	localparam MAX_WIDTH    = CARRY4_COUNT * 4;
+	localparam PAD_WIDTH    = MAX_WIDTH - WIDTH;
+
+	wire [MAX_WIDTH-1:0] S  = {{PAD_WIDTH{1'b0}}, P & ~G};
+	wire [MAX_WIDTH-1:0] C  = CO;
+
+	generate for (i = 0; i < CARRY4_COUNT; i = i + 1) begin:slice
+
+		// Partially occupied CARRY4
+		if ((i+1)*4 > WIDTH) begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 carry4_1st_part
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (G [(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4]),
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_part
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (G [(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4]),
+				);
+			end
+
+		// Fully occupied CARRY4
+		end else begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 carry4_1st_full
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (G [((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4]),
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_full
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (G [((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4]),
+				);
+			end
+
+		end
+
+	end endgenerate
+
+`elsif _EXPLICIT_CARRY
+
 	wire [WIDTH-1:0] C = {CO, CI};
 	wire [WIDTH-1:0] S = P & ~G;
 
-	genvar i;
 	generate for (i = 0; i < WIDTH; i = i + 1) begin:slice
 		MUXCY muxcy (
 			.CI(C[i]),
@@ -40,8 +111,28 @@ module _80_xilinx_lcu (P, G, CI, CO);
 			.O(CO[i])
 		);
 	end endgenerate
+
+`else
+
+	wire [WIDTH-1:0] C = {CO, CI};
+	wire [WIDTH-1:0] S = P & ~G;
+
+	generate for (i = 0; i < WIDTH; i = i + 1) begin:slice
+		MUXCY muxcy (
+			.CI(C[i]),
+			.DI(G[i]),
+			.S(S[i]),
+			.O(CO[i])
+		);
+	end endgenerate
+`endif
+
 endmodule
 
+
+// ============================================================================
+// ALU
+
 (* techmap_celltype = "$alu" *)
 module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 	parameter A_SIGNED = 0;
@@ -49,6 +140,8 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 	parameter A_WIDTH = 1;
 	parameter B_WIDTH = 1;
 	parameter Y_WIDTH = 1;
+	parameter _TECHMAP_CONSTVAL_CI_ = 0;
+	parameter _TECHMAP_CONSTMSK_CI_ = 0;
 
 	input [A_WIDTH-1:0] A;
 	input [B_WIDTH-1:0] B;
@@ -66,16 +159,189 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 	wire [Y_WIDTH-1:0] AA = A_buf;
 	wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf;
 
-	wire [Y_WIDTH-1:0] P = AA ^ BB;
-	wire [Y_WIDTH-1:0] G = AA & BB;
-	wire [Y_WIDTH-1:0] C = {CO, CI};
-	wire [Y_WIDTH-1:0] S = P & ~G;
+	genvar i;
+
+`ifdef _CLB_CARRY
+
+	localparam CARRY4_COUNT = (Y_WIDTH + 3) / 4;
+	localparam MAX_WIDTH    = CARRY4_COUNT * 4;
+	localparam PAD_WIDTH    = MAX_WIDTH - Y_WIDTH;
+
+	wire [MAX_WIDTH-1:0] S  = {{PAD_WIDTH{1'b0}}, AA ^ BB};
+	wire [MAX_WIDTH-1:0] DI = {{PAD_WIDTH{1'b0}}, AA & BB};
+
+	wire [MAX_WIDTH-1:0] C  = CO;
 
 	genvar i;
+	generate for (i = 0; i < CARRY4_COUNT; i = i + 1) begin:slice
+
+		// Partially occupied CARRY4
+		if ((i+1)*4 > Y_WIDTH) begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 #(.IS_INITIALIZED(1'd1)) carry4_1st_part
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (DI[(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.O     (Y [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4])
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_part
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (DI[(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.O     (Y [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4])
+				);
+			end
+
+		// Fully occupied CARRY4
+		end else begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 #(.IS_INITIALIZED(1'd1)) carry4_1st_full
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (DI[((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.O     (Y [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4])
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_full
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (DI[((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.O     (Y [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4])
+				);
+			end
+
+		end
+
+	end endgenerate
+
+`elsif _EXPLICIT_CARRY
+
+	wire [Y_WIDTH-1:0] S = AA ^ BB;
+	wire [Y_WIDTH-1:0] DI = AA & BB;
+
+	wire CINIT;
+	// Carry chain.
+	//
+	// VPR requires that the carry chain never hit the fabric.	The CO input
+	// to this techmap is the carry outputs for synthesis, e.g. might hit the
+	// fabric.
+	//
+	// So we maintain two wire sets, CO_CHAIN is the carry that is for VPR,
+	// e.g. off fabric dedicated chain.  CO is the carry outputs that are
+	// available to the fabric.
+	wire [Y_WIDTH-1:0] CO_CHAIN;
+	wire [Y_WIDTH-1:0] C = {CO_CHAIN, CINIT};
+
+	// If carry chain is being initialized to a constant, techmap the constant
+	// source.	Otherwise techmap the fabric source.
+	generate for (i = 0; i < 1; i = i + 1) begin:slice
+		CARRY0 #(.CYINIT_FABRIC(1)) carry(
+			.CI_INIT(CI),
+			.DI(DI[0]),
+			.S(S[0]),
+			.CO_CHAIN(CO_CHAIN[0]),
+			.CO_FABRIC(CO[0]),
+			.O(Y[0])
+		);
+	end endgenerate
+
+	generate for (i = 1; i < Y_WIDTH-1; i = i + 1) begin:slice
+		if(i % 4 == 0) begin
+			CARRY0 carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.CO_FABRIC(CO[i]),
+				.O(Y[i])
+			);
+		end
+		else
+		begin
+			CARRY carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.CO_FABRIC(CO[i]),
+				.O(Y[i])
+			);
+		end
+	end endgenerate
+
+	generate for (i = Y_WIDTH-1; i < Y_WIDTH; i = i + 1) begin:slice
+		if(i % 4 == 0) begin
+			CARRY0 top_of_carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.O(Y[i])
+			);
+		end
+		else
+		begin
+			CARRY top_of_carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.O(Y[i])
+			);
+		end
+		// Turns out CO_FABRIC and O both use [ABCD]MUX, so provide
+		// a non-congested path to output the top of the carry chain.
+		// Registering the output of the CARRY block would solve this, but not
+		// all designs do that.
+		if((i+1) % 4 == 0) begin
+			CARRY0 carry_output (
+				.CI(CO_CHAIN[i]),
+				.DI(0),
+				.S(0),
+				.O(CO[i])
+			);
+		end
+		else
+		begin
+			CARRY carry_output (
+				.CI(CO_CHAIN[i]),
+				.DI(0),
+				.S(0),
+				.O(CO[i])
+			);
+		end
+	end endgenerate
+
+`else
+
+	wire [Y_WIDTH-1:0] S = AA ^ BB;
+	wire [Y_WIDTH-1:0] DI = AA & BB;
+
+	wire [Y_WIDTH-1:0] C = {CO, CI};
+
 	generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice
 		MUXCY muxcy (
 			.CI(C[i]),
-			.DI(G[i]),
+			.DI(DI[i]),
 			.S(S[i]),
 			.O(CO[i])
 		);
@@ -86,6 +352,8 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 		);
 	end endgenerate
 
-	assign X = P;
+`endif
+
+	assign X = S;
 endmodule