From 95867109ea4201d77a95a22f51cd3c4309ff8240 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Thu, 2 May 2019 11:25:10 -0700 Subject: [PATCH] Revert to pre-muxcover approach --- techlibs/xilinx/cells_map.v | 94 +++++++++++++++++++++++++++------ techlibs/xilinx/synth_xilinx.cc | 13 ++--- 2 files changed, 82 insertions(+), 25 deletions(-) diff --git a/techlibs/xilinx/cells_map.v b/techlibs/xilinx/cells_map.v index a80988480..0ec72b6a4 100644 --- a/techlibs/xilinx/cells_map.v +++ b/techlibs/xilinx/cells_map.v @@ -150,24 +150,84 @@ module \$__XILINX_SHREG_ (input C, input D, input [31:0] L, input E, output Q, o endgenerate endmodule -`ifndef NO_MUXFN -module \$_MUX8_ (A, B, C, D, E, F, G, H, S, T, U, Y); - input A, B, C, D, E, F, G, H, S, T, U; - output Y; +module \$shiftx (A, B, Y); + parameter A_SIGNED = 0; + parameter B_SIGNED = 0; + parameter A_WIDTH = 1; + parameter B_WIDTH = 1; + parameter Y_WIDTH = 1; - wire [1:0] Z; - assign Z = T ? (S ? {D,H} : {C,G}) : - (S ? {B,F} : {A,E}); - MUXF7 fpga_muxf7 (.I0(Z[0]), .I1(Z[1]), .S(U), .O(Y)); -endmodule + input [A_WIDTH-1:0] A; + input [B_WIDTH-1:0] B; + output [Y_WIDTH-1:0] Y; -module \$_MUX16_ (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, S, T, U, V, Y); - input A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, S, T, U, V; - output Y; + parameter [B_WIDTH-1:0] _TECHMAP_CONSTMSK_B_ = 0; + parameter [B_WIDTH-1:0] _TECHMAP_CONSTVAL_B_ = 0; - wire [1:0] Z; - \$_MUX8_ fpga_mux8_0 (.A(A), .B(B), .C(C), .D(D), .E(E), .F(F), .G(G), .H(H), .S(S), .T(T), .U(U), .Y(Z[0])); - \$_MUX8_ fpga_mux8_1 (.A(I), .B(J), .C(K), .D(L), .E(M), .F(N), .G(O), .H(P), .S(S), .T(T), .U(U), .Y(Z[1])); - MUXF8 fpga_muxf8 (.I0(Z[0]), .I1(Z[1]), .S(V), .O(Y)); + generate + genvar i, j; + if (B_SIGNED) begin + if (_TECHMAP_CONSTMSK_B_[B_WIDTH-1] && _TECHMAP_CONSTVAL_B_[B_WIDTH-1] == 1'b0) + // Optimisation to remove B_SIGNED if sign bit of B is constant-0 + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(0), .A_WIDTH(A_WIDTH), .B_WIDTH(B_WIDTH-1'd1), .Y_WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A), .B(B[B_WIDTH-2:0]), .Y(Y)); + else + wire _TECHMAP_FAIL_ = 1; + end + else if (Y_WIDTH > 1) begin + for (i = 0; i < Y_WIDTH; i++) + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(A_WIDTH-Y_WIDTH+1), .B_WIDTH(B_WIDTH), .Y_WIDTH(1'd1)) bitblast (.A(A[A_WIDTH-Y_WIDTH+i:i]), .B(B), .Y(Y[i])); + end + // If the LSB of B is constant zero (and Y_WIDTH is 1) then + // we can optimise by removing every other entry from A + // and popping the constant zero from B + else if (_TECHMAP_CONSTMSK_B_[0] && !_TECHMAP_CONSTVAL_B_[0]) begin + wire [(A_WIDTH+1)/2-1:0] A_i; + for (i = 0; i < (A_WIDTH+1)/2; i++) + assign A_i[i] = A[i*2]; + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH((A_WIDTH+1'd1)/2'd2), .B_WIDTH(B_WIDTH-1'd1), .Y_WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A_i), .B(B[B_WIDTH-1:1]), .Y(Y)); + end + else if (B_WIDTH < 3 || A_WIDTH <= 4) begin + wire _TECHMAP_FAIL_ = 1; + end + else if (B_WIDTH == 3) begin + localparam a_width0 = 2 ** 2; + localparam a_widthN = A_WIDTH - a_width0; + wire T0, T1; + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(a_width0), .B_WIDTH(2), .Y_WIDTH(Y_WIDTH)) fpga_shiftx (.A(A[a_width0-1:0]), .B(B[2-1:0]), .Y(T0)); + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(a_widthN), .B_WIDTH($clog2(a_widthN)), .Y_WIDTH(Y_WIDTH)) fpga_shiftx_last (.A(A[A_WIDTH-1:a_width0]), .B(B[$clog2(a_widthN)-1:0]), .Y(T1)); + MUXF7 fpga_mux (.I0(T0), .I1(T1), .S(B[B_WIDTH-1]), .O(Y)); + end + else if (B_WIDTH == 4) begin + localparam a_width0 = 2 ** 2; + localparam num_mux8 = A_WIDTH / a_width0; + localparam a_widthN = A_WIDTH - num_mux8*a_width0; + wire [4-1:0] T; + wire T0, T1; + for (i = 0; i < 4; i++) + if (i < num_mux8) + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(a_width0), .B_WIDTH(2), .Y_WIDTH(Y_WIDTH)) fpga_shiftx (.A(A[i*a_width0+:a_width0]), .B(B[2-1:0]), .Y(T[i])); + else if (i == num_mux8 && a_widthN > 0) + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(a_widthN), .B_WIDTH($clog2(a_widthN)), .Y_WIDTH(Y_WIDTH)) fpga_shiftx_last (.A(A[A_WIDTH-1:i*a_width0]), .B(B[$clog2(a_widthN)-1:0]), .Y(T[i])); + else + assign T[i] = 1'bx; + MUXF7 fpga_mux_0 (.I0(T[0]), .I1(T[1]), .S(B[2]), .O(T0)); + MUXF7 fpga_mux_1 (.I0(T[2]), .I1(T[3]), .S(B[2]), .O(T1)); + MUXF8 fpga_mux_2 (.I0(T0), .I1(T1), .S(B[3]), .O(Y)); + end + else begin + localparam a_width0 = 2 ** 4; + localparam num_mux16 = A_WIDTH / a_width0; + localparam a_widthN = A_WIDTH - num_mux16*a_width0; + wire [(2**(B_WIDTH-4))-1:0] T; + for (i = 0; i < 2 ** (B_WIDTH-4); i++) + if (i < num_mux16) + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(a_width0), .B_WIDTH(4), .Y_WIDTH(Y_WIDTH)) fpga_shiftx (.A(A[i*a_width0+:a_width0]), .B(B[4-1:0]), .Y(T[i])); + else if (i == num_mux16 && a_widthN > 0) begin + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(a_widthN), .B_WIDTH($clog2(a_widthN)), .Y_WIDTH(Y_WIDTH)) fpga_shiftx_last (.A(A[A_WIDTH-1:i*a_width0]), .B(B[$clog2(a_widthN)-1:0]), .Y(T[i])); + end + else + assign T[i] = 1'bx; + \$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(2**(B_WIDTH-4)), .B_WIDTH(B_WIDTH-4), .Y_WIDTH(Y_WIDTH)) fpga_shiftx (.A(T), .B(B[B_WIDTH-1:4]), .Y(Y)); + end + endgenerate endmodule -`endif // NO_MUXFN diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc index dd8b51818..7d7a05616 100644 --- a/techlibs/xilinx/synth_xilinx.cc +++ b/techlibs/xilinx/synth_xilinx.cc @@ -232,7 +232,7 @@ struct SynthXilinxPass : public ScriptPass // cells for identifying variable-length shift registers, // so attempt to convert $pmux-es to the former // Also: wide multiplexer inference benefits from this too - if (!nosrl || !nomux || help_mode) + if ((!nosrl && !nomux) || help_mode) run("pmux2shiftx", "(skip if '-nosrl' and '-nomux')"); run("opt -fast -full"); @@ -254,18 +254,15 @@ struct SynthXilinxPass : public ScriptPass run("shregmap -tech xilinx -minlen 3", "(skip if '-nosrl')"); } + if (!nomux || help_mode) + run("techmap -map +/xilinx/cells_map.v"); + run("techmap"); run("opt -fast"); - - if (!nomux || help_mode) - run("muxcover -mux8 -mux16"); } if (check_label("map_cells")) { - std::string define; - if (nomux) - define += " -D NO_MUXFN"; - run("techmap -map +/techmap.v -map +/xilinx/cells_map.v" + define); + run("techmap -map +/techmap.v -map +/xilinx/cells_map.v"); run("clean"); } -- 2.30.2