/* * yosys -- Yosys Open SYnthesis Suite * * Copyright (C) 2012 Claire Xenia Wolf <claire@yosyshq.com> * 2019 Eddie Hung <eddie@fpgeh.com> * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * */ // The purpose of these mapping rules is to allow preserve all (sufficiently // wide) $shiftx cells during 'techmap' so that they can be mapped to hard // resources, rather than being bit-blasted to gates during 'techmap' // execution 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; (* force_downto *) input [A_WIDTH-1:0] A; (* force_downto *) input [B_WIDTH-1:0] B; (* force_downto *) output [Y_WIDTH-1:0] Y; parameter [B_WIDTH-1:0] _TECHMAP_CONSTMSK_B_ = 0; parameter [B_WIDTH-1:0] _TECHMAP_CONSTVAL_B_ = 0; generate if (B_SIGNED) begin if (_TECHMAP_CONSTMSK_B_[B_WIDTH-1] && (_TECHMAP_CONSTVAL_B_[B_WIDTH-1] == 1'b0 || _TECHMAP_CONSTVAL_B_[B_WIDTH-1] === 1'bx)) // 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 begin if (((A_WIDTH + Y_WIDTH - 1) / Y_WIDTH) < `MIN_MUX_INPUTS) wire _TECHMAP_FAIL_ = 1; else \$__XILINX_SHIFTX #( .A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(A_WIDTH), .B_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH) ) _TECHMAP_REPLACE_ ( .A(A), .B(B), .Y(Y) ); end endgenerate endmodule