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Fix for mux_case_* mappings

This commit is contained in:
Eddie Hung 2019-04-22 16:56:18 -07:00
parent ac1e13819e
commit 61161faefc
1 changed files with 9 additions and 17 deletions
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24
techlibs/xilinx/cells_map.v
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@ -157,32 +157,24 @@ module \$shiftx (A, B, Y);
parameter [B_WIDTH-1:0] _TECHMAP_CONSTMSK_B_ = 0;
parameter [B_WIDTH-1:0] _TECHMAP_CONSTVAL_B_ = 0;
function integer first_B_nonzero;
integer i;
begin
for (i = B_WIDTH-1; i >= 0; i--)
if (_TECHMAP_CONSTMSK_B_[i] == 1'b0 || _TECHMAP_CONSTVAL_B_ != 1'b0)
first_B_nonzero = i;
end
endfunction
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), .Y_WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(A), .B(B[B_WIDTH-2:0]), .Y(Y));
\$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
localparam inc = first_B_nonzero();
for (i = 0; i < Y_WIDTH; i++) begin
wire [A_WIDTH/Y_WIDTH-1:0] A_i;
for (j = 0; j*(1<<inc)+i < A_WIDTH; j++)
assign A_i[j] = A[j*(1<<inc)+i];
\$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(A_WIDTH/Y_WIDTH), .B_WIDTH(B_WIDTH-inc), .Y_WIDTH(1'b1)) bitblast (.A(A_i), .B(B[B_WIDTH-1:inc]), .Y(Y[i]));
for (i = 0; i < Y_WIDTH; i++)
\$shiftx #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(A_WIDTH), .B_WIDTH(B_WIDTH), .Y_WIDTH(1'd1)) bitblast (.A({{i{1'bx}}, A[A_WIDTH-1:i]}), .B(B), .Y(Y[i]));
end
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) begin
wire _TECHMAP_FAIL_ = 1;