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Improved techmap of shift with wide B inputs

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This commit is contained in:
Clifford Wolf 2014-03-06 11:54:22 +01:00
parent a1bfde8c5e
commit d7f29bb23f
1 changed files with 37 additions and 13 deletions
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50
techlibs/common/stdcells.v
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@ -165,6 +165,7 @@ parameter B_WIDTH = 1;
parameter Y_WIDTH = 1; parameter Y_WIDTH = 1;
parameter WIDTH = Y_WIDTH; parameter WIDTH = Y_WIDTH;
localparam BB_WIDTH = $clog2(WIDTH) + 1 < B_WIDTH ? $clog2(WIDTH) + 1 : B_WIDTH;
input [A_WIDTH-1:0] A; input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B; input [B_WIDTH-1:0] B;
@ -181,11 +182,16 @@ generate
.A(A), .A(A),
.Y(chain[WIDTH-1:0]) .Y(chain[WIDTH-1:0])
); );
assign Y = chain[WIDTH*(B_WIDTH+1)-1 : WIDTH*B_WIDTH]; assign Y = chain[WIDTH*(BB_WIDTH+1)-1 : WIDTH*BB_WIDTH];
for (i = 0; i < B_WIDTH; i = i + 1) begin:V for (i = 0; i < BB_WIDTH; i = i + 1) begin:V
wire [WIDTH-1:0] unshifted, shifted, result; wire [WIDTH-1:0] unshifted, shifted, result;
assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i]; assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i];
assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result; assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result;
wire BBIT;
if (i == BB_WIDTH-1 && BB_WIDTH < B_WIDTH)
assign BBIT = |B[B_WIDTH-1:BB_WIDTH-1];
else
assign BBIT = B[i];
\$__shift #( \$__shift #(
.WIDTH(WIDTH), .WIDTH(WIDTH),
.SHIFT(0 - (2 ** (i > 30 ? 30 : i))) .SHIFT(0 - (2 ** (i > 30 ? 30 : i)))
@ -200,7 +206,7 @@ generate
.A(unshifted), .A(unshifted),
.B(shifted), .B(shifted),
.Y(result), .Y(result),
.S(B[i]) .S(BBIT)
); );
end end
endgenerate endgenerate
@ -218,6 +224,7 @@ parameter B_WIDTH = 1;
parameter Y_WIDTH = 1; parameter Y_WIDTH = 1;
localparam WIDTH = A_WIDTH > Y_WIDTH ? A_WIDTH : Y_WIDTH; localparam WIDTH = A_WIDTH > Y_WIDTH ? A_WIDTH : Y_WIDTH;
localparam BB_WIDTH = $clog2(WIDTH) + 1 < B_WIDTH ? $clog2(WIDTH) + 1 : B_WIDTH;
input [A_WIDTH-1:0] A; input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B; input [B_WIDTH-1:0] B;
@ -225,7 +232,7 @@ output [Y_WIDTH-1:0] Y;
genvar i; genvar i;
generate generate
wire [WIDTH*(B_WIDTH+1)-1:0] chain; wire [WIDTH*(BB_WIDTH+1)-1:0] chain;
\$pos #( \$pos #(
.A_SIGNED(A_SIGNED), .A_SIGNED(A_SIGNED),
.A_WIDTH(A_WIDTH), .A_WIDTH(A_WIDTH),
@ -234,11 +241,16 @@ generate
.A(A), .A(A),
.Y(chain[WIDTH-1:0]) .Y(chain[WIDTH-1:0])
); );
assign Y = chain[WIDTH*(B_WIDTH+1)-1 : WIDTH*B_WIDTH]; assign Y = chain[WIDTH*(BB_WIDTH+1)-1 : WIDTH*BB_WIDTH];
for (i = 0; i < B_WIDTH; i = i + 1) begin:V for (i = 0; i < BB_WIDTH; i = i + 1) begin:V
wire [WIDTH-1:0] unshifted, shifted, result; wire [WIDTH-1:0] unshifted, shifted, result;
assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i]; assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i];
assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result; assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result;
wire BBIT;
if (i == BB_WIDTH-1 && BB_WIDTH < B_WIDTH)
assign BBIT = |B[B_WIDTH-1:BB_WIDTH-1];
else
assign BBIT = B[i];
\$__shift #( \$__shift #(
.WIDTH(WIDTH), .WIDTH(WIDTH),
.SHIFT(2 ** (i > 30 ? 30 : i)) .SHIFT(2 ** (i > 30 ? 30 : i))
@ -253,7 +265,7 @@ generate
.A(unshifted), .A(unshifted),
.B(shifted), .B(shifted),
.Y(result), .Y(result),
.S(B[i]) .S(BBIT)
); );
end end
endgenerate endgenerate
@ -271,6 +283,7 @@ parameter B_WIDTH = 1;
parameter Y_WIDTH = 1; parameter Y_WIDTH = 1;
localparam WIDTH = Y_WIDTH; localparam WIDTH = Y_WIDTH;
localparam BB_WIDTH = $clog2(WIDTH) + 1 < B_WIDTH ? $clog2(WIDTH) + 1 : B_WIDTH;
input [A_WIDTH-1:0] A; input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B; input [B_WIDTH-1:0] B;
@ -292,6 +305,11 @@ generate
wire [WIDTH-1:0] unshifted, shifted, result; wire [WIDTH-1:0] unshifted, shifted, result;
assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i]; assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i];
assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result; assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result;
wire BBIT;
if (i == BB_WIDTH-1 && BB_WIDTH < B_WIDTH)
assign BBIT = |B[B_WIDTH-1:BB_WIDTH-1];
else
assign BBIT = B[i];
\$__shift #( \$__shift #(
.WIDTH(WIDTH), .WIDTH(WIDTH),
.SHIFT(0 - (2 ** (i > 30 ? 30 : i))) .SHIFT(0 - (2 ** (i > 30 ? 30 : i)))
@ -306,7 +324,7 @@ generate
.A(unshifted), .A(unshifted),
.B(shifted), .B(shifted),
.Y(result), .Y(result),
.S(B[i]) .S(BBIT)
); );
end end
endgenerate endgenerate
@ -324,6 +342,7 @@ parameter B_WIDTH = 1;
parameter Y_WIDTH = 1; parameter Y_WIDTH = 1;
localparam WIDTH = A_WIDTH > Y_WIDTH ? A_WIDTH : Y_WIDTH; localparam WIDTH = A_WIDTH > Y_WIDTH ? A_WIDTH : Y_WIDTH;
localparam BB_WIDTH = $clog2(WIDTH) + 1 < B_WIDTH ? $clog2(WIDTH) + 1 : B_WIDTH;
input [A_WIDTH-1:0] A; input [A_WIDTH-1:0] A;
input [B_WIDTH-1:0] B; input [B_WIDTH-1:0] B;
@ -331,7 +350,7 @@ output [Y_WIDTH-1:0] Y;
genvar i; genvar i;
generate generate
wire [WIDTH*(B_WIDTH+1)-1:0] chain; wire [WIDTH*(BB_WIDTH+1)-1:0] chain;
\$pos #( \$pos #(
.A_SIGNED(A_SIGNED), .A_SIGNED(A_SIGNED),
.A_WIDTH(A_WIDTH), .A_WIDTH(A_WIDTH),
@ -342,18 +361,23 @@ generate
); );
for (i = 0; i < Y_WIDTH; i = i + 1) begin:Y for (i = 0; i < Y_WIDTH; i = i + 1) begin:Y
if (i < WIDTH) begin if (i < WIDTH) begin
assign Y[i] = chain[WIDTH*B_WIDTH + i]; assign Y[i] = chain[WIDTH*BB_WIDTH + i];
end else end else
if (A_SIGNED) begin if (A_SIGNED) begin
assign Y[i] = chain[WIDTH*B_WIDTH + WIDTH-1]; assign Y[i] = chain[WIDTH*BB_WIDTH + WIDTH-1];
end else begin end else begin
assign Y[i] = 0; assign Y[i] = 0;
end end
end end
for (i = 0; i < B_WIDTH; i = i + 1) begin:V for (i = 0; i < BB_WIDTH; i = i + 1) begin:V
wire [WIDTH-1:0] unshifted, shifted, result; wire [WIDTH-1:0] unshifted, shifted, result;
assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i]; assign unshifted = chain[WIDTH*i + WIDTH-1 : WIDTH*i];
assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result; assign chain[WIDTH*(i+1) + WIDTH-1 : WIDTH*(i+1)] = result;
wire BBIT;
if (i == BB_WIDTH-1 && BB_WIDTH < B_WIDTH)
assign BBIT = |B[B_WIDTH-1:BB_WIDTH-1];
else
assign BBIT = B[i];
\$__shift #( \$__shift #(
.WIDTH(WIDTH), .WIDTH(WIDTH),
.SHIFT(2 ** (i > 30 ? 30 : i)) .SHIFT(2 ** (i > 30 ? 30 : i))
@ -368,7 +392,7 @@ generate
.A(unshifted), .A(unshifted),
.B(shifted), .B(shifted),
.Y(result), .Y(result),
.S(B[i]) .S(BBIT)
); );
end end
endgenerate endgenerate