Added $shift and $shiftx cell types (needed for correct part select behavior)

1 files changed, 48 insertions, 0 deletions

diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v
index 1b50959c9..76aa4a52d 100644
--- a/techlibs/common/simlib.v
+++ b/techlibs/common/simlib.v
@@ -418,6 +418,54 @@ endmodule
 
 // --------------------------------------------------------
 
+module \$shift (A, B, Y);
+
+parameter A_SIGNED = 0;
+parameter B_SIGNED = 0;
+parameter A_WIDTH = 0;
+parameter B_WIDTH = 0;
+parameter Y_WIDTH = 0;
+
+input [A_WIDTH-1:0] A;
+input [B_WIDTH-1:0] B;
+output [Y_WIDTH-1:0] Y;
+
+generate
+	if (B_SIGNED) begin:BLOCK1
+		assign Y = $signed(B) < 0 ? A << -B : A >> B;
+	end else begin:BLOCK2
+		assign Y = A >> B;
+	end
+endgenerate
+
+endmodule
+
+// --------------------------------------------------------
+
+module \$shiftx (A, B, Y);
+
+parameter A_SIGNED = 0;
+parameter B_SIGNED = 0;
+parameter A_WIDTH = 0;
+parameter B_WIDTH = 0;
+parameter Y_WIDTH = 0;
+
+input [A_WIDTH-1:0] A;
+input [B_WIDTH-1:0] B;
+output [Y_WIDTH-1:0] Y;
+
+generate
+	if (B_SIGNED) begin:BLOCK1
+		assign Y = A[$signed(B) +: Y_WIDTH];
+	end else begin:BLOCK2
+		assign Y = A[B +: Y_WIDTH];
+	end
+endgenerate
+
+endmodule
+
+// --------------------------------------------------------
+
 module \$lt (A, B, Y);
 
 parameter A_SIGNED = 0;