Add #1460 testcase

tests/arch/xilinx/bug1460.ys

@@ -0,0 +1,34 @@
+read_verilog <<EOT
+module register_file(
+    input wire clk,
+    input wire write_enable,
+    input wire [63:0] write_data,
+    input wire [4:0] write_reg,
+    input wire [4:0] read1_reg,
+    input wire [4:0] read2_reg,
+    input wire [4:0] read3_reg,
+    output reg [63:0] read1_data,
+    output reg [63:0] read2_data,
+    output reg [63:0] read3_data
+    );
+
+    reg [63:0] registers[0:31];
+
+    always @(posedge clk) begin
+      if (write_enable == 1'b1) begin
+        registers[write_reg] <= write_data;
+      end
+    end
+
+    always @(all) begin
+      read1_data <= registers[read1_reg];
+      read2_data <= registers[read2_reg];
+      read3_data <= registers[read3_reg];
+    end
+endmodule
+EOT
+
+synth_xilinx
+cd register_file
+select -assert-count 32 t:RAM32M
+select -assert-none t:* t:BUFG %d t:RAM32M %d