When I tried Xilinx Webpack 6.3, I noticed that the XST (Xilinx Synthesis Technology) was missing some Verilog-2001 features.
For me, the showstoppers were no $signed and $unsigned system- tasks. (I know they don't do anything when moving between signedunsigned vectors of identical bit-width, but our RTL uses them to clearly denote the designer's intent.)
And lack of Verilog macro-arguments ...
`define MINIMUM2( x , y ) ( ((x) < (y)) ? (x) : (y) )
^^^ This causes XST preprocessor to throw a syntax-error.
Have these issues been addressed?