Advantages of LPM_COMPARE vs. LPM_XOR vs. XOR when comparing two 32 bit numbers

I am not particularly experienced in reference material and I depend wholly on vendors descriptions. But you need really few things to switch to fpga if you are already familiar with general logic design.

The main theme in our post can be summarised as follows:

using lpm is example of structural approach when you instantiate somebody else's work or your own lower work.

using logic expressions is example of data flow or gate level and are dealt with by tool

using my vhdl expression is example of behavioral level when I leave it to tool to translate.

The above example also shows three layers of logic(aluts) which could compromise timing and registers may be needed between these levels in order to break long paths.