[tejuis]

There are some contradictions in here. If you map your functionality from software (on CPU) to FPGA, your software becomes hardware. FPGA is hardware. FPGA is retargetable, but it is not programmable in the sense what SW requires. The resources are preallocated, which is the essential property of hardware.

In software you allocate and deallocate memory, which is your dynamic resource. You don't have that in HW. You can implement a memory manager in HW, but your system will not be flexible enough to be soft. Also you can synthesize your CPU on FPGA, but the performance is poor compared to a hard CPU on FPGA.

Currently FPGAs are becoming popular in accelerating software functions to offload the CPU. The most powerful FPGAs have a lot of fixed logic CPUs in them (i.e. hard macros).

You can't just say that I'll just go ahead and run my software functions as hardware. For certain type of workloads you always need software, in practice (not in theory).

[wyatwerp]

Does it matter which workloads always need software? If anything, the networking use-case shows that a workload, any workload, that is ubiquitous & can benefit tremendously from programmable hardware is what matters.

In a shared-memory system, just implementing libc (or the Java VM, or the Erlang VM) on an FPGA might be a win. It has to be enough bang for the buck for FPGA, but not so much that somebody would make fixed-hardware for it.

On that note, haven't networking end-points had fixed hardware also for ages now? Maybe it is inevitable that a successful application of FPGA's breeds interest in fixed-function hardware for it.