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> As I have argued above, knowing the FPGA vendors lower-level abstractions won't make the problem any better. Where did you argue that? Why is it reasonable t
by nickysielicki 7y ago
> As I have argued above, knowing the FPGA vendors lower-level abstractions won't make the problem any better.
Where did you argue that? Why is it reasonable to expect that proprietary synthesis tools are going to be better than an open source one? That definitely was not the case, long term, with proprietary C compilers of yesteryears. LLVM is the future, and mostly because of LLVM-IR. So ASTs are well optimized in a general format, why shouldn't digital logic circuits be similar? Yes, actually mapping this to xlnx (etc.) primitives is going to be different for each vendor... In the same sense that mapping LLVM-IR to aarch64 and amd64 is going to be different. So what? That doesn't mean that all is lost.
> The hard work is mapping onto gates/LUTs.
I think it's reasonable to expect that things like FIRRTL have the potential to outperform the synthesis tools that exist currently. The closer the representation gets to a pure graph theory problem, the better chance we have at reasoning about it.
The author makes a good point about Verilog being the current interface. Look at how FIRRTL has to be transpiled back to Verilog to be piped into synthesis tools. That's madness, and it's very opaque, and there's a lot of information lost that we just have to trust the tools to recover. Verilog is a lossy format, and that's the takeaway from this article for me, and you haven't addressed that point at all.
- badamp 7y ago> Why is it reasonable to expect that proprietary synthesis tools are going to be better than an open source one? That definitely was not the case, long term, with proprietary C compilers of yesteryears. LLVM is the future, and mostly because of LLVM-IR. Lol citation needed. Last I checked the performance oriented commercial closed source C/C++ compilers still outperform Clang and LLVM. And so does gcc for most cases for that matter.
- ncmncm 7y agoClue: Gcc is Free Software too. New languages typically are not implemented with Gcc, though. So, long term, LLVM probably wins.
- badamp 7y agoI don’t follow. Though gcc still trumps clang in some areas, neither gcc nor llvm beat the commercial compilers like ICC in a wide range of workloads.. obviously there is still a market for ICC and AOCC. The original point was that open sourcing would necessarily lead to better performing tooling. And again to that I maintain... citation needed.
- nonlinearzone 7y agoI argued it in the second quote: "The hard word is mapping onto gates/LUTs". It doesn't matter whether its gates or FPGA luts, the work is the same. I never argued anything regarding proprietary vs opensource tools. I love opensource tools and appreciate projects such as FIRRTL, Symbiflow, Yosys, Chisel, Clash, etc have amazing potential. Having access to the FPGA vendors low-level abstractions enables the broader use and development of these tools, which is important. My point was only that gates/LUTs are the fundamental building blocks of all digital computing. They are not easily abstractable, and to say that FPGAs have the wrong abstraction is not the best way to look at the problem. FPGAs aren't going to fundamentally change, they aren't going to evolve from FPGA : GPFPGA (to answer the author's analogy). But, tools can always be improved and make FPGA design more accessible.