Wholly ignorant passer by here. Is this a thing that’d make (notoriously) slow FPGA synthesis (by which I think I mean the conversion of VHDL or Verilog to something that can be injected into an FPGA) much faster?
ashtonsix•1mo ago
No, but it could help people build those synthesis tools much faster.
P4Synth takes a (mathematical) group of functions/expressions and finds strong candidate implementations for every class in that group. Then, as long we have a fast (expression → class) mapping for that group we can use the generated solutions as a database embedded within the compiler for automated expression replacement (or mapping from expressions to circuits/technology).
Vivado/Quartus (FPGA) technology mapping and LLVM's InstCombine stage are essentially this. InstCombine's pattern library is partially human-authored, partially generated by search tools; it lists ~30k subexpression replacements like a+a+a → a*3. P4Synth competes with those search tools. For hard function classes, existing methods might take weeks on a supercomputer: P4Synth speeds that up exponentially.
It only solves a narrow toy problem right now (4-input boolean functions), but I believe the technique could scale with modifications (like A* style prioritisation over signal-set novelty and implementation score).
colinb•1mo ago
ashtonsix•1mo ago
P4Synth takes a (mathematical) group of functions/expressions and finds strong candidate implementations for every class in that group. Then, as long we have a fast (expression → class) mapping for that group we can use the generated solutions as a database embedded within the compiler for automated expression replacement (or mapping from expressions to circuits/technology).
Vivado/Quartus (FPGA) technology mapping and LLVM's InstCombine stage are essentially this. InstCombine's pattern library is partially human-authored, partially generated by search tools; it lists ~30k subexpression replacements like a+a+a → a*3. P4Synth competes with those search tools. For hard function classes, existing methods might take weeks on a supercomputer: P4Synth speeds that up exponentially.
It only solves a narrow toy problem right now (4-input boolean functions), but I believe the technique could scale with modifications (like A* style prioritisation over signal-set novelty and implementation score).