Compile Solidity to assembly keeping a correspondence with the source code

Question

I would like to compile a contract written in Solidity (or even just the part relating to a single method) to study it and understand if I can optimize it. I already managed to get the bytecode as binary or in its assembly representation using solc but I would prefer to keep the original source in the assembly like comments, line per line, similar to what happens with gcc -S.

Moreover, I can't understand if the solc compiler uses the Yul language as intermediate representation between Solidity and assembly during the compilation, in case it did, how can I view this representation?

Answer 1

Probably, the closest you will get is to use --asm output from solc.

With solc 0.8 you can get the intermediate Yul representation with --ir.

The command

solc -o build --asm --ir MetaCoin.sol

should generate MetaCoin.evm and MetaCoin.yul files in build directory.

Answer 2

If you want to manually optimize solc --asm output you can do it with my EVM assembler :) https://github.com/RafaelSalguero/evm-assembler

It's compatible with solc --asm output