feat: `forge build --maximize-optimizer-runs` to find max number of optimizer runs

[mds1]

Component

Forge

Describe the feature you would like

Setting the optimizer's --optimize-runs count to 1 results in the smallest contract size, but higher runtime gas costs. As that number increases, contract size increases and gas costs decrease.

Therefore, a useful method would be forge build --optimize-size. This would basically be a binary search that keeps re-compiling the contracts until they exceed the size limit. Specifically:

• The maximum number of optimizer runs is 2^32 - 1. Start by compiling the contracts with the number of runs set to half this value.
• If the contracts are above the size limit, reduce the optimizer runs by half and re-build.
• If the contracts are below the size limit, increase the optimizer runs to mean(2^32 - 1, (2^32 - 1) / 2) and re-build.
• Repeat until we find the maximum number of optimizer runs that results in all contracts being below the size limit, and print that number of runs
• If all attempts fail and are over the size limit, exit with an error

In practice I've noticed diminishing returns as you increase the runs very high, with 10M+ runs all typically giving the same results. Therefore we can speed up the above search by assuming the max number of runs is smaller, such as 10M or 100M

Additional context

Pulled out of #992

[sambacha]

Would very much be interested in a VIA_IR=true and normal output with optimizer runs comparison. This could also be expanded to include peephole optimization settings potentially (not 1:1 obviously)

[gakonst]

@robertabbott check this out

[0xfarhaan]

Would be interested in this feature. @mds1 is this still being considered ?

[mds1]

@0xfarhaan Yea I can assign this to you if you'd like. Note that you'll also have to specify a contract name to optimize for. The command should use whatever profile is specified, and if that profile has no optimizer enabled it should error

Note that currently I don't think you can use different optimizer settings for different contracts, so to use the output of this flag you'd apply the result to all contracts

[0xfarhaan]

Would love to but would be a bit of a stretch for me atm 🥲