julia

fae6b785 - inlining: avoid source deserialization by using volatile inference result (#51934)

inlining: avoid source deserialization by using volatile inference result (#51934) Currently the inlining algorithm is allowed to use inferred source of const-prop'ed call that is always locally available (since const-prop' result isn't cached globally). For non const-prop'ed and globally cached calls, however, it undergoes a more expensive process, making a round-trip through serialized inferred source. We can improve efficiency by bypassing the serialization round-trip for newly-inferred and globally-cached frames. As these frames are never cached locally, they can be viewed as volatile. This means we can use their source destructively while inline-expanding them. The benchmark results show that this optimization achieves 2-4% allocation reduction and about 5% speed up in the real-world-ish compilation targets (`allinference`). Note that it would be more efficient to propagate `IRCode` object directly and skip inflation from `CodeInfo` to `IRCode` as experimented in #47137, but currently the round-trip through `CodeInfo`-representation is necessary because it often leads to better CFG simplification while `cfg_simplify!` being expensive (xref: #51960).