1849759 - Use hint for direct wasm calls whether callee can perform a tail calls

Status: NEW

(Core :: JavaScript: WebAssembly, enhancement, P2)

Description

[Yury Delendik (:yury)]

Investigate if the regressions of bug 1571998 can be mitigated by guessing information about a callee. The Ion compiled code adds extra lea sp, fp[xx] operation even if it is not needed or will not be used to for return calls.

The metadata does not have the information if the callee function maybe perform the tail calls, however it can be inferred from the module validation or baseline compilation. The idea is to collect this information, and feed during Ion compilation at CodeGenerator::visitWasmCall.

The analysis will only answer the question if the wasm function has tail call instruction, and will be useful for call $func operation.