GH-142305: JIT: Deduplicating GOT symbols in the trace #142316
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diegorusso
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savannahostrowski
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| // Get the symbol slot memory location for a given symbol ordinal. | ||
| static unsigned char * | ||
| get_symbol_slot(int ordinal, symbol_state *state, int size) |
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IMO, merging GOT and trampoline symbols into the same structure makes things a bit more challenging to understand, since they serve different purposes. Would it be worth keeping them as separate structures with their own ordinals? I know it means some duplication, but it might be easier to reason about.
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The purpose of the symbol map is just to track the symbols available, independently how they are reached (either by GOT or trampolines). In fact the symbol map won't change at all, it's just an enumeration of the symbols across different stencils.
The way that differentiates how they are reached is the relocation tag associated to it. For example:
R_AARCH64_CALL26will use trampolinesR_AARCH64_ADR_GOT_PAGE/R_AARCH64_LD64_GOT_LO12_NCwill use the GOT
but the ordinal of the symbol is consistent because the collection of the symbol is unified.
Indeed in the trace, trampolines and got entries are allocated in separate areas.
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