Bug 27480 - Consider .debug_loclists optimizations
Summary: Consider .debug_loclists optimizations
Status: NEW
Alias: None
Product: dwz
Classification: Unclassified
Component: default (show other bugs)
Version: unspecified
: P2 enhancement
Target Milestone: ---
Assignee: Nobody
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Reported: 2021-02-27 10:45 UTC by Jakub Jelinek
Modified: 2021-03-02 07:51 UTC (History)
2 users (show)

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Description Jakub Jelinek 2021-02-27 10:45:45 UTC
As mentioned in https://gcc.gnu.org/pipermail/gcc-patches/2021-February/565965.html
GCC for non-partitioned TUs emits DW_LLE_offset_pair which will be likely a win for small TUs, but might be too large for very large TUs - both operands are offsets from base, so say 256KB TU would near the end of the .text section have
3 bytes for each of the operands, and for 2MB TU even 4 bytes for each operand.
Compared to one DW_LLE_base_address with 4 (or 8) byte operand and then DW_LLE_offset_pair with likely just 1 byte operands.
Similarly, for partitioned TUs, we emit DW_LLE_start_end or DW_LLE_base_address + DW_LLE_offset_pair, but maybe DW_LLE_offset_pair would be smaller.