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[DWARF] Emit DW_AT_call_pc for tail calls

Authored by vsk on Mar 17 2020, 5:56 PM.

Description

[DWARF] Emit DW_AT_call_pc for tail calls

Record the address of a tail-calling branch instruction within its call
site entry using DW_AT_call_pc. This allows a debugger to determine the
address to use when creating aritificial frames.

This creates an extra attribute + relocation at tail call sites, which
constitute 3-5% of all call sites in xnu/clang respectively.

rdar://60307600

Differential Revision: https://reviews.llvm.org/D76336

Details

Committed
vskMar 24 2020, 12:01 PM
Differential Revision
D76336: [DWARF] Emit DW_AT_call_pc for tail calls
Parents
rGc5f4b7283533: NFC: Fix typos in TestingGuide documentation
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