[all-commits] [llvm/llvm-project] 71eed4: [DebugInfo] Remove Dwarf5AccelTableWriter::Header:...

[Igor Kudrin via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 71eed4808fbc5e5baa016210f727683610139014
      https://github.com/llvm/llvm-project/commit/71eed4808fbc5e5baa016210f727683610139014
  Author: Igor Kudrin <ikudrin at accesssoftek.com>
  Date:   2020-09-02 (Wed, 02 Sep 2020)

  Changed paths:
    M llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp

  Log Message:
  -----------
  [DebugInfo] Remove Dwarf5AccelTableWriter::Header::UnitLength. NFC.

The member is not in use; the unit length for the table is emitted as
a difference between two labels. Moreover, the type of the member might
be misleading, because for DWARF64 the field should be 64 bit long.

Differential Revision: https://reviews.llvm.org/D86912


  Commit: 3445ec9ba718035b27c0140dc1e892be843236f5
      https://github.com/llvm/llvm-project/commit/3445ec9ba718035b27c0140dc1e892be843236f5
  Author: Igor Kudrin <ikudrin at accesssoftek.com>
  Date:   2020-09-02 (Wed, 02 Sep 2020)

  Changed paths:
    M llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
    A llvm/test/DebugInfo/X86/debug-names-end-of-list.ll

  Log Message:
  -----------
  [DebugInfo] Emit a 1-byte value as a terminator of entries list in the name index.

As stated in section 6.1.1.2, DWARFv5, p. 142,
| The last entry for each name is followed by a zero byte that
| terminates the list. There may be gaps between the lists.

The patch changes emitting a 4-byte zero value to a 1-byte one, which
effectively removes the gap between entry lists, and thus saves
approximately 3 bytes per name; the calculation is not exact because
the total size of the table is aligned to 4.

Differential Revision: https://reviews.llvm.org/D86927


Compare: https://github.com/llvm/llvm-project/compare/4820af2bfc71...3445ec9ba718