[PATCH] D68620: DebugInfo: Use base address selection entries for debug_loc

[Orlando Cazalet-Hyams via Phabricator via llvm-commits]

Orlando added a comment.



> @Orlando mentioned he was collecting some size data that would be relevant here, he'll post it when he's done. Basically .debug_loc sizes at various points.

Hi!

I've built a benchmark suite of 85 programs with "-O2 -g" with our downstream branch targeting X86 emitting DWARF v4.

This table provides a summary of the data. It shows the mean for some size data normalized as a percentage of the llvm-3 results for each benchmark.

For reference:
Largest binary built with llvm-3: 6010 kB
Smallest binary built with llvm-3: 79 kB

  +------------------------------------------------------------------------------------------- +
  | Mean binary size for benchmarks normalized as a percentage of llvm-3 builds                |
  +---------------------------------+------------+------------------+-----------------+--------+
  | llvm version                    | .debug_loc | other debug info | everything else | Total  |
  +---------------------------------+------------+------------------+-----------------+--------+
  | llvm-3                          | 13.7       | 33.2             | 53.1            | 100    |
  | llvm-4                          | 12.7       | 33.8             | 53.8            | 100.3  |
  | llvm-5                          | 13.4       | 35.6             | 54.6            | 103.7  |
  | llvm-7                          | 18.4       | 35.6             | 54.0            | 108.0  |
  | llvm-8                          | 17.5       | 37.1             | 54.5            | 109.1  |
  | llvm-9                          | 19.7       | 37.2             | 54.6            | 111.5  |
  | llvm-10 before dblaikie commit  | 19.8       | 37.4             | 54.9            | 112.1  |
  | llvm-10 with dblaikie commit    | 25.6       | 37.4             | 54.9            | 117.9  |
  | llvm-10                         | 25.8       | 37.5             | 54.8            | 118.1  |
  | llvm-master before my commits   | 26.2       | 37.4             | 54.8            | 118.4  |
  | llvm-master with my commits     | 18.4       | 35.5             | 55.3            | 109.3  |
  +---------------------------------+------------+------------------+-----------------+--------+

Here's an image of that data in graph form: M3 <https://reviews.llvm.org/M3>.

The llvm-6 entry has been omitted because the non debug-info size is a distracting outlier. The .debug_loc section size is ~16.5% for that one.

If you'd like to see the data in another format or see data for the benchmarks individually please let me know.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68620/new/

https://reviews.llvm.org/D68620