[PATCH v3 0/2] Optimization batch 6: make full use of exact renames

This series makes full use of exact renames; removing not only a destination pair, but a source pair as well when an exact rename is found and copy detection is not turned on.

Changes since v2:

 * Fix a comment typo, and fix a multi-line comment that didn't need to be a
   multi-line comment

Elijah Newren (2):
  diffcore-rename: no point trying to find a match better than exact
  diffcore-rename: filter rename_src list when possible

 diffcore-rename.c | 71 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 61 insertions(+), 10 deletions(-)

base-commit: f0117958910fbc734457a83a9f8ecc3c62463417
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-842%2Fnewren%2Fort-perf-batch-6-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-842/newren/ort-perf-batch-6-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/842

Range-diff vs v2:

 1:  770e894b4abd = 1:  a59c1960f614 diffcore-rename: no point trying to find a match better than exact
 2:  7ae9460d3dba ! 2:  dd6595b45640 diffcore-rename: filter rename_src list when possible
     @@ diffcore-rename.c: static int find_renames(struct diff_score *mx, int dst_cnt, i
      +	if (detecting_copies)
      +		return; /* nothing to remove */
      +	if (break_idx)
     -+		return; /* culling incompatbile with break detection */
     ++		return; /* culling incompatible with break detection */
      +
      +	/*
      +	 * Note on reasons why we cull unneeded sources but not destinations:
     @@ diffcore-rename.c: static int find_renames(struct diff_score *mx, int dst_cnt, i
       {
       	int detect_rename = options->detect_rename;
      @@ diffcore-rename.c: void diffcore_rename(struct diff_options *options)
     + 	if (minimum_score == MAX_SCORE)
       		goto cleanup;
       
     - 	/*
     +-	/*
      -	 * Calculate how many renames are left (but all the source
      -	 * files still remain as options for rename/copies!)
     -+	 * Calculate how many renames are left
     - 	 */
     +-	 */
     ++	/* Calculate how many renames are left */
       	num_destinations = (rename_dst_nr - rename_count);
      +	remove_unneeded_paths_from_src(want_copies);
       	num_sources = rename_src_nr;