[PATCH 2/3] xdiff: avoid unnecessary memory allocations
- From
- Phillip Wood via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Nov 17, 2021, 11:20 UTC
- Message-ID
- <eef46c71840d7f36b503a92b899c95632c023351.1637148025.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.1079.git.1637148025.gitgitgadget@gmail.com>
From: Phillip Wood <phillip.wood@dunelm.org.uk>
rindex and ha are only used by xdl_cleanup_records() which is not called by the histogram or patience algorithms. The perf test results show a small reduction in run time but that is probably within the noise.
Test HEAD^ HEAD ----------------------------------------------------------------------------- 4000.1: log -3000 (baseline) 0.19(0.17+0.02) 0.19(0.12+0.07) +0.0% 4000.2: log --raw -3000 (tree-only) 0.98(0.78+0.20) 0.98(0.81+0.16) +0.0% 4000.3: log -p -3000 (Myers) 4.81(4.15+0.64) 4.81(4.23+0.56) +0.0% 4000.4: log -p -3000 --histogram 5.87(5.19+0.66) 5.83(5.11+0.70) -0.7% 4000.5: log -p -3000 --patience 5.35(4.60+0.73) 5.31(4.61+0.69) -0.7%
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> --- xdiff/xprepare.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c index 7fae0727a02..4527a4a07c4 100644 --- a/xdiff/xprepare.c +++ b/xdiff/xprepare.c @@ -213,10 +213,13 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_ goto abort; memset(rchg, 0, (nrec + 2) * sizeof(char)); - if (!(rindex = (long *) xdl_malloc((nrec + 1) * sizeof(long)))) - goto abort; - if (!(ha = (unsigned long *) xdl_malloc((nrec + 1) * sizeof(unsigned long)))) - goto abort; + if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) && + (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)) { + if (!(rindex = xdl_malloc((nrec + 1) * sizeof(*rindex)))) + goto abort; + if (!(ha = xdl_malloc((nrec + 1) * sizeof(*ha)))) + goto abort; + } xdf->nrec = nrec; xdf->recs = recs;
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