diffcore-rename: simplify limit check
diffcore-rename had two different checks of the form if ((a < limit || b < limit) && a * b <= limit * limit) This can be simplified to if (st_mult(a, b) <= st_mult(limit, limit)) which makes it clearer how we are checking for overflow, and makes it much easier to parse given the drop from 8 to 4 variable appearances. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren committed
Dec 11, 2020 at 09:08 UTC
ad8a1be529ea9e0bd6346a3cb1d53fec16e3bd10
1 file changed
+9
-6
diffcore-rename.c
+9
-6
@@ -447,12 +447,16 @@ static int too_many_rename_candidates(int num_destinations, int num_sources,
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* growing larger than a "rename_limit" square matrix, ie:
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*
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* num_destinations * num_sources > rename_limit * rename_limit
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+ *
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+ * We use st_mult() to check overflow conditions; in the
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+ * exceptional circumstance that size_t isn't large enough to hold
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+ * the multiplication, the system won't be able to allocate enough
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+ * memory for the matrix anyway.
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*/
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if (rename_limit <= 0)
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rename_limit = 32767;
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- if ((num_destinations <= rename_limit || num_sources <= rename_limit) &&
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- ((uint64_t)num_destinations * (uint64_t)num_sources
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- <= (uint64_t)rename_limit * (uint64_t)rename_limit))
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+ if (st_mult(num_destinations, num_sources)
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+ <= st_mult(rename_limit, rename_limit))
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return 0;
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options->needed_rename_limit =
@@ -468,9 +472,8 @@ static int too_many_rename_candidates(int num_destinations, int num_sources,
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continue;
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limited_sources++;
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}
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- if ((num_destinations <= rename_limit || limited_sources <= rename_limit) &&
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- ((uint64_t)num_destinations * (uint64_t)limited_sources
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- <= (uint64_t)rename_limit * (uint64_t)rename_limit))
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+ if (st_mult(num_destinations, limited_sources)
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+ <= st_mult(rename_limit, rename_limit))
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return 2;
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return 1;
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}