From: Elijah Newren <newren@xxxxxxxxx>
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@xxxxxxxxx>
---
diffcore-rename.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/diffcore-rename.c b/diffcore-rename.c
index 1d6675c040d..16553ab259f 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -447,12 +447,16 @@ static int too_many_rename_candidates(int num_destinations, int num_sources,
* growing larger than a "rename_limit" square matrix, ie:
*
* num_destinations * num_sources > rename_limit * rename_limit
+ *
+ * We use st_mult() to check overflow conditions; in the
+ * exceptional circumstance that size_t isn't large enough to hold
+ * the multiplication, the system won't be able to allocate enough
+ * memory for the matrix anyway.
*/
if (rename_limit <= 0)
rename_limit = 32767;
- if ((num_destinations <= rename_limit || num_sources <= rename_limit) &&
- ((uint64_t)num_destinations * (uint64_t)num_sources
- <= (uint64_t)rename_limit * (uint64_t)rename_limit))
+ if (st_mult(num_destinations, num_sources)
+ <= st_mult(rename_limit, rename_limit))
return 0;
options->needed_rename_limit =
@@ -468,9 +472,8 @@ static int too_many_rename_candidates(int num_destinations, int num_sources,
continue;
limited_sources++;
}
- if ((num_destinations <= rename_limit || limited_sources <= rename_limit) &&
- ((uint64_t)num_destinations * (uint64_t)limited_sources
- <= (uint64_t)rename_limit * (uint64_t)rename_limit))
+ if (st_mult(num_destinations, limited_sources)
+ <= st_mult(rename_limit, rename_limit))
return 2;
return 1;
}
--
gitgitgadget
