From: "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: Elijah Newren <newren@gmail.com>, Taylor Blau <me@ttaylorr.com>,
Elijah Newren <newren@gmail.com>,
Elijah Newren <newren@gmail.com>
Subject: [PATCH v2 3/9] diffcore-rename: simplify limit check
Date: Fri, 11 Dec 2020 09:08:42 +0000 [thread overview]
Message-ID: <7214fa73fdd13418744903f6c769fdb77c9512ce.1607677728.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.929.v2.git.git.1607677728.gitgitgadget@gmail.com>
From: Elijah Newren <newren@gmail.com>
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>
---
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
next prev parent reply other threads:[~2020-12-11 9:10 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 2:54 [PATCH 0/7] diffcore-rename improvements Elijah Newren via GitGitGadget
2020-12-06 2:54 ` [PATCH 1/7] diffcore-rename: avoid usage of global in too_many_rename_candidates() Elijah Newren via GitGitGadget
2020-12-09 22:06 ` Taylor Blau
2020-12-06 2:54 ` [PATCH 2/7] diffcore-rename: remove unnecessary if-clause Elijah Newren via GitGitGadget
2020-12-09 22:10 ` Taylor Blau
2020-12-10 0:32 ` Elijah Newren
2020-12-10 2:03 ` Junio C Hamano
2020-12-10 2:17 ` Elijah Newren
2020-12-10 6:56 ` Junio C Hamano
2020-12-06 2:54 ` [PATCH 3/7] diffcore-rename: rename num_create to num_targets Elijah Newren via GitGitGadget
2020-12-10 2:20 ` Junio C Hamano
2020-12-10 2:25 ` Elijah Newren
2020-12-06 2:54 ` [PATCH 4/7] diffcore-rename: change a few comments to use 'add' instead of 'create' Elijah Newren via GitGitGadget
2020-12-10 2:29 ` Junio C Hamano
2020-12-06 2:54 ` [PATCH 5/7] diffcore-rename: reduce jumpiness in progress counters Elijah Newren via GitGitGadget
2020-12-09 22:24 ` Taylor Blau
2020-12-10 2:36 ` Junio C Hamano
2020-12-06 2:54 ` [PATCH 6/7] diffcore-rename: simplify and accelerate register_rename_src() Elijah Newren via GitGitGadget
2020-12-09 22:40 ` Taylor Blau
2020-12-10 0:25 ` Elijah Newren
2020-12-10 0:41 ` Taylor Blau
2020-12-10 2:51 ` Junio C Hamano
2020-12-06 2:54 ` [PATCH 7/7] Accelerate rename_dst setup Elijah Newren via GitGitGadget
2020-12-09 23:01 ` Taylor Blau
2020-12-10 0:57 ` Elijah Newren
2020-12-10 1:43 ` Junio C Hamano
2020-12-06 3:01 ` [PATCH 0/7] diffcore-rename improvements Elijah Newren
2020-12-11 9:08 ` [PATCH v2 0/9] " Elijah Newren via GitGitGadget
2020-12-11 9:08 ` [PATCH v2 1/9] diffcore-rename: rename num_create to num_destinations Elijah Newren via GitGitGadget
2020-12-11 9:08 ` [PATCH v2 2/9] diffcore-rename: avoid usage of global in too_many_rename_candidates() Elijah Newren via GitGitGadget
2020-12-11 9:08 ` Elijah Newren via GitGitGadget [this message]
2020-12-11 9:08 ` [PATCH v2 4/9] diffcore-rename: reduce jumpiness in progress counters Elijah Newren via GitGitGadget
2020-12-11 9:08 ` [PATCH v2 5/9] t4058: add more tests and documentation for duplicate tree entry handling Elijah Newren via GitGitGadget
2020-12-11 9:08 ` [PATCH v2 6/9] t4058: explore duplicate tree entry handling in a bit more detail Elijah Newren via GitGitGadget
2021-04-21 12:29 ` Ævar Arnfjörð Bjarmason
2021-04-21 17:38 ` Elijah Newren
2020-12-11 9:08 ` [PATCH v2 7/9] diffcore-rename: simplify and accelerate register_rename_src() Elijah Newren via GitGitGadget
2020-12-11 9:08 ` [PATCH v2 8/9] diffcore-rename: accelerate rename_dst setup Elijah Newren via GitGitGadget
2020-12-11 9:08 ` [PATCH v2 9/9] diffcore-rename: remove unneccessary duplicate entry checks Elijah Newren via GitGitGadget
2020-12-29 8:31 ` Christian Couder
2020-12-29 18:09 ` Elijah Newren
2020-12-29 20:05 ` [PATCH v3 0/9] diffcore-rename improvements Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 1/9] diffcore-rename: rename num_create to num_destinations Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 2/9] diffcore-rename: avoid usage of global in too_many_rename_candidates() Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 3/9] diffcore-rename: simplify limit check Elijah Newren via GitGitGadget
2021-11-09 21:14 ` Başar Uğur
2021-11-10 20:06 ` Elijah Newren
2021-11-11 9:02 ` Başar Uğur
2021-11-11 16:19 ` Elijah Newren
2020-12-29 20:05 ` [PATCH v3 4/9] diffcore-rename: reduce jumpiness in progress counters Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 5/9] t4058: add more tests and documentation for duplicate tree entry handling Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 6/9] t4058: explore duplicate tree entry handling in a bit more detail Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 7/9] diffcore-rename: simplify and accelerate register_rename_src() Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 8/9] diffcore-rename: accelerate rename_dst setup Elijah Newren via GitGitGadget
2020-12-29 20:05 ` [PATCH v3 9/9] diffcore-rename: remove unnecessary duplicate entry checks Elijah Newren via GitGitGadget
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