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From: "Christian Göttsche" <cgzones@googlemail.com>
To: selinux@vger.kernel.org
Cc: "Christian Göttsche" <cgzones@googlemail.com>
Subject: [PATCH v2 7/7] libsepol: skip superfluous memset calls in ebitmap operations
Date: Tue, 19 Jul 2022 17:30:44 +0200	[thread overview]
Message-ID: <20220719153045.70041-7-cgzones@googlemail.com> (raw)
In-Reply-To: <20220719153045.70041-1-cgzones@googlemail.com>

The three members of struct ebitmap_node are all unconditionally
initialized.  Hinder compilers to optimize malloc() and memset() into
calloc(), which might be slightly slower.  Especially affects
ebitmap_or().

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
 libsepol/src/ebitmap.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/libsepol/src/ebitmap.c b/libsepol/src/ebitmap.c
index 7d26f949..3ec1042f 100644
--- a/libsepol/src/ebitmap.c
+++ b/libsepol/src/ebitmap.c
@@ -31,7 +31,6 @@ int ebitmap_or(ebitmap_t * dst, const ebitmap_t * e1, const ebitmap_t * e2)
 			ebitmap_destroy(dst);
 			return -ENOMEM;
 		}
-		memset(new, 0, sizeof(ebitmap_node_t));
 		if (n1 && n2 && n1->startbit == n2->startbit) {
 			new->startbit = n1->startbit;
 			new->map = n1->map | n2->map;
@@ -290,7 +289,6 @@ int ebitmap_cpy(ebitmap_t * dst, const ebitmap_t * src)
 			ebitmap_destroy(dst);
 			return -ENOMEM;
 		}
-		memset(new, 0, sizeof(ebitmap_node_t));
 		new->startbit = n->startbit;
 		new->map = n->map;
 		new->next = 0;
@@ -430,7 +428,6 @@ int ebitmap_set_bit(ebitmap_t * e, unsigned int bit, int value)
 	new = (ebitmap_node_t *) malloc(sizeof(ebitmap_node_t));
 	if (!new)
 		return -ENOMEM;
-	memset(new, 0, sizeof(ebitmap_node_t));
 
 	new->startbit = startbit;
 	new->map = (MAPBIT << (bit - new->startbit));
-- 
2.36.1


  parent reply	other threads:[~2022-07-19 15:31 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-19 15:30 [PATCH v2 1/7] libsepol/tests: add ebitmap tests Christian Göttsche
2022-07-19 15:30 ` [PATCH v2 2/7] libsepol: add ebitmap_init_range Christian Göttsche
2022-07-19 15:30 ` [PATCH v2 3/7] libsepol/cil: use ebitmap_init_range Christian Göttsche
2022-07-19 15:30 ` [PATCH v2 4/7] libsepol: optimize ebitmap_not Christian Göttsche
2022-07-19 15:30 ` [PATCH v2 5/7] libsepol: optimize ebitmap_and Christian Göttsche
2022-07-19 15:30 ` [PATCH v2 6/7] libsepol: optimize ebitmap_xor Christian Göttsche
2022-07-19 15:30 ` Christian Göttsche [this message]
2022-07-20 19:51 ` [PATCH v2 1/7] libsepol/tests: add ebitmap tests James Carter
2022-08-09 15:19   ` James Carter

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