aboutsummaryrefslogtreecommitdiff
path: root/lib/libc
diff options
context:
space:
mode:
authorAlex Richardson <arichardson@FreeBSD.org>2021-04-19 23:19:20 +0000
committerAlex Richardson <arichardson@FreeBSD.org>2021-04-20 00:46:43 +0000
commitab147542b7c0bbc41f7f0499b16933bd8f3f31d7 (patch)
treef437b834675d59616178d9b67a3337b779f5407f /lib/libc
parent0b4ad01d91a3b24cea00d54d25beed0f487c0183 (diff)
downloadsrc-ab147542b7c0bbc41f7f0499b16933bd8f3f31d7.tar.gz
src-ab147542b7c0bbc41f7f0499b16933bd8f3f31d7.zip
libc/string/memset.c: Use unsigned long for stores
While most 64-bit architectures have an assembly implementation of this file, RISC-V does not. As we now store 8 bytes instead of 4 it should speed up RISC-V. Reviewed By: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D29536
Diffstat (limited to 'lib/libc')
-rw-r--r--lib/libc/string/memset.c19
1 files changed, 11 insertions, 8 deletions
diff --git a/lib/libc/string/memset.c b/lib/libc/string/memset.c
index 7d9909a76083..e2d4027eea0c 100644
--- a/lib/libc/string/memset.c
+++ b/lib/libc/string/memset.c
@@ -42,7 +42,7 @@ __FBSDID("$FreeBSD$");
#include <limits.h>
-#define wsize sizeof(u_int)
+#define wsize sizeof(u_long)
#define wmask (wsize - 1)
#ifdef BZERO
@@ -67,7 +67,7 @@ memset(void *dst0, int c0, size_t length)
{
size_t t;
#ifndef BZERO
- u_int c;
+ u_long c;
#endif
u_char *dst;
@@ -84,6 +84,9 @@ memset(void *dst0, int c0, size_t length)
*
* but we use a minimum of 3 here since the overhead of the code
* to do word writes is substantial.
+ *
+ * TODO: This threshold might not be sensible for 64-bit u_long.
+ * We should benchmark and revisit this decision.
*/
if (length < 3 * wsize) {
while (length != 0) {
@@ -95,12 +98,12 @@ memset(void *dst0, int c0, size_t length)
#ifndef BZERO
if ((c = (u_char)c0) != 0) { /* Fill the word. */
- c = (c << 8) | c; /* u_int is 16 bits. */
-#if UINT_MAX > 0xffff
- c = (c << 16) | c; /* u_int is 32 bits. */
+ c = (c << 8) | c; /* u_long is 16 bits. */
+#if ULONG_MAX > 0xffff
+ c = (c << 16) | c; /* u_long is 32 bits. */
#endif
-#if UINT_MAX > 0xffffffff
- c = (c << 32) | c; /* u_int is 64 bits. */
+#if ULONG_MAX > 0xffffffff
+ c = (c << 32) | c; /* u_long is 64 bits. */
#endif
}
#endif
@@ -116,7 +119,7 @@ memset(void *dst0, int c0, size_t length)
/* Fill words. Length was >= 2*words so we know t >= 1 here. */
t = length / wsize;
do {
- *(u_int *)dst = WIDEVAL;
+ *(u_long *)(void *)dst = WIDEVAL;
dst += wsize;
} while (--t != 0);