[Skiboot] [PATCH v2] libc/string: speed up common string functions
Nicholas Piggin
npiggin at gmail.com
Fri May 10 14:47:09 AEST 2019
Use compiler builtins for the string functions, and compile the
libc/string/ directory with -O2.
This reduces instructions booting skiboot in mambo by 2.9 million in
slow-sim mode, or 3.8 in normal mode, for less than 1kB image size
increase.
This can result in the compiler warning more cases of string function
problems.
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
core/init.c | 6 ++---
libc/include/string.h | 44 ++++++++++++++++++++----------------
libc/string/Makefile.inc | 2 ++
libc/string/memchr.c | 7 +++---
libc/string/memcmp.c | 7 +++---
libc/string/memcpy.c | 27 ++++++++++++++--------
libc/string/memcpy_from_ci.c | 4 ++--
libc/string/memmove.c | 28 +++++++++--------------
libc/string/memset.c | 8 +++----
libc/string/strcasecmp.c | 5 ++--
libc/string/strcat.c | 8 ++++---
libc/string/strchr.c | 6 ++---
libc/string/strcmp.c | 7 ++----
libc/string/strcpy.c | 6 ++---
libc/string/strdup.c | 4 +++-
libc/string/strlen.c | 10 ++++----
libc/string/strncasecmp.c | 6 ++---
libc/string/strncmp.c | 7 +++---
libc/string/strncpy.c | 6 ++---
libc/string/strrchr.c | 6 ++---
libc/string/strstr.c | 8 ++++---
libc/string/strtok.c | 6 ++---
22 files changed, 112 insertions(+), 106 deletions(-)
diff --git a/core/init.c b/core/init.c
index c97a1c3ee..9f60d7855 100644
--- a/core/init.c
+++ b/core/init.c
@@ -385,7 +385,7 @@ static bool load_kernel(void)
*/
if (kernel_entry < EXCEPTION_VECTORS_END) {
cpu_set_sreset_enable(false);
- memcpy(NULL, old_vectors, EXCEPTION_VECTORS_END);
+ memcpy_null(NULL, old_vectors, EXCEPTION_VECTORS_END);
sync_icache();
} else {
/* Hack for STB in Mambo, assume at least 4kb in mem */
@@ -787,7 +787,7 @@ static void setup_branch_null_catcher(void)
* ABI v1 (ie. big endian). This will be broken if we ever
* move to ABI v2 (ie little endian)
*/
- memcpy(0, bn, 16);
+ memcpy_null(0, bn, 16);
}
#else
static void setup_branch_null_catcher(void)
@@ -824,7 +824,7 @@ void copy_exception_vectors(void)
/* Backup previous vectors as this could contain a kernel
* image.
*/
- memcpy(old_vectors, NULL, EXCEPTION_VECTORS_END);
+ memcpy_null(old_vectors, NULL, EXCEPTION_VECTORS_END);
/* Copy from 0x100 to EXCEPTION_VECTORS_END, avoid below 0x100 as
* this is the boot flag used by CPUs still potentially entering
diff --git a/libc/include/string.h b/libc/include/string.h
index d2597bb6f..f3d6117fb 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -15,28 +15,34 @@
#include "stddef.h"
-char *strcpy(char *dest, const char *src);
-char *strncpy(char *dest, const char *src, size_t n);
-char *strcat(char *dest, const char *src);
-int strcmp(const char *s1, const char *s2);
-int strncmp(const char *s1, const char *s2, size_t n);
-int strcasecmp(const char *s1, const char *s2);
-int strncasecmp(const char *s1, const char *s2, size_t n);
-char *strchr(const char *s, int c);
-char *strrchr(const char *s, int c);
-char *strrchr(const char *s, int c);
-size_t strlen(const char *s);
-size_t strnlen(const char *s, size_t n);
-char *strstr(const char *hay, const char *needle);
+#define strcpy __builtin_strcpy
+#define strncpy __builtin_strncpy
+#define strcat __builtin_strcat
+#define strcmp __builtin_strcmp
+#define strncmp __builtin_strncmp
+#define strcasecmp __builtin_strcasecmp
+#define strncasecmp __builtin_strncasecmp
+#define strchr __builtin_strchr
+#define strrchr __builtin_strrchr
+#define strlen __builtin_strlen
+#define strlen __builtin_strlen
+size_t strnlen(const char *s, size_t maxlen);
+#define strstr __builtin_strstr
+#define strdup __builtin_strdup
char *strtok(char *src, const char *pattern);
-char *strdup(const char *src);
-void *memset(void *s, int c, size_t n);
-void *memchr(const void *s, int c, size_t n);
-void *memcpy(void *dest, const void *src, size_t n);
+#define memset __builtin_memset
+#define memchr __builtin_memchr
+#define memcpy __builtin_memcpy
+#define memmove __builtin_memmove
+#define memcmp __builtin_memcmp
+static inline void *memcpy_null(void *dest, const void *src, size_t n)
+{
+ asm("" : "+r"(dest));
+ asm("" : "+r"(src));
+ return memcpy(dest, src, n);
+}
void *memcpy_from_ci(void *destpp, const void *srcpp, size_t len);
-void *memmove(void *dest, const void *src, size_t n);
-int memcmp(const void *s1, const void *s2, size_t n);
static inline int ffs(unsigned long val)
{
diff --git a/libc/string/Makefile.inc b/libc/string/Makefile.inc
index 26582aa05..2f038219f 100644
--- a/libc/string/Makefile.inc
+++ b/libc/string/Makefile.inc
@@ -19,3 +19,5 @@ STRING_OBJS = strcat.o strchr.o strrchr.o strcmp.o strcpy.o strlen.o \
STRING = $(LIBCDIR)/string/built-in.a
$(STRING): $(STRING_OBJS:%=$(LIBCDIR)/string/%)
+CFLAGS_SKIP_libc/string/ += -Os
+CFLAGS_libc/string/ += -O2
diff --git a/libc/string/memchr.c b/libc/string/memchr.c
index c3fe751c6..db9a147c6 100644
--- a/libc/string/memchr.c
+++ b/libc/string/memchr.c
@@ -10,11 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include "string.h"
+#include <stddef.h>
-
-void *
-memchr(const void *ptr, int c, size_t n)
+void *memchr(const void *ptr, int c, size_t n);
+void *memchr(const void *ptr, int c, size_t n)
{
unsigned char ch = (unsigned char)c;
const unsigned char *p = ptr;
diff --git a/libc/string/memcmp.c b/libc/string/memcmp.c
index 3b69cefb9..b270b597b 100644
--- a/libc/string/memcmp.c
+++ b/libc/string/memcmp.c
@@ -10,11 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include "string.h"
+#include <stddef.h>
-
-int
-memcmp(const void *ptr1, const void *ptr2, size_t n)
+int memcmp(const void *ptr1, const void *ptr2, size_t n);
+int memcmp(const void *ptr1, const void *ptr2, size_t n)
{
const unsigned char *p1 = ptr1;
const unsigned char *p2 = ptr2;
diff --git a/libc/string/memcpy.c b/libc/string/memcpy.c
index 00f419b80..26f953d2e 100644
--- a/libc/string/memcpy.c
+++ b/libc/string/memcpy.c
@@ -10,18 +10,27 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include "string.h"
+#include <stddef.h>
+#include <ccan/short_types/short_types.h>
-void *
-memcpy(void *dest, const void *src, size_t n)
+void *memcpy(void *dest, const void *src, size_t n);
+void *memcpy(void *dest, const void *src, size_t n)
{
- char *cdest;
- const char *csrc = src;
+ void *ret = dest;
- cdest = dest;
- while (n-- > 0) {
- *cdest++ = *csrc++;
+ while (n >= 8) {
+ *(uint64_t *)dest = *(uint64_t *)src;
+ dest += 8;
+ src += 8;
+ n -= 8;
}
- return dest;
+ while (n > 0) {
+ *(uint8_t *)dest = *(uint8_t *)src;
+ dest += 1;
+ src += 1;
+ n -= 1;
+ }
+
+ return ret;
}
diff --git a/libc/string/memcpy_from_ci.c b/libc/string/memcpy_from_ci.c
index 02affa38c..4c5582fe5 100644
--- a/libc/string/memcpy_from_ci.c
+++ b/libc/string/memcpy_from_ci.c
@@ -14,11 +14,11 @@
* limitations under the License.
*/
-#include <string.h>
#include <ccan/short_types/short_types.h>
#include <io.h>
+#include <string.h>
-void* memcpy_from_ci(void *destpp, const void *srcpp, size_t len)
+void *memcpy_from_ci(void *destpp, const void *srcpp, size_t len)
{
const size_t block = sizeof(uint64_t);
unsigned long int destp = (long int) destpp;
diff --git a/libc/string/memmove.c b/libc/string/memmove.c
index 3acf1a973..76aef6c87 100644
--- a/libc/string/memmove.c
+++ b/libc/string/memmove.c
@@ -10,33 +10,27 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include "string.h"
+#include <stddef.h>
-
-void *
-memmove(void *dest, const void *src, size_t n)
+void *memcpy(void *dest, const void *src, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
+void *memmove(void *dest, const void *src, size_t n)
{
- char *cdest;
- const char *csrc;
- int i;
-
/* Do the buffers overlap in a bad way? */
if (src < dest && src + n >= dest) {
+ char *cdest;
+ const char *csrc;
+ int i;
+
/* Copy from end to start */
cdest = dest + n - 1;
csrc = src + n - 1;
for (i = 0; i < n; i++) {
*cdest-- = *csrc--;
}
- }
- else {
+ return dest;
+ } else {
/* Normal copy is possible */
- cdest = dest;
- csrc = src;
- for (i = 0; i < n; i++) {
- *cdest++ = *csrc++;
- }
+ return memcpy(dest, src, n);
}
-
- return dest;
}
diff --git a/libc/string/memset.c b/libc/string/memset.c
index dae43660f..f96a0231f 100644
--- a/libc/string/memset.c
+++ b/libc/string/memset.c
@@ -10,12 +10,12 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include "string.h"
-
#define CACHE_LINE_SIZE 128
-void *
-memset(void *dest, int c, size_t size)
+#include <stddef.h>
+
+void *memset(void *dest, int c, size_t size);
+void *memset(void *dest, int c, size_t size)
{
unsigned char *d = (unsigned char *)dest;
unsigned long big_c = 0;
diff --git a/libc/string/strcasecmp.c b/libc/string/strcasecmp.c
index f75294fb9..ba1aedb5f 100644
--- a/libc/string/strcasecmp.c
+++ b/libc/string/strcasecmp.c
@@ -10,11 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
#include <ctype.h>
-int
-strcasecmp(const char *s1, const char *s2)
+int strcasecmp(const char *s1, const char *s2);
+int strcasecmp(const char *s1, const char *s2)
{
while (*s1 != 0 && *s2 != 0) {
if (toupper(*s1) != toupper(*s2))
diff --git a/libc/string/strcat.c b/libc/string/strcat.c
index 936e5b103..329cc88e1 100644
--- a/libc/string/strcat.c
+++ b/libc/string/strcat.c
@@ -10,10 +10,12 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-char *
-strcat(char *dst, const char *src)
+size_t strlen(const char *s);
+char *strcpy(char *dst, const char *src);
+char *strcat(char *dst, const char *src);
+char *strcat(char *dst, const char *src)
{
size_t p;
diff --git a/libc/string/strchr.c b/libc/string/strchr.c
index 528a319c9..88f25f96b 100644
--- a/libc/string/strchr.c
+++ b/libc/string/strchr.c
@@ -10,10 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-char *
-strchr(const char *s, int c)
+char *strchr(const char *s, int c);
+char *strchr(const char *s, int c)
{
char cb = c;
diff --git a/libc/string/strcmp.c b/libc/string/strcmp.c
index 48eaed246..5afbae2a7 100644
--- a/libc/string/strcmp.c
+++ b/libc/string/strcmp.c
@@ -10,11 +10,8 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
-
-
-int
-strcmp(const char *s1, const char *s2)
+int strcmp(const char *s1, const char *s2);
+int strcmp(const char *s1, const char *s2)
{
while (*s1 != 0 && *s2 != 0) {
if (*s1 != *s2)
diff --git a/libc/string/strcpy.c b/libc/string/strcpy.c
index 48eb62cb5..514be1714 100644
--- a/libc/string/strcpy.c
+++ b/libc/string/strcpy.c
@@ -10,10 +10,8 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
-
-char *
-strcpy(char *dst, const char *src)
+char *strcpy(char *dst, const char *src);
+char *strcpy(char *dst, const char *src)
{
char *ptr = dst;
diff --git a/libc/string/strdup.c b/libc/string/strdup.c
index be91e233b..b0a4b4d70 100644
--- a/libc/string/strdup.c
+++ b/libc/string/strdup.c
@@ -10,9 +10,11 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
#include <stdlib.h>
+size_t strlen(const char *s);
+void *memcpy(void *dest, const void *src, size_t n);
+char *strdup(const char *src);
char *strdup(const char *src)
{
size_t len = strlen(src) + 1;
diff --git a/libc/string/strlen.c b/libc/string/strlen.c
index 5b408e7ef..f3c5a8362 100644
--- a/libc/string/strlen.c
+++ b/libc/string/strlen.c
@@ -10,10 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-size_t
-strlen(const char *s)
+size_t strlen(const char *s);
+size_t strlen(const char *s)
{
size_t len = 0;
@@ -25,8 +25,8 @@ strlen(const char *s)
return len;
}
-size_t
-strnlen(const char *s, size_t n)
+size_t strnlen(const char *s, size_t n);
+size_t strnlen(const char *s, size_t n)
{
size_t len = 0;
diff --git a/libc/string/strncasecmp.c b/libc/string/strncasecmp.c
index 4140931e3..c6b158e60 100644
--- a/libc/string/strncasecmp.c
+++ b/libc/string/strncasecmp.c
@@ -10,12 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
#include <ctype.h>
-
-int
-strncasecmp(const char *s1, const char *s2, size_t n)
+int strncasecmp(const char *s1, const char *s2, size_t n);
+int strncasecmp(const char *s1, const char *s2, size_t n)
{
if (n < 1)
return 0;
diff --git a/libc/string/strncmp.c b/libc/string/strncmp.c
index a886736a9..a5422c0dc 100644
--- a/libc/string/strncmp.c
+++ b/libc/string/strncmp.c
@@ -10,11 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-
-int
-strncmp(const char *s1, const char *s2, size_t n)
+int strncmp(const char *s1, const char *s2, size_t n);
+int strncmp(const char *s1, const char *s2, size_t n)
{
if (n < 1)
return 0;
diff --git a/libc/string/strncpy.c b/libc/string/strncpy.c
index 0f41f93c9..621c89b64 100644
--- a/libc/string/strncpy.c
+++ b/libc/string/strncpy.c
@@ -10,10 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-char *
-strncpy(char *dst, const char *src, size_t n)
+char *strncpy(char *dst, const char *src, size_t n);
+char *strncpy(char *dst, const char *src, size_t n)
{
char *ret = dst;
diff --git a/libc/string/strrchr.c b/libc/string/strrchr.c
index 6652fad34..262a68287 100644
--- a/libc/string/strrchr.c
+++ b/libc/string/strrchr.c
@@ -10,10 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-char *
-strrchr(const char *s, int c)
+char *strrchr(const char *s, int c);
+char *strrchr(const char *s, int c)
{
char *last = NULL;
char cb = c;
diff --git a/libc/string/strstr.c b/libc/string/strstr.c
index a6e96187f..cd9ccae9a 100644
--- a/libc/string/strstr.c
+++ b/libc/string/strstr.c
@@ -10,10 +10,12 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-char *
-strstr(const char *hay, const char *needle)
+size_t strlen(const char *s);
+int strncmp(const char *s1, const char *s2, size_t n);
+char *strstr(const char *hay, const char *needle);
+char *strstr(const char *hay, const char *needle)
{
char *pos;
size_t hlen, nlen;
diff --git a/libc/string/strtok.c b/libc/string/strtok.c
index aa42d77ed..fcc3fce32 100644
--- a/libc/string/strtok.c
+++ b/libc/string/strtok.c
@@ -10,10 +10,10 @@
* IBM Corporation - initial implementation
*****************************************************************************/
-#include <string.h>
+#include <stddef.h>
-char *
-strtok(char *src, const char *pattern)
+char *strtok(char *src, const char *pattern);
+char *strtok(char *src, const char *pattern)
{
static char *nxtTok;
char *retVal = NULL;
--
2.20.1
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