aboutsummaryrefslogtreecommitdiff
path: root/string
diff options
context:
space:
mode:
authorMaxim Kuvyrkov <maxim@codesourcery.com>2012-05-28 23:32:12 -0700
committerMaxim Kuvyrkov <maxim@codesourcery.com>2012-08-21 18:07:47 -0700
commit99677e575504ec526546501b1fdb86221493768a (patch)
treec47132f702760e9ac7d3fb140828c58e0d889fa1 /string
parent400726deef57d8da8d6c7cd5c8e7891eaabab041 (diff)
downloadglibc-99677e575504ec526546501b1fdb86221493768a.tar
glibc-99677e575504ec526546501b1fdb86221493768a.tar.gz
glibc-99677e575504ec526546501b1fdb86221493768a.tar.bz2
glibc-99677e575504ec526546501b1fdb86221493768a.zip
Use pointers for traversing arrays in strstr, strcasestr and memmem.
Diffstat (limited to 'string')
-rw-r--r--string/str-two-way.h65
-rw-r--r--string/strcasestr.c2
2 files changed, 49 insertions, 18 deletions
diff --git a/string/str-two-way.h b/string/str-two-way.h
index aab627a27b..1b7a8baea0 100644
--- a/string/str-two-way.h
+++ b/string/str-two-way.h
@@ -240,17 +240,24 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len,
j = 0;
while (AVAILABLE (haystack, haystack_len, j, needle_len))
{
+ const unsigned char *pneedle;
+ const unsigned char *phaystack;
+
/* Scan for matches in right half. */
i = MAX (suffix, memory);
- while (i < needle_len && (CANON_ELEMENT (needle[i])
- == CANON_ELEMENT (haystack[i + j])))
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
+ while (i < needle_len && (CANON_ELEMENT (*pneedle++)
+ == CANON_ELEMENT (*phaystack++)))
++i;
if (needle_len <= i)
{
/* Scan for matches in left half. */
i = suffix - 1;
- while (memory < i + 1 && (CANON_ELEMENT (needle[i])
- == CANON_ELEMENT (haystack[i + j])))
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
+ while (memory < i + 1 && (CANON_ELEMENT (*pneedle--)
+ == CANON_ELEMENT (*phaystack--)))
--i;
if (i + 1 < memory + 1)
return (RETURN_TYPE) (haystack + j);
@@ -268,6 +275,7 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len,
}
else
{
+ const unsigned char *phaystack = &haystack[suffix];
/* The comparison always starts from needle[suffix], so cache it
and use an optimized first-character loop. */
unsigned char needle_suffix = CANON_ELEMENT (needle[suffix]);
@@ -279,23 +287,28 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len,
while (AVAILABLE1 (haystack, haystack_len, j, needle_len))
{
unsigned char haystack_char;
+ const unsigned char *pneedle;
/* TODO: The first-character loop can be sped up by adapting
longword-at-a-time implementation of memchr/strchr. */
if (needle_suffix
- != (haystack_char = CANON_ELEMENT (haystack[suffix + j])))
+ != (haystack_char = CANON_ELEMENT (*phaystack++)))
{
RET0_IF_0 (haystack_char);
++j;
continue;
}
+ /* Calculate J. */
+ j = phaystack - &haystack[suffix] - 1;
+
/* Scan for matches in right half. */
i = suffix + 1;
+ pneedle = &needle[i];
while (i < needle_len)
{
- if (CANON_ELEMENT (needle[i])
- != (haystack_char = CANON_ELEMENT (haystack[i + j])))
+ if (CANON_ELEMENT (*pneedle++)
+ != (haystack_char = CANON_ELEMENT (*phaystack++)))
{
RET0_IF_0 (haystack_char);
break;
@@ -306,10 +319,12 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len,
{
/* Scan for matches in left half. */
i = suffix - 1;
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
while (i != SIZE_MAX)
{
- if (CANON_ELEMENT (needle[i])
- != (haystack_char = CANON_ELEMENT (haystack[i + j])))
+ if (CANON_ELEMENT (*pneedle--)
+ != (haystack_char = CANON_ELEMENT (*phaystack--)))
{
RET0_IF_0 (haystack_char);
break;
@@ -325,6 +340,8 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len,
if (!AVAILABLE2 (haystack, haystack_len, j, needle_len))
break;
+
+ phaystack = &haystack[suffix + j];
}
}
ret0: __attribute__ ((unused))
@@ -379,6 +396,9 @@ two_way_long_needle (const unsigned char *haystack, size_t haystack_len,
j = 0;
while (AVAILABLE (haystack, haystack_len, j, needle_len))
{
+ const unsigned char *pneedle;
+ const unsigned char *phaystack;
+
/* Check the last byte first; if it does not match, then
shift to the next possible match location. */
shift = shift_table[CANON_ELEMENT (haystack[j + needle_len - 1])];
@@ -398,15 +418,19 @@ two_way_long_needle (const unsigned char *haystack, size_t haystack_len,
/* Scan for matches in right half. The last byte has
already been matched, by virtue of the shift table. */
i = MAX (suffix, memory);
- while (i < needle_len - 1 && (CANON_ELEMENT (needle[i])
- == CANON_ELEMENT (haystack[i + j])))
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
+ while (i < needle_len - 1 && (CANON_ELEMENT (*pneedle++)
+ == CANON_ELEMENT (*phaystack++)))
++i;
if (needle_len - 1 <= i)
{
/* Scan for matches in left half. */
i = suffix - 1;
- while (memory < i + 1 && (CANON_ELEMENT (needle[i])
- == CANON_ELEMENT (haystack[i + j])))
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
+ while (memory < i + 1 && (CANON_ELEMENT (*pneedle--)
+ == CANON_ELEMENT (*phaystack--)))
--i;
if (i + 1 < memory + 1)
return (RETURN_TYPE) (haystack + j);
@@ -431,6 +455,9 @@ two_way_long_needle (const unsigned char *haystack, size_t haystack_len,
j = 0;
while (AVAILABLE (haystack, haystack_len, j, needle_len))
{
+ const unsigned char *pneedle;
+ const unsigned char *phaystack;
+
/* Check the last byte first; if it does not match, then
shift to the next possible match location. */
shift = shift_table[CANON_ELEMENT (haystack[j + needle_len - 1])];
@@ -442,15 +469,19 @@ two_way_long_needle (const unsigned char *haystack, size_t haystack_len,
/* Scan for matches in right half. The last byte has
already been matched, by virtue of the shift table. */
i = suffix;
- while (i < needle_len - 1 && (CANON_ELEMENT (needle[i])
- == CANON_ELEMENT (haystack[i + j])))
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
+ while (i < needle_len - 1 && (CANON_ELEMENT (*pneedle++)
+ == CANON_ELEMENT (*phaystack++)))
++i;
if (needle_len - 1 <= i)
{
/* Scan for matches in left half. */
i = suffix - 1;
- while (i != SIZE_MAX && (CANON_ELEMENT (needle[i])
- == CANON_ELEMENT (haystack[i + j])))
+ pneedle = &needle[i];
+ phaystack = &haystack[i + j];
+ while (i != SIZE_MAX && (CANON_ELEMENT (*pneedle--)
+ == CANON_ELEMENT (*phaystack--)))
--i;
if (i == SIZE_MAX)
return (RETURN_TYPE) (haystack + j);
diff --git a/string/strcasestr.c b/string/strcasestr.c
index 184ca68deb..b6458aef52 100644
--- a/string/strcasestr.c
+++ b/string/strcasestr.c
@@ -36,7 +36,7 @@
#include <stdbool.h>
#include <strings.h>
-#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+#define TOLOWER(Ch) tolower (Ch)
/* Two-Way algorithm. */
#define RETURN_TYPE char *