[PATCH 3/4] String: expand to word-at-a-time

[Nathan McSween <nwmcsween@gmail.com>]

---
 src/string/memcmp.c  | 38 ++++++++++++++++++++++++++++++++++----
 src/string/strcmp.c  | 35 ++++++++++++++++++++++++++++++++---
 src/string/strncmp.c | 36 +++++++++++++++++++++++++++++++-----
 3 files changed, 97 insertions(+), 12 deletions(-)

diff --git a/src/string/memcmp.c b/src/string/memcmp.c
index bdbce9f..c5e8e59 100644
--- a/src/string/memcmp.c
+++ b/src/string/memcmp.c
@@ -1,8 +1,38 @@
+#include <stddef.h>
 #include <string.h>
+#include "word.h"
 
-int memcmp(const void *vl, const void *vr, size_t n)
+/**
+ * memcmp - Word sized c standard memcmp.
+ * @s: Source
+ * @c: Comparative
+ * @n: Max size of @s
+ */
+int memcmp(const void *s, const void *c, size_t n)
 {
-	const unsigned char *l=vl, *r=vr;
-	for (; n && *l == *r; n--, l++, r++);
-	return n ? *l-*r : 0;
+	const unsigned char *cs = (const unsigned char *)s;
+	const unsigned char *cc = (const unsigned char *)c;
+	const size_t *ws, *wc;
+
+
+	if ((uintptr_t)cs % sizeof(size_t) != (uintptr_t)cc % sizeof(size_t))
+		goto misaligned;
+
+	for (; (uintptr_t)cs % sizeof(size_t); cs++, cc++, n--) {
+		if (!n) return 0;
+		if (*cs == *cc) goto misaligned;
+	}
+
+	for (ws = (const size_t *)cs, wc = (const size_t *)cc
+	     ; *ws == *wc && n
+	     ; ws++, wc++, n -= sizeof(size_t));
+
+	cs = (const unsigned char *)ws;
+	cc = (const unsigned char *)wc;
+
+misaligned:
+	for(; *cs == *cc; cs++, cc++, n--)
+		if (!n) return 0;
+
+	return *cs - *cc;
 }
diff --git a/src/string/strcmp.c b/src/string/strcmp.c
index 91eb740..2a6983c 100644
--- a/src/string/strcmp.c
+++ b/src/string/strcmp.c
@@ -1,7 +1,36 @@
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
+#include "word.h"
 
-int strcmp(const char *l, const char *r)
+/**
+ * strcmp - Word sized c standard strcmp.
+ * @c: Comparative
+ * @s: Source
+ */
+#undef strcmp
+int strcmp(const char *c, const char *s)
 {
-	for (; *l==*r && *l && *r; l++, r++);
-	return *(unsigned char *)l - *(unsigned char *)r;
+	const size_t *wc, *ws;
+
+	if ((uintptr_t)c % sizeof(size_t) != (uintptr_t)s % sizeof(size_t))
+		goto misaligned;
+
+	for (; (uintptr_t)c % sizeof(size_t); c++, s++) {
+		if (*c != *s || !*c || !*s)
+			return *(const unsigned char *)c
+			        - *(const unsigned char *)s;
+	}
+
+	for (wc = (const size_t *)c, ws = (const size_t *)s
+	     ; (!word_has_zero(*wc) || !word_has_zero(*ws)) && *wc == *ws
+	     ; wc++, ws++);
+
+	c = (const char *)wc;
+	s = (const char *)ws;
+
+misaligned:
+	for(; *c == *s && *c && *s; c++, s++);
+
+	return *(const unsigned char *)c - *(const unsigned char *)s;
 }
diff --git a/src/string/strncmp.c b/src/string/strncmp.c
index e228843..5c60895 100644
--- a/src/string/strncmp.c
+++ b/src/string/strncmp.c
@@ -1,9 +1,35 @@
+#include <stdint.h>
 #include <string.h>
+#include "word.h"
 
-int strncmp(const char *_l, const char *_r, size_t n)
+/**
+ * strncmp - Word sized c standard strncmp.
+ * @c: Comparative
+ * @s: Source
+ * @n: Max size of @s
+ */
+int strncmp(const char *c, const char *s, size_t n)
 {
-	const unsigned char *l=(void *)_l, *r=(void *)_r;
-	if (!n--) return 0;
-	for (; *l && *r && n && *l == *r ; l++, r++, n--);
-	return *l - *r;
+	const size_t *wc, *ws;
+
+	if ((uintptr_t)c % sizeof(size_t) != (uintptr_t)s % sizeof(size_t))
+		goto misaligned;
+
+	for (; (uintptr_t)c % sizeof(size_t); c++, s++, n--) {
+		if (*c != *s || !*c || !*s || !n)
+			return *(const unsigned char *)c
+				- *(const unsigned char *)s;
+	}
+
+	for (wc = (const size_t *)c, ws = (const size_t *)s
+	     ; !word_has_zero(*wc) || !word_has_zero(*ws)
+	     ; wc++, ws++);
+
+	c = (const char *)wc;
+	s = (const char *)ws;
+
+misaligned:
+	for(; *c == *s && *c && *s && n; c++, s++, n--);
+
+	return *(const unsigned char *)c - *(const unsigned char *)s;
 }
-- 
1.7.11.4