Merge branch 'master' into ft_ssl

1 files changed, 33 insertions, 8 deletions

diff --git a/src/mem/ft_memchr.c b/src/mem/ft_memchr.c
index 4fd8689..848b436 100644
--- a/src/mem/ft_memchr.c
+++ b/src/mem/ft_memchr.c
@@ -6,21 +6,46 @@
 /*   By: cacharle <marvin@42.fr>                    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2019/10/07 09:55:31 by cacharle          #+#    #+#             */
-/*   Updated: 2020/02/13 04:28:00 by cacharle         ###   ########.fr       */
+/*   Updated: 2020/05/12 21:39:04 by charles          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
 #include "libft.h"
 
+/*
+** Determining if a long word contain byte n
+**
+** xor all bytes with n, then check for zero byte like in ft_strlen.
+*/
+
+#define HIMAGIC 0x8080808080808080L
+#define LOMAGIC 0x0101010101010101L
+
 void	*ft_memchr(const void *s, int c, size_t n)
 {
-	size_t		i;
-	t_ftbyte	*cast_s;
+	uint64_t	buf;
+	uint64_t	lw;
 
-	cast_s = (t_ftbyte*)s;
-	i = -1;
-	while (++i < n)
-		if (cast_s[i] == (unsigned char)c)
-			return (cast_s + i);
+	c = (uint8_t)c;
+	while (((uint64_t)s & 0b111) != 0 && n > 0)
+	{
+		if (*(uint8_t*)s == (uint8_t)c)
+			return ((void*)s);
+		n--;
+		s++;
+	}
+	buf = c | c << 8 | c << 16 | c << 24;
+	buf |= buf << 32;
+	while (n >= 8)
+	{
+		lw = *(uint64_t*)s ^ buf;
+		if ((lw - LOMAGIC) & ~lw & HIMAGIC)
+			break ;
+		n -= 8;
+		s += 8;
+	}
+	while (n-- > 0)
+		if (*(uint8_t*)s++ == (uint8_t)c)
+			return ((void*)(s - 1));
 	return (NULL);
 }