From c128213daa677d548bfc2905496257fe4a4faf79 Mon Sep 17 00:00:00 2001
From: Charles <sircharlesaze@gmail.com>
Date: Wed, 11 Mar 2020 21:07:32 +0100
Subject: ft_mem* and ft_strlen optimization

---
 src/mem/ft_memccpy.c | 56 ++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 46 insertions(+), 10 deletions(-)

(limited to 'src/mem/ft_memccpy.c')

diff --git a/src/mem/ft_memccpy.c b/src/mem/ft_memccpy.c
index 8ce656a..0f52242 100644
--- a/src/mem/ft_memccpy.c
+++ b/src/mem/ft_memccpy.c
@@ -12,20 +12,56 @@
 
 #include "libft.h"
 
+#define HIMAGIC 0x8080808080808080L
+#define LOMAGIC 0x0101010101010101L
+
 void	*ft_memccpy(void *dest, const void *src, int c, size_t n)
 {
-	size_t		i;
-	t_ftbyte	*cast_dest;
-	t_ftbyte	*cast_src;
+	uint64_t	buf;
+	uint64_t	lw;
 
-	cast_dest = (t_ftbyte*)dest;
-	cast_src = (t_ftbyte*)src;
-	i = -1;
-	while (++i < n)
+	if (dest == src)
+		return (dest);
+	c = (uint8_t)c;
+	while ((n & 0b111) != 0)
+	{
+		*(uint8_t*)dest = *(uint8_t*)src;
+		if (*(uint8_t*)dest == c)
+			return ((uint8_t*)dest + 1);
+		src++;
+		dest++;
+		n--;
+	}
+	buf = (uint64_t)c | (uint64_t)c << 8 | (uint64_t)c << 16
+		| (uint64_t)c << 24 | (uint64_t)c << 32 | (uint64_t)c << 40
+		| (uint64_t)c << 48 | (uint64_t)c << 56;
+	while (n > 0)
 	{
-		cast_dest[i] = cast_src[i];
-		if (cast_dest[i] == (unsigned char)c)
-			return (cast_dest + i + 1);
+		lw = *(uint64_t*)src ^ buf;
+		if ((lw - LOMAGIC) & ~lw & HIMAGIC)
+		{
+			if ( (((uint8_t*)dest)[0] = ((uint8_t*)src)[0]) == (uint8_t)c)
+				return ((uint8_t*)dest + 1);
+			if ( (((uint8_t*)dest)[1] = ((uint8_t*)src)[1]) == (uint8_t)c)
+				return ((uint8_t*)dest + 2);
+			if ( (((uint8_t*)dest)[2] = ((uint8_t*)src)[2]) == (uint8_t)c)
+				return ((uint8_t*)dest + 3);
+			if ( (((uint8_t*)dest)[3] = ((uint8_t*)src)[3]) == (uint8_t)c)
+				return ((uint8_t*)dest + 4);
+			if ( (((uint8_t*)dest)[4] = ((uint8_t*)src)[4]) == (uint8_t)c)
+				return ((uint8_t*)dest + 5);
+			if ( (((uint8_t*)dest)[5] = ((uint8_t*)src)[5]) == (uint8_t)c)
+				return ((uint8_t*)dest + 6);
+			if ( (((uint8_t*)dest)[6] = ((uint8_t*)src)[6]) == (uint8_t)c)
+				return ((uint8_t*)dest + 7);
+			if ( (((uint8_t*)dest)[7] = ((uint8_t*)src)[7]) == (uint8_t)c)
+				return ((uint8_t*)dest + 8);
+		}
+		else
+			*(uint64_t*)dest = *(uint64_t*)src;
+		n -= 8;
+		dest += 8;
+		src += 8;
 	}
 	return (NULL);
 }
-- 
cgit