feat: ft_strcmp

Makefile

@@ -3,6 +3,7 @@ NAME = libasm
 SRC = \
 	ft_strlen.s \
 	ft_strcpy.s \
+	ft_strcmp.s \
 
 OBJ = $(SRC:.s=.o)
 

ft_strcmp.s

@@ -0,0 +1,19 @@
+global ft_strcmp
+
+ft_strcmp:
+	xor rdx, rdx 
+	xor rax, rax
+.loop:
+	mov al, [rsi + rdx]
+	cmp byte [rdi + rdx], al 
+	jne .done
+	cmp byte [rdi + rdx], 0
+	je .done
+	inc rdx
+	jmp .loop
+.done:
+	movsx rax, byte [rdi + rdx]
+	movsx rbx, byte [rsi + rdx]
+	sub rax, rbx
+	ret
+

libasm.h

@@ -5,5 +5,6 @@
 
 size_t ft_strlen(const char *);
 char *ft_strcpy(char *, const char *);
+int ft_strcmp(const char *, const char *);
 
 #endif

main.c

@@ -2,7 +2,8 @@
 #include <stdlib.h>
 
 int main() {
-	printf("%ld\n", ft_strlen("c'est moi la chaine de 36 caracteres"));
+	char my_string[37] = "c'est moi la chaine de 36 caracteres"; 
+	printf("%ld\n", ft_strlen(my_string));
 
 	char *str;
 	str = (char *)malloc(150 * sizeof(char));
@@ -13,5 +14,13 @@ int main() {
 	printf("%s\n", str);
 	printf("%s\n", dst);
 	printf("%s\n", test);
+	printf("should be 0: %d\n", ft_strcmp(str, dst));
+	printf("should be 0 and not segv: %d\n", ft_strcmp(dst, test));
+	printf("should be 16 %d\n", ft_strcmp(my_string, str));
+	printf("should be -16 %d\n", ft_strcmp(str, my_string));
+	dst = "Salut c'est moi la diff mdr\0";
+	printf("should be 22: %d\n", ft_strcmp(str, dst));
+	dst = "Salut\0 c'est moi la diff mdr\0";
+	printf("should be 32: %d\n", ft_strcmp(str, dst));
 	return 0;
 }