feat: atoibase skel

src/ft_atoibase.asm

@@ -0,0 +1,249 @@
+global ft_atoibase
+extern ft_bzero
+extern ft_isspace
+extern __errno_location
+
+section .text
+
+;int has_dup(const char *s) {
+;    uint32_t bits[8] = {0}; // 8*32 = 256 bits
+;    for (const unsigned char *p = (const unsigned char*)s; *p; ++p) {
+;        unsigned int v = *p;
+;        unsigned int idx = v >> 5;        // division par 32
+;        unsigned int bit = v & 31;        // v % 32
+;        uint32_t mask = 1u << bit;
+;        if (bits[idx] & mask) return -1;
+;        bits[idx] |= mask;
+;    }
+;    return 0;
+;}
+
+; return base_len and check for "-+" or duplicate char
+; rdi: base
+check_base:
+	; uint32_t buffer[8]
+	push	rbp
+	mov	rbp, rsp
+	sub	rsp, 40
+
+	mov	qword [rsp + 32], rdi
+
+	; bzero buffer, 32
+	mov	rdi, rsp
+	mov	rsi, 32
+	call	ft_bzero wrt ..plt
+
+	mov	rax, qword [rsp + 32]
+
+.loop:
+	mov	dl, byte [rax]
+	test	dl, dl
+	je	.done
+
+	; if (*p == '-' || *p == '+') return -1
+	cmp	dl, 45 ; '-'
+	je	.error
+	cmp	dl, 43 ; '+'
+	je	.error
+
+	; r10(idx) = *p / 32
+	; rdx(bit) = *p % 32
+	mov	r10, [rax]
+	shr	r10, 5
+	mov	rdx, [rax]
+	and	rdx, 31
+
+	; mask = 1 << rdx(bit)
+	mov	r11, 1
+	mov	cl, dl
+	shl	r11, cl
+
+	; if (bits[idx] & mask) return -1
+	mov	r9, [rsp + rdx]
+	and	r9, r11
+	test	r9, r9
+	jne	.error
+
+	; bits[idx] |= mask
+	or	[rsp + rdx], r11
+
+	; ++p
+	inc	rax
+
+	jmp	.loop
+.done:
+	sub	rax, qword [rsp + 32]
+
+.return:
+	add	rsp, 40
+	pop	rbp
+	ret
+
+.error:
+	mov	rax, -1
+	jmp	.return
+
+; rdi:	str
+; skip whitespace
+; return :
+; rax	str + x
+; dl	is_signed
+; rax = 0 if 2 sign
+find_start:
+	push	r12
+	mov	r12, rdi
+.loop:
+	mov	dil, byte [r12]
+	call	ft_isspace wrt ..plt
+
+	test	rax, rax
+	je	.done
+	test	dil, dil
+	je	.done
+	
+	inc	r12
+	jmp	.loop
+.done:
+	mov	rax, r12
+	mov	dl, 0
+
+	pop	r12
+
+	cmp	byte [rax], '-'
+	je	.is_signed
+	
+	ret
+.is_signed:
+	inc	dl
+	inc	rax
+	ret
+
+; rdi base
+; rsi char
+is_in_base:
+.loop:
+	mov	dl, byte [rdi]
+	test	dl, dl
+	je	.is_not_in
+
+	cmp	dl, sil
+	je	.is_in
+	
+	inc	rdi
+	jmp	.loop
+
+.is_in:
+	mov	rax, 1
+	ret
+
+.is_not_in:
+	xor	rax, rax	
+	ret
+
+; rdi: base
+; rsi: char
+; rdx: baselen
+
+; int i = 0
+; while i < baselen
+;   if (c == base[i])
+;     return 1
+;   inc i
+; return -1
+
+get_num_from_base:
+	xor	rax, rax; rax = i = 0
+	
+.loop:
+	cmp	rax, rdx
+	jge	.not_found
+	
+	mov	cl, byte [rdi + rax]
+	cmp	cl, sil
+	je	.found
+	
+	inc	rax
+	jmp	.loop
+	
+.found:
+	mov	rax, 1
+	ret
+	
+.not_found:
+	mov	rax, -1
+	ret
+
+; r12: str
+; r13: base
+ft_atoibase:
+	push	r12
+	push	r13
+	push	r14
+	push	r15
+
+	mov	r12, rdi
+	mov	r13, rsi
+
+	; if (check_base(base) <= 0 ) return 0;
+	mov	rdi, r13
+	call	check_base
+	test	rax, rax
+	jle	.invalid_base
+
+	; r14 = base_len
+	mov	r14, rax
+
+	; str += start + is_signed
+	; rb9 = is_signed
+	mov	rdi, r12
+	call	find_start
+	mov	r12, rax
+	mov	r15b, dl
+
+	; r11 = r = 0
+	xor	r11, r11
+.loop:
+	cmp	byte [r12], 0
+	je	.done
+	
+
+	mul	r11, r14
+	mov	rdi, r13
+	movzx	rsi, byte [r12]
+	mov	rdx, r14
+
+	push	r11
+	call	get_num_from_base
+	pop	r11
+	cmp	rax, rax
+	jl	.done
+
+	add	r11, rax
+	; r += rax
+
+	inc	r12
+	jmp	.loop
+.done:
+	mov	rax, r11
+
+	test	r9b, r9b
+	je	.pos
+	neg	rax
+.pos:
+
+	pop	r12
+	pop	r13
+	pop	r14
+	pop	r15
+	ret
+
+.invalid_base:
+	; errno = EINVAL
+	call	__errno_location wrt ..plt
+	mov	dword [rax], 22
+	xor	rax, rax
+	jmp	.done
+
+.overflow:
+	xor	rax, rax ; TODO: LONG_MAX | LONG_MIN
+	jmp	.done