Adds int2str() and uint2str() (=>itoa)

src/convert.asm

@@ -1 +1,99 @@
 %include "src/constants.asm"
+
+section .bss
+	cnvtBuff	resb	21
+section .text
+	global	int2str
+	global	uint2str
+
+;----- int2str(num) -----;
+; Converts a signed integer to a string
+; Return value: Pointer to string containing the converted number
+; Used registers:
+;	rax*	num stored for div >> (ret) pointer to cnvtBuff[]
+;	rcx*	Counts length of created string
+;	rdx*	modulo as calculated by div >> character storage for cnvtBuff
+;	rdi*	(arg) number to convert to string >> Remembers if num is negative
+;	rsi*	Points to cnvtBuff for writing characters
+;	r8*	Dividor for div
+int2str:
+	mov	rsi, cnvtBuff
+	test	rdi, rdi
+	jnz	.notZero
+	mov	byte [rsi], '0'
+	mov	byte [rsi+1], EOS
+	jmp	.quit
+
+	.notZero:
+	mov	rax, rdi
+	xor	dil, dil
+	xor	rcx, rcx
+	test	rax, rax
+	jns	.convert
+	neg	rax
+	mov	dil, 1
+	.convert:
+		xor	rdx, rdx
+		mov	r8, 10
+		div	r8
+		add	rdx, '0'
+		push	rdx
+		inc	rcx
+		test	rax, rax
+		jnz	.convert
+		test	dil, dil
+		jz	.makeString
+	push	byte '-'
+	inc	rcx
+	.makeString:
+		pop	rdx
+		mov	byte [rsi], dl
+		inc	rsi
+		loop	.makeString
+	mov	byte [rsi], EOS
+
+	.quit:
+	mov	rax, cnvtBuff
+	ret
+
+;----- uint2str(num) -----;
+; Converts an unsigned integer to a string
+; Return value: Pointer to string containing the converted number
+; Used registers:
+;	rax*	num stored for div >> (ret) pointer to cnvtBuff[]
+;	rcx*	Counts length of created string
+;	rdx*	modulo as calculated by div >> character storage for cnvtBuff
+;	rdi*	(arg) number to convert to string
+;	rsi*	Points to cnvtBuff for writing characters
+;	r8*	Dividor for div
+uint2str:
+	mov	rsi, cnvtBuff
+	test	rdi, rdi
+	jnz	.notZero
+	mov	byte [rsi], '0'
+	mov	byte [rsi+1], EOS
+	jmp	.quit
+
+	.notZero:
+	mov	rax, rdi
+	xor	dil, dil
+	xor	rcx, rcx
+	.convert:
+		xor	rdx, rdx
+		mov	r8, 10
+		div	r8
+		add	rdx, '0'
+		push	rdx
+		inc	rcx
+		test	rax, rax
+		jnz	.convert
+	.makeString:
+		pop	rdx
+		mov	byte [rsi], dl
+		inc	rsi
+		loop	.makeString
+	mov	byte [rsi], EOS
+
+	.quit:
+	mov	rax, cnvtBuff
+	ret