itoa

input/core/itoa.asm

@@ -0,0 +1,29 @@
+section .bss
+    buffer resb 20
+
+section .text
+    global itoa
+
+itoa:
+    push rbx
+    push rsi
+    push rdx
+    mov rax, rdi
+    mov rsi, buffer + 19
+    mov byte [rsi], 0
+    dec rsi
+.loop:
+    xor rdx, rdx
+    mov rbx, 10
+    div rbx
+    add dl, '0'
+    mov [rsi], dl
+    dec rsi
+    test rax, rax
+    jnz .loop
+    inc rsi
+    mov rax, rsi
+    pop rdx
+    pop rsi
+    pop rbx
+    ret

input/core/print.nub

@@ -2,14 +2,12 @@ let SYS_WRITE = 1;
 let STD_OUT = 1;
 let STD_ERR = 2;
 
-extern func print_int(value: int64);
-
 func print(msg: String) {
     syscall(SYS_WRITE, STD_OUT, msg, str_len(msg));
 }
 
 func print(value: int64) {
-    print_int(value);
+    print(itoa(value));
 }
 
 func print(value: bool) {

input/core/print_int.asm

@@ -1,42 +0,0 @@
-section .bss
-    buffer resb 20  ; Reserve 20 bytes for number string
-
-section .text
-    global print_int  ; Make function callable from outside
-
-print_int:
-    push rbx         ; Save rbx (callee-saved register)
-    push rsi         ; Save rsi (callee-saved register)
-    push rdx         ; Save rdx (callee-saved register)
-
-    mov rax, rdi     ; Move input number to rax
-    mov rsi, buffer + 19  ; Point to the last byte in buffer
-    mov byte [rsi], 0    ; Null terminator (not necessary for sys_write)
-    dec rsi               ; Move back for digits
-
-.loop:
-    xor rdx, rdx         ; Clear remainder
-    mov rbx, 10          ; Divisor
-    div rbx              ; RAX / 10 -> Quotient in RAX, remainder in RDX
-
-    add dl, '0'          ; Convert remainder to ASCII
-    mov [rsi], dl        ; Store character in buffer
-    dec rsi              ; Move buffer pointer back
-
-    test rax, rax        ; Check if quotient is 0
-    jnz .loop        ; Continue if not 0
-
-    inc rsi              ; Adjust pointer to first digit
-
-    ; Print using sys_write
-    mov rax, 1           ; syscall: sys_write
-    mov rdi, 1           ; file descriptor: stdout
-    mov rdx, buffer + 20 ; End of buffer
-    sub rdx, rsi         ; Compute actual length
-    syscall
-
-    ; Restore registers and return
-    pop rdx
-    pop rsi
-    pop rbx
-    ret

input/core/string.nub

@@ -1 +1,2 @@
 extern func str_len(msg: String): int64;
+extern func itoa(value: int64): String;

input/program.nub

@@ -1,5 +1,5 @@
 import "core";
 
 func main() {
-    println(58963475689457686745867567656769845676984567698475698674589675);
+    println(69);
 }

output/build.sh

@@ -2,6 +2,6 @@
 nasm -g -felf64 out.asm -o out.o
 nasm -g -felf64 ../input/core/str_len.asm -o str_len.o
 nasm -g -felf64 ../input/core/arr_size.asm -o arr_size.o
-nasm -g -felf64 ../input/core/print_int.asm -o print_int.o
+nasm -g -felf64 ../input/core/itoa.asm -o itoa.o
 
-ld -o out str_len.o arr_size.o print_int.o out.o
+ld -o out str_len.o arr_size.o itoa.o out.o