proc_print_time enhancement

wtfstopw.asm

 	badval_msg: db "Value for -r should be in [1..8] but got "
 	badval_msglen: equ $ - badval_msg
 
-	hours: db "000000000"
+	hours: db "000000000" ; increase size of this string to increase hours max
 	timestr: db ":00:00.0           ", 0x0a
 	timestrlen: equ $ - timestr
+	hourslen: equ timestr - hours ; hours len -> the max number of digits
 
 	time_res: dq 2 ; 2 digits bellow seconds can grow to 8
 
 setsleep_endloop:
 mov [ts_sleep.tv_nsec], rax
 
+std ; set DF for string operations
 main_loop:
 	mov rax, 2 ; stderr
 	mov rdi, 0xD ; \r
 ; Print current time on FD and add a leading char CHR
 ; push FD & push CHR to set arguments
 ; rax the FS & rdi the leading CHR
+; 	Warning : DF must be set
 ;
 proc_print_time:
 	
 
 	print_time_us_cont:
 	; Divide result given time_res
-	mov r10, rax
-	mov rax, 1000000000
-	mov r9, [time_res]
-	mov r8, 10
-	xor rdx, rdx
-	print_time_respow:
-		div r8
-		sub r9, 1
-		cmp r9, 0
-		jg print_time_respow
-	mov rcx, rax
-	mov rax, r10
 	xor rdx, rdx
-	div rcx
+	div qword [ts_sleep.tv_nsec]
 
-	; set the us char in timestr
-	mov r8, timestr
-	mov r9, [time_res] ; r9 count the number of digits
-	add r8, 6 ; first digits after seconds
-	add r8, r9 ; r8 points on last char before \r
+	; set the nsec char in timestr
+	mov rdi, timestr + 6
+	mov rsi, rdi
+	add rdi, [time_res] ; r8 points on last char before \r
+	mov r8, 10
 	print_time_us_loop:
 		xor rdx, rdx
-		mov rcx, 10
-		div rcx
-		add dl, 0x30
-		mov [r8], dl
-		sub r8, 1
-		sub r9, 1
-		cmp r9, 0
-		jg print_time_us_loop
+		div r8
+		xchg al, dl
+		add al, 0x30
+		stosb
+		mov al, dl
+		cmp rsi, rdi
+		loopne print_time_us_loop
 
 	; handling seconds, minutes & hours
 	mov rax, [ts_cur.tv_sec]
-	mov rbx, [ts_start.tv_sec]
-	sub rax, rbx
+	sub rax, [ts_start.tv_sec]
 	; rax now contain elapsed seconds
 	; filling timestr with seconds & minutes
 
 	add dl, 0x30
 	mov byte [timestr + 5], dl
 
-	xor rdx, rdx
+	xor dl, dl
 	mov rcx, 6
 	div rcx
-	push rax
 	add dl, 0x30
 	mov byte [timestr + 4], dl
 
-	xor rdx, rdx
+	xor dl, dl
 	mov rcx, 10
 	div rcx
 	add dl, 0x30
 	mov byte [timestr + 2], dl
 
-	pop rax
-	xor rdx, rdx
+	xor dl, dl
 	mov rcx, 6
 	div rcx
 	add dl, 0x30
 	mov byte[timestr + 1], dl
 
 	; filling the hours buffer
-	; r8 will contain our digits counter : max is 8
-	mov r8, 8
+	; rcx will contain max_digits - digits_count
+	; digits max is hourslen - 1
+	mov rcx, hourslen - 1
+	mov rdi, hours + hourslen - 1
+	mov r10, 10
 	print_time_hours_loop:
-		mov rcx, 10
-		xor rdx, rdx
-		div rcx
-		add dl, 0x30
+		xor dl, dl
+		div r10
 		cmp rax, 0
 		jne print_time_hours_print_mod
-		cmp rdx, 0
+		cmp dl, 0
 		je print_time_hours_loop_end
 
 		print_time_hours_print_mod:
-		mov r9, hours
-		add r9, r8
-		mov byte [r9], dl
-		cmp r8, 0
+		xchg al, dl
+		add al, 0x30
+		stosb
+		mov al, dl
+		cmp rcx, 0
 		je fault
-		sub r8, 1
 		cmp rax, 0
-		jne print_time_hours_loop
+		loopne print_time_hours_loop
 	print_time_hours_loop_end:
 
-	; print hours + timestr
-	add r8, 1
-	cmp r8, 7
-	jle print_time_hours_cont
-	mov r8, 7 ; maximum value for r8
-	print_time_hours_cont:
-	mov r9, hours
-	add r9, r8
-	mov rcx, 9
-	sub rcx, r8 ; rcx is hours size 
-	add rcx, timestrlen ; add to timestrlen
-
-	; Set leading char
-	pop r10
+	; set rcx for 2 digits at least for hours
+	mov r9, hourslen - 2
+	add rcx, 1
+	cmp rcx, r9
+	cmovnle rcx, r9
+
+	pop r10 ; pop leading char argument
 	mov byte [timestr+timestrlen-1], r10b
 
 	mov rax, 1 ; write
-	pop r10 ; print_time FD arg
-	mov rdi, r10 ; print_time arg
-	mov rsi, r9 ; start hours pointer
-	mov rdx, rcx ; size to timestr end
+	pop rdi ; pop fd argument
+	mov rdx, timestrlen + 9
+	sub rdx, rcx ; timestr + hours len
+	lea rsi, [hours + rcx] ; hours start pointer
 	syscall
 
 	ret
 
 	mov rax, 1 ; stdout
 	mov rdi, 0xA ; \n
+	std ; set DF for string operations
 	call proc_print_time
 
 	ret