Set hours string in a single memory access

For nano sec, sec and min printing

wtfstopw.asm

@@ -26,21 +26,20 @@
 ; Interact :
 ; 	press enter to exit
 ; 	send SIGINT (with kill -2 ir ctrl + c) for a new lap
-
-
-
 [bits 64]
 
+%define O_NONBLOCK 0x800
+
 STRUC TIMESPEC_STRUC
 	.tv_sec: resq 1
 	.tv_nsec: resq 1
 ENDSTRUC
 
 
-%macro TIMESPEC 3
+%macro TIMESPEC 1
 	%1: ISTRUC TIMESPEC_STRUC
-		at TIMESPEC_STRUC.tv_sec, dq %2
-		at TIMESPEC_STRUC.tv_nsec, dq %3
+		at TIMESPEC_STRUC.tv_sec, resq 1
+		at TIMESPEC_STRUC.tv_nsec, resq 1
 	IEND
 	%define %1.tv_sec %1+TIMESPEC_STRUC.tv_sec
 	%define %1.tv_nsec %1+TIMESPEC_STRUC.tv_nsec
@@ -53,9 +52,9 @@ STRUC SIGACTION_STRUC
 	.sa_mask:         resb      128
 ENDSTRUC
 
-section .data
-
-	sigaction: ISTRUC SIGACTION_STRUC
+; from https://www.linuxnasm.be/home/library/lib-includes/signals-inc
+%macro SIGACTION 1
+	%1: ISTRUC SIGACTION_STRUC
 		at  SIGACTION_STRUC.sa_handler, dq 0
 		at  SIGACTION_STRUC.sa_flags, dq 0
 		at  SIGACTION_STRUC.sa_restorer, dq 0
@@ -65,17 +64,40 @@ section .data
 	%define sigaction.sa_flags sigaction+SIGACTION_STRUC.sa_flags
 	%define sigaction.sa_restorer sigaction+SIGACTION_STRUC.sa_restorer
 	%define sigaction.sa_mask sigaction+SIGACTION_STRUC.sa_mask
+%endmacro
 
-	TIMESPEC ts_start, 0, 0
-	TIMESPEC ts_cur, 0, 0
-	TIMESPEC ts_sleep, 0, 100000000 ; set before mainloop
+section .bss
+align 8
+	TIMESPEC ts_start
+	TIMESPEC ts_cur
+	TIMESPEC ts_sleep
+	buf: resb 1
 
+section .data
 
-	faultmsg: db "Fault !", 0xA
-	faultmsglen: equ $ - faultmsg
+	time_res: dq 2 ; 2 digits bellow seconds can grow to 8
+	fcntl_flag: dq 0
+	SIGACTION sigaction
+
+	align 8
+	hours: times 8 db '0' ; 8 digits is the max for hours
+	timestr: db ":00:00." 
+		times 8 db '0' ; 8 digits for nanoseconds
+		times 0xE db ' '
+		db 0
+	timestrend: align 8
+	timestrlen: equ timestrend - timestr
+	%define HOURSLEN 8
+
+	lapsmsg: db "Lap : "
+	lapsmsglen: equ $ - lapsmsg
+
+	lapcount: times 20 db '0' ; allows storing decimal repr of 1<<64
+	lapcountlen: equ $ - lapcount
+	laplen: dq 2
 
 	startmsg: db "Press Enter or ctrl+d to exit and ctrl+c for new lap."
-	db 0xA
+		db 0xA
 	startmsglen: equ $ - startmsg
 
 	usage_pre: db "Usage : "
@@ -100,23 +122,12 @@ section .data
 	badval_msg: db "Value for -r should be in [1..8] but got "
 	badval_msglen: equ $ - badval_msg
 
-	hours: db "000000000"
-	timestr: db ":00:00.0           ", 0x0a
-	timestrlen: equ $ - timestr
-
-	time_res: dq 2 ; 2 digits bellow seconds can grow to 8
+	faultmsg: db "Fault !", 0xA
+	faultmsglen: equ $ - faultmsg
 
 	nl: db 0x0A
-	buf: db 0
+	cr: db 0xd
 
-	lapsmsg: db 0x0d, "Lap : "
-	lapsmsglen: equ $ - lapsmsg
-
-	lapcount: db "00000000"
-	lapcountlen: equ $ - lapcount
-	laplen: dq 2
-
-	fcntl_flag: dq 0
 
 section .text
 global _start
@@ -126,7 +137,7 @@ _start:
 jmp arg_parse
 arg_ok:
 
-; set stdin non blocking
+; set stdin reads non blocking
 xor rdx, rdx
 xor rdi, rdi
 mov rax, 72 ; fcntl
@@ -134,15 +145,13 @@ mov rsi, 3 ; F_GETFL
 syscall
 mov [fcntl_flag], rax
 mov rdx, rax
-or rdx, 0x800 ; O_NONBLOCK
+or rdx, O_NONBLOCK
 mov rax, 72 ; fcntl
 mov rsi, 4 ; F_SETFL
 syscall
 cmp rax, 0
 jne fault
 
-; initializing lapptr
-
 ; preparing SIGINT catch
 mov rax, proc_lap_handler
 mov qword [sigaction.sa_handler], rax
@@ -173,6 +182,7 @@ syscall
 
 ; set value for ts_sleep.tv_nsec given time_res
 ; div sleep time by 10 for each digits added bellow seconds
+mov qword [ts_sleep.tv_sec], 0
 mov rax, 100000000
 mov r8, [time_res]
 mov r9, 10
@@ -186,9 +196,10 @@ setsleep_loop:
 setsleep_endloop:
 mov [ts_sleep.tv_nsec], rax
 
+std ; set DF for string operations
 main_loop:
 	push 2 ; stderr
-	push 0x0D ; \r
+	push 0xD ; \r
 	call proc_print_time
 
 	; Attempt to read from stdin
@@ -240,11 +251,8 @@ exit:
 	pop rdi ; return code
 	syscall
 fault:
-	mov rax, 1 ; write
 	mov rdi, 2 ; stderr
-	mov rsi, nl
-	mov rdx, 1
-	syscall
+	call proc_nl
 	mov rax, 1
 	mov rsi, faultmsg
 	mov rdx, faultmsglen
@@ -254,11 +262,8 @@ fault:
 	jmp exit
 
 newline_exit:
-	mov rax, 1
 	mov rdi, 1
-	mov rsi, nl
-	mov rdx, 1
-	syscall
+	call proc_nl
 
 	mov rdi, 0 ; exit OK
 	jmp exit
@@ -266,201 +271,149 @@ newline_exit:
 ;
 ; Print current time on FD and add a leading char CHR
 ; push FD & push CHR to set arguments
+; 	Warning : DF must be set
 ;
 proc_print_time:
-	; push ret addr before arguments
-	pop r8
-	pop r9
-	pop r10
-	push r8
-	push r10
-	push r9
-
-	; updating ts_cur time
+	
 	mov rax, 228 ; clock_gettime
 	mov rdi, 0 ; CLOCK_REALTIME
 	mov rsi, ts_cur
-	syscall
+	syscall ; updating ts_cur time
 
-	; Calculating elapsed ns
 	mov rax, [ts_cur.tv_nsec]
-	mov rbx, [ts_start.tv_nsec]
-	sub rax, rbx
-	cmp rax, 0
+	sub rax, [ts_start.tv_nsec]
+	cmp rax, 0 ; Calculating elapsed ns
 	jge print_time_us_cont
-	; negativ result
-	add rax, 1000000000
-	mov rbx, [ts_cur.tv_sec]
-	sub rbx, 1
-	mov [ts_cur.tv_sec], rbx
+	add rax, 1000000000 ; negativ result
+	sub qword [ts_cur.tv_sec], 1
 	print_time_us_cont:
-	
-	; Divide result given time_res
-	mov r10, rax
-	mov rax, 1000000000
-	mov r9, [time_res]
+
+	xor rdx, rdx
+	div qword [ts_sleep.tv_nsec] ; Divide result given time_res
+
+	mov r9, [rsp + 8]
+	mov byte [timestr+timestrlen-1], r9b ; set last chr from 1st argument
+
+	; set the nanosec chars (time_res chars) in timestr
+	mov rbx, 0x2020202020202020
+	mov rcx, [time_res]
 	mov r8, 10
-	xor rdx, rdx
-	print_time_respow:
+	procpt_loopns:
+		xor rdx, rdx
 		div r8
-		sub r9, 1
-		cmp r9, 0
-		jg print_time_respow
-	mov rcx, rax
-	mov rax, r10
-	xor rdx, rdx
-	div rcx
+		or dl, 0x30 ; '0'
+		shl rbx, 8
+		mov bl, dl
+		loop procpt_loopns
+	mov [timestr+7], rbx
 
-	; 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
-	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
-
-	; handling seconds, minutes & hours
+	; filling timestr with seconds & minutes chars
 	mov rax, [ts_cur.tv_sec]
-	mov rbx, [ts_start.tv_sec]
-	sub rax, rbx
-	; rax now contain elapsed seconds
-	; filling timestr with seconds & minutes
+	sub rax, [ts_start.tv_sec] ; rax now contain elapsed seconds
+
+	mov r8, 10
+	mov r9, 6
 
 	xor rdx, rdx
-	mov rcx, 10
-	div rcx
-	add dl, 0x30
-	mov byte [timestr + 5], dl
+	div r8
+	mov bh, dl
+	xor dl, dl
+	div r9
+	mov bl, dl
+	or bx, 0x3030
+	mov word [timestr + 4], bx
 
-	xor rdx, rdx
-	mov rcx, 6
-	div rcx
-	push rax
-	add dl, 0x30
-	mov byte [timestr + 4], dl
+	xor dl, dl
+	div r8
+	mov bh, dl
+	xor dl, dl
+	div r9
+	mov bl, dl
+	or bx, 0x3030
+	mov word [timestr + 1], bx
 
-	xor rdx, rdx
-	mov rcx, 10
-	div rcx
-	add dl, 0x30
-	mov byte [timestr + 2], dl
-
-	pop rax
-	xor rdx, rdx
-	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
-	print_time_hours_loop:
-		mov rcx, 10
-		xor rdx, rdx
-		div rcx
-		add dl, 0x30
+	; using rbx to stores the hours string
+	xor rbx, rbx
+	mov rcx, HOURSLEN
+	mov r8, 10
+	procpt_looph:
+		xor dl, dl
+		div r8
+		shl rbx, 8
+		mov bl, dl
 		cmp rax, 0
-		jne print_time_hours_print_mod
-		cmp rdx, 0
-		je print_time_hours_loop_end
+		loopne procpt_looph
+	procpt_looph_end:
 
-		print_time_hours_print_mod:
-		mov r9, hours
-		add r9, r8
-		mov byte [r9], dl
-		cmp r8, 0
-		je fault
-		sub r8, 1
-		cmp rax, 0
-		jne print_time_hours_loop
-	print_time_hours_loop_end:
+	mov r8, HOURSLEN - 2
+	cmp rcx, HOURSLEN - 2
+	cmovl r8, rcx ; r8 stores hours digit count (at least 2)
+	cmp rcx, 0
+	jz procpt_looph2_end
+	procpt_looph2:
+		shl rbx, 8
+		loopne procpt_looph2
+	procpt_looph2_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
-	mov byte [timestr+timestrlen-1], r10b
+	mov r9, 0x3030303030303030 ; ASCII convertion
+	or rbx, r9
+	mov [hours], rbx
 
 	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
+	mov rdi, [rsp + 16] ; fd as 2nd argument
+	lea rsi, [hours + r8] ; hours start pointer
+	mov rdx, timestrlen + HOURSLEN
+	sub rdx, r8 ; timestr + hours len
 	syscall
 
-	ret
+	ret 16
 
 ;
 ;	sig handler for SIGINT displaying lap count and time on stdout
 ;
 proc_lap_handler:
+	mov rax, 1
+	mov rdi, 2
+	mov rsi, cr
+	mov rdx, 1
+	syscall ; \r on stderr
+
 	mov rax, 1
 	mov rdi, 1
 	mov rsi, lapsmsg
-	mov rdx, 5 ; "Lap "
+	mov rdx, 4 ; "Lap "
 	syscall
 
 	; increment the lapcount str directly
-	mov rbx, lapcount ; first digit ptr
-	add rbx, lapcountlen ; rightmost digit ptr
-	sub rbx, 1
-	mov r8, 1 ; counter
-	lap_handler_inc_lap:
-		mov r10b, [rbx]
-		cmp r10b, 0x39 ; '9'
-		jl lap_handler_inc_end
+	mov rcx, lapcountlen - 1; digit counter starting by the right most
+	proclap_loop:
+		cmp byte [lapcount + rcx], '9'
+		jl proclap_loopend
+		mov byte [lapcount + rcx], '0' ; set current digit to '0'
+		loop proclap_loop
+	proclap_loopend:
+	add byte [lapcount + rcx], 1 ; increment current digit
 
-		add r8, 1
-		cmp r8, [laplen]
-		jl lap_handler_laplen_noupd
-		mov [laplen], r8 ; update laplen
-
-		lap_handler_laplen_noupd:
-		mov byte [rbx], 0x30 ; set current digit to '0'
-		sub rbx, 1
-		cmp rbx, lapcount
-		jl fault
-		jmp lap_handler_inc_lap
-	lap_handler_inc_end:
-		add r10b, 1
-		mov [rbx], r10b
+	mov rdx, lapcountlen
+	sub rdx, rcx
+	cmp rdx, [laplen] ; update laplen if needed
+	cmovl rdx, [laplen]
+	mov [laplen], rdx
+	mov rsi, lapcount + lapcountlen
+	sub rsi, rdx
 	
-
 	mov rax, 1
-	mov rdi, 1
-	mov rdx, [laplen]
-	mov rsi, lapcount
-	add rsi, lapcountlen
-	sub rsi, rdx ; leftmost digit ptr
+	mov rdi, 1 ; stdout
 	syscall
 
-	mov rax, 1
-	mov rdi, 1
-	mov rsi, lapsmsg + 4
+	mov rax, 1 ; write
+	mov rsi, lapsmsg + 3
 	mov rdx, 3 ; " : "
 	syscall
 
+	std ; set DF for string operations
 	push 1 ; stdout
-	push 0x0A ; \n
+	push 0xA ; \n
 	call proc_print_time
 
 	ret
@@ -550,11 +503,8 @@ arg_strerr:
 	call proc_strlen
 	mov rax, 1
 	syscall
-	mov rax, 1
-	mov rsi, nl
-	mov rdx, 1
-	syscall
-	syscall
+	call proc_nl
+	call proc_nl
 	jmp arg_err
 
 ;
@@ -590,9 +540,9 @@ usage:
 proc_strlen:
 	mov r8, rax
 	mov r9, r8
-	sub r9, 1
+	dec r9
 	strlen_loop:
-		add r9, 1
+		inc r9
 		mov al, [r9]
 		cmp al, 0
 		jne strlen_loop
@@ -600,4 +550,12 @@ proc_strlen:
 	mov rdx, r9
 	ret
 
+; with rdi the fd
+proc_nl:
+	mov rax, 1
+	mov rsi, nl
+	mov rdx, 1
+	syscall
+	ret
+
 .end: