6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-11-18 00:07:21 +00:00
Code Issues Projects Releases Wiki Activity
0e947d594f
cc65/libsrc/apple2/gettime.s

95 lines
2.1 KiB
ArmAsm
Raw Normal View History

Replaced _systime with clock_gettime. We want to add the capability to not only get the time but also set the time, but there's no "setter" for the "getter" time(). The first ones that come into mind are gettimeofday() and settimeofday(). However, they take a struct timezone argument that doesn't make sense - even the man pages says "The use of the timezone structure is obsolete; the tz argument should normally be specified as NULL." And POSIX says "Applications should use the clock_gettime() function instead of the obsolescent gettimeofday() function." The ...timeofday() functions work with microseconds while the clock_...time() functions work with nanoseconds. Given that we expect our targets to support only 1/10 of seconds the microseconds look preferable at first sight. However, already microseconds require the cc65 data type 'long' so it's not such a relevant difference to nanoseconds. Additionally clock_getres() seems useful. In order to avoid code duplication clock_gettime() takes over the role of the actual time getter from _systime(). So time() now calls clock_gettime() instead of _systime(). For some reason beyond my understanding _systime() was mentioned in time.h. _systime() worked exactly like e.g. _sysremove() and those _sys...() functions are all considered internal. The only reason I could see would be a performance gain of bypassing the time() wrapper. However, all known _systime() implementations internally called mktime(). And mktime() is implemented in C using an iterative algorithm so I really can't see what would be left to gain here. From that perspective I decided to just remove _systime().
2018-08-15 13:59:11 +00:00
;
; Oliver Schmidt, 14.08.2018
;
Adjusted comments to match actual prototypes.
2018-11-06 10:13:23 +00:00
; int __fastcall__ clock_gettime (clockid_t clk_id, struct timespec *tp);
Replaced _systime with clock_gettime. We want to add the capability to not only get the time but also set the time, but there's no "setter" for the "getter" time(). The first ones that come into mind are gettimeofday() and settimeofday(). However, they take a struct timezone argument that doesn't make sense - even the man pages says "The use of the timezone structure is obsolete; the tz argument should normally be specified as NULL." And POSIX says "Applications should use the clock_gettime() function instead of the obsolescent gettimeofday() function." The ...timeofday() functions work with microseconds while the clock_...time() functions work with nanoseconds. Given that we expect our targets to support only 1/10 of seconds the microseconds look preferable at first sight. However, already microseconds require the cc65 data type 'long' so it's not such a relevant difference to nanoseconds. Additionally clock_getres() seems useful. In order to avoid code duplication clock_gettime() takes over the role of the actual time getter from _systime(). So time() now calls clock_gettime() instead of _systime(). For some reason beyond my understanding _systime() was mentioned in time.h. _systime() worked exactly like e.g. _sysremove() and those _sys...() functions are all considered internal. The only reason I could see would be a performance gain of bypassing the time() wrapper. However, all known _systime() implementations internally called mktime(). And mktime() is implemented in C using an iterative algorithm so I really can't see what would be left to gain here. From that perspective I decided to just remove _systime().
2018-08-15 13:59:11 +00:00
;
.import pushax, steaxspidx, incsp1, incsp3, return0
.include "time.inc"
.include "zeropage.inc"
.include "errno.inc"
.include "mli.inc"
_clock_gettime:
jsr pushax
; Clear tv_nsec (+ tv_sec)
sta ptr1
stx ptr1+1
lda #$00
ldy #.sizeof(timespec)-1
: sta (ptr1),y
dey
bpl :-
; Update date + time
lda #GET_TIME_CALL
ldx #GET_TIME_COUNT
jsr callmli
bcs oserr
; Get date
lda DATELO+1
lsr
php ; Save month msb
cmp #70 ; Year < 70?
bcs :+ ; No, leave alone
adc #100 ; Move 19xx to 20xx
: sta TM + tm::tm_year
lda DATELO
tax ; Save day
plp ; Restore month msb
ror
lsr
lsr
lsr
lsr
beq erange ; [1..12] allows for validity check
tay
dey ; Move [1..12] to [0..11]
sty TM + tm::tm_mon
txa ; Restore day
and #%00011111
sta TM + tm::tm_mday
; Get time
lda TIMELO+1
sta TM + tm::tm_hour
lda TIMELO
sta TM + tm::tm_min
; Make time_t
lda #<TM
ldx #>TM
jsr _mktime
; Store tv_sec
ldy #timespec::tv_sec
jsr steaxspidx
Minor style fix.
2018-08-15 17:40:56 +00:00
; Cleanup stack
Replaced _systime with clock_gettime. We want to add the capability to not only get the time but also set the time, but there's no "setter" for the "getter" time(). The first ones that come into mind are gettimeofday() and settimeofday(). However, they take a struct timezone argument that doesn't make sense - even the man pages says "The use of the timezone structure is obsolete; the tz argument should normally be specified as NULL." And POSIX says "Applications should use the clock_gettime() function instead of the obsolescent gettimeofday() function." The ...timeofday() functions work with microseconds while the clock_...time() functions work with nanoseconds. Given that we expect our targets to support only 1/10 of seconds the microseconds look preferable at first sight. However, already microseconds require the cc65 data type 'long' so it's not such a relevant difference to nanoseconds. Additionally clock_getres() seems useful. In order to avoid code duplication clock_gettime() takes over the role of the actual time getter from _systime(). So time() now calls clock_gettime() instead of _systime(). For some reason beyond my understanding _systime() was mentioned in time.h. _systime() worked exactly like e.g. _sysremove() and those _sys...() functions are all considered internal. The only reason I could see would be a performance gain of bypassing the time() wrapper. However, all known _systime() implementations internally called mktime(). And mktime() is implemented in C using an iterative algorithm so I really can't see what would be left to gain here. From that perspective I decided to just remove _systime().
2018-08-15 13:59:11 +00:00
jsr incsp1
Minor style fix.
2018-08-15 17:40:56 +00:00
; Return success
Replaced _systime with clock_gettime. We want to add the capability to not only get the time but also set the time, but there's no "setter" for the "getter" time(). The first ones that come into mind are gettimeofday() and settimeofday(). However, they take a struct timezone argument that doesn't make sense - even the man pages says "The use of the timezone structure is obsolete; the tz argument should normally be specified as NULL." And POSIX says "Applications should use the clock_gettime() function instead of the obsolescent gettimeofday() function." The ...timeofday() functions work with microseconds while the clock_...time() functions work with nanoseconds. Given that we expect our targets to support only 1/10 of seconds the microseconds look preferable at first sight. However, already microseconds require the cc65 data type 'long' so it's not such a relevant difference to nanoseconds. Additionally clock_getres() seems useful. In order to avoid code duplication clock_gettime() takes over the role of the actual time getter from _systime(). So time() now calls clock_gettime() instead of _systime(). For some reason beyond my understanding _systime() was mentioned in time.h. _systime() worked exactly like e.g. _sysremove() and those _sys...() functions are all considered internal. The only reason I could see would be a performance gain of bypassing the time() wrapper. However, all known _systime() implementations internally called mktime(). And mktime() is implemented in C using an iterative algorithm so I really can't see what would be left to gain here. From that perspective I decided to just remove _systime().
2018-08-15 13:59:11 +00:00
jmp return0
; Load errno code
erange: lda #ERANGE
; Cleanup stack
jsr incsp3 ; Preserves A
; Set __errno
jmp __directerrno
; Cleanup stack
oserr: jsr incsp3 ; Preserves A
; Set __oserror
jmp __mappederrno
.bss
TM: .tag tm
Reference in New Issue Copy Permalink