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ORCALib
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Rework time "factor" routine to work for the full 32-bit time range. 

ORCA/C uses an unsigned 32-bit time_t which should give a range up to 2105, but calculations on it were being done with signed types, causing them not to work correctly beyond 2036-2038. Now the factor routine, mktime(), and time() should work up to 2105. (In the case of time(), this assumes ReadTimeHex reports the time correctly.)

The factor routine actually computes a 64-bit time value. Currently, the rest of the code only takes the bottom 32 bits of it, but this could be extended if we ever wanted to switch to 64-bit time_t.
This commit is contained in:
Stephen Heumann 2022-12-29 22:31:31 -06:00
parent d30ee1a2e5
commit 17faeda1de
2 changed files with 126 additions and 35 deletions
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132
time.asm
View File

@ -38,7 +38,7 @@ day ds 4 day 1..31
hour ds 4 hour 0..23
minute ds 4 minute 0..59
second ds 4 second 0..59
count ds 4 seconds since 13 Nov 1969
count ds 8 seconds since 13 Nov 1969
t1 ds 4 work variable
t2 ds 4 work variable
@ -229,59 +229,121 @@ mk1 inx
*
* Inputs:
* year,month,day,hour,minute,second - time to convert
* (each treated as a signed 16-bit value)
*
* Outputs:
* count - seconds since 13 Nov 1969
* count - seconds since 13 Nov 1969 (signed 64-bit value)
*
****************************************************************
*
factor private
using TimeCommon
;
; sign-extend time components to 4 bytes
;
stz year+2
lda year
bpl lb0
dec year+2
lb0 stz month+2
lda month
bpl lb0a
dec month+2
lb0a stz day+2
lda day
bpl lb0b
dec day+2
lb0b stz hour+2
lda hour
bpl lb0c
dec hour+2
lb0c stz minute+2
lda minute
bpl lb0d
dec minute+2
lb0d stz second+2
lda second
bpl lb0e
dec second+2
;
; compute the # of days since 13 Nov 1969
;
mul4 year,#365,count count := 365*year + day + 31*(month-1)
lb0e mul4 year,#365,count count := 365*year + day + 31*(month-1)
add4 count,day
mul4 month,#31,t1
add4 count,t1
sub4 count,#31
move4 year,t2 t2 := year
add4 year,#32800,t2 t2 := year + 32800 (so it is positive)
lda month if January or February then
cmp #3
bge lb1
dec t2 year := year-1
dec4 t2 year := year-1
bra lb2 else
lb1 mul4 month,#4,t1 count := count - (month*4+23) div 10
add4 t1,#23
div4 t1,#10
sub4 count,t1
lb2 lda t2 count := count + year div 4
lsr A
lsr A
clc
adc count
sta count
bcc lb3
inc count+2
lb3 add4 t2,#300 count := count -
div4 t2,#100 ((300+year) div 100+1)*3 div 4
lb2 div4 t2,#4,t1 count := count + (year+32800) div 4
add4 count,t1
add4 t2,#300 count := count -
div4 t2,#100 ((300+year+32800) div 100+1)*3 div 4
inc4 t2
mul4 t2,#3
div4 t2,#4
sub4 count,t2
sub4 count,#25516 subtract off days between 1 Jan 1900
sub4 count,#25518-2+7954 subtract off days between 1 Jan 1900
! and 13 Nov 1969, minus 2 to adjust for
! skipped leap days in 1700 and 1800
! skipped leap days in 1700 and 1800,
! plus 7954 to adjust for leap days in
! an additional 32800 years
;
; Convert to seconds and add in time of day in seconds
;
mul4 count,#24*60*60 convert to seconds
mul4 hour,#3600,t1 add in hours*3600
add4 count,t1
lda count+2 convert to 64-bit count of seconds
pha
bpl lb3 if count is negative, negate it
sub4 #0,count,count
lb3 tsc compute count*24*60*60
sec
sbc #8
tcs
ph4 count
ph4 #24*60*60
_LongMul
pla
sta count
pla
sta count+2
pla
sta count+4
pla
sta count+6
pla
bpl lb4 if count was negative, negate result
negate8 count
lb4 mul4 hour,#3600,t1 add in hours*3600
jsr add_t1_to_count
mul4 minute,#60,t1 add in minutes*60
add4 count,t1
add4 count,second add in seconds
rts
jsr add_t1_to_count
move4 second,t1 add in seconds
;
; Add t1 (4 bytes) to count (8 bytes).
; (This is called as a subroutine and also run at the end of factor.)
;
add_t1_to_count anop
clc
lda count
adc t1
sta count
lda count+2
adc t1+2
sta count+2
bcc ret
inc count+4
bne ret
inc count+6
ret rts
end
****************************************************************
@ -537,13 +599,10 @@ temp2 equ 5 temp variable
phk
plb
lla temp,-1 assume we can't do it
ldy #10 error if year < 70
ldy #10 set time parameters
lda [tmptr],Y
sta year
cmp #70
jlt lb1
dey set the other time parameters
dey
dey
lda [tmptr],Y
inc A
@ -563,7 +622,14 @@ temp2 equ 5 temp variable
lda [tmptr]
sta second
jsr factor compute seconds since 13 Nov 1969
move4 count,temp save the value for later return
lda count+4 if time is unrepresentable
ora count+6
beq lb0
lda #-1 return -1
sta temp
sta temp+2
brl lb1
lb0 move4 count,temp save the value for later return
lda #1 compute the days since the start of the
sta month year
sta day
@ -638,7 +704,13 @@ time start
pla
pla
jsr factor convert the seconds
lda tptr if tptr <> nil then
lda count+4 if time is unrepresentable
ora count+6
beq lb0
lda #-1 set return value to -1
sta count
sta count+2
lb0 lda tptr if tptr <> nil then
ora tptr+2
beq lb1
ldy #2 place the result there

29
time.macros
View File

@ -477,11 +477,6 @@
~&SYSCNT ~RESTM
MEND
MACRO
&LAB JLT &BP
&LAB BGE *+5
BRL &BP
MEND
MACRO
&LAB LLA &AD1,&AD2
&LAB ANOP
LCLA &L
@ -636,3 +631,27 @@
&lab ldx #$1138
jsl $E10000
MEND
MACRO
&lab _LongMul
&lab ldx #$0C0B
jsl $E10000
MEND
macro
&l negate8 &n1
&l ~setm
sec
ldy #0
tya
sbc &n1
sta &n1
tya
sbc &n1+2
sta &n1+2
tya
sbc &n1+4
sta &n1+4
tya
sbc &n1+6
sta &n1+6
~restm
mend