Rewrite the decsp and subysp functions now since they are used more often.

git-svn-id: svn://svn.cc65.org/cc65/trunk@665 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2001-03-24 16:15:01 +00:00
parent eec01763c4
commit 1e1199cb2b
7 changed files with 66 additions and 39 deletions

View file

@ -5,27 +5,23 @@
;
.export decsp2
.importzp sp
.importzp sp
.proc decsp2
ldy sp
beq @L1
dey
beq @L2
dey
sty sp
rts
lda sp
sec
sbc #2
sta sp
bcc @L1
rts
@L1: dey
@L2: dey
sty sp
dec sp+1
@L1: dec sp+1
rts
.endproc

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@ -5,16 +5,23 @@
;
.export decsp3
.import subysp
.importzp sp
.proc decsp3
ldy #3
jmp subysp
lda sp
sec
sbc #3
sta sp
bcc @L1
rts
@L1: dec sp+1
rts
.endproc

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@ -5,16 +5,23 @@
;
.export decsp4
.import subysp
.importzp sp
.proc decsp4
ldy #4
jmp subysp
lda sp
sec
sbc #4
sta sp
bcc @L1
rts
@L1: dec sp+1
rts
.endproc

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@ -5,16 +5,23 @@
;
.export decsp5
.import subysp
.importzp sp
.proc decsp5
ldy #5
jmp subysp
lda sp
sec
sbc #5
sta sp
bcc @L1
rts
@L1: dec sp+1
rts
.endproc

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@ -5,16 +5,23 @@
;
.export decsp6
.import subysp
.importzp sp
.proc decsp6
ldy #6
jmp subysp
lda sp
sec
sbc #6
sta sp
bcc @L1
rts
@L1: dec sp+1
rts
.endproc

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@ -5,16 +5,21 @@
;
.export decsp7
.import subysp
.importzp sp
.proc decsp7
ldy #7
jmp subysp
lda sp
sec
sbc #7
sta sp
bcc @L1
rts
@L1: dec sp+1
rts
.endproc

View file

@ -9,7 +9,6 @@
.proc subysp
pha ; Save A
sty tmp1 ; Save the value
lda sp ; Get lo byte
sec
@ -17,12 +16,11 @@
sta sp ; Put result back
bcs @L1
dec sp+1
@L1: pla ; Restore A
rts ; Done
@L1: rts ; Done
.endproc