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Minor optimization suggested by Greg King

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git-svn-id: svn://svn.cc65.org/cc65/trunk@1468 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2002-10-24 19:23:24 +00:00
parent 89fe03a728
commit 82684d98fb
2 changed files with 7 additions and 9 deletions
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9
libsrc/runtime/lmod.s
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@ -15,8 +15,9 @@ tosmodeax:
jsr poplsargs ; Get arguments from stack, adjust sign jsr poplsargs ; Get arguments from stack, adjust sign
jsr udiv32 ; Do the division, remainder is in (ptr2:tmp3:tmp4) jsr udiv32 ; Do the division, remainder is in (ptr2:tmp3:tmp4)
; Load the result with the exception of the low byte ; Load the result
lda ptr2
ldx ptr2+1 ldx ptr2+1
ldy tmp3 ldy tmp3
sty sreg sty sreg
@ -25,16 +26,14 @@ tosmodeax:
; Check the sign of the result. It is the sign of the left operand. ; Check the sign of the result. It is the sign of the left operand.
lda tmp1 ; Check sign of left operand bit tmp1 ; Check sign of left operand
bpl Pos ; Jump if result is positive bpl Pos ; Jump if result is positive
; Result is negative ; Result is negative
lda ptr2 ; Load byte 0 of result
jmp negeax ; Negate result jmp negeax ; Negate result
; Result is positive ; Result is positive
Pos: lda ptr2 ; Load byte 0 of result Pos: rts ; Done
rts ; Done

7
libsrc/runtime/mod.s
View File

@ -16,6 +16,7 @@ tosmoda0:
tosmodax: tosmodax:
jsr popsargs ; Get arguments from stack, adjust sign jsr popsargs ; Get arguments from stack, adjust sign
jsr udiv16 ; Do the division jsr udiv16 ; Do the division
lda ptr1 ; Load low byte of result
ldx ptr1+1 ; Load high byte of result ldx ptr1+1 ; Load high byte of result
; Adjust the sign of the result. tmp1 contains the high byte of the left ; Adjust the sign of the result. tmp1 contains the high byte of the left
@ -23,16 +24,14 @@ tosmodax:
; the result of the modulo operation is the same as that of the left ; the result of the modulo operation is the same as that of the left
; operand ; operand
lda tmp1 bit tmp1
bpl Pos ; Jump if sign of result positive bpl Pos ; Jump if sign of result positive
; Result is negative ; Result is negative
lda ptr1 ; Load low byte of result
jmp negax ; Adjust the sign jmp negax ; Adjust the sign
; Result is positive ; Result is positive
Pos: lda ptr1 Pos: rts
rts