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cc65/libsrc/runtime/ldec.s
cuz c413c5feeb Several SBC optimizations suggested by Piotr Fusik
git-svn-id: svn://svn.cc65.org/cc65/trunk@1121 b7a2c559-68d2-44c3-8de9-860c34a00d81
2001-11-17 11:25:12 +00:00

27 lines
280 B
ArmAsm

;
; Ullrich von Bassewitz, 29.12.1999
;
; CC65 runtime: Decrement eax by value in Y
;
.export deceaxy
.importzp sreg, tmp1
deceaxy:
sty tmp1
sec
sbc tmp1
sta tmp1
txa
sbc #0
tax
lda sreg
sbc #0
sta sreg
lda sreg+1
sbc #0
sta sreg+1
lda tmp1
rts