Mercurial > repos > blastem
view runtime_win.S @ 1925:039553703c20
Don't apply address and cd register changes to the 'live' registers until pending flag is cleared, but do preserve the upper address bits in the latch. Fixes regression in Overdrive 2 while preserving fix to Mona in 344 bytes
author | Michael Pavone <pavone@retrodev.com> |
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date | Mon, 13 Apr 2020 20:43:25 -0700 |
parents | 80a67be1770b |
children |
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invalid_msg: .asciz "Invalid instruction at %X\n" .global _m68k_invalid _m68k_invalid: push %ecx push invalid_msg xor %eax, %eax call _printf push $1 call _exit .global _bcd_add _bcd_add: xchg %eax, %edi mov %cl, %ch mov %al, %ah and $0xF, %ch and $0xF, %ah and $0xF0, %cl and $0xF0, %al add %ah, %ch cmp $10, %ch jb no_adjust add $6, %ch no_adjust: add %ch, %al add %al, %cl mov $0, %ch jc def_adjust cmp $0xA0, %cl jb no_adjust_h def_adjust: add $0x60, %cl mov $1, %ch no_adjust_h: mov %edi, %eax ret .global _bcd_sub _bcd_sub: xchg %eax, %edi mov %cl, %ch mov %al, %ah and $0xF, %ch and $0xF, %ah and $0xF0, %cl and $0xF0, %al sub %ah, %ch cmp $10, %ch jb no_adjusts sub $6, %ch no_adjusts: add %ch, %cl sub %al, %cl mov $0, %ch jc def_adjusts cmp $0xA0, %cl jb no_adjust_hs def_adjusts: sub $0x60, %cl mov $1, %ch no_adjust_hs: mov %edi, %eax ret