fxemu2b.asm

著名SFC模拟器Snes9x的源代码。

; Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
;
; Super FX assembler emulator code
; (c) Copyright 1998, 1999 zsKnight and _Demo_.
;
; Permission to use, copy, modify and distribute Snes9x in both binary and
; source form, for non-commercial purposes, is hereby granted without fee,
; providing that this license information and copyright notice appear with
; all copies and any derived work.
;
; This software is provided 'as-is', without any express or implied
; warranty. In no event shall the authors be held liable for any damages
; arising from the use of this software.
;
; Snes9x is freeware for PERSONAL USE only. Commercial users should
; seek permission of the copyright holders first. Commercial use includes
; charging money for Snes9x or software derived from Snes9x.
;
; The copyright holders request that bug fixes and improvements to the code
; should be forwarded to them so everyone can benefit from the modifications
; in future versions.
;
; Super NES and Super Nintendo Entertainment System are trademarks of
; Nintendo Co., Limited and its subsidiary companies.
;
%include "i386/macros.mac"
%include "i386/fxemu2.mac"
%include "i386/fxemu2b.mac"
EXTSYM FxTable,FxTableb,FxTablec,SfxB,SfxCPB,SfxCROM,SfxCarry,SfxOverflow
EXTSYM SfxR0,SfxR14,SfxR15,SfxRomBuffer,SfxSignZero,withr15sk

SECTION .text

NEWSYM FxOpb05      ; BRA    branch always      ; Verified.
   movsx eax,byte[ebp]
   mov cl,[ebp+1]
   inc ebp
   add ebp,eax
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb06      ; BGE    branch on greater or equals        ; Verified.
   movsx eax,byte[ebp]
   mov ebx,[SfxSignZero]
   shr ebx,15
   inc ebp
   xor bl,[SfxOverflow]
   mov cl,[ebp]
   test bl,01h
   jnz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb07      ; BLT    branch on lesss than       ; Verified.
   movsx eax,byte[ebp]
   mov ebx,[SfxSignZero]
   shr ebx,15
   inc ebp
   xor bl,[SfxOverflow]
   mov cl,[ebp]
   test bl,01h
   jz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb08      ; BNE    branch on not equal        ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],0FFFFh
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb09      ; BEQ    branch on equal (z=1)      ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],0FFFFh
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb0A      ; BPL    branch on plus     ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],088000h
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb0B      ; BMI    branch on minus    ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],088000h
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb0C      ; BCC    branch on carry clear      ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxCarry],01h
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb0D      ; BCS    branch on carry set        ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxCarry],01h
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb0E      ; BVC    branch on overflow clear   ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxOverflow],01h
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb0F      ; BVS    branch on overflow set     ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxOverflow],01h
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTableb+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTableb+ecx*4]
   ret

NEWSYM FxOpb10      ; TO RN  set register n as destination register
   TORNb 0
NEWSYM FxOpb11      ; TO RN  set register n as destination register
   TORNb 1   
NEWSYM FxOpb12      ; TO RN  set register n as destination register
   TORNb 2   
NEWSYM FxOpb13      ; TO RN  set register n as destination register
   TORNb 3   
NEWSYM FxOpb14      ; TO RN  set register n as destination register
   TORNb 4   
NEWSYM FxOpb15      ; TO RN  set register n as destination register
   TORNb 5   
NEWSYM FxOpb16      ; TO RN  set register n as destination register
   TORNb 6   
NEWSYM FxOpb17      ; TO RN  set register n as destination register
   TORNb 7   
NEWSYM FxOpb18      ; TO RN  set register n as destination register
   TORNb 8   
NEWSYM FxOpb19      ; TO RN  set register n as destination register
   TORNb 9   
NEWSYM FxOpb1A      ; TO RN  set register n as destination register
   TORNb 10   
NEWSYM FxOpb1B      ; TO RN  set register n as destination register
   TORNb 11   
NEWSYM FxOpb1C      ; TO RN  set register n as destination register
   TORNb 12   
NEWSYM FxOpb1D      ; TO RN  set register n as destination register
   TORNb 13
NEWSYM FxOpb1E      ; TO RN  set register n as destination register
   FETCHPIPE
   test dword [SfxB],1
   jnz .VersionB
   mov edi,SfxR0+14*4
   inc ebp
   mov eax,ebp
   sub eax,[SfxCPB]
   mov dword[withr15sk],1
   mov [SfxR15],eax
   call [FxTableb+ecx*4]
   mov edi,SfxR0
   UpdateR14
   ret
.VersionB
   mov eax,[esi]            ; Read Source
   mov dword[withr15sk],1
   mov [SfxR0+14*4],eax             ; Write
   CLRFLAGS
   UpdateR14
   inc ebp                ; Increase program counter
   ret
NEWSYM FxOpb1F      ; TO RN  set register n as destination register
   FETCHPIPE
   test dword [SfxB],1
   jnz .VersionB
   mov edi,SfxR0+15*4
   inc ebp
   mov eax,ebp
   sub eax,[SfxCPB]
   mov [SfxR15],eax
   call [FxTableb+ecx*4]
   mov ebp,[SfxCPB]
   mov dword[withr15sk],1
   add ebp,[SfxR15]
   mov edi,SfxR0
   ret
.VersionB
   mov eax,[esi]            ; Read Source
   mov ebp,[SfxCPB]
   mov dword[withr15sk],1
   add ebp,eax
   CLRFLAGS
   ret

NEWSYM FxOpb3D      ; ALT1   set alt1 mode      ; Verified.
   FETCHPIPE
   mov dword [SfxB],0
   or ch,01h
   inc ebp
   mov eax,ebp
   sub eax,[SfxCPB]
   mov [SfxR15],eax
   call [FxTableb+ecx*4]
   xor ch,ch
   ret

NEWSYM FxOpb3E      ; ALT2   set alt1 mode      ; Verified.
   FETCHPIPE
   mov dword [SfxB],0
   or ch,02h
   inc ebp
   mov eax,ebp
   sub eax,[SfxCPB]
   mov [SfxR15],eax
   call [FxTable+ecx*4]
   xor ch,ch
   ret

NEWSYM FxOpb3F      ; ALT3   set alt3 mode      ; Verified.
   FETCHPIPE
   mov dword [SfxB],0
   or ch,03h
   inc ebp
   mov eax,ebp
   sub eax,[SfxCPB]
   mov [SfxR15],eax
   call [FxTable+ecx*4]
   xor ch,ch
   ret

NEWSYM FxOpbB0      ; FROM rn   set source register
   FROMRNb 0
NEWSYM FxOpbB1      ; FROM rn   set source register
   FROMRNb 1
NEWSYM FxOpbB2      ; FROM rn   set source register
   FROMRNb 2
NEWSYM FxOpbB3      ; FROM rn   set source register
   FROMRNb 3
NEWSYM FxOpbB4      ; FROM rn   set source register
   FROMRNb 4
NEWSYM FxOpbB5      ; FROM rn   set source register
   FROMRNb 5
NEWSYM FxOpbB6      ; FROM rn   set source register
   FROMRNb 6
NEWSYM FxOpbB7      ; FROM rn   set source register
   FROMRNb 7
NEWSYM FxOpbB8      ; FROM rn   set source register
   FROMRNb 8
NEWSYM FxOpbB9      ; FROM rn   set source register
   FROMRNb 9
NEWSYM FxOpbBA      ; FROM rn   set source register
   FROMRNb 10
NEWSYM FxOpbBB      ; FROM rn   set source register
   FROMRNb 11
NEWSYM FxOpbBC      ; FROM rn   set source register
   FROMRNb 12
NEWSYM FxOpbBD      ; FROM rn   set source register
   FROMRNb 13
NEWSYM FxOpbBE      ; FROM rn   set source register
   FROMRNb 14
NEWSYM FxOpbBF      ; FROM rn   set source register
   test dword [SfxB],1
   jnz .VersionB
   mov esi,SfxR0+15*4
   inc ebp                ; Increase program counter
   mov eax,ebp
   sub eax,[SfxCPB]
   mov [SfxR15],eax
   call [FxTableb+ecx*4]
   mov esi,SfxR0
   ret
.VersionB
   FETCHPIPE
   mov eax,ebp
   sub eax,[SfxCPB]
   inc ebp
   mov [edi],eax        ; Write Destination
   mov [SfxSignZero],eax
   shr al,7
   mov byte[SfxOverflow],al
   CLRFLAGS
   ret

NEWSYM FxOpc05      ; BRA    branch always      ; Verified.
   movsx eax,byte[ebp]
   mov cl,[ebp+1]
   inc ebp
   add ebp,eax
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc06      ; BGE    branch on greater or equals        ; Verified.
   movsx eax,byte[ebp]
   mov ebx,[SfxSignZero]
   shr ebx,15
   inc ebp
   xor bl,[SfxOverflow]
   mov cl,[ebp]
   test bl,01h
   jnz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc07      ; BLT    branch on lesss than       ; Verified.
   movsx eax,byte[ebp]
   mov ebx,[SfxSignZero]
   shr ebx,15
   inc ebp
   xor bl,[SfxOverflow]
   mov cl,[ebp]
   test bl,01h
   jz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc08      ; BNE    branch on not equal        ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],0FFFFh
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc09      ; BEQ    branch on equal (z=1)      ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],0FFFFh
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc0A      ; BPL    branch on plus     ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],088000h
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc0B      ; BMI    branch on minus    ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test dword[SfxSignZero],088000h
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc0C      ; BCC    branch on carry clear      ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxCarry],01h
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc0D      ; BCS    branch on carry set        ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxCarry],01h
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc0E      ; BVC    branch on overflow clear   ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxOverflow],01h
   mov cl,[ebp]
   jnz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc0F      ; BVS    branch on overflow set     ; Verified.
   movsx eax,byte[ebp]
   inc ebp
   test byte[SfxOverflow],01h
   mov cl,[ebp]
   jz .nojump
   add ebp,eax
   call [FxTablec+ecx*4]
   ret
.nojump
   inc ebp
   call [FxTablec+ecx*4]
   ret

NEWSYM FxOpc10      ; TO RN  set register n as destination register
   TORNc 0
NEWSYM FxOpc11      ; TO RN  set register n as destination register
   TORNc 1   
NEWSYM FxOpc12      ; TO RN  set register n as destination register
   TORNc 2   
NEWSYM FxOpc13      ; TO RN  set register n as destination register
   TORNc 3   
NEWSYM FxOpc14      ; TO RN  set register n as destination register
   TORNc 4   
NEWSYM FxOpc15      ; TO RN  set register n as destination register
   TORNc 5   
NEWSYM FxOpc16      ; TO RN  set register n as destination register
   TORNc 6   
NEWSYM FxOpc17      ; TO RN  set register n as destination register
   TORNc 7   
NEWSYM FxOpc18      ; TO RN  set register n as destination register
   TORNc 8   
NEWSYM FxOpc19      ; TO RN  set register n as destination register
   TORNc 9   
NEWSYM FxOpc1A      ; TO RN  set register n as destination register
   TORNc 10   
NEWSYM FxOpc1B      ; TO RN  set register n as destination register
   TORNc 11   
NEWSYM FxOpc1C      ; TO RN  set register n as destination register
   TORNc 12   
NEWSYM FxOpc1D      ; TO RN  set register n as destination register
   TORNc 13
NEWSYM FxOpc1E      ; TO RN  set register n as destination register
   FETCHPIPE
   mov eax,[esi]            ; Read Source
   mov [SfxR0+14*4],eax             ; Write
   CLRFLAGS
   UpdateR14
   inc ebp                ; Increase program counter
   ret
NEWSYM FxOpc1F      ; TO RN  set register n as destination register
   FETCHPIPE
   mov eax,[esi]            ; Read Source
   mov ebp,[SfxCPB]
   mov [SfxR15],eax
   add ebp,eax
   CLRFLAGS
   ret

NEWSYM FxOpc3D      ; ALT1   set alt1 mode      ; Verified.
   FETCHPIPE
   mov dword [SfxB],0
   or ch,01h
   inc ebp
   call [FxTablec+ecx*4]
   xor ch,ch
   ret

NEWSYM FxOpc3E      ; ALT2   set alt1 mode      ; Verified.
   FETCHPIPE
   mov dword [SfxB],0
   or ch,02h
   inc ebp
   call [FxTablec+ecx*4]
   xor ch,ch
   ret

NEWSYM FxOpc3F      ; ALT3   set alt3 mode      ; Verified.
   FETCHPIPE
   mov dword [SfxB],0
   or ch,03h
   inc ebp
   call [FxTablec+ecx*4]
   xor ch,ch
   ret

NEWSYM FxOpcB0      ; FROM rn   set source register
   FROMRNc 0
NEWSYM FxOpcB1      ; FROM rn   set source register
   FROMRNc 1
NEWSYM FxOpcB2      ; FROM rn   set source register
   FROMRNc 2
NEWSYM FxOpcB3      ; FROM rn   set source register
   FROMRNc 3
NEWSYM FxOpcB4      ; FROM rn   set source register
   FROMRNc 4
NEWSYM FxOpcB5      ; FROM rn   set source register
   FROMRNc 5
NEWSYM FxOpcB6      ; FROM rn   set source register
   FROMRNc 6
NEWSYM FxOpcB7      ; FROM rn   set source register
   FROMRNc 7
NEWSYM FxOpcB8      ; FROM rn   set source register
   FROMRNc 8
NEWSYM FxOpcB9      ; FROM rn   set source register
   FROMRNc 9
NEWSYM FxOpcBA      ; FROM rn   set source register
   FROMRNc 10
NEWSYM FxOpcBB      ; FROM rn   set source register
   FROMRNc 11
NEWSYM FxOpcBC      ; FROM rn   set source register
   FROMRNc 12
NEWSYM FxOpcBD      ; FROM rn   set source register
   FROMRNc 13
NEWSYM FxOpcBE      ; FROM rn   set source register
   FROMRNc 14
NEWSYM FxOpcBF      ; FROM rn   set source register
   FETCHPIPE
   mov eax,ebp
   sub eax,[SfxCPB]
   inc ebp
   mov [edi],eax        ; Write Destination
   mov [SfxSignZero],eax
   shr al,7
   mov byte[SfxOverflow],al
   CLRFLAGS
   ret