mirror of https://github.com/bsnes-emu/bsnes.git
35 lines
866 B
C++
35 lines
866 B
C++
auto M68K::signExtend(uint2 size, uint32 data) -> int32 {
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if(size == 0) return (int8)data;
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if(size == 1) return (int16)data;
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if(size == 2) return (int32)data;
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return 0;
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}
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//
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auto M68K::address(EA& ea) -> uint32 {
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if(ea.valid) return ea.address;
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ea.valid = true;
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if(ea.mode == 0) return ea.address = r.d(ea.reg);
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if(ea.mode == 1) return ea.address = r.a(ea.reg);
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if(ea.mode == 7) {
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if(ea.reg == 0) return ea.address = (int16)readWordPC();
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if(ea.reg == 1) return ea.address = readLongPC();
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if(ea.reg == 2) return ea.address = r.pc, ea.address += (int16)readWordPC();
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}
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return ea.address = 0;
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}
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auto M68K::read(EA& ea) -> uint32 {
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address(ea);
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if(ea.mode < 2 || (ea.mode == 7 && ea.reg == 4)) return ea.address;
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return readAbsolute(ea.size, ea.address);
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}
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auto M68K::write(EA& ea, uint32 data) -> void {
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address(ea);
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}
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