mirror of https://github.com/bsnes-emu/bsnes.git
38 lines
902 B
C++
38 lines
902 B
C++
auto Bus::mirror(uint addr, uint size) -> uint {
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if(size == 0) return 0;
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uint base = 0;
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uint mask = 1 << 23;
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while(addr >= size) {
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while(!(addr & mask)) mask >>= 1;
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addr -= mask;
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if(size > mask) {
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size -= mask;
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base += mask;
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}
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mask >>= 1;
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}
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return base + addr;
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}
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auto Bus::reduce(uint addr, uint mask) -> uint {
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while(mask) {
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uint bits = (mask & -mask) - 1;
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addr = ((addr >> 1) & ~bits) | (addr & bits);
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mask = (mask & (mask - 1)) >> 1;
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}
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return addr;
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}
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auto Bus::read(uint24 addr, uint8 data) -> uint8 {
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data = reader[lookup[addr]](target[addr], data);
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if(cheat) {
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if(!(addr & 0x40e000)) addr = 0x7e0000 | (addr & 0x1fff); //de-mirror WRAM
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if(auto result = cheat.find(addr, data)) return result();
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}
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return data;
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}
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auto Bus::write(uint24 addr, uint8 data) -> void {
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return writer[lookup[addr]](target[addr], data);
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}
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