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Implements rolls and shifts.

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This commit is contained in:
Thomas Harte 2020-10-06 21:34:39 -04:00
parent 3933bf49cf
commit 5c809e5fbf
1 changed files with 30 additions and 1 deletions
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31
Processors/65816/Implementation/65816Implementation.hpp
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@ -507,11 +507,40 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
pc_ += int16_t(instruction_buffer_.value);
break;
//
// Shifts and rolls.
//
case ASL:
flags_.carry = data_buffer_.value >> (7 + m_shift_);
data_buffer_.value <<= 1;
flags_.set_nz(m_top());
break;
case LSR:
flags_.carry = data_buffer_.value & 1;
data_buffer_.value >>= 1;
flags_.set_nz(m_top());
break;
case ROL:
data_buffer_.value = (data_buffer_.value << 1) | flags_.carry;
flags_.carry = data_buffer_.value >> (7 + m_shift_);
flags_.set_nz(m_top());
break;
case ROR: {
const uint8_t next_carry = data_buffer_.value & 1;
data_buffer_.value = (data_buffer_.value >> 1) | (flags_.carry << (7 + m_shift_));
flags_.carry = next_carry;
flags_.set_nz(m_top());
} break;
// TODO:
// ADC, BIT, CMP, CPX, CPY, SBC,
// PLP,
// PHP, PHD, PHK,
// ASL, LSR, ROL, ROR, TRB, TSB,
// TRB, TSB,
// REP, SEP,
// TAX, TAY, TCD, TCS, TDC, TSC, TSX, TXA, TXS, TXY, TYA, TYX,
// XCE, XBA,