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Attempts a full implementation of memory shifts.

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Thomas Harte 2019-04-09 22:04:25 -04:00
parent 7a0319cfe5
commit 85d25068a8
1 changed files with 70 additions and 0 deletions
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70
Processors/68000/Implementation/68000Implementation.hpp
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@ -514,6 +514,76 @@ template <class T, bool dtack_is_implicit> void Processor<T, dtack_is_implicit>:
active_program_->destination->full -= active_program_->source->full;
break;
/*
Shifts and rotates.
*/
#define set_flags(v, m, t) \
zero_result_ = v; \
negative_flag_ = zero_result_ & m; \
overflow_flag_ = (value ^ zero_result_) & m; \
extend_flag_ = carry_flag_ = value & t;
#define set_flags_b(t) set_flags(active_program_->destination->halves.low.halves.low, 0x80, t)
#define set_flags_w(t) set_flags(active_program_->destination->halves.low.full, 0x8000, t)
#define set_flags_l(t) set_flags(active_program_->destination->full, 0x80000000, t)
case Operation::LSLm:
case Operation::ASLm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full <<= 1;
set_flags_w(0x8000);
} break;
case Operation::LSRm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full >>= 1;
set_flags_w(0x0001);
} break;
case Operation::ASRm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full = (active_program_->destination->halves.low.full >> 1) | (value & 0x8000);
set_flags_w(0x0001);
} break;
#undef set_flags
#define set_flags(v, m, t) \
zero_result_ = v; \
negative_flag_ = zero_result_ & m; \
overflow_flag_ = 0; \
carry_flag_ = value & t;
case Operation::ROLm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full = (active_program_->destination->halves.low.full << 1) | (value >> 15);
set_flags_w(0x8000);
} break;
case Operation::RORm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full = (active_program_->destination->halves.low.full >> 1) | (value << 15);
set_flags_w(0x0001);
} break;
case Operation::ROXLm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full = (active_program_->destination->halves.low.full << 1) | (extend_flag_ ? 0x0001 : 0x0000);
extend_flag_ = value & 0x8000;
set_flags_w(0x8000);
} break;
case Operation::ROXRm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full = (active_program_->destination->halves.low.full >> 1) | (extend_flag_ ? 0x8000 : 0x0000);
extend_flag_ = value & 0x0001;
set_flags_w(0x0001);
} break;
#undef set_flags
#undef set_flags_b
#undef set_flags_w
#undef set_flags_l
/*
Development period debugging.
*/