6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2024-12-26 09:29:45 +00:00
Code Issues Projects Releases Wiki Activity

Attempts to correct flags for ASL, ASR, LSL, LSR.

Browse Source
This commit is contained in:
Thomas Harte 2019-04-24 21:04:47 -04:00
parent dcb8176d90
commit fa0accf251
1 changed files with 77 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

112
Processors/68000/Implementation/68000Implementation.hpp
View File

@ -932,10 +932,6 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
negative_flag_ = zero_result_ & (m); \ negative_flag_ = zero_result_ & (m); \
overflow_flag_ = (value ^ zero_result_) & (m); overflow_flag_ = (value ^ zero_result_) & (m);
#define set_flags(v, m, t) \
set_neg_zero_overflow(v, m) \
extend_flag_ = carry_flag_ = value & (t);
#define decode_shift_count() \ #define decode_shift_count() \
int shift_count = (decoded_instruction_ & 32) ? data_[(decoded_instruction_ >> 9) & 7].full&63 : ( ((decoded_instruction_ >> 9)&7) ? ((decoded_instruction_ >> 9)&7) : 8) ; \ int shift_count = (decoded_instruction_ & 32) ? data_[(decoded_instruction_ >> 9) & 7].full&63 : ( ((decoded_instruction_ >> 9)&7) ? ((decoded_instruction_ >> 9)&7) : 8) ; \
active_step_->microcycle.length = HalfCycles(4 * shift_count); active_step_->microcycle.length = HalfCycles(4 * shift_count);
@ -944,45 +940,89 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
#define set_flags_w(t) set_flags(active_program_->destination->halves.low.full, 0x8000, 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) #define set_flags_l(t) set_flags(active_program_->destination->full, 0x80000000, t)
#define shift_op(name, op, mb, mw, ml) \ #define lsl(destination, size) {\
case Operation::name##b: { \
decode_shift_count(); \ decode_shift_count(); \
const auto value = active_program_->destination->halves.low.halves.low; \ const auto value = destination; \
op(active_program_->destination->halves.low.halves.low, shift_count, 0xff, 7); \
set_flags_b(mb); \
} break; \
\ \
case Operation::name##w: { \ if(!shift_count) { \
decode_shift_count(); \ carry_flag_ = 0; \
const auto value = active_program_->destination->halves.low.full; \ } else { \
op(active_program_->destination->halves.low.full, shift_count, 0xffff, 15); \ destination = value << shift_count; \
set_flags_w(mw); \ extend_flag_ = carry_flag_ = value & ((1 << (size - 1)) >> (shift_count - 1)); \
} break; \ } \
\ \
case Operation::name##l: { \ set_neg_zero_overflow(destination, 1 << (size - 1)); \
decode_shift_count(); \ }
const auto value = active_program_->destination->full; \
op(active_program_->destination->full, shift_count, 0xffffffff, 31); \ case Operation::ASLm:
set_flags_l(ml); \ case Operation::LSLm: {
} break; \ const auto value = active_program_->destination->halves.low.full;
\ active_program_->destination->halves.low.full = value >> 1;
case Operation::name##m: { \ extend_flag_ = carry_flag_ = value & 1;
const auto value = active_program_->destination->halves.low.full; \ set_neg_zero_overflow(active_program_->destination->halves.low.full, 0x8000);
op(active_program_->destination->halves.low.full, 1, 0xffff, 15); \
set_flags_w(mw); \
} break; } break;
case Operation::ASLb:
case Operation::LSLb: lsl(active_program_->destination->halves.low.halves.low, 8); break;
case Operation::ASLw:
case Operation::LSLw: lsl(active_program_->destination->halves.low.full, 16); break;
case Operation::ASLl:
case Operation::LSLl: lsl(active_program_->destination->full, 32); break;
#define lsl(x, c, m, d) x <<= c #undef lsl
#define lsr(x, c, m, d) x >>= c
#define asl(x, c, m, d) x <<= c
#define asr(x, c, m, d) x = (x >> c) | (((value >> d) & 1) * (m ^ (m >> c)))
// TODO: carry/extend is incorrect for shifts of greater than one digit. #define lsr(destination, size) {\
decode_shift_count(); \
const auto value = destination; \
\
if(!shift_count) { \
carry_flag_ = 0; \
} else { \
destination = value >> shift_count; \
extend_flag_ = carry_flag_ = value & (1 << (shift_count - 1)); \
} \
\
set_neg_zero_overflow(destination, 1 << (size - 1)); \
}
shift_op(LSL, lsl, 0x80, 0x8000, 0x80000000); case Operation::LSRm: {
shift_op(ASL, lsl, 0x80, 0x8000, 0x80000000); const auto value = active_program_->destination->halves.low.full;
shift_op(LSR, lsr, 0x01, 0x0001, 0x00000001); active_program_->destination->halves.low.full = value >> 1;
shift_op(ASR, asr, 0x01, 0x0001, 0x00000001); extend_flag_ = carry_flag_ = value & 1;
set_neg_zero_overflow(active_program_->destination->halves.low.full, 0x8000);
} break;
case Operation::LSRb: lsr(active_program_->destination->halves.low.halves.low, 8); break;
case Operation::LSRw: lsr(active_program_->destination->halves.low.full, 16); break;
case Operation::LSRl: lsr(active_program_->destination->full, 32); break;
#undef lsr
#define asr(destination, size) {\
decode_shift_count(); \
const auto value = destination; \
\
if(!shift_count) { \
carry_flag_ = 0; \
} else { \
destination = \
(value >> shift_count) | \
((value & (1 << (size - 1)) ? 0xffffffff : 0x000000000) << (size - shift_count)); \
extend_flag_ = carry_flag_ = value & (1 << (shift_count - 1)); \
} \
\
set_neg_zero_overflow(destination, 1 << (size - 1)); \
}
case Operation::ASRm: {
const auto value = active_program_->destination->halves.low.full;
active_program_->destination->halves.low.full = (value&0x80) | (value >> 1);
extend_flag_ = carry_flag_ = value & 1;
set_neg_zero_overflow(active_program_->destination->halves.low.full, 0x8000);
} break;
case Operation::ASRb: asr(active_program_->destination->halves.low.halves.low, 8); break;
case Operation::ASRw: asr(active_program_->destination->halves.low.full, 16); break;
case Operation::ASRl: asr(active_program_->destination->full, 32); break;
#undef asr
#undef set_flags #undef set_flags
#define set_flags(v, m, t) \ #define set_flags(v, m, t) \