6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2024-06-17 21:30:14 +00:00
Code Issues Projects Releases Wiki Activity

Convert set_rotate_flags and decline_conditional macros.

Browse Source
This commit is contained in:
Thomas Harte 2024-01-16 13:40:44 -05:00
parent 5b5ae69a18
commit ea4cc4c9b3
1 changed files with 36 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
Processors/Z80/Implementation/Z80Implementation.hpp
View File

@ -86,6 +86,29 @@ template < class T,
set_did_compute_flags();
};
/// Sets flags as expected at the end of a rotate operation.
/// Specifically:
/// * N and H are set to 0;
/// * C is set to whatever is supplied as new_carry; and
/// * 5 and 3 are set from the result now stored in A.
const auto set_rotate_flags = [&](uint8_t new_carry) {
bit53_result_ = a_;
carry_result_ = new_carry;
subtract_flag_ = half_carry_result_ = 0;
set_did_compute_flags();
};
/// Takes appropriate action for an untaken conditional branch; this might mean just skipping to the next instruction or it might mean taking
/// some other alternative follow-up action.
const auto decline_conditional = [&](const MicroOp *operation) {
if(operation->source) {
scheduled_program_counter_ = static_cast<MicroOp *>(operation->source);
} else {
advance_operation();
}
};
number_of_cycles_ += cycles;
if(!scheduled_program_counter_) {
advance_operation();
@ -443,23 +466,14 @@ template < class T,
// MARK: - Conditionals
#define decline_conditional() \
if(operation->source) { \
scheduled_program_counter_ = (MicroOp *)operation->source; \
} else { \
advance_operation(); \
}
case MicroOp::TestNZ: if(!zero_result_) { decline_conditional(); } break;
case MicroOp::TestZ: if(zero_result_) { decline_conditional(); } break;
case MicroOp::TestNC: if(carry_result_ & Flag::Carry) { decline_conditional(); } break;
case MicroOp::TestC: if(!(carry_result_ & Flag::Carry)) { decline_conditional(); } break;
case MicroOp::TestPO: if(parity_overflow_result_ & Flag::Parity) { decline_conditional(); } break;
case MicroOp::TestPE: if(!(parity_overflow_result_ & Flag::Parity)) { decline_conditional(); } break;
case MicroOp::TestP: if(sign_result_ & Flag::Sign) { decline_conditional(); } break;
case MicroOp::TestM: if(!(sign_result_ & Flag::Sign)) { decline_conditional(); } break;
#undef decline_conditional
case MicroOp::TestNZ: if(!zero_result_) { decline_conditional(operation); } break;
case MicroOp::TestZ: if(zero_result_) { decline_conditional(operation); } break;
case MicroOp::TestNC: if(carry_result_ & Flag::Carry) { decline_conditional(operation); } break;
case MicroOp::TestC: if(!(carry_result_ & Flag::Carry)) { decline_conditional(operation); } break;
case MicroOp::TestPO: if(parity_overflow_result_ & Flag::Parity) { decline_conditional(operation); } break;
case MicroOp::TestPE: if(!(parity_overflow_result_ & Flag::Parity)) { decline_conditional(operation); } break;
case MicroOp::TestP: if(sign_result_ & Flag::Sign) { decline_conditional(operation); } break;
case MicroOp::TestM: if(!(sign_result_ & Flag::Sign)) { decline_conditional(operation); } break;
// MARK: - Exchange
@ -674,38 +688,30 @@ template < class T,
// MARK: - Rotation and shifting
#define set_rotate_flags() \
bit53_result_ = a_; \
carry_result_ = new_carry; \
subtract_flag_ = half_carry_result_ = 0; \
set_did_compute_flags();
case MicroOp::RLA: {
const uint8_t new_carry = a_ >> 7;
a_ = uint8_t((a_ << 1) | (carry_result_ & Flag::Carry));
set_rotate_flags();
set_rotate_flags(new_carry);
} break;
case MicroOp::RRA: {
const uint8_t new_carry = a_ & 1;
a_ = uint8_t((a_ >> 1) | (carry_result_ << 7));
set_rotate_flags();
set_rotate_flags(new_carry);
} break;
case MicroOp::RLCA: {
const uint8_t new_carry = a_ >> 7;
a_ = uint8_t((a_ << 1) | new_carry);
set_rotate_flags();
set_rotate_flags(new_carry);
} break;
case MicroOp::RRCA: {
const uint8_t new_carry = a_ & 1;
a_ = uint8_t((a_ >> 1) | (new_carry << 7));
set_rotate_flags();
set_rotate_flags(new_carry);
} break;
#undef set_rotate_flags
#define set_shift_flags() \
sign_result_ = zero_result_ = bit53_result_ = *static_cast<uint8_t *>(operation->source); \
set_parity(sign_result_); \
@ -883,7 +889,7 @@ template < class T,
// MARK: - Internal bookkeeping
case MicroOp::SetInstructionPage:
current_instruction_page_ = (InstructionPage *)operation->source;
current_instruction_page_ = static_cast<InstructionPage *>(operation->source);
scheduled_program_counter_ = current_instruction_page_->fetch_decode_execute_data;
break;