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A flow controller feels more natural than an exception handler.

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This commit is contained in:
Thomas Harte 2022-04-28 20:42:04 -04:00
parent 1d8d2b373b
commit 33c9ea2cf7
2 changed files with 14 additions and 14 deletions
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16
InstructionSets/M68k/Implementation/PerformImplementation.hpp
View File

@ -29,8 +29,8 @@ namespace M68k {
template <
Operation operation,
Model model,
typename ExceptionHandler
> void perform(CPU::RegisterPair32 &src, CPU::RegisterPair32 &dest, Status &status, ExceptionHandler &exception_handler) {
typename FlowController
> void perform(CPU::RegisterPair32 &src, CPU::RegisterPair32 &dest, Status &status, FlowController &flow_controller) {
#define sub_overflow() ((result ^ destination) & (destination ^ source))
#define add_overflow() ((result ^ destination) & ~(destination ^ source))
@ -545,7 +545,7 @@ template <
convert_to_bit_count_16(number_of_ones);
// Time taken = 38 cycles + 2 cycles for every 1 in the source.
exception_handler.consume_cycles(2 * number_of_ones + 34);
flow_controller.consume_cycles(2 * number_of_ones + 34);
} break;
case Operation::MULS: {
@ -562,7 +562,7 @@ template <
convert_to_bit_count_16(number_of_pairs);
// Time taken = 38 cycles + 2 cycles per 1 in the source.
exception_handler.consume_cycles(2 * number_of_pairs + 34);
flow_controller.consume_cycles(2 * number_of_pairs + 34);
} break;
/*
@ -591,7 +591,7 @@ template <
// If overflow would occur, appropriate flags are set and the result is not written back.
if(quotient > 65535) {
status.overflow_flag_ = status.zero_result_ = status.negative_flag_ = 1;
exception_handler.consume_cycles(3*2);
flow_controller.consume_cycles(3*2);
return;
}
@ -629,7 +629,7 @@ template <
}
}
}
exception_handler.consume_cycles(cycles_expended);
flow_controller.consume_cycles(cycles_expended);
} break;
case Operation::DIVS: {
@ -660,7 +660,7 @@ template <
const auto quotient = dividend / divisor;
if(quotient > 32767) {
status.overflow_flag_ = 1;
exception_handler.consume_cycles(6*2);
flow_controller.consume_cycles(6*2);
break;
}
@ -689,7 +689,7 @@ template <
} else if(signed_dividend < 0) {
cycles_expended += 4;
}
exception_handler.consume_cycles(cycles_expended);
flow_controller.consume_cycles(cycles_expended);
} break;
#undef announce_divide_by_zero

12
InstructionSets/M68k/Perform.hpp
View File

@ -17,20 +17,20 @@
namespace InstructionSet {
namespace M68k {
struct NullExceptionHandler {
struct NullFlowController {
void raise_exception(int) {}
void consume_cycles(int) {}
};
/// Performs @c op using @c source and @c dest (which mmay be ignored as per the semantics of the operation).
/// And change in provcessor status will be applied to @c status. If this operation raises an exception or consumes
/// additional cycles due to the particular value of the operands (on the 68000, think DIV or MUL), that'll be notified to
/// @c exception_handler.
/// And change in provcessor status will be applied to @c status. If this operation raises an exception, causes a
/// branch, or consumes additional cycles due to the particular value of the operands (on the 68000, think DIV or MUL),
/// that'll be notified to the @c flow_controller.
template <
Operation op,
Model model,
typename ExceptionHandler
> void perform(CPU::RegisterPair32 &source, CPU::RegisterPair32 &dest, Status &status, ExceptionHandler &exception_handler);
typename FlowController
> void perform(CPU::RegisterPair32 &source, CPU::RegisterPair32 &dest, Status &status, FlowController &flow_controller);
}
}