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Implements MOVE to/from USP.

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This commit is contained in:
Thomas Harte 2019-04-17 16:58:59 -04:00
parent c265ea9847
commit b8a0f4e831
2 changed files with 26 additions and 0 deletions
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4
Processors/68000/Implementation/68000Implementation.hpp
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@ -478,6 +478,10 @@ template <class T, bool dtack_is_implicit> void Processor<T, dtack_is_implicit>:
set_ccr(active_program_->source->full);
break;
/*
Multiplications.
*/
case Operation::MULU: {
active_program_->destination->full =
active_program_->destination->halves.low.full * active_program_->source->halves.low.full;

22
Processors/68000/Implementation/68000Storage.cpp
View File

@ -375,6 +375,8 @@ struct ProcessorStorageConstructor {
TST, // Maps a mode and register to a TST.
RTS, // Maps to an RST.
MOVEUSP, // Maps a direction and register to a MOVE [to/from] USP.
};
using Operation = ProcessorStorage::Operation;
@ -553,6 +555,8 @@ struct ProcessorStorageConstructor {
{0xf1c0, 0xc0c0, Operation::MULU, Decoder::MULU_MULS}, // 4-139 (p243)
{0xf1c0, 0xc1c0, Operation::MULS, Decoder::MULU_MULS}, // 4-136 (p240)
{0xfff0, 0x4e60, Operation::MOVEAl, Decoder::MOVEUSP}, // 6-21 (p475)
};
#ifndef NDEBUG
@ -2027,6 +2031,24 @@ struct ProcessorStorageConstructor {
op(is_to_m ? Action::MOVEMtoMComplete : Action::MOVEMtoRComplete, seq("np"));
} break;
case Decoder::MOVEUSP: {
storage_.instructions[instruction].requires_supervisor = true;
// Observation here: because this is a privileged instruction, the user stack pointer
// definitely isn't currently A7.
if(instruction & 0x8) {
// Transfer FROM the USP.
storage_.instructions[instruction].destination = &storage_.stack_pointers_[0];
storage_.instructions[instruction].set_source(storage_, An, ea_register);
} else {
// Transfer TO the USP.
storage_.instructions[instruction].source = &storage_.stack_pointers_[0];
storage_.instructions[instruction].set_destination(storage_, An, ea_register);
}
op(Action::PerformOperation, seq("np"));
} break;
// Decodes the format used by most MOVEs and all MOVEAs.
case Decoder::MOVE: {
const int destination_mode = (instruction >> 6) & 7;