dynarmic/src/frontend/A32/translate/conditional_state.cpp

80 lines
2.7 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2020 MerryMage
* SPDX-License-Identifier: 0BSD
*/
#include <algorithm>
#include <dynarmic/A32/config.h>
#include "common/assert.h"
#include "common/common_types.h"
#include "frontend/A32/ir_emitter.h"
#include "frontend/A32/translate/conditional_state.h"
#include "frontend/ir/cond.h"
namespace Dynarmic::A32 {
bool CondCanContinue(ConditionalState cond_state, const A32::IREmitter& ir) {
ASSERT_MSG(cond_state != ConditionalState::Break, "Should never happen.");
if (cond_state == ConditionalState::None)
return true;
// TODO: This is more conservative than necessary.
return std::all_of(ir.block.begin(), ir.block.end(), [](const IR::Inst& inst) { return !inst.WritesToCPSR(); });
}
bool IsConditionPassed(IR::Cond cond, ConditionalState& cond_state, A32::IREmitter& ir, int instruction_size) {
ASSERT_MSG(cond_state != ConditionalState::Break,
"This should never happen. We requested a break but that wasn't honored.");
if (cond == IR::Cond::NV) {
// NV conditional is obsolete
ir.ExceptionRaised(Exception::UnpredictableInstruction);
return false;
}
if (cond_state == ConditionalState::Translating) {
if (ir.block.ConditionFailedLocation() != ir.current_location || cond == IR::Cond::AL) {
cond_state = ConditionalState::Trailing;
} else {
if (cond == ir.block.GetCondition()) {
ir.block.SetConditionFailedLocation(ir.current_location.AdvancePC(instruction_size).AdvanceIT());
ir.block.ConditionFailedCycleCount()++;
return true;
}
// cond has changed, abort
cond_state = ConditionalState::Break;
ir.SetTerm(IR::Term::LinkBlockFast{ir.current_location});
return false;
}
}
if (cond == IR::Cond::AL) {
// Everything is fine with the world
return true;
}
// non-AL cond
if (!ir.block.empty()) {
// We've already emitted instructions. Quit for now, we'll make a new block here later.
cond_state = ConditionalState::Break;
ir.SetTerm(IR::Term::LinkBlockFast{ir.current_location});
return false;
}
// We've not emitted instructions yet.
// We'll emit one instruction, and set the block-entry conditional appropriately.
cond_state = ConditionalState::Translating;
ir.block.SetCondition(cond);
ir.block.SetConditionFailedLocation(ir.current_location.AdvancePC(instruction_size).AdvanceIT());
ir.block.ConditionFailedCycleCount() = ir.block.CycleCount() + 1;
return true;
}
} // namespace Dynarmic::A32