dynarmic/src/frontend/translate/translate_arm.cpp
2016-08-06 20:03:15 +01:00

148 lines
5.1 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2016 MerryMage
* This software may be used and distributed according to the terms of the GNU
* General Public License version 2 or any later version.
*/
#include "common/assert.h"
#include "frontend/arm_types.h"
#include "frontend/decoder/arm.h"
#include "frontend/decoder/vfp2.h"
#include "frontend/ir/ir.h"
#include "frontend/translate/translate.h"
#include "frontend/translate/translate_arm/translate_arm.h"
namespace Dynarmic {
namespace Arm {
IR::Block TranslateArm(LocationDescriptor descriptor, MemoryRead32FuncType memory_read_32) {
ArmTranslatorVisitor visitor{descriptor};
bool should_continue = true;
while (should_continue && visitor.cond_state == ConditionalState::None) {
const u32 arm_pc = visitor.ir.current_location.PC();
const u32 arm_instruction = (*memory_read_32)(arm_pc);
if (auto vfp_decoder = DecodeVFP2<ArmTranslatorVisitor>(arm_instruction)) {
should_continue = vfp_decoder->call(visitor, arm_instruction);
} else if (auto decoder = DecodeArm<ArmTranslatorVisitor>(arm_instruction)) {
should_continue = decoder->call(visitor, arm_instruction);
} else {
should_continue = visitor.arm_UDF();
}
if (visitor.cond_state == ConditionalState::Break) {
break;
}
visitor.ir.current_location = visitor.ir.current_location.AdvancePC(4);
visitor.ir.block.cycle_count++;
}
if (visitor.cond_state == ConditionalState::Translating) {
if (should_continue) {
visitor.ir.SetTerm(IR::Term::LinkBlock{visitor.ir.current_location});
}
visitor.ir.block.cond_failed = { visitor.ir.current_location };
}
return std::move(visitor.ir.block);
}
bool ArmTranslatorVisitor::ConditionPassed(Cond cond) {
ASSERT_MSG(cond_state != ConditionalState::Translating,
"In the current impl, ConditionPassed should never be called again once a non-AL cond is hit. "
"(i.e.: one and only one conditional instruction per block)");
ASSERT_MSG(cond_state != ConditionalState::Break,
"This should never happen. We requested a break but that wasn't honored.");
if (cond == Cond::AL) {
// Everything is fine with the world
return true;
}
if (cond == Cond::NV) {
// NV conditional is obsolete, but still seems to be used in some places!
return false;
}
// non-AL cond
if (!ir.block.instructions.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::LinkBlock{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.cond = cond;
return true;
}
bool ArmTranslatorVisitor::InterpretThisInstruction() {
ir.SetTerm(IR::Term::Interpret(ir.current_location));
return false;
}
bool ArmTranslatorVisitor::UnpredictableInstruction() {
ASSERT_MSG(false, "UNPREDICTABLE");
return false;
}
bool ArmTranslatorVisitor::LinkToNextInstruction() {
auto next_location = ir.current_location.AdvancePC(4);
ir.SetTerm(IR::Term::LinkBlock{next_location});
return false;
}
IREmitter::ResultAndCarry ArmTranslatorVisitor::EmitImmShift(IR::Value value, ShiftType type, Imm5 imm5, IR::Value carry_in) {
IREmitter::ResultAndCarry result_and_carry;
switch (type)
{
case ShiftType::LSL:
result_and_carry = ir.LogicalShiftLeft(value, ir.Imm8(imm5), carry_in);
break;
case ShiftType::LSR:
imm5 = imm5 ? imm5 : 32;
result_and_carry = ir.LogicalShiftRight(value, ir.Imm8(imm5), carry_in);
break;
case ShiftType::ASR:
imm5 = imm5 ? imm5 : 32;
result_and_carry = ir.ArithmeticShiftRight(value, ir.Imm8(imm5), carry_in);
break;
case ShiftType::ROR:
if (imm5)
result_and_carry = ir.RotateRight(value, ir.Imm8(imm5), carry_in);
else
result_and_carry = ir.RotateRightExtended(value, carry_in);
break;
}
return result_and_carry;
}
IREmitter::ResultAndCarry ArmTranslatorVisitor::EmitRegShift(IR::Value value, ShiftType type, IR::Value amount, IR::Value carry_in) {
IREmitter::ResultAndCarry result_and_carry;
switch (type)
{
case ShiftType::LSL:
result_and_carry = ir.LogicalShiftLeft(value, amount, carry_in);
break;
case ShiftType::LSR:
result_and_carry = ir.LogicalShiftRight(value, amount, carry_in);
break;
case ShiftType::ASR:
result_and_carry = ir.ArithmeticShiftRight(value, amount, carry_in);
break;
case ShiftType::ROR:
result_and_carry = ir.RotateRight(value, amount, carry_in);
break;
}
return result_and_carry;
}
} // namespace Arm
} // namespace Dynarmic