dynarmic/src/frontend/A32/translate/translate_arm/branch.cpp
2020-04-22 20:33:30 +01:00

81 lines
2.4 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/bit_util.h"
#include "translate_arm.h"
namespace Dynarmic {
namespace A32 {
bool ArmTranslatorVisitor::arm_B(Cond cond, Imm24 imm24) {
u32 imm32 = Common::SignExtend<26, u32>(imm24 << 2) + 8;
// B <label>
if (ConditionPassed(cond)) {
auto new_location = ir.current_location.AdvancePC(imm32);
ir.SetTerm(IR::Term::LinkBlock{ new_location });
return false;
}
return true;
}
bool ArmTranslatorVisitor::arm_BL(Cond cond, Imm24 imm24) {
u32 imm32 = Common::SignExtend<26, u32>(imm24 << 2) + 8;
// BL <label>
if (ConditionPassed(cond)) {
ir.PushRSB(ir.current_location.AdvancePC(4));
ir.SetRegister(Reg::LR, ir.Imm32(ir.current_location.PC() + 4));
auto new_location = ir.current_location.AdvancePC(imm32);
ir.SetTerm(IR::Term::LinkBlock{ new_location });
return false;
}
return true;
}
bool ArmTranslatorVisitor::arm_BLX_imm(bool H, Imm24 imm24) {
u32 imm32 = Common::SignExtend<26, u32>((imm24 << 2)) + (H ? 2 : 0) + 8;
// BLX <label>
ir.PushRSB(ir.current_location.AdvancePC(4));
ir.SetRegister(Reg::LR, ir.Imm32(ir.current_location.PC() + 4));
auto new_location = ir.current_location.AdvancePC(imm32).SetTFlag(true);
ir.SetTerm(IR::Term::LinkBlock{ new_location });
return false;
}
bool ArmTranslatorVisitor::arm_BLX_reg(Cond cond, Reg m) {
if (m == Reg::PC)
return UnpredictableInstruction();
// BLX <Rm>
if (ConditionPassed(cond)) {
ir.PushRSB(ir.current_location.AdvancePC(4));
ir.BXWritePC(ir.GetRegister(m));
ir.SetRegister(Reg::LR, ir.Imm32(ir.current_location.PC() + 4));
ir.SetTerm(IR::Term::ReturnToDispatch{});
return false;
}
return true;
}
bool ArmTranslatorVisitor::arm_BX(Cond cond, Reg m) {
// BX <Rm>
if (ConditionPassed(cond)) {
ir.BXWritePC(ir.GetRegister(m));
if (m == Reg::R14)
ir.SetTerm(IR::Term::PopRSBHint{});
else
ir.SetTerm(IR::Term::ReturnToDispatch{});
return false;
}
return true;
}
bool ArmTranslatorVisitor::arm_BXJ(Cond cond, Reg m) {
// Jazelle not supported
return arm_BX(cond, m);
}
} // namespace A32
} // namespace Dynarmic