dynarmic/src/frontend/A32/translate/impl/thumb32_branch.cpp
2021-03-06 17:29:55 +00:00

89 lines
3.3 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2016 MerryMage
* SPDX-License-Identifier: 0BSD
*/
#include "frontend/A32/translate/impl/translate_thumb.h"
namespace Dynarmic::A32 {
// BL <label>
bool ThumbTranslatorVisitor::thumb32_BL_imm(Imm<1> S, Imm<10> hi, Imm<1> j1, Imm<1> j2, Imm<11> lo) {
const Imm<1> i1{j1 == S};
const Imm<1> i2{j2 == S};
if (ir.current_location.IT().IsInITBlock() && !ir.current_location.IT().IsLastInITBlock()) {
return UnpredictableInstruction();
}
ir.PushRSB(ir.current_location.AdvancePC(4));
ir.SetRegister(Reg::LR, ir.Imm32((ir.current_location.PC() + 4) | 1));
const s32 imm32 = static_cast<s32>((concatenate(S, i1, i2, hi, lo).SignExtend<u32>() << 1) + 4);
const auto new_location = ir.current_location
.AdvancePC(imm32)
.AdvanceIT();
ir.SetTerm(IR::Term::LinkBlock{new_location});
return false;
}
// BLX <label>
bool ThumbTranslatorVisitor::thumb32_BLX_imm(Imm<1> S, Imm<10> hi, Imm<1> j1, Imm<1> j2, Imm<11> lo) {
const Imm<1> i1{j1 == S};
const Imm<1> i2{j2 == S};
if (ir.current_location.IT().IsInITBlock() && !ir.current_location.IT().IsLastInITBlock()) {
return UnpredictableInstruction();
}
if (lo.Bit<0>()) {
return UnpredictableInstruction();
}
ir.PushRSB(ir.current_location.AdvancePC(4));
ir.SetRegister(Reg::LR, ir.Imm32((ir.current_location.PC() + 4) | 1));
const s32 imm32 = static_cast<s32>(concatenate(S, i1, i2, hi, lo).SignExtend<u32>() << 1);
const auto new_location = ir.current_location
.SetPC(ir.AlignPC(4) + imm32)
.SetTFlag(false)
.AdvanceIT();
ir.SetTerm(IR::Term::LinkBlock{new_location});
return false;
}
bool ThumbTranslatorVisitor::thumb32_B(Imm<1> S, Imm<10> hi, Imm<1> j1, Imm<1> j2, Imm<11> lo) {
const Imm<1> i1{j1 == S};
const Imm<1> i2{j2 == S};
if (ir.current_location.IT().IsInITBlock() && !ir.current_location.IT().IsLastInITBlock()) {
return UnpredictableInstruction();
}
const s32 imm32 = static_cast<s32>((concatenate(S, i1, i2, hi, lo).SignExtend<u32>() << 1) + 4);
const auto new_location = ir.current_location
.AdvancePC(imm32)
.AdvanceIT();
ir.SetTerm(IR::Term::LinkBlock{new_location});
return false;
}
bool ThumbTranslatorVisitor::thumb32_B_cond(Imm<1> S, Cond cond, Imm<6> hi, Imm<1> i1, Imm<1> i2, Imm<11> lo) {
if (ir.current_location.IT().IsInITBlock()) {
return UnpredictableInstruction();
}
// Note: i1 and i2 were not inverted from encoding and are opposite compared to the other B instructions.
const s32 imm32 = static_cast<s32>((concatenate(S, i2, i1, hi, lo).SignExtend<u32>() << 1) + 4);
const auto then_location = ir.current_location
.AdvancePC(imm32)
.AdvanceIT();
const auto else_location = ir.current_location
.AdvancePC(4)
.AdvanceIT();
ir.SetTerm(IR::Term::If{cond, IR::Term::LinkBlock{then_location}, IR::Term::LinkBlock{else_location}});
return false;
}
} // namespace Dynarmic::A32