melonDS/src/ARMJIT_x64/ARMJIT_Branch.cpp
2023-11-04 00:21:46 +01:00

301 lines
7.3 KiB
C++

/*
Copyright 2016-2023 melonDS team
This file is part of melonDS.
melonDS is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with melonDS. If not, see http://www.gnu.org/licenses/.
*/
#include "ARMJIT_Compiler.h"
using namespace Gen;
namespace ARMJIT
{
template <typename T>
int squeezePointer(T* ptr)
{
int truncated = (int)((u64)ptr);
assert((T*)((u64)truncated) == ptr);
return truncated;
}
void Compiler::Comp_JumpTo(u32 addr, bool forceNonConstantCycles)
{
// we can simplify constant branches by a lot
IrregularCycles = true;
u32 newPC;
u32 cycles = 0;
if (addr & 0x1 && !Thumb)
{
CPSRDirty = true;
OR(32, R(RCPSR), Imm8(0x20));
}
else if (!(addr & 0x1) && Thumb)
{
CPSRDirty = true;
AND(32, R(RCPSR), Imm32(~0x20));
}
if (Num == 0)
{
ARMv5* cpu9 = (ARMv5*)CurCPU;
u32 regionCodeCycles = cpu9->MemTimings[addr >> 12][0];
u32 compileTimeCodeCycles = cpu9->RegionCodeCycles;
cpu9->RegionCodeCycles = regionCodeCycles;
if (Exit)
MOV(32, MDisp(RCPU, offsetof(ARMv5, RegionCodeCycles)), Imm32(regionCodeCycles));
if (addr & 0x1)
{
addr &= ~0x1;
newPC = addr+2;
// two-opcodes-at-once fetch
// doesn't matter if we put garbage in the MSbs there
if (addr & 0x2)
{
cpu9->CodeRead32(addr-2, true);
cycles += cpu9->CodeCycles;
cpu9->CodeRead32(addr+2, false);
cycles += CurCPU->CodeCycles;
}
else
{
cpu9->CodeRead32(addr, true);
cycles += cpu9->CodeCycles;
}
}
else
{
addr &= ~0x3;
newPC = addr+4;
cpu9->CodeRead32(addr, true);
cycles += cpu9->CodeCycles;
cpu9->CodeRead32(addr+4, false);
cycles += cpu9->CodeCycles;
}
cpu9->RegionCodeCycles = compileTimeCodeCycles;
}
else
{
ARMv4* cpu7 = (ARMv4*)CurCPU;
u32 codeRegion = addr >> 24;
u32 codeCycles = addr >> 15; // cheato
cpu7->CodeRegion = codeRegion;
cpu7->CodeCycles = codeCycles;
if (Exit)
{
MOV(32, MDisp(RCPU, offsetof(ARM, CodeRegion)), Imm32(codeRegion));
MOV(32, MDisp(RCPU, offsetof(ARM, CodeCycles)), Imm32(codeCycles));
}
if (addr & 0x1)
{
addr &= ~0x1;
newPC = addr+2;
// this is necessary because ARM7 bios protection
u32 compileTimePC = CurCPU->R[15];
CurCPU->R[15] = newPC;
cycles += NDS::ARM7MemTimings[codeCycles][0] + NDS::ARM7MemTimings[codeCycles][1];
CurCPU->R[15] = compileTimePC;
}
else
{
addr &= ~0x3;
newPC = addr+4;
u32 compileTimePC = CurCPU->R[15];
CurCPU->R[15] = newPC;
cycles += NDS::ARM7MemTimings[codeCycles][2] + NDS::ARM7MemTimings[codeCycles][3];
CurCPU->R[15] = compileTimePC;
}
cpu7->CodeRegion = R15 >> 24;
cpu7->CodeCycles = addr >> 15;
}
if (Exit)
MOV(32, MDisp(RCPU, offsetof(ARM, R[15])), Imm32(newPC));
if ((Thumb || CurInstr.Cond() >= 0xE) && !forceNonConstantCycles)
ConstantCycles += cycles;
else
ADD(32, MDisp(RCPU, offsetof(ARM, Cycles)), Imm8(cycles));
}
void ARMv4JumpToTrampoline(ARMv4* arm, u32 addr, bool restorecpsr)
{
arm->JumpTo(addr, restorecpsr);
}
void ARMv5JumpToTrampoline(ARMv5* arm, u32 addr, bool restorecpsr)
{
arm->JumpTo(addr, restorecpsr);
}
void Compiler::Comp_JumpTo(Gen::X64Reg addr, bool restoreCPSR)
{
IrregularCycles = true;
bool cpsrDirty = CPSRDirty;
SaveCPSR();
PushRegs(restoreCPSR, true);
MOV(64, R(ABI_PARAM1), R(RCPU));
MOV(32, R(ABI_PARAM2), R(addr));
if (!restoreCPSR)
XOR(32, R(ABI_PARAM3), R(ABI_PARAM3));
else
MOV(32, R(ABI_PARAM3), Imm32(true)); // what a waste
if (Num == 0)
CALL((void*)&ARMv5JumpToTrampoline);
else
CALL((void*)&ARMv4JumpToTrampoline);
PopRegs(restoreCPSR, true);
LoadCPSR();
// in case this instruction is skipped
if (CurInstr.Cond() < 0xE)
CPSRDirty = cpsrDirty;
}
void Compiler::A_Comp_BranchImm()
{
int op = (CurInstr.Instr >> 24) & 1;
s32 offset = (s32)(CurInstr.Instr << 8) >> 6;
u32 target = R15 + offset;
bool link = op;
if (CurInstr.Cond() == 0xF) // BLX_imm
{
target += (op << 1) + 1;
link = true;
}
if (link)
MOV(32, MapReg(14), Imm32(R15 - 4));
Comp_JumpTo(target);
}
void Compiler::A_Comp_BranchXchangeReg()
{
OpArg rn = MapReg(CurInstr.A_Reg(0));
MOV(32, R(RSCRATCH), rn);
if ((CurInstr.Instr & 0xF0) == 0x30) // BLX_reg
MOV(32, MapReg(14), Imm32(R15 - 4));
Comp_JumpTo(RSCRATCH);
}
void Compiler::T_Comp_BCOND()
{
u32 cond = (CurInstr.Instr >> 8) & 0xF;
FixupBranch skipExecute = CheckCondition(cond);
s32 offset = (s32)(CurInstr.Instr << 24) >> 23;
Comp_JumpTo(R15 + offset + 1, true);
Comp_SpecialBranchBehaviour(true);
FixupBranch skipFailed = J();
SetJumpTarget(skipExecute);
Comp_SpecialBranchBehaviour(false);
Comp_AddCycles_C(true);
SetJumpTarget(skipFailed);
}
void Compiler::T_Comp_B()
{
s32 offset = (s32)((CurInstr.Instr & 0x7FF) << 21) >> 20;
Comp_JumpTo(R15 + offset + 1);
}
void Compiler::T_Comp_BranchXchangeReg()
{
bool link = CurInstr.Instr & (1 << 7);
if (link)
{
if (Num == 1)
{
Log(LogLevel::Warn, "BLX unsupported on ARM7!!!\n");
return;
}
MOV(32, R(RSCRATCH), MapReg(CurInstr.A_Reg(3)));
MOV(32, MapReg(14), Imm32(R15 - 1));
Comp_JumpTo(RSCRATCH);
}
else
{
OpArg rn = MapReg(CurInstr.A_Reg(3));
Comp_JumpTo(rn.GetSimpleReg());
}
}
void Compiler::T_Comp_BL_LONG_1()
{
s32 offset = (s32)((CurInstr.Instr & 0x7FF) << 21) >> 9;
MOV(32, MapReg(14), Imm32(R15 + offset));
Comp_AddCycles_C();
}
void Compiler::T_Comp_BL_LONG_2()
{
OpArg lr = MapReg(14);
s32 offset = (CurInstr.Instr & 0x7FF) << 1;
LEA(32, RSCRATCH, MDisp(lr.GetSimpleReg(), offset));
MOV(32, lr, Imm32((R15 - 2) | 1));
if (Num == 1 || CurInstr.Instr & (1 << 12))
OR(32, R(RSCRATCH), Imm8(1));
Comp_JumpTo(RSCRATCH);
}
void Compiler::T_Comp_BL_Merged()
{
Comp_AddCycles_C();
R15 += 2;
u32 upperPart = CurInstr.Instr >> 16;
u32 target = (R15 - 2) + ((s32)((CurInstr.Instr & 0x7FF) << 21) >> 9);
target += (upperPart & 0x7FF) << 1;
if (Num == 1 || upperPart & (1 << 12))
target |= 1;
MOV(32, MapReg(14), Imm32((R15 - 2) | 1));
Comp_JumpTo(target);
}
}