aboutsummaryrefslogtreecommitdiff
path: root/src/ARMInterpreter_Branch.cpp
blob: 015f5682e1f78d071e24da5468c9be6c41e3b6dc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
/*
    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 "ARM.h"
#include "Platform.h"

namespace melonDS::ARMInterpreter
{
using Platform::Log;
using Platform::LogLevel;


void A_B(ARM* cpu)
{
    s32 offset = (s32)(cpu->CurInstr << 8) >> 6;
    cpu->JumpTo(cpu->R[15] + offset);
}

void A_BL(ARM* cpu)
{
    s32 offset = (s32)(cpu->CurInstr << 8) >> 6;
    cpu->R[14] = cpu->R[15] - 4;
    cpu->JumpTo(cpu->R[15] + offset);
}

void A_BLX_IMM(ARM* cpu)
{
    s32 offset = (s32)(cpu->CurInstr << 8) >> 6;
    if (cpu->CurInstr & 0x01000000) offset += 2;
    cpu->R[14] = cpu->R[15] - 4;
    cpu->JumpTo(cpu->R[15] + offset + 1);
}

void A_BX(ARM* cpu)
{
    cpu->JumpTo(cpu->R[cpu->CurInstr & 0xF]);
}

void A_BLX_REG(ARM* cpu)
{
    u32 lr = cpu->R[15] - 4;
    cpu->JumpTo(cpu->R[cpu->CurInstr & 0xF]);
    cpu->R[14] = lr;
}



void T_BCOND(ARM* cpu)
{
    if (cpu->CheckCondition((cpu->CurInstr >> 8) & 0xF))
    {
        s32 offset = (s32)(cpu->CurInstr << 24) >> 23;
        cpu->JumpTo(cpu->R[15] + offset + 1);
    }
    else
        cpu->AddCycles_C();
}

void T_BX(ARM* cpu)
{
    cpu->JumpTo(cpu->R[(cpu->CurInstr >> 3) & 0xF]);
}

void T_BLX_REG(ARM* cpu)
{
    if (cpu->Num==1)
    {
        Log(LogLevel::Warn, "!! THUMB BLX_REG ON ARM7\n");
        return;
    }

    u32 lr = cpu->R[15] - 1;
    cpu->JumpTo(cpu->R[(cpu->CurInstr >> 3) & 0xF]);
    cpu->R[14] = lr;
}

void T_B(ARM* cpu)
{
    s32 offset = (s32)((cpu->CurInstr & 0x7FF) << 21) >> 20;
    cpu->JumpTo(cpu->R[15] + offset + 1);
}

void T_BL_LONG_1(ARM* cpu)
{
    s32 offset = (s32)((cpu->CurInstr & 0x7FF) << 21) >> 9;
    cpu->R[14] = cpu->R[15] + offset;
    cpu->AddCycles_C();
}

void T_BL_LONG_2(ARM* cpu)
{
    s32 offset = (cpu->CurInstr & 0x7FF) << 1;
    u32 pc = cpu->R[14] + offset;
    cpu->R[14] = (cpu->R[15] - 2) | 1;

    if ((cpu->Num==1) || (cpu->CurInstr & (1<<12)))
        pc |= 1;

    cpu->JumpTo(pc);
}



}