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negativeExponent wants to merge 3 commits into from
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Arm fixes #134

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8af0b75
GBA: Use CPUReadMemory instead of CPUReadMemoryQuick in LDR to get pr…
negativeExponent Dec 12, 2025
2df1ea2
Fix SETCOND_MULL Z flag: use bitwise OR instead of logical OR
negativeExponent Dec 12, 2025
b1992e9
Use constexpr table for CPU bit-count instead of runtime initialization
negativeExponent Dec 12, 2025
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7 changes: 2 additions & 5 deletions src/core/gba/gba.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3637,9 +3637,6 @@ void applyTimer()
timerOnOffDelay = 0;
}

uint8_t cpuBitsSet[256];
uint8_t cpuLowestBitSet[256];

void CPUInit(const char* biosFileName, bool useBiosFile)
{
#ifdef WORDS_BIGENDIAN
Expand Down Expand Up @@ -3677,7 +3674,7 @@ void CPUInit(const char* biosFileName, bool useBiosFile)
biosProtected[2] = 0x29;
biosProtected[3] = 0xe1;

for (i = 0; i < 256; i++) {
/*for (i = 0; i < 256; i++) {
int count = 0;
int j;
for (j = 0; j < 8; j++)
Expand All @@ -3689,7 +3686,7 @@ void CPUInit(const char* biosFileName, bool useBiosFile)
if (i & (1 << j))
break;
cpuLowestBitSet[i] = DowncastU8(j);
}
}*/

for (i = 0; i < 0x400; i++)
ioReadable[i] = true;
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22 changes: 20 additions & 2 deletions src/core/gba/gbaCpu.h
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Expand Up @@ -45,6 +45,26 @@ extern int thumbExecute();

#define THUMB_PREFETCH_NEXT cpuPrefetch[1] = CPUReadHalfWordQuick(armNextPC + 2);

constexpr uint8_t cpuBitsSet[256] =
{
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
};

extern int SWITicks;
extern uint32_t mastercode;
extern bool busPrefetch;
Expand All @@ -58,8 +78,6 @@ extern uint8_t memoryWait[16];
extern uint8_t memoryWait32[16];
extern uint8_t memoryWaitSeq[16];
extern uint8_t memoryWaitSeq32[16];
extern uint8_t cpuBitsSet[256];
extern uint8_t cpuLowestBitSet[256];
extern void CPUSwitchMode(int mode, bool saveState, bool breakLoop);
extern void CPUSwitchMode(int mode, bool saveState);
extern void CPUUpdateCPSR();
Expand Down
2 changes: 1 addition & 1 deletion src/core/gba/gbaCpuArm.cpp
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Expand Up @@ -1063,7 +1063,7 @@ static void count(uint32_t opcode, int cond_res)
#ifndef SETCOND_MULL
#define SETCOND_MULL \
N_FLAG = (reg[dest].I & 0x80000000) ? true : false; \
Z_FLAG = reg[dest].I || reg[acc].I ? false : true;
Z_FLAG = (reg[dest].I | reg[acc].I) ? false : true;
#endif

#ifndef ALU_FINISH
Expand Down
4 changes: 2 additions & 2 deletions src/core/gba/gbaCpuThumb.cpp
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Expand Up @@ -1317,7 +1317,7 @@ static INSN_REGPARM void thumb48(uint32_t opcode)
if (busPrefetchCount == 0)
busPrefetch = busPrefetchEnable;
uint32_t address = (reg[15].I & 0xFFFFFFFC) + ((opcode & 0xFF) << 2);
reg[regist].I = CPUReadMemoryQuick(address);
reg[regist].I = CPUReadMemory(address);
busPrefetchCount = 0;
clockTicks = 3 + dataTicksAccess32(address) + codeTicksAccess16(armNextPC);
}
Expand Down Expand Up @@ -1480,7 +1480,7 @@ static INSN_REGPARM void thumb98(uint32_t opcode)
if (busPrefetchCount == 0)
busPrefetch = busPrefetchEnable;
uint32_t address = reg[13].I + ((opcode & 255) << 2);
reg[regist].I = CPUReadMemoryQuick(address);
reg[regist].I = CPUReadMemory(address);
clockTicks = 3 + dataTicksAccess32(address) + codeTicksAccess16(armNextPC);
}

Expand Down
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