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improve implementation

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This commit is contained in:
Jaklyy
2024-06-02 10:13:50 -04:00
parent 960f063eaa
commit 63d4b78733
4 changed files with 44 additions and 52 deletions
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56
src/ARMInterpreter_LoadStore.cpp
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@ -395,12 +395,14 @@ void A_LDM(ARM* cpu)
u32 baseid = (cpu->CurInstr >> 16) & 0xF;
u32 base = cpu->R[baseid];
u32 wbbase;
u32 oldbase = base;
u32 preinc = (cpu->CurInstr & (1<<24));
bool first = true;
int abortreg = 16;
bool dataabort = false;
if (!(cpu->CurInstr & (1<<23)))
if (!(cpu->CurInstr & (1<<23))) // decrement
{
// decrement is actually an increment starting from the end address
for (int i = 0; i < 16; i++)
{
if (cpu->CurInstr & (1<<i))
@ -416,61 +418,43 @@ void A_LDM(ARM* cpu)
preinc = !preinc;
}
// check for data aborts
if (cpu->Num == 0)
{
u32 tmpbase = base;
for (int i = 0; i < 16; i++)
{
if (cpu->CurInstr & (1<<i))
{
if (preinc) tmpbase += 4;
if(((ARMv5*)cpu)->PU_Map[tmpbase>>12] & 0x01)
{
if (!preinc) tmpbase += 4;
}
else
{
abortreg = i;
break;
}
}
}
}
// switch to user mode regs
if ((cpu->CurInstr & (1<<22)) && !(cpu->CurInstr & (1<<15)))
cpu->UpdateMode(cpu->CPSR, (cpu->CPSR&~0x1F)|0x10, true);
for (int i = 0; i < std::min(15, abortreg); i++)
for (int i = 0; i < 15; i++)
{
if (cpu->CurInstr & (1<<i))
{
if (preinc) base += 4;
if (first) cpu->DataRead32 (base, &cpu->R[i]);
else cpu->DataRead32S(base, &cpu->R[i]);
if (first) {if (!cpu->DataRead32 (base, &cpu->R[i])) {dataabort = true; goto abortjump;}}
else if (!cpu->DataRead32S(base, &cpu->R[i])) {dataabort = true; goto abortjump;}
first = false;
if (!preinc) base += 4;
}
}
u32 pc;
if ((cpu->CurInstr & (1<<15)) && (abortreg == 16))
if ((cpu->CurInstr & (1<<15)))
{
if (preinc) base += 4;
if (first) cpu->DataRead32 (base, &pc);
else cpu->DataRead32S(base, &pc);
if (first) {if (!cpu->DataRead32 (base, &pc)) dataabort = true;}
else if (!cpu->DataRead32S(base, &pc)) dataabort = true;
if (!preinc) base += 4;
if (cpu->Num == 1)
pc &= ~0x1;
}
abortjump:
// switch back to previous regs
if ((cpu->CurInstr & (1<<22)) && !(cpu->CurInstr & (1<<15)))
cpu->UpdateMode((cpu->CPSR&~0x1F)|0x10, cpu->CPSR, true);
// if it's 16 then there was no data abort
if (abortreg == 16)
if (!dataabort)
{
// writeback to base
if (cpu->CurInstr & (1<<21))
{
// post writeback
@ -489,14 +473,12 @@ void A_LDM(ARM* cpu)
else
cpu->R[baseid] = wbbase;
}
// jump if pc got written
if (cpu->CurInstr & (1<<15))
cpu->JumpTo(pc, cpu->CurInstr & (1<<22));
}
else
{
((ARMv5*)cpu)->DataAbort();
}
else cpu->R[baseid] = oldbase; // restore original value of base in case the reg got written to
cpu->AddCycles_CDI();
}