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ARM (26-bit): TST/TEQ should only update flags

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This eliminates the need for patches in poizone/ertictac, all deco32 games 
still run (including hvysmsh), and it better matches the documentation.
This commit is contained in:
R. Belmont 2009-07-05 17:32:15 +00:00
parent ce8e7c07ab
commit c79dfb05f3
2 changed files with 21 additions and 45 deletions
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50
src/emu/cpu/arm/arm.c
View File

@ -333,7 +333,7 @@ static CPU_EXECUTE( arm )
cpustate->icount = cycles;
do
{
debugger_instruction_hook(device, R15);
debugger_instruction_hook(device, R15 & ADDRESS_MASK);
/* load instruction */
pc = R15;
@ -805,7 +805,6 @@ static void HandleALU( ARM_REGS* cpustate, UINT32 insn )
rd = (rn + op2);
HandleALUAddFlags(rd, rn, op2);
break;
/* Logical operations */
case OPCODE_AND:
case OPCODE_TST:
@ -866,36 +865,25 @@ static void HandleALU( ARM_REGS* cpustate, UINT32 insn )
}
}
/* TST & TEQ can affect R15 (the condition code register) with the S bit set */
} else if (rdn==eR15) {
if (insn & INSN_S) {
if (ARM_DEBUG_CORE)
logerror("%08x: TST class on R15 s bit set\n",R15);
/* Dubious hack for 'TEQS R15, #$3', the docs suggest execution
should continue two instructions later (because pipelined R15
is read back as already being incremented), but it seems the
hardware should execute the instruction in the delay slot.
Simulate it by just setting the PC back to the previously
skipped instruction.
See Heavy Smash (Data East) at 0x1c4
*/
if (insn==0xe33ff003)
rd-=4;
cpustate->icount -= S_CYCLE + N_CYCLE;
if ((R15&MODE_MASK)!=0)
{
SetRegister(cpustate, 15, rd);
}
else
{
SetRegister(cpustate, 15, (rd&ADDRESS_MASK) | (rd&PSR_MASK) | (R15&IRQ_MASK) | (R15&MODE_MASK));
}
} else {
if (ARM_DEBUG_CORE)
logerror("%08x: TST class on R15 no s bit set\n",R15);
}
else if ((rdn==eR15) && (insn & INSN_S))
{
// update only the flags
if ((R15&MODE_MASK)!=0)
{
// combine the flags from rd with the address from R15
rd &= ~ADDRESS_MASK;
rd |= (R15 & ADDRESS_MASK);
SetRegister(cpustate,rdn,rd);
}
else
{
// combine the flags from rd with the address from R15
rd &= ~ADDRESS_MASK; // clear address part of RD
rd |= (R15 & ADDRESS_MASK); // RD = address part of R15
SetRegister(cpustate, rdn,(rd&ADDRESS_MASK) | (rd&PSR_MASK) | (R15&IRQ_MASK) | (R15&MODE_MASK));
}
cpustate->icount -= S_CYCLE + N_CYCLE;
}
}

16
src/mame/drivers/ertictac.c
View File

@ -439,18 +439,6 @@ ROM_START( poizone )
ROM_LOAD32_BYTE( "p_son24.bin", 0x140003, 0x10000, CRC(a09d7f55) SHA1(e0d562c655c16034b40db93de801b98b7948beb2) )
ROM_END
static DRIVER_INIT( ertictac )
{
((UINT32 *)memory_region(machine, "user1"))[0x55]=0;// patched TSTS r11,r15,lsl #32 @ $3800154
}
static DRIVER_INIT( poizone )
{
((UINT32 *)memory_region(machine, "user1"))[0x21C/4]=0;// patched TSTS r11,r15,lsl #32 @ $380021C
}
GAME( 1990, ertictac, 0, ertictac, ertictac, ertictac, ROT0, "Sisteme", "Erotictac/Tactic" ,GAME_NO_SOUND)
GAME( 1991, poizone, 0, ertictac, poizone, poizone, ROT0, "Eterna" ,"Poizone" ,GAME_NO_SOUND|GAME_NOT_WORKING)
GAME( 1990, ertictac, 0, ertictac, ertictac, 0, ROT0, "Sisteme", "Erotictac/Tactic" ,GAME_NO_SOUND)
GAME( 1991, poizone, 0, ertictac, poizone, 0, ROT0, "Eterna" ,"Poizone" ,GAME_NO_SOUND|GAME_NOT_WORKING)