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THUMB: 

- fix Carry & Negative flags in ADC, SBC opcodes;
This commit is contained in:
mtabachenko 2010-04-06 17:24:31 +00:00
parent d2d18907c3
commit 833f4fcdb9
1 changed files with 2 additions and 38 deletions
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40
desmume/src/thumb_instructions.cpp
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@ -441,8 +441,6 @@ TEMPLATE static u32 FASTCALL OP_EOR(const u32 i)
TEMPLATE static u32 FASTCALL OP_ADC_REG(const u32 i)
{
#if 0
printf("THUMB%c: ADC\n", PROCNUM?'7':'9');
u32 Rd = cpu->R[REG_NUM(i, 0)];
u32 Rm = cpu->R[REG_NUM(i, 3)];
@ -451,25 +449,8 @@ TEMPLATE static u32 FASTCALL OP_ADC_REG(const u32 i)
cpu->CPSR.bits.N = BIT31(cpu->R[REG_NUM(i, 0)]);
cpu->CPSR.bits.Z = (cpu->R[REG_NUM(i, 0)] == 0);
// TODO!!!!
cpu->CPSR.bits.C = CarryFrom(Rd, Rm + cpu->CPSR.bits.C);
cpu->CPSR.bits.V = OverflowFromADD(cpu->R[REG_NUM(i, 0)], Rd, Rm + cpu->CPSR.bits.C);
//cpu->CPSR.bits.C = UNSIGNED_OVERFLOW(b, (u32) cpu->CPSR.bits.C, tmp) | UNSIGNED_OVERFLOW(tmp, a, res);
//cpu->CPSR.bits.V = SIGNED_OVERFLOW(b, (u32) cpu->CPSR.bits.C, tmp) | SIGNED_OVERFLOW(tmp, a, res);
#else
u32 a = cpu->R[REG_NUM(i, 0)];
u32 b = cpu->R[REG_NUM(i, 3)];
u32 tmp = b + cpu->CPSR.bits.C;
u32 res = a + tmp;
cpu->R[REG_NUM(i, 0)] = res;
cpu->CPSR.bits.N = BIT31(res);
cpu->CPSR.bits.Z = res == 0;
cpu->CPSR.bits.C = UNSIGNED_OVERFLOW(b, (u32) cpu->CPSR.bits.C, tmp) | UNSIGNED_OVERFLOW(tmp, a, res);
cpu->CPSR.bits.V = SIGNED_OVERFLOW(b, (u32) cpu->CPSR.bits.C, tmp) | SIGNED_OVERFLOW(tmp, a, res);
#endif
return 1;
}
@ -480,7 +461,6 @@ TEMPLATE static u32 FASTCALL OP_ADC_REG(const u32 i)
TEMPLATE static u32 FASTCALL OP_SBC_REG(const u32 i)
{
#if 0
u32 Rd = cpu->R[REG_NUM(i, 0)];
u32 Rm = cpu->R[REG_NUM(i, 3)];
@ -489,23 +469,8 @@ TEMPLATE static u32 FASTCALL OP_SBC_REG(const u32 i)
cpu->CPSR.bits.N = BIT31(cpu->R[REG_NUM(i, 0)]);
cpu->CPSR.bits.Z = (cpu->R[REG_NUM(i, 0)] == 0);
// TODO
#else
u32 a = cpu->R[REG_NUM(i, 0)];
u32 b = cpu->R[REG_NUM(i, 3)];
u32 tmp = a - (!cpu->CPSR.bits.C);
u32 res = tmp - b;
cpu->R[REG_NUM(i, 0)] = res;
cpu->CPSR.bits.N = BIT31(res);
cpu->CPSR.bits.Z = res == 0;
//zero 31-dec-2008 - apply normatt's fixed logic from the arm SBC instruction
//although it seemed a bit odd to me and to whomever wrote this for SBC not to work similar to ADC..
//but thats how it is.
cpu->CPSR.bits.C = !UNSIGNED_UNDERFLOW(a, b, res);
cpu->CPSR.bits.V = SIGNED_UNDERFLOW(a, b, res);
#endif
cpu->CPSR.bits.C = !CarryFrom(Rd, Rm - !cpu->CPSR.bits.C);
cpu->CPSR.bits.V = OverflowFromSUB(cpu->R[REG_NUM(i, 0)], Rd, Rm - !cpu->CPSR.bits.C);
return 1;
}
@ -812,7 +777,6 @@ TEMPLATE static u32 FASTCALL OP_LDR_REG_OFF(const u32 i)
return MMU_aluMemAccessCycles<PROCNUM,32,MMU_AD_READ>(3, adr);
}
TEMPLATE static u32 FASTCALL OP_STR_SPREL(const u32 i)
{
u32 adr = cpu->R[13] + ((i&0xFF)<<2);