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Correct SP arithmetic methods: All Blargg CPU tests now pass. Hurrah!

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Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
This commit is contained in:
Adrian.Conlon 2017-08-28 23:04:25 +01:00
parent 91c8855183
commit ec15a2c90c
2 changed files with 23 additions and 16 deletions
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31
LR35902/src/LR35902.cpp
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@ -13,7 +13,7 @@ EightBit::LR35902::LR35902(Bus& memory)
void EightBit::LR35902::reset() {
IntelProcessor::reset();
SP().word = 0xfffe;
SP().word = Mask16 - 1;
di();
}
@ -21,11 +21,10 @@ void EightBit::LR35902::initialise() {
IntelProcessor::initialise();
AF().word = 0xffff;
BC().word = 0xffff;
DE().word = 0xffff;
HL().word = 0xffff;
AF().word = Mask16;
BC().word = Mask16;
DE().word = Mask16;
HL().word = Mask16;
m_prefixCB = false;
}
@ -687,13 +686,13 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
break;
case 5: { // GB: ADD SP,dd
auto before = SP().word;
auto value = fetchByte();
auto result = before + (int8_t)value;
int8_t value = fetchByte();
auto result = before + value;
SP().word = result;
auto carried = before ^ value ^ result;
auto carried = before ^ value ^ (result & Mask16);
clearFlag(f, ZF | NF);
setFlag(f, CF, carried & 0x100);
setFlag(f, HC, carried & 0x10);
setFlag(f, CF, carried & Bit8);
setFlag(f, HC, carried & Bit4);
}
cycles += 4;
break;
@ -703,13 +702,13 @@ void EightBit::LR35902::executeOther(int x, int y, int z, int p, int q) {
break;
case 7: { // GB: LD HL,SP + dd
auto before = SP().word;
auto value = fetchByte();
auto result = before + (int8_t)value;
int8_t value = fetchByte();
auto result = before + value;
HL().word = result;
auto carried = before ^ value ^ result;
auto carried = before ^ value ^ (result & Mask16);
clearFlag(f, ZF | NF);
setFlag(f, CF, carried & 0x100);
setFlag(f, HC, carried & 0x10);
setFlag(f, CF, carried & Bit8);
setFlag(f, HC, carried & Bit4);
}
cycles += 3;
break;

8
inc/Processor.h
View File

@ -36,6 +36,14 @@ namespace EightBit {
Mask6 = Bit6 - 1,
Mask7 = Bit7 - 1,
Mask8 = Bit8 - 1,
Mask9 = Bit9 - 1,
Mask10 = Bit10 - 1,
Mask11 = Bit11 - 1,
Mask12 = Bit12 - 1,
Mask13 = Bit13 - 1,
Mask14 = Bit14 - 1,
Mask15 = Bit15 - 1,
Mask16 = Bit16 - 1,
};
static int highNibble(int value) { return value >> 4; }