mirror of
https://github.com/MoleskiCoder/EightBit.git
synced 2025-01-22 12:30:44 +00:00
A few minor consistency tweaks to the i8080 and z80 processors.
Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
This commit is contained in:
Adrian.Conlon
parent
8f57fac3ee
commit
6af1857cb0
@ -79,8 +79,7 @@ namespace EightBit {
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}
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void adjustReservedFlags() {
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F() &= ~(Bit5 | Bit3);
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F() |= Bit1;
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F() = (F() | Bit1) & ~(Bit5 | Bit3);
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}
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static void adjustAuxiliaryCarryAdd(uint8_t& f, uint8_t before, uint8_t value, int calculation) {
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@ -150,9 +149,9 @@ namespace EightBit {
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void dad(uint16_t value) {
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auto& f = F();
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uint32_t sum = HL().word + value;
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setFlag(f, CF, sum > 0xffff);
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HL().word = (uint16_t)sum;
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auto sum = HL().word + value;
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setFlag(f, CF, sum & Bit16);
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HL().word = sum;
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}
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void sub(uint8_t& operand, uint8_t value, int carry = 0) {
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@ -527,13 +526,11 @@ namespace EightBit {
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}
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void sbi() {
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auto value = fetchByte();
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sbb(value);
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sbb(fetchByte());
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}
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void sui() {
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auto value = fetchByte();
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sub(value);
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sub(fetchByte());
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}
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// logical
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@ -603,35 +600,31 @@ namespace EightBit {
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void rlc() {
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auto& a = A();
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auto carry = a & Bit7;
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a <<= 1;
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carry ? a |= Bit0 : a &= ~Bit0;
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a = (a << 1) | (carry >> 7);
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setFlag(F(), CF, carry);
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}
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void rrc() {
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auto& a = A();
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auto carry = a & Bit0;
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a >>= 1;
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carry ? a |= Bit7 : a &= ~Bit7;
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a = (a >> 1) | (carry << 7);
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setFlag(F(), CF, carry);
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}
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void ral() {
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auto& a = A();
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auto& f = F();
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auto carry = a & Bit7;
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a <<= 1;
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a |= (f & CF);
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setFlag(f, CF, carry);
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const auto carry = f & CF;
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setFlag(f, CF, a & Bit7);
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a = (a << 1) | carry;
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}
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void rar() {
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auto& a = A();
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auto& f = F();
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auto carry = a & 1;
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a >>= 1;
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a |= (f & CF) << 7;
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setFlag(f, CF, carry);
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const auto carry = f & CF;
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setFlag(f, CF, a & Bit0);
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a = (a >> 1) | (carry << 7);
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}
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// specials
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@ -221,6 +221,8 @@ namespace EightBit {
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}
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register16_t& RP(int rp) {
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__assume(rp < 4);
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__assume(rp >= 0);
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switch (rp) {
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case 3:
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return SP();
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@ -241,6 +243,8 @@ namespace EightBit {
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}
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register16_t& RP2(int rp) {
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__assume(rp < 4);
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__assume(rp >= 0);
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switch (rp) {
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case 3:
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return AF();
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@ -148,6 +148,8 @@ bool EightBit::Z80::jrConditionalFlag(uint8_t& f, int flag) {
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return jrConditional(!(f & SF));
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case 7: // M
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return jrConditional(f & SF);
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default:
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__assume(0);
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}
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throw std::logic_error("Unhandled JR conditional");
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}
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@ -170,6 +172,8 @@ bool EightBit::Z80::jumpConditionalFlag(uint8_t& f, int flag) {
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return jumpConditional(!(f & SF));
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case 7: // M
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return jumpConditional(f & SF);
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default:
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__assume(0);
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}
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throw std::logic_error("Unhandled JP conditional");
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}
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@ -201,6 +205,8 @@ bool EightBit::Z80::returnConditionalFlag(uint8_t& f, int flag) {
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return returnConditional(!(f & SF));
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case 7: // M
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return returnConditional(f & SF);
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default:
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__assume(0);
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}
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throw std::logic_error("Unhandled RET conditional");
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}
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@ -223,6 +229,8 @@ bool EightBit::Z80::callConditionalFlag(uint8_t& f, int flag) {
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return callConditional(!(f & SF));
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case 7: // M
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return callConditional(f & SF);
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default:
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__assume(0);
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}
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throw std::logic_error("Unhandled CALL conditional");
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}
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@ -435,7 +443,7 @@ uint8_t& EightBit::Z80::srl(uint8_t& f, uint8_t& operand) {
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uint8_t& EightBit::Z80::bit(uint8_t& f, int n, uint8_t& operand) {
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setFlag(f, HC);
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clearFlag(f, NF);
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const uint8_t discarded = operand & (1 << n);
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const auto discarded = operand & (1 << n);
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adjustSZXY<Z80>(f, discarded);
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clearFlag(f, PF, discarded);
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return operand;
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@ -543,8 +551,7 @@ void EightBit::Z80::blockCompare(uint8_t a, uint8_t& f) {
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adjustHalfCarrySub(f, a, value, result);
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setFlag(f, NF);
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if (f & HC)
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result -= 1;
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result -= ((f & HC) >> 4);
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setFlag(f, YF, result & Bit1);
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setFlag(f, XF, result & Bit3);
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@ -825,18 +832,18 @@ void EightBit::Z80::executeCB(int x, int y, int z) {
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adjustSZP<Z80>(f, m_displaced ? R2(z, a) = srl(f, DISPLACED()) : srl(f, R(z, a)));
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break;
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}
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cycles += 8;
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if (!m_displaced) {
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cycles += 8;
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if (z == 6)
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cycles += 7;
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} else {
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cycles += 23;
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cycles += 15;
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}
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break;
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case 1: // BIT y, r[z]
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cycles += 8;
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if (!m_displaced) {
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auto operand = bit(f, y, R(z, a));
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cycles += 8;
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if (z == 6) {
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adjustXY<Z80>(f, MEMPTR().high);
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cycles += 4;
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@ -846,29 +853,29 @@ void EightBit::Z80::executeCB(int x, int y, int z) {
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} else {
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bit(f, y, DISPLACED());
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adjustXY<Z80>(f, MEMPTR().high);
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cycles += 20;
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cycles += 12;
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}
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break;
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case 2: // RES y, r[z]
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cycles += 8;
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if (!m_displaced) {
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res(y, R(z, a));
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cycles += 8;
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if (z == 6)
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cycles += 7;
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} else {
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R2(z, a) = res(y, DISPLACED());
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cycles += 23;
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cycles += 15;
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}
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break;
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case 3: // SET y, r[z]
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cycles += 8;
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if (!m_displaced) {
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set(y, R(z, a));
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cycles += 8;
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if (z == 6)
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cycles += 7;
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} else {
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R2(z, a) = set(y, DISPLACED());
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cycles += 23;
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cycles += 15;
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}
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break;
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default:
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@ -19,24 +19,3 @@
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#include <bitset>
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#include <boost/format.hpp>
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//#include <SDL.h>
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//#include <SDL_mixer.h>
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//
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//#if SDL_BYTEORDER == SDL_LIL_ENDIAN
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//#define HOST_LITTLE_ENDIAN
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//#endif
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//
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//#if SDL_BYTEORDER == SDL_BIG_ENDIAN
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//#define HOST_BIG_ENDIAN
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//#endif
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//
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//#define RUN_TESTS
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////#define RUN_CPM
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////#define RUN_INVADERS
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//
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//#ifdef _MSC_VER
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//#pragma comment(lib, "SDL2.lib")
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//#pragma comment(lib, "SDL2main.lib")
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//#pragma comment(lib, "SDL2_mixer.lib")
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//#endif
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@ -54,7 +54,7 @@ namespace EightBit {
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}
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template<class T> static void adjustParity(uint8_t& f, uint8_t value) {
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static const uint8_t lookup[0x10] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
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static const int lookup[0x10] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
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auto set = lookup[highNibble(value)] + lookup[lowNibble(value)];
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clearFlag(f, T::PF, set % 2);
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}
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@ -87,16 +87,19 @@ namespace EightBit {
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//
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static int buildHalfCarryIndex(uint8_t before, uint8_t value, int calculation) {
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__assume(calculation < 0x1ffff);
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return ((before & 0x88) >> 1) | ((value & 0x88) >> 2) | ((calculation & 0x88) >> 3);
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}
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static bool calculateHalfCarryAdd(uint8_t before, uint8_t value, int calculation) {
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__assume(calculation < 0x1ffff);
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static std::array<bool, 8> m_halfCarryTableAdd = { { false, false, true, false, true, false, true, true } };
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auto index = buildHalfCarryIndex(before, value, calculation);
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return m_halfCarryTableAdd[index & Mask3];
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}
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static bool calculateHalfCarrySub(uint8_t before, uint8_t value, int calculation) {
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__assume(calculation < 0x1ffff);
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std::array<bool, 8> m_halfCarryTableSub = { { false, true, true, true, false, false, false, true } };
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auto index = buildHalfCarryIndex(before, value, calculation);
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return m_halfCarryTableSub[index & Mask3];
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