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Some more optimisations, up to 225Mhz now.

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Reordered if statements to give "then" case "expected"
Better use of "__assume" in switch statements

Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
This commit is contained in:
Adrian.Conlon 2017-06-29 21:25:58 +01:00
parent 10ed04bf90
commit 3439523865
1 changed files with 32 additions and 25 deletions
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57
Z80/src/Z80.cpp
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@ -778,12 +778,15 @@ int EightBit::Z80::execute(uint8_t opcode) {
auto p = decoded.p;
auto q = decoded.q;
if (m_prefixCB)
executeCB(x, y, z);
else if (m_prefixED)
executeED(x, y, z, p, q);
else
auto prefixed = m_prefixCB || m_prefixED;
if (!prefixed) {
executeOther(x, y, z, p, q);
} else {
if (m_prefixCB)
executeCB(x, y, z);
else if (m_prefixED)
executeED(x, y, z, p, q);
}
if (cycles == 0)
throw std::logic_error("Unhandled opcode");
@ -822,20 +825,16 @@ void EightBit::Z80::executeCB(int x, int y, int z) {
adjustSZP<Z80>(f, m_displaced ? R2(z, a) = srl(f, DISPLACED()) : srl(f, R(z, a)));
break;
}
if (m_displaced) {
cycles += 23;
} else {
if (!m_displaced) {
cycles += 8;
if (z == 6)
cycles += 7;
} else {
cycles += 23;
}
break;
case 1: // BIT y, r[z]
if (m_displaced) {
bit(f, y, DISPLACED());
adjustXY<Z80>(f, MEMPTR().high);
cycles += 20;
} else {
if (!m_displaced) {
auto operand = bit(f, y, R(z, a));
cycles += 8;
if (z == 6) {
@ -844,30 +843,36 @@ void EightBit::Z80::executeCB(int x, int y, int z) {
} else {
adjustXY<Z80>(f, operand);
}
} else {
bit(f, y, DISPLACED());
adjustXY<Z80>(f, MEMPTR().high);
cycles += 20;
}
break;
case 2: // RES y, r[z]
if (m_displaced) {
R2(z, a) = res(y, DISPLACED());
cycles += 23;
} else {
if (!m_displaced) {
res(y, R(z, a));
cycles += 8;
if (z == 6)
cycles += 7;
} else {
R2(z, a) = res(y, DISPLACED());
cycles += 23;
}
break;
case 3: // SET y, r[z]
if (m_displaced) {
R2(z, a) = set(y, DISPLACED());
cycles += 23;
} else {
if (!m_displaced) {
set(y, R(z, a));
cycles += 8;
if (z == 6)
cycles += 7;
} else {
R2(z, a) = set(y, DISPLACED());
cycles += 23;
}
break;
default:
__assume(0);
}
}
@ -1380,8 +1385,9 @@ void EightBit::Z80::executeOther(int x, int y, int z, int p, int q) {
default:
__assume(0);
}
////default:
//// __assume(0);
break;
default:
__assume(0);
}
break;
case 2: // Conditional jump
@ -1462,8 +1468,9 @@ void EightBit::Z80::executeOther(int x, int y, int z, int p, int q) {
default:
__assume(0);
}
////default:
//// __assume(0);
break;
default:
__assume(0);
}
break;
case 6: // Operate on accumulator and immediate operand: alu[y] n