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mirror of https://github.com/TomHarte/CLK.git synced 2024-11-26 08:49:37 +00:00

Bends to using 8-bit lookups for M50740 instructions.

This commit is contained in:
Thomas Harte 2021-01-17 20:03:36 -05:00
parent 17c3a3eb4b
commit 54b26c7991
7 changed files with 277 additions and 232 deletions

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@ -38,7 +38,18 @@ template <uint64_t max_value> struct MinIntTypeValue {
};
/*!
A caching executor makes use of an instruction set-specific executor to cache 'performers' (i.e. function pointers)
that result from decoding.
In other words, it's almost a JIT compiler, but producing threaded code (in the Forth sense) and then incurring whatever
costs sit behind using the C ABI for calling. Since there'll always be exactly one parameter, being the specific executor,
hopefully the calling costs are acceptable.
Intended usage is for specific executors to subclass from this and declare it a friend.
TODO: determine promises re: interruption, amongst other things.
*/
template <
/// Indicates the Executor for this platform.
typename Executor,
@ -53,11 +64,13 @@ template <
protected:
using Performer = void (*)(Executor *);
using PerformerIndex = typename MinIntTypeValue<max_performer_count>::type;
std::array<Performer, max_performer_count> performers_;
typename MinIntTypeValue<max_address>::type program_counter_;
private:
typename MinIntTypeValue<max_performer_count>::type actions_[100];
PerformerIndex actions_[100];
};
}

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@ -13,6 +13,224 @@
namespace InstructionSet {
namespace M50740 {
Instruction Decoder::instrucion_for_opcode(uint8_t opcode) {
switch(opcode) {
default: return Instruction(opcode);
#define Map(opcode, operation, addressing_mode) case opcode: return Instruction(Operation::operation, AddressingMode::addressing_mode, opcode);
/* 0x00 0x0f */
Map(0x00, BRK, Implied); Map(0x01, ORA, XIndirect);
Map(0x02, JSR, ZeroPageIndirect); Map(0x03, BBS, Bit0AccumulatorRelative);
Map(0x05, ORA, ZeroPage);
Map(0x06, ASL, ZeroPage); Map(0x07, BBS, Bit0ZeroPageRelative);
Map(0x08, PHP, Implied); Map(0x09, ORA, Immediate);
Map(0x0a, ASL, Accumulator); Map(0x0b, SEB, Bit0Accumulator);
Map(0x0d, ORA, Absolute);
Map(0x0e, ASL, Absolute); Map(0x0f, SEB, Bit0ZeroPage);
/* 0x10 0x1f */
Map(0x10, BPL, Relative); Map(0x11, ORA, IndirectY);
Map(0x12, CLT, Implied); Map(0x13, BBC, Bit0AccumulatorRelative);
Map(0x15, ORA, ZeroPageX);
Map(0x16, ASL, ZeroPageX); Map(0x17, BBC, Bit0ZeroPageRelative);
Map(0x18, CLC, Implied); Map(0x19, ORA, AbsoluteY);
Map(0x1a, DEC, Accumulator); Map(0x1b, CLB, Bit0Accumulator);
Map(0x1d, ORA, AbsoluteX);
Map(0x1e, ASL, AbsoluteX); Map(0x1f, CLB, Bit0ZeroPage);
/* 0x20 0x2f */
Map(0x20, JSR, Absolute); Map(0x21, AND, XIndirect);
Map(0x22, JSR, SpecialPage); Map(0x23, BBS, Bit1AccumulatorRelative);
Map(0x24, BIT, ZeroPage); Map(0x25, AND, ZeroPage);
Map(0x26, ROL, ZeroPage); Map(0x27, BBS, Bit1ZeroPageRelative);
Map(0x28, PLP, Implied); Map(0x29, AND, Immediate);
Map(0x2a, ROL, Accumulator); Map(0x2b, SEB, Bit1Accumulator);
Map(0x2c, BIT, Absolute); Map(0x2d, AND, Absolute);
Map(0x2e, ROL, Absolute); Map(0x2f, SEB, Bit1ZeroPage);
/* 0x30 0x3f */
Map(0x30, BMI, Relative); Map(0x31, AND, IndirectY);
Map(0x32, SET, Implied); Map(0x33, BBC, Bit1AccumulatorRelative);
Map(0x35, AND, ZeroPageX);
Map(0x36, ROL, ZeroPageX); Map(0x37, BBC, Bit1ZeroPageRelative);
Map(0x38, SEC, Implied); Map(0x39, AND, AbsoluteY);
Map(0x3a, INC, Accumulator); Map(0x3b, CLB, Bit1Accumulator);
Map(0x3c, LDM, ImmediateZeroPage); Map(0x3d, AND, AbsoluteX);
Map(0x3e, ROL, AbsoluteX); Map(0x3f, CLB, Bit1ZeroPage);
/* 0x40 0x4f */
Map(0x40, RTI, Implied); Map(0x41, EOR, XIndirect);
Map(0x42, STP, Implied); Map(0x43, BBS, Bit2AccumulatorRelative);
Map(0x44, COM, ZeroPage); Map(0x45, EOR, ZeroPage);
Map(0x46, LSR, ZeroPage); Map(0x47, BBS, Bit2ZeroPageRelative);
Map(0x48, PHA, Implied); Map(0x49, EOR, Immediate);
Map(0x4a, LSR, Accumulator); Map(0x4b, SEB, Bit2Accumulator);
Map(0x4c, JMP, Absolute); Map(0x4d, EOR, Absolute);
Map(0x4e, LSR, Absolute); Map(0x4f, SEB, Bit2ZeroPage);
/* 0x50 0x5f */
Map(0x50, BVC, Relative); Map(0x51, EOR, IndirectY);
Map(0x53, BBC, Bit2AccumulatorRelative);
Map(0x55, EOR, ZeroPageX);
Map(0x56, LSR, ZeroPageX); Map(0x57, BBC, Bit2ZeroPageRelative);
Map(0x58, CLI, Implied); Map(0x59, EOR, AbsoluteY);
Map(0x5b, CLB, Bit2Accumulator);
Map(0x5d, EOR, AbsoluteX);
Map(0x5e, LSR, AbsoluteX); Map(0x5f, CLB, Bit2ZeroPage);
/* 0x60 0x6f */
Map(0x60, RTS, Implied); Map(0x61, ADC, XIndirect);
Map(0x63, BBS, Bit3AccumulatorRelative);
Map(0x64, TST, ZeroPage); Map(0x65, ADC, ZeroPage);
Map(0x66, ROR, ZeroPage); Map(0x67, BBS, Bit3ZeroPageRelative);
Map(0x68, PLA, Implied); Map(0x69, ADC, Immediate);
Map(0x6a, ROR, Accumulator); Map(0x6b, SEB, Bit3Accumulator);
Map(0x6c, JMP, AbsoluteIndirect); Map(0x6d, ADC, Absolute);
Map(0x6e, ROR, Absolute); Map(0x6f, SEB, Bit3ZeroPage);
/* 0x70 0x7f */
Map(0x70, BVS, Relative); Map(0x71, ADC, IndirectY);
Map(0x73, BBC, Bit3AccumulatorRelative);
Map(0x75, ADC, ZeroPageX);
Map(0x76, ROR, ZeroPageX); Map(0x77, BBC, Bit3ZeroPageRelative);
Map(0x78, SEI, Implied); Map(0x79, ADC, AbsoluteY);
Map(0x7b, CLB, Bit3Accumulator);
Map(0x7d, ADC, AbsoluteX);
Map(0x7e, ROR, AbsoluteX); Map(0x7f, CLB, Bit3ZeroPage);
/* 0x80 0x8f */
Map(0x80, BRA, Relative); Map(0x81, STA, XIndirect);
Map(0x82, RRF, ZeroPage); Map(0x83, BBS, Bit4AccumulatorRelative);
Map(0x84, STY, ZeroPage); Map(0x85, STA, ZeroPage);
Map(0x86, STX, ZeroPage); Map(0x87, BBS, Bit4ZeroPageRelative);
Map(0x88, DEY, Implied);
Map(0x8a, TXA, Implied); Map(0x8b, SEB, Bit4Accumulator);
Map(0x8c, STY, Absolute); Map(0x8d, STA, Absolute);
Map(0x8e, STX, Absolute); Map(0x8f, SEB, Bit4ZeroPage);
/* 0x90 0x9f */
Map(0x90, BCC, Relative); Map(0x91, STA, IndirectY);
Map(0x93, BBC, Bit4AccumulatorRelative);
Map(0x94, STY, ZeroPageX); Map(0x95, STA, ZeroPageX);
Map(0x96, STX, ZeroPageX); Map(0x97, BBC, Bit4ZeroPageRelative);
Map(0x98, TYA, Implied); Map(0x99, STA, AbsoluteY);
Map(0x9a, TXS, AbsoluteY); Map(0x9b, CLB, Bit4Accumulator);
Map(0x9d, ADC, AbsoluteX);
Map(0x9f, CLB, Bit4ZeroPage);
/* 0xa0 0xaf */
Map(0xa0, LDY, Immediate); Map(0xa1, LDA, XIndirect);
Map(0xa2, LDX, Immediate); Map(0xa3, BBS, Bit5AccumulatorRelative);
Map(0xa4, LDY, ZeroPage); Map(0xa5, LDA, ZeroPage);
Map(0xa6, LDX, ZeroPage); Map(0xa7, BBS, Bit5ZeroPageRelative);
Map(0xa8, TAY, Implied); Map(0xa9, LDA, Immediate);
Map(0xaa, TAX, Implied); Map(0xab, SEB, Bit5Accumulator);
Map(0xac, LDY, Absolute); Map(0xad, LDA, Absolute);
Map(0xae, LDX, Absolute); Map(0xaf, SEB, Bit5ZeroPage);
/* 0xb0 0xbf */
Map(0xb0, BCS, Relative); Map(0xb1, STA, IndirectY);
Map(0xb2, JMP, ZeroPageIndirect); Map(0xb3, BBC, Bit5AccumulatorRelative);
Map(0xb4, LDY, ZeroPageX); Map(0xb5, LDA, ZeroPageX);
Map(0xb6, LDX, ZeroPageY); Map(0xb7, BBC, Bit5ZeroPageRelative);
Map(0xb8, CLV, Implied); Map(0xb9, LDA, AbsoluteY);
Map(0xba, TSX, AbsoluteY); Map(0xbb, CLB, Bit5Accumulator);
Map(0xbc, LDY, AbsoluteX); Map(0xbd, LDA, AbsoluteX);
Map(0xbe, LDX, AbsoluteY); Map(0xbf, CLB, Bit5ZeroPage);
/* 0xc0 0xcf */
Map(0xc0, CPY, Immediate); Map(0xc1, CMP, XIndirect);
Map(0xc2, SLW, Implied); Map(0xc3, BBS, Bit6AccumulatorRelative);
Map(0xc4, CPY, ZeroPage); Map(0xc5, CMP, ZeroPage);
Map(0xc6, DEC, ZeroPage); Map(0xc7, BBS, Bit6ZeroPageRelative);
Map(0xc8, INY, Implied); Map(0xc9, CMP, Immediate);
Map(0xca, DEX, Implied); Map(0xcb, SEB, Bit6Accumulator);
Map(0xcc, CPY, Absolute); Map(0xcd, CMP, Absolute);
Map(0xce, DEC, Absolute); Map(0xcf, SEB, Bit6ZeroPage);
/* 0xd0 0xdf */
Map(0xd0, BNE, Relative); Map(0xd1, CMP, IndirectY);
Map(0xd3, BBC, Bit6AccumulatorRelative);
Map(0xd5, CMP, ZeroPageX);
Map(0xd6, DEC, ZeroPageX); Map(0xd7, BBC, Bit6ZeroPageRelative);
Map(0xd8, CLD, Implied); Map(0xd9, CMP, AbsoluteY);
Map(0xdb, CLB, Bit6Accumulator);
Map(0xdd, CMP, AbsoluteX);
Map(0xde, DEC, AbsoluteX); Map(0xdf, CLB, Bit6ZeroPage);
/* 0xe0 0xef */
Map(0xe0, CPX, Immediate); Map(0xe1, SBC, XIndirect);
Map(0xe2, FST, Implied); Map(0xe3, BBS, Bit7AccumulatorRelative);
Map(0xe4, CPX, ZeroPage); Map(0xe5, SBC, ZeroPage);
Map(0xe6, INC, ZeroPage); Map(0xe7, BBS, Bit7ZeroPageRelative);
Map(0xe8, INX, Implied); Map(0xe9, SBC, Immediate);
Map(0xea, NOP, Implied); Map(0xeb, SEB, Bit7Accumulator);
Map(0xec, CPX, Absolute); Map(0xed, SBC, Absolute);
Map(0xee, INC, Absolute); Map(0xef, SEB, Bit7ZeroPage);
/* 0xf0 0xff */
Map(0xf0, BEQ, Relative); Map(0xf1, SBC, IndirectY);
Map(0xf3, BBC, Bit7AccumulatorRelative);
Map(0xf5, SBC, ZeroPageX);
Map(0xf6, INC, ZeroPageX); Map(0xf7, BBC, Bit7ZeroPageRelative);
Map(0xf8, SED, Implied); Map(0xf9, SBC, AbsoluteY);
Map(0xfb, CLB, Bit7Accumulator);
Map(0xfd, SBC, AbsoluteX);
Map(0xfe, INC, AbsoluteX); Map(0xff, CLB, Bit7ZeroPage);
#undef Map
}
}
std::pair<int, InstructionSet::M50740::Instruction> Decoder::decode(const uint8_t *source, size_t length) {
const uint8_t *const end = source + length;
@ -21,224 +239,14 @@ std::pair<int, InstructionSet::M50740::Instruction> Decoder::decode(const uint8_
++source;
++consumed_;
switch(instruction) {
default:
consumed_ = 0;
return std::make_pair(1, Instruction());
#define Map(opcode, operation, addressing_mode) case opcode: instr_ = Instruction(Operation::operation, AddressingMode::addressing_mode); break
/* 0x00 0x0f */
Map(0x00, BRK, Implied); Map(0x01, ORA, XIndirect);
Map(0x02, JSR, ZeroPageIndirect); Map(0x03, BBS, Bit0AccumulatorRelative);
Map(0x05, ORA, ZeroPage);
Map(0x06, ASL, ZeroPage); Map(0x07, BBS, Bit0ZeroPageRelative);
Map(0x08, PHP, Implied); Map(0x09, ORA, Immediate);
Map(0x0a, ASL, Accumulator); Map(0x0b, SEB, Bit0Accumulator);
Map(0x0d, ORA, Absolute);
Map(0x0e, ASL, Absolute); Map(0x0f, SEB, Bit0ZeroPage);
/* 0x10 0x1f */
Map(0x10, BPL, Relative); Map(0x11, ORA, IndirectY);
Map(0x12, CLT, Implied); Map(0x13, BBC, Bit0AccumulatorRelative);
Map(0x15, ORA, ZeroPageX);
Map(0x16, ASL, ZeroPageX); Map(0x17, BBC, Bit0ZeroPageRelative);
Map(0x18, CLC, Implied); Map(0x19, ORA, AbsoluteY);
Map(0x1a, DEC, Accumulator); Map(0x1b, CLB, Bit0Accumulator);
Map(0x1d, ORA, AbsoluteX);
Map(0x1e, ASL, AbsoluteX); Map(0x1f, CLB, Bit0ZeroPage);
/* 0x20 0x2f */
Map(0x20, JSR, Absolute); Map(0x21, AND, XIndirect);
Map(0x22, JSR, SpecialPage); Map(0x23, BBS, Bit1AccumulatorRelative);
Map(0x24, BIT, ZeroPage); Map(0x25, AND, ZeroPage);
Map(0x26, ROL, ZeroPage); Map(0x27, BBS, Bit1ZeroPageRelative);
Map(0x28, PLP, Implied); Map(0x29, AND, Immediate);
Map(0x2a, ROL, Accumulator); Map(0x2b, SEB, Bit1Accumulator);
Map(0x2c, BIT, Absolute); Map(0x2d, AND, Absolute);
Map(0x2e, ROL, Absolute); Map(0x2f, SEB, Bit1ZeroPage);
/* 0x30 0x3f */
Map(0x30, BMI, Relative); Map(0x31, AND, IndirectY);
Map(0x32, SET, Implied); Map(0x33, BBC, Bit1AccumulatorRelative);
Map(0x35, AND, ZeroPageX);
Map(0x36, ROL, ZeroPageX); Map(0x37, BBC, Bit1ZeroPageRelative);
Map(0x38, SEC, Implied); Map(0x39, AND, AbsoluteY);
Map(0x3a, INC, Accumulator); Map(0x3b, CLB, Bit1Accumulator);
Map(0x3c, LDM, ImmediateZeroPage); Map(0x3d, AND, AbsoluteX);
Map(0x3e, ROL, AbsoluteX); Map(0x3f, CLB, Bit1ZeroPage);
/* 0x40 0x4f */
Map(0x40, RTI, Implied); Map(0x41, EOR, XIndirect);
Map(0x42, STP, Implied); Map(0x43, BBS, Bit2AccumulatorRelative);
Map(0x44, COM, ZeroPage); Map(0x45, EOR, ZeroPage);
Map(0x46, LSR, ZeroPage); Map(0x47, BBS, Bit2ZeroPageRelative);
Map(0x48, PHA, Implied); Map(0x49, EOR, Immediate);
Map(0x4a, LSR, Accumulator); Map(0x4b, SEB, Bit2Accumulator);
Map(0x4c, JMP, Absolute); Map(0x4d, EOR, Absolute);
Map(0x4e, LSR, Absolute); Map(0x4f, SEB, Bit2ZeroPage);
/* 0x50 0x5f */
Map(0x50, BVC, Relative); Map(0x51, EOR, IndirectY);
Map(0x53, BBC, Bit2AccumulatorRelative);
Map(0x55, EOR, ZeroPageX);
Map(0x56, LSR, ZeroPageX); Map(0x57, BBC, Bit2ZeroPageRelative);
Map(0x58, CLI, Implied); Map(0x59, EOR, AbsoluteY);
Map(0x5b, CLB, Bit2Accumulator);
Map(0x5d, EOR, AbsoluteX);
Map(0x5e, LSR, AbsoluteX); Map(0x5f, CLB, Bit2ZeroPage);
/* 0x60 0x6f */
Map(0x60, RTS, Implied); Map(0x61, ADC, XIndirect);
Map(0x63, BBS, Bit3AccumulatorRelative);
Map(0x64, TST, ZeroPage); Map(0x65, ADC, ZeroPage);
Map(0x66, ROR, ZeroPage); Map(0x67, BBS, Bit3ZeroPageRelative);
Map(0x68, PLA, Implied); Map(0x69, ADC, Immediate);
Map(0x6a, ROR, Accumulator); Map(0x6b, SEB, Bit3Accumulator);
Map(0x6c, JMP, AbsoluteIndirect); Map(0x6d, ADC, Absolute);
Map(0x6e, ROR, Absolute); Map(0x6f, SEB, Bit3ZeroPage);
/* 0x70 0x7f */
Map(0x70, BVS, Relative); Map(0x71, ADC, IndirectY);
Map(0x73, BBC, Bit3AccumulatorRelative);
Map(0x75, ADC, ZeroPageX);
Map(0x76, ROR, ZeroPageX); Map(0x77, BBC, Bit3ZeroPageRelative);
Map(0x78, SEI, Implied); Map(0x79, ADC, AbsoluteY);
Map(0x7b, CLB, Bit3Accumulator);
Map(0x7d, ADC, AbsoluteX);
Map(0x7e, ROR, AbsoluteX); Map(0x7f, CLB, Bit3ZeroPage);
/* 0x80 0x8f */
Map(0x80, BRA, Relative); Map(0x81, STA, XIndirect);
Map(0x82, RRF, ZeroPage); Map(0x83, BBS, Bit4AccumulatorRelative);
Map(0x84, STY, ZeroPage); Map(0x85, STA, ZeroPage);
Map(0x86, STX, ZeroPage); Map(0x87, BBS, Bit4ZeroPageRelative);
Map(0x88, DEY, Implied);
Map(0x8a, TXA, Implied); Map(0x8b, SEB, Bit4Accumulator);
Map(0x8c, STY, Absolute); Map(0x8d, STA, Absolute);
Map(0x8e, STX, Absolute); Map(0x8f, SEB, Bit4ZeroPage);
/* 0x90 0x9f */
Map(0x90, BCC, Relative); Map(0x91, STA, IndirectY);
Map(0x93, BBC, Bit4AccumulatorRelative);
Map(0x94, STY, ZeroPageX); Map(0x95, STA, ZeroPageX);
Map(0x96, STX, ZeroPageX); Map(0x97, BBC, Bit4ZeroPageRelative);
Map(0x98, TYA, Implied); Map(0x99, STA, AbsoluteY);
Map(0x9a, TXS, AbsoluteY); Map(0x9b, CLB, Bit4Accumulator);
Map(0x9d, ADC, AbsoluteX);
Map(0x9f, CLB, Bit4ZeroPage);
/* 0xa0 0xaf */
Map(0xa0, LDY, Immediate); Map(0xa1, LDA, XIndirect);
Map(0xa2, LDX, Immediate); Map(0xa3, BBS, Bit5AccumulatorRelative);
Map(0xa4, LDY, ZeroPage); Map(0xa5, LDA, ZeroPage);
Map(0xa6, LDX, ZeroPage); Map(0xa7, BBS, Bit5ZeroPageRelative);
Map(0xa8, TAY, Implied); Map(0xa9, LDA, Immediate);
Map(0xaa, TAX, Implied); Map(0xab, SEB, Bit5Accumulator);
Map(0xac, LDY, Absolute); Map(0xad, LDA, Absolute);
Map(0xae, LDX, Absolute); Map(0xaf, SEB, Bit5ZeroPage);
/* 0xb0 0xbf */
Map(0xb0, BCS, Relative); Map(0xb1, STA, IndirectY);
Map(0xb2, JMP, ZeroPageIndirect); Map(0xb3, BBC, Bit5AccumulatorRelative);
Map(0xb4, LDY, ZeroPageX); Map(0xb5, LDA, ZeroPageX);
Map(0xb6, LDX, ZeroPageY); Map(0xb7, BBC, Bit5ZeroPageRelative);
Map(0xb8, CLV, Implied); Map(0xb9, LDA, AbsoluteY);
Map(0xba, TSX, AbsoluteY); Map(0xbb, CLB, Bit5Accumulator);
Map(0xbc, LDY, AbsoluteX); Map(0xbd, LDA, AbsoluteX);
Map(0xbe, LDX, AbsoluteY); Map(0xbf, CLB, Bit5ZeroPage);
/* 0xc0 0xcf */
Map(0xc0, CPY, Immediate); Map(0xc1, CMP, XIndirect);
Map(0xc2, SLW, Implied); Map(0xc3, BBS, Bit6AccumulatorRelative);
Map(0xc4, CPY, ZeroPage); Map(0xc5, CMP, ZeroPage);
Map(0xc6, DEC, ZeroPage); Map(0xc7, BBS, Bit6ZeroPageRelative);
Map(0xc8, INY, Implied); Map(0xc9, CMP, Immediate);
Map(0xca, DEX, Implied); Map(0xcb, SEB, Bit6Accumulator);
Map(0xcc, CPY, Absolute); Map(0xcd, CMP, Absolute);
Map(0xce, DEC, Absolute); Map(0xcf, SEB, Bit6ZeroPage);
/* 0xd0 0xdf */
Map(0xd0, BNE, Relative); Map(0xd1, CMP, IndirectY);
Map(0xd3, BBC, Bit6AccumulatorRelative);
Map(0xd5, CMP, ZeroPageX);
Map(0xd6, DEC, ZeroPageX); Map(0xd7, BBC, Bit6ZeroPageRelative);
Map(0xd8, CLD, Implied); Map(0xd9, CMP, AbsoluteY);
Map(0xdb, CLB, Bit6Accumulator);
Map(0xdd, CMP, AbsoluteX);
Map(0xde, DEC, AbsoluteX); Map(0xdf, CLB, Bit6ZeroPage);
/* 0xe0 0xef */
Map(0xe0, CPX, Immediate); Map(0xe1, SBC, XIndirect);
Map(0xe2, FST, Implied); Map(0xe3, BBS, Bit7AccumulatorRelative);
Map(0xe4, CPX, ZeroPage); Map(0xe5, SBC, ZeroPage);
Map(0xe6, INC, ZeroPage); Map(0xe7, BBS, Bit7ZeroPageRelative);
Map(0xe8, INX, Implied); Map(0xe9, SBC, Immediate);
Map(0xea, NOP, Implied); Map(0xeb, SEB, Bit7Accumulator);
Map(0xec, CPX, Absolute); Map(0xed, SBC, Absolute);
Map(0xee, INC, Absolute); Map(0xef, SEB, Bit7ZeroPage);
/* 0xf0 0xff */
Map(0xf0, BEQ, Relative); Map(0xf1, SBC, IndirectY);
Map(0xf3, BBC, Bit7AccumulatorRelative);
Map(0xf5, SBC, ZeroPageX);
Map(0xf6, INC, ZeroPageX); Map(0xf7, BBC, Bit7ZeroPageRelative);
Map(0xf8, SED, Implied); Map(0xf9, SBC, AbsoluteY);
Map(0xfb, CLB, Bit7Accumulator);
Map(0xfd, SBC, AbsoluteX);
Map(0xfe, INC, AbsoluteX); Map(0xff, CLB, Bit7ZeroPage);
#undef Map
// Determine the instruction in hand, and finish now if its undefined.
instr_ = instrucion_for_opcode(instruction);
if(instr_.operation == Operation::Invalid) {
consumed_ = 0;
return std::make_pair(1, instr_);
}
// Obtain an operand size and roll onto the correct phase.
operand_size_ = size(instr_.addressing_mode);
phase_ = operand_size_ ? Phase::AwaitingOperand : Phase::ReadyToPost;
operand_bytes_ = 0;
@ -266,6 +274,7 @@ std::pair<int, InstructionSet::M50740::Instruction> Decoder::decode(const uint8_
return result;
}
// Decoding didn't complete, without it being clear how many more bytes are required.
return std::make_pair(0, Instruction());
}

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@ -20,6 +20,7 @@ namespace M50740 {
class Decoder {
public:
std::pair<int, Instruction> decode(const uint8_t *source, size_t length);
Instruction instrucion_for_opcode(uint8_t opcode);
private:
enum class Phase {

View File

@ -10,12 +10,18 @@
using namespace InstructionSet::M50740;
Executor::Executor() {
// Cut down the list of all generated performers to those the processor actually uses, and install that
// for future referencing by action_for.
Decoder decoder;
for(size_t c = 0; c < 256; c++) {
const auto instruction = decoder.instrucion_for_opcode(uint8_t(c));
performers_[c] = performer_lookup_.performer(instruction.operation, instruction.addressing_mode);
}
}
template <Operation operation> void Executor::perform(uint8_t *operand [[maybe_unused]]) {
}
template <Operation operation, AddressingMode addressing_mode> void Executor::perform(Executor *) {
}
Action Executor::action_for(Instruction instruction) {
return Action(performer_lookup_.performer(instruction.operation, instruction.addressing_mode));
}

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@ -31,20 +31,23 @@ struct Action {
class Executor: public CachingExecutor<Executor, 0x2000, 256, false> {
public:
Executor();
private:
// MARK: - CachingExecutor-facing interface.
friend CachingExecutor<Executor, 0x2000, 256, false>;
Action action_for(Instruction);
/*!
Performs @c operation using @c operand as the value fetched from memory, if any.
Maps instructions to performers; called by the CachingExecutor and for this instruction set, extremely trivial.
*/
template <Operation operation> static void perform(uint8_t *operand);
inline PerformerIndex action_for(Instruction instruction) {
// This is a super-simple processor, so the opcode can be used directly to index the performers.
return instruction.opcode;
}
/*!
Performs @c operation in @c addressing_mode.
*/
template <Operation operation, AddressingMode addressing_mode> static void perform(Executor *);
private:
// MARK: - Internal framework for generator performers.
/*!
Provides dynamic lookup of @c perform(Executor*).
@ -77,8 +80,20 @@ class Executor: public CachingExecutor<Executor, 0x2000, 256, false> {
}
}
};
inline static PerformerLookup performer_lookup_;
/*!
Performs @c operation using @c operand as the value fetched from memory, if any.
*/
template <Operation operation> static void perform(uint8_t *operand);
/*!
Performs @c operation in @c addressing_mode.
*/
template <Operation operation, AddressingMode addressing_mode> static void perform(Executor *);
private:
// MARK: - Instruction set state.
uint8_t memory_[0x2000];
};

View File

@ -116,9 +116,10 @@ constexpr AccessType access_type(Operation operation) {
struct Instruction {
Operation operation = Operation::Invalid;
AddressingMode addressing_mode = AddressingMode::Implied;
uint8_t opcode = 0;
Instruction(Operation operation, AddressingMode addressing_mode) : operation(operation), addressing_mode(addressing_mode) {}
Instruction(Operation operation) : operation(operation) {}
Instruction(Operation operation, AddressingMode addressing_mode, uint8_t opcode) : operation(operation), addressing_mode(addressing_mode), opcode(opcode) {}
Instruction(uint8_t opcode) : opcode(opcode) {}
Instruction() {}
};

View File

@ -4405,8 +4405,8 @@
4BEDA40925B2844B000C2DBD /* M50740 */ = {
isa = PBXGroup;
children = (
4BEDA42F25B3C700000C2DBD /* Executor.cpp */,
4BEDA40B25B2844B000C2DBD /* Decoder.cpp */,
4BEDA42F25B3C700000C2DBD /* Executor.cpp */,
4BEDA40A25B2844B000C2DBD /* Decoder.hpp */,
4BEDA42E25B3C613000C2DBD /* Executor.hpp */,
4BEDA41725B2845D000C2DBD /* Instruction.hpp */,