Implement instructions 0x03C-0x053, add flag constants and fix execute dispatch

src/spider/runtime/Runtime.cpp

@@ -17,8 +17,10 @@ namespace spider {
     // Stepping/Running the Machine //
 
     void Runtime::step() {
+        // fetchInstr() decodes the opcode, addressing mode and type siz
         cpu.fetchInstr();
-        // TODO: Call instruction
+        // execute() completes the fetch-decode-execute cycle by calling the correct instruction method based on the opcode.
+        cpu.execute();
     }
 
     void Runtime::step(u64 n) {

src/spider/runtime/cpu/CPU.cpp

@@ -95,8 +95,12 @@ namespace spider {
         _addrm++;
     }
 
+    /**
+        instrMap[] is the correct 512-entry dispatch
+        table that maps operation codes to instruction methods.
+    */
     void CPU::execute() {
-        (this->*(CPU::addrModes[_opcode]))();
+        (this->*(CPU::instrMap[_opcode]))();
     }
 
     // Addressing Modes //

src/spider/runtime/cpu/CPU.hpp

@@ -15,6 +15,14 @@ namespace spider {
         static constexpr const u64 FLAG_INTERRUPT_REQUEST = 0b0000000000000000000000000000000000000000000000000000000000000100;
         static constexpr const u64 FLAG_EXCEPTION         = 0b0000000000000000000000000000000000000000000000000000000000001000;
         static constexpr const u64 FLAG_MEMORY_MODE       = 0b0000000000000000000000000000000000000000000000000000000000110000;
+        static constexpr const u64 FLAG_EXT_INT_DISABLE = 0b0000000000000000000000000000000000000000000000000000000010000000; // bit 7
+        static constexpr const u64 FLAG_EQUAL           = 0b0000000000000000000000000000000000000000000000000000010000000000; // bit 10
+        static constexpr const u64 FLAG_EPSILON_ENABLE  = 0b0000000000000000000000000000000000000000000000000001000000000000; // bit 12
+        static constexpr const u64 FLAG_HOTSWAP_SIGNAL  = 0b0000000000000000000000000000000000000000000000010000000000000000; // bit 16
+        static constexpr const u64 FLAG_USER_A          = 0b0000000000000000000000000000000000000000000100000000000000000000; // bit 20
+        static constexpr const u64 FLAG_USER_B          = 0b0000000000000000000000000000000000000000001000000000000000000000; // bit 21
+        static constexpr const u64 FLAG_USER_C          = 0b0000000000000000000000000000000000000000010000000000000000000000; // bit 22
+        static constexpr const u64 FLAG_USER_D          = 0b0000000000000000000000000000000000000000100000000000000000000000; // bit 23
 
     public: // Map of addressing modes & Instructions
 

src/spider/runtime/instr/Instr_020-03F.cpp

@@ -154,20 +154,75 @@ namespace spider {
         // TODO: Implement JIF
     }
 
+    /**
+     * 0x03C — Jump Relative.
+     * Adds a signed offset (Dst) to the instruction register.
+     */
     void CPU::JMR() {
-        // TODO: Implement JMR
+        fetchOperDst();
+        i64 offset;
+        switch (_size) {
+            case 0b00: offset = static_cast<i64>(_dst->_i8);  break; // 1 byte
+            case 0b01: offset = static_cast<i64>(_dst->_i16); break; // 2 bytes
+            case 0b10: offset = static_cast<i64>(_dst->_i32); break; // 4 bytes
+            case 0b11: offset = _dst->_i64;                   break; // 8 bytes
+        }
+        RI = static_cast<u64>(static_cast<i64>(RI) + offset);
     }
 
+    /**
+     * 0x03D — Jump Relative if Equal.
+     * Adds a signed offset (Dst) to RI only if the Equal flag (bit 10) is set.
+     */
     void CPU::JER() {
-        // TODO: Implement JER
+        fetchOperDst();
+        if (RF & CPU::FLAG_EQUAL) {
+            i64 offset;
+            switch (_size) {
+                case 0b00: offset = static_cast<i64>(_dst->_i8);  break;
+                case 0b01: offset = static_cast<i64>(_dst->_i16); break;
+                case 0b10: offset = static_cast<i64>(_dst->_i32); break;
+                case 0b11: offset = _dst->_i64;                   break;
+            }
+            RI = static_cast<u64>(static_cast<i64>(RI) + offset);
+        }
     }
 
+    /**
+     * 0x03E — Jump Relative if Not Equal.
+     * Adds a signed offset (Dst) to RI only if the Equal flag (bit 10) is cleared.
+     */
     void CPU::JNR() {
-        // TODO: Implement JNR
+        fetchOperDst();
+        if (!(RF & CPU::FLAG_EQUAL)) {
+            i64 offset;
+            switch (_size) {
+                case 0b00: offset = static_cast<i64>(_dst->_i8);  break;
+                case 0b01: offset = static_cast<i64>(_dst->_i16); break;
+                case 0b10: offset = static_cast<i64>(_dst->_i32); break;
+                case 0b11: offset = _dst->_i64;                   break;
+            }
+            RI = static_cast<u64>(static_cast<i64>(RI) + offset);
+        }
     }
 
+    /**
+     * 0x03F — Jump Relative if Src is true.
+     * Adds a signed offset (Dst) to RI only if Src is booleanly true (non-zero).
+     */
     void CPU::JIR() {
-        // TODO: Implement JIR
+        fetchOperSrc();
+        fetchOperDst();
+        if (_src->_u64 != 0) {
+            i64 offset;
+            switch (_size) {
+                case 0b00: offset = static_cast<i64>(_dst->_i8);  break;
+                case 0b01: offset = static_cast<i64>(_dst->_i16); break;
+                case 0b10: offset = static_cast<i64>(_dst->_i32); break;
+                case 0b11: offset = _dst->_i64;                   break;
+            }
+            RI = static_cast<u64>(static_cast<i64>(RI) + offset);
+        }
     }
 
 }

src/spider/runtime/instr/Instr_040-05F.cpp

@@ -4,71 +4,224 @@
  */
 
 #include <spider/runtime/cpu/CPU.hpp>
+#include <spider/runtime/memory/RAM.hpp>
 
 namespace spider {
 
+// ── 0x040 — SFB: Store (User) Flag Bit ─────────────────────────────
+    //   bool(Src) -> User Flag at index (Dst & 0x3)
+    //   Flags A-D are bits 20-23 of RF.
     void CPU::SFB() {
-        // TODO: Implement SFB
+        fetchOperSrc();
+        fetchOperDst();
+        u8 flag_idx = _dst->_u8 & 0x3;
+        u64 flag_bit = CPU::FLAG_USER_A << flag_idx;
+        if (_src->_u64 != 0) {
+            RF |= flag_bit;
+        } else {
+            RF &= ~flag_bit;
+        }
     }
 
+    // ── 0x041 — LFB: Load (User) Flag Bit ──────────────────────────────
+    //   User Flag at index (Src & 0x3) -> Dst
     void CPU::LFB() {
-        // TODO: Implement LFB
+        fetchOperSrc();
+        fetchOperDst();
+        u8 flag_idx = _src->_u8 & 0x3;
+        u64 flag_bit = CPU::FLAG_USER_A << flag_idx;
+        _dst->_u64 = (RF & flag_bit) ? 1 : 0;
+        (this->*_post)();
     }
 
+    // ── 0x042 — JUF: Jump absolute if User Flag is true ────────────────
+    //   Dst -> RI  IF User Flag at index (Src & 0x3) is set
     void CPU::JUF() {
-        // TODO: Implement JUF
+        fetchOperSrc();
+        fetchOperDst();
+        u8 flag_idx = _src->_u8 & 0x3;
+        u64 flag_bit = CPU::FLAG_USER_A << flag_idx;
+        if (RF & flag_bit) {
+            RI = _dst->_u64;
+        }
     }
 
+    // ── 0x043 — JUR: Jump relative if User Flag is true ────────────────
+    //   Dst + RI -> RI  IF User Flag at index (Src & 0x3) is set
     void CPU::JUR() {
-        // TODO: Implement JUR
+        fetchOperSrc();
+        fetchOperDst();
+        u8 flag_idx = _src->_u8 & 0x3;
+        u64 flag_bit = CPU::FLAG_USER_A << flag_idx;
+        if (RF & flag_bit) {
+            i64 offset;
+            switch (_size) {
+                case 0b00: offset = static_cast<i64>(_dst->_i8);  break;
+                case 0b01: offset = static_cast<i64>(_dst->_i16); break;
+                case 0b10: offset = static_cast<i64>(_dst->_i32); break;
+                case 0b11: offset = _dst->_i64;                   break;
+            }
+            RI = static_cast<u64>(static_cast<i64>(RI) + offset);
+        }
     }
 
+    // ── 0x044 — PUSH: Push to stack ─────────────────────────────────────
+    //   Dst -> RAM[RS],  RS += (1 << _size)
+    //   The stack grows upward from the bottom of memory.
     void CPU::PUSH() {
-        // TODO: Implement PUSH
+        fetchOperDst();
+        u8 bytes = 1 << _size;
+        for (u8 i = 0; i < bytes; i++) {
+            _ram->at(RS + i) = (*_dst)[i];
+        }
+        RS += bytes;
     }
 
+    // ── 0x045 — POP: Pop from stack ─────────────────────────────────────
+    //   RS -= (1 << _size),  RAM[RS] -> Dst
     void CPU::POP() {
-        // TODO: Implement POP
+        fetchOperDst();
+        u8 bytes = 1 << _size;
+        RS -= bytes;
+        _ram->loadRegister(RS, _size, _dst);
+        (this->*_post)();
     }
 
+    // ── 0x046 — ALLOC: Allocate to heap ─────────────────────────────────
+    //   Stub: returns 0 (null) until proper heap management is implemented.
     void CPU::ALLOC() {
-        // TODO: Implement ALLOC
+        fetchOperDst();
+        // TODO: Proper heap allocation with gap tracking.
+        _dst->_u64 = 0;
+        (this->*_post)();
     }
 
+    // ── 0x047 — HFREE: Delete from heap ─────────────────────────────────
+    //   Stub: no-op until proper heap management is implemented.
     void CPU::HFREE() {
-        // TODO: Implement HFREE
+        fetchOperDst();
+        // TODO: Proper heap deallocation.
     }
 
+    //────────────────────────────────────────────────────────
+
+    // ── 0x04A — CALL: Call function at instruction index ────────────────
+    //   Minimal version: saves RZ and RI to the stack,
+    //   updates the stack base, then jumps to Dst.
+    //   The calling convention (parameter passing, caller-saved
+    //   registers) is the compiler's responsibility.
     void CPU::CALL() {
-        // TODO: Implement CALL
+        fetchOperDst();
+        u64 target = _dst->_u64;
+
+        // Push old stack base (RZ) — always 8 bytes
+        register_t rz_save;
+        rz_save._u64 = RZ;
+        for (u8 i = 0; i < 8; i++) {
+            _ram->at(RS + i) = rz_save[i];
+        }
+        RS += 8;
+
+        // Push return address (RI) — always 8 bytes
+        register_t ri_save;
+        ri_save._u64 = RI;
+        for (u8 i = 0; i < 8; i++) {
+            _ram->at(RS + i) = ri_save[i];
+        }
+        RS += 8;
+
+        // New stack base is the current stack top
+        RZ = RS;
+
+        // Jump to target
+        RI = target;
     }
 
+    // ── 0x04B — RET: Return from a function ─────────────────────────────
+    //   Undoes what CALL did: restores RI and RZ from the stack.
     void CPU::RET() {
-        // TODO: Implement RET
+        // Wind the stack back to the current frame base
+        RS = RZ;
+
+        // Pop return address
+        RS -= 8;
+        register_t ri_restore;
+        _ram->loadRegister(RS, 0b11, &ri_restore);
+        RI = ri_restore._u64;
+
+        // Pop previous stack base
+        RS -= 8;
+        register_t rz_restore;
+        _ram->loadRegister(RS, 0b11, &rz_restore);
+        RZ = rz_restore._u64;
     }
 
+    // ── 0x04C — EDI: Enable/Disable External Interrupts ────────────────
+    //   bool(Dst) == true  -> enable  (clear the disable bit)
+    //   bool(Dst) == false -> disable (set the disable bit)
     void CPU::EDI() {
-        // TODO: Implement EDI
+        fetchOperDst();
+        if (_dst->_u64 != 0) {
+            RF &= ~CPU::FLAG_EXT_INT_DISABLE;
+        } else {
+            RF |= CPU::FLAG_EXT_INT_DISABLE;
+        }
     }
 
+    // ── 0x04D — SHSS: Set Hotswap Signal Bit ────────────────────────────
+    //   bool(Dst) -> Hotswap Signal flag (bit 16 of RF)
     void CPU::SHSS() {
-        // TODO: Implement SHSS
+        fetchOperDst();
+        if (_dst->_u64 != 0) {
+            RF |= CPU::FLAG_HOTSWAP_SIGNAL;
+        } else {
+            RF &= ~CPU::FLAG_HOTSWAP_SIGNAL;
+        }
     }
 
+    //────────────────────────────────────────────────────────────────────────────────────
+
+    // ── 0x050 — FLI: Float Load Immediate ───────────────────────────────
+    //   The addressing mode already loads the raw bytes into Dst.
+    //   _size == 0b10 for f32, 0b11 for f64.
     void CPU::FLI() {
-        // TODO: Implement FLI
+        fetchOperDst();
+        (this->*_post)();
     }
 
+    // ── 0x051 — FNEG: Float negate ──────────────────────────────────────
+    //   -Dst -> Dst
     void CPU::FNEG() {
-        // TODO: Implement FNEG
+        fetchOperDst();
+        switch (_size) {
+            case 0b10: _dst->_f32 = -_dst->_f32; break;
+            case 0b11: _dst->_f64 = -_dst->_f64; break;
+        }
+        (this->*_post)();
     }
 
+    // ── 0x052 — FADD: Float add ─────────────────────────────────────────
+    //   Dst + Src -> Dst
     void CPU::FADD() {
-        // TODO: Implement FADD
+        fetchOperSrc();
+        fetchOperDst();
+        switch (_size) {
+            case 0b10: _dst->_f32 += _src->_f32; break;
+            case 0b11: _dst->_f64 += _src->_f64; break;
+        }
+        (this->*_post)();
     }
 
+    // ── 0x053 — FSUB: Float subtract ────────────────────────────────────
+    //   Dst - Src -> Dst
     void CPU::FSUB() {
-        // TODO: Implement FSUB
+        fetchOperSrc();
+        fetchOperDst();
+        switch (_size) {
+            case 0b10: _dst->_f32 -= _src->_f32; break;
+            case 0b11: _dst->_f64 -= _src->_f64; break;
+        }
+        (this->*_post)();
     }
 
     void CPU::FMUL() {