changes to pygen

src/spider/runtime/cpu/CPU.cpp

@@ -22,7 +22,7 @@ namespace spider {
           RE{}, RN{}, RV{}, RM{},
           ALU0{}, ALU1{},
         _dst(nullptr), _src(nullptr),
-        _instr(0), _addrm(0), _size(0),
+        _opcode(0), _addrm(0), _size(0),
         _store(0), _post(&CPU::imp),
         _ram(nullptr), _reel(nullptr) {
     }
@@ -67,7 +67,7 @@ namespace spider {
 
     void CPU::fetchInstr() {
         u16 i = _reel->readU16(RI);
-        _instr = (i >> 7) & 0x1FF;
+        _opcode = (i >> 7) & 0x1FF;
         _addrm = (i >> 2) & 0x1F;
         _size = i & 0x3;
         RI += 2;
@@ -79,7 +79,7 @@ namespace spider {
         _opers[1] = _opers[0];
 
         // call specific addressing mode
-        (this->*(CPU::addrModes[_addrm & 0x7]))();
+        (this->*(CPU::addrModes[_addrm]))();
     }
 
     void CPU::fetchOperSrc() {
@@ -87,13 +87,17 @@ namespace spider {
         _alu = &ALU1;
 
         // call specific addressing mode
-        (this->*(CPU::addrModes[_addrm & 0x7]))();
+        (this->*(CPU::addrModes[_addrm]))();
 
         // modify the _addrm register
         _addrm >>= 3;
         _addrm++;
     }
 
+    void CPU::execute() {
+        (this->*(CPU::addrModes[_opcode]))();
+    }
+
     // Addressing Modes //
 
     /**

src/spider/runtime/cpu/CPU.hpp

@@ -16,9 +16,10 @@ namespace spider {
         static constexpr const u64 FLAG_EXCEPTION         = 0b0000000000000000000000000000000000000000000000000000000000001000;
         static constexpr const u64 FLAG_MEMORY_MODE       = 0b0000000000000000000000000000000000000000000000000000000000110000;
 
-    public: // Map of addressing modes
+    public: // Map of addressing modes & Instructions
 
         static CPU::Fn addrModes[];
+        static CPU::Fn instrMap[];
 
     public: // General Purpose Registers
         union {
@@ -61,7 +62,7 @@ namespace spider {
         };
 
         // Holds the current instruction opcode
-        u16 _instr : 9;
+        u16 _opcode : 9;
 
         // Holds the current addressing modes,
         // before they were used
@@ -163,6 +164,23 @@ namespace spider {
          */
         void fetchOperSrc();
 
+        /**
+         * Executes an opcode, by means of directly
+         * accessing the instruction map and
+         * calling that function pointer.
+         */
+        void execute();
+
+        /**
+         * Executes an opcode, by means of using
+         * a large switch statement. Only suitable
+         * for environments where the instruction
+         * map is not possible.
+         * 
+         * This has yet to be proved!!!
+         */
+        void executeSwLk();
+
     public: // Addressing Modes
 
         /**
@@ -862,4 +880,4 @@ namespace spider {
 
     };
 
-}
+}

src/spider/runtime/instr/InstrMap.cpp

@@ -17,7 +17,7 @@
  *
  */
 
-#include "CPU.hpp"
+#include <spider/runtime/cpu/CPU.hpp>
 
 namespace spider {
 
@@ -25,18 +25,16 @@ namespace spider {
 //  Version 1 — Lookup table of member-function pointers
 // =============================================================
 
-/** Pointer-to-member type for a zero-argument CPU instruction. */
-using CPUInstr = void (CPU::*)();
 
 /**
  * Instruction dispatch table (512 entries, 9-bit opcode space).
  *
  * Usage:
  *     u16 opcode = fetch();
- *     CPUInstr fn = InstrMap[opcode];
+ *     CPU::Fn fn = InstrMap[opcode];
  *     if (fn) (cpu.*fn)();
  */
-CPUInstr InstrMap[512] = {
+CPU::Fn CPU::instrMap[] = {
     &CPU::NOP,                        // 0x000 — No Operation
     &CPU::SPDR,                       // 0x001 — Will place the Spider version of the interpreter in RA
     &CPU::MMODE,                      // 0x002 — Set Memory Mode
@@ -563,10 +561,10 @@ CPUInstr InstrMap[512] = {
  * but expressed as a switch so the compiler can choose the best
  * lowering strategy (jump table, binary search, etc.).
  *
- * @param opcode  9-bit instruction opcode (0x000 – 0x1FF).
+ * @param opcode  9-bit instruction opcode (0x000 - 0x1FF).
  */
-void CPU::execute(u16 opcode) {
-    switch (opcode) {
+void CPU::executeSwLk() {
+    switch (_opcode) {
 
     // ── System ──────────────────────────────────────
     case 0x000:  NOP();  break;