Simplify instruction comments and add default cases to switches

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

@@ -154,10 +154,7 @@ namespace spider {
         // TODO: Implement JIF
     }
 
-    /**
-     * 0x03C — Jump Relative.
-     * Adds a signed offset (Dst) to the instruction register.
-     */
+    // ── 0x03C — JMR: Dst + Instruction Register -> Instruction Register ──
     void CPU::JMR() {
         fetchOperDst();
         i64 offset;
@@ -170,10 +167,7 @@ namespace spider {
         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.
-     */
+    // ── 0x03D — JER: Dst + Instruction Register -> Instruction Register IF Flags.EQ ──
     void CPU::JER() {
         fetchOperDst();
         if (RF & CPU::FLAG_EQUAL) {
@@ -188,10 +182,7 @@ namespace spider {
         }
     }
 
-    /**
-     * 0x03E — Jump Relative if Not Equal.
-     * Adds a signed offset (Dst) to RI only if the Equal flag (bit 10) is cleared.
-     */
+    // ── 0x03E — JNR: Dst + Instruction Register -> Instruction Register IF NOT Flags.EQ ──
     void CPU::JNR() {
         fetchOperDst();
         if (!(RF & CPU::FLAG_EQUAL)) {
@@ -206,10 +197,7 @@ namespace spider {
         }
     }
 
-    /**
-     * 0x03F — Jump Relative if Src is true.
-     * Adds a signed offset (Dst) to RI only if Src is booleanly true (non-zero).
-     */
+    // ── 0x03F — JIR: Dst + Instruction Register -> Instruction Register IF Src ──
     void CPU::JIR() {
         fetchOperSrc();
         fetchOperDst();