(De)serialize operands pointer in CPU (#39)

kremi151 · Jan 2, 2021 · 5651182 · 5651182
1 parent 2cee6a1
commit 5651182
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Showing 4 changed files with 69 additions and 5 deletions.
diff --git a/core/source/emulator/cpu.cpp b/core/source/emulator/cpu.cpp
@@ -22,7 +22,9 @@
 #include <emulator/io_registers.h>
 #include <operands/registry.h>
 #include <operands/tables.h>
+#include <operands/prefix.h>
 #include <exception/read_exception.h>
+#include <exception/state_exception.h>
 
 using namespace FunkyBoy;
 
@@ -387,19 +389,66 @@ void CPU::writeAF(FunkyBoy::u16 val) {
 
 void CPU::serialize(std::ostream &ostream) const {
     instrContext.serialize(ostream);
+
+    const Operand *operandTable;
+    u8 operandIndex;
+    if (instrContext.instr == 0xCB) {
+        if (*operands == Operands::decodePrefix) {
+            operandIndex = 0;
+        } else if (*operands == Operands::prefixPlaceholder) {
+            operandIndex = 1;
+        } else {
+            operandTable = Operands::Tables::prefixInstructions[instrContext.cbInstr];
+            for (int i = 0 ;; i++) {
+                if (*(operandTable++) == *operands) {
+                    operandIndex = i + 2; // For Operands::decodePrefix and Operands::prefixPlaceholder
+                    break;
+                } else if (*operandTable == nullptr) {
+                    throw Exception::WrongStateException("Prefix operand index could not be determined");
+                }
+            }
+        }
+    } else {
+        operandTable = Operands::Tables::instructions[instrContext.instr];
+        for (int i = 0 ;; i++) {
+            if (*(operandTable++) == *operands) {
+                operandIndex = i;
+                break;
+            } else if (*operandTable == nullptr) {
+                throw Exception::WrongStateException("Operand index could not be determined");
+            }
+        }
+    }
+    ostream.put(operandIndex);
+
     ostream.put(timerOverflowingCycles);
     ostream.put(delayedTIMAIncrease);
     ostream.put(joypadWasNotPressed);
 }
 
 void CPU::deserialize(std::istream &istream) {
     instrContext.deserialize(istream);
-    char buffer[3];
+
+    char buffer[4];
     istream.read(buffer, sizeof(buffer));
     if (!istream) {
         throw Exception::ReadException("Stream is too short");
     }
-    timerOverflowingCycles = buffer[0];
-    delayedTIMAIncrease = buffer[1];
-    joypadWasNotPressed = buffer[2];
+
+    u8 operandIndex = buffer[0];
+    if (instrContext.instr == 0xCB) {
+        if (operandIndex == 0) {
+            operands = Operands::Tables::instructions[0xCB];
+        } else if (operandIndex == 1) {
+            operands = Operands::Tables::instructions[0xCB] + 1;
+        } else {
+            operands = Operands::Tables::prefixInstructions[instrContext.cbInstr] + (operandIndex - 2);
+        }
+    } else {
+        operands = Operands::Tables::instructions[instrContext.instr] + operandIndex;
+    }
+
+    timerOverflowingCycles = buffer[1];
+    delayedTIMAIncrease = buffer[2];
+    joypadWasNotPressed = buffer[3];
 }
diff --git a/core/source/operands/prefix.cpp b/core/source/operands/prefix.cpp
@@ -695,3 +695,8 @@ bool Operands::decodePrefix(InstrContext &context, Memory &memory) {
 #endif
     return true;
 }
+
+bool Operands::prefixPlaceholder(InstrContext &context, Memory &memory) {
+    // No-op
+    return true;
+}
diff --git a/core/source/operands/prefix.h b/core/source/operands/prefix.h
@@ -28,6 +28,14 @@ namespace FunkyBoy::Operands {
      */
     bool decodePrefix(InstrContext &context, Memory &memory);
 
+    /**
+     * No-operator as a placeholder for prefix operands to be fetched
+     * @param context
+     * @param memory
+     * @return
+     */
+    bool prefixPlaceholder(InstrContext &context, Memory &memory);
+
 }
 
 #endif //FB_CORE_OPERANDS_PREFIX_PREFIX_H
diff --git a/core/source/operands/registry.cpp b/core/source/operands/registry.cpp
@@ -552,7 +552,9 @@ namespace FunkyBoy::Operands::Registry {
 
     const Operand decodePrefix[3] = {
             Operands::decodePrefix,
-            Operands::nop, // This is a workaround, the decodePrefix operand will fetch the effective operand list to use
+            // This is a workaround, the decodePrefix operand will fetch the effective operand list to use
+            // When changing this, please also adapt CPU::serialize and CPU::deserialize
+            Operands::prefixPlaceholder,
             nullptr
     };
 }