diff --git a/include/c64/cia.h b/include/c64/cia.h
index 0578fd3..e4cd00c 100644
--- a/include/c64/cia.h
+++ b/include/c64/cia.h
@@ -14,8 +14,8 @@ struct CIA
 	byte	cra, crb;
 };
 
-#define cia1	(*((CIA *)0xdc00))
-#define cia2	(*((CIA *)0xdd00))
+#define cia1	(*((struct CIA *)0xdc00))
+#define cia2	(*((struct CIA *)0xdd00))
 
 #endif
 
diff --git a/include/c64/rasterirq.h b/include/c64/rasterirq.h
index 1fb9f65..6ec4171 100644
--- a/include/c64/rasterirq.h
+++ b/include/c64/rasterirq.h
@@ -26,11 +26,11 @@ enum RIRQCodeIndex
 	RIRQ_SIZE   = 31
 };
 
-struct RIRQCode
+typedef struct RIRQCode
 {	
 	byte		size;
 	byte		code[RIRQ_SIZE];
-};
+} RIRQCode;
 
 void rirq_build(RIRQCode * ic, byte size);
 
diff --git a/include/c64/vic.h b/include/c64/vic.h
index a245d32..4d8b3ff 100644
--- a/include/c64/vic.h
+++ b/include/c64/vic.h
@@ -75,7 +75,7 @@ struct VIC
 
 void vic_setbank(char bank);
 
-#define vic	(*((VIC *)0xd000))
+#define vic	(*((struct VIC *)0xd000))
 
 #pragma compile("vic.c")
 
diff --git a/oscar64/NativeCodeGenerator.cpp b/oscar64/NativeCodeGenerator.cpp
index cac281c..65524e0 100644
--- a/oscar64/NativeCodeGenerator.cpp
+++ b/oscar64/NativeCodeGenerator.cpp
@@ -7068,6 +7068,29 @@ bool NativeCodeBasicBlock::MoveAbsoluteLoadStoreUp(int at)
 	return false;
 }
 
+bool NativeCodeBasicBlock::MoveStoreXUp(int at)
+{
+	bool	done = false;
+
+	while (at > 0)
+	{
+		if (mIns[at - 1].ChangesXReg())
+			return done;
+		if ((mIns[at - 1].mMode == ASMIM_ZERO_PAGE || mIns[at - 1].mMode == ASMIM_INDIRECT_Y) && mIns[at - 1].mAddress == mIns[at].mAddress)
+			return done;
+		if (mIns[at - 1].mMode == ASMIM_INDIRECT_Y && mIns[at - 1].mAddress == mIns[at].mAddress + 1)
+			return done;
+
+		NativeCodeInstruction	ins = mIns[at - 1];
+		mIns[at - 1] = mIns[at];
+		mIns[at] = ins; 
+		at--;
+		done = true;
+	}
+
+	return done;
+}
+
 bool NativeCodeBasicBlock::MoveLoadStoreUp(int at)
 {
 	int	j = at;
@@ -7621,6 +7644,9 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(void)
 		// shorten x/y register livetime
 
 #if 1
+		//
+		// move ldy down
+
 		for (int i = 0; i + 1 < mIns.Size(); i++)
 		{
 			if (mIns[i].mType == ASMIT_LDY && mIns[i].mMode == ASMIM_IMMEDIATE)
@@ -7635,6 +7661,19 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(void)
 		}
 #endif
 
+#if 1
+		// move stx up
+
+		for (int i = 1; i + 1 < mIns.Size(); i++)
+		{
+			if (mIns[i].mType == ASMIT_STX && mIns[i].mMode == ASMIM_ZERO_PAGE)
+			{
+				if (MoveStoreXUp(i))
+					changed = true;
+			}
+		}
+#endif
+
 		bool	progress = false;
 		do {
 			progress = false;
@@ -7853,6 +7892,34 @@ bool NativeCodeBasicBlock::PeepHoleOptimizer(void)
 						mIns[i + 0].mLive |= LIVE_CPU_REG_A;
 						progress = true;
 					}
+					else if (
+						mIns[i + 0].mType == ASMIT_TXA &&
+						mIns[i + 1].mType == ASMIT_STA && mIns[i + 1].mMode == ASMIM_ZERO_PAGE)
+					{
+						mIns[i + 1].mType = ASMIT_STX;
+						progress = true;
+					}
+					else if (
+						mIns[i + 0].mType == ASMIT_TYA &&
+						mIns[i + 1].mType == ASMIT_STA && mIns[i + 1].mMode == ASMIM_ZERO_PAGE)
+					{
+						mIns[i + 1].mType = ASMIT_STY;
+						progress = true;
+					}
+					else if (
+						mIns[i + 0].mType == ASMIT_TAX &&
+						mIns[i + 1].mType == ASMIT_STX && mIns[i + 1].mMode == ASMIM_ZERO_PAGE)
+					{
+						mIns[i + 1].mType = ASMIT_STA;
+						progress = true;
+					}
+					else if (
+						mIns[i + 0].mType == ASMIT_TAY &&
+						mIns[i + 1].mType == ASMIT_STY && mIns[i + 1].mMode == ASMIM_ZERO_PAGE)
+					{
+						mIns[i + 1].mType = ASMIT_STA;
+						progress = true;
+					}
 					else if (
 						(mIns[i + 0].mType == ASMIT_ASL || mIns[i + 0].mType == ASMIT_LSR || mIns[i + 0].mType == ASMIT_ROL || mIns[i + 0].mType == ASMIT_ROR) && mIns[i + 0].mMode == ASMIM_ZERO_PAGE &&
 						mIns[i + 1].mType == ASMIT_LDA && mIns[i + 1].mMode == ASMIM_ZERO_PAGE && mIns[i + 1].mAddress == mIns[i + 0].mAddress && !(mIns[i + 1].mLive & LIVE_MEM))
diff --git a/oscar64/NativeCodeGenerator.h b/oscar64/NativeCodeGenerator.h
index 65c7c46..8132610 100644
--- a/oscar64/NativeCodeGenerator.h
+++ b/oscar64/NativeCodeGenerator.h
@@ -166,6 +166,7 @@ public:
 	bool FindAddressSumY(int at, int reg, int & apos, int& breg, int& ireg);
 	bool FindGlobalAddress(int at, int reg, int& apos);
 	bool FindGlobalAddressSumY(int at, int reg, bool direct, int& apos, const NativeCodeInstruction * & ains, int& ireg);
+	bool MoveStoreXUp(int at);
 
 	bool ValueForwarding(const NativeRegisterDataSet& data);
 
diff --git a/oscar64/Parser.cpp b/oscar64/Parser.cpp
index c2ed6a0..3a04a23 100644
--- a/oscar64/Parser.cpp
+++ b/oscar64/Parser.cpp
@@ -33,16 +33,24 @@ Declaration* Parser::ParseStructDeclaration(uint32 flags, DecType dt)
 	{
 		structName = mScanner->mTokenIdent;
 		mScanner->NextToken();
-		Declaration* pdec = mScope->Insert(structName, dec);
-		if (pdec)
+		Declaration* edec = mScope->Lookup(structName);
+		if (edec && mScanner->mToken != TK_OPEN_BRACE)
 		{
-			if (pdec->mType == dt && (pdec->mFlags & DTF_DEFINED))
+			dec = edec;
+		}
+		else
+		{
+			Declaration* pdec = mScope->Insert(structName, dec);
+			if (pdec)
 			{
-				dec = pdec;
-			}
-			else
-			{
-				mErrors->Error(mScanner->mLocation, EERR_DUPLICATE_DEFINITION, "Error duplicate struct declaration", structName->mString);
+				if (pdec->mType == dt && (pdec->mFlags & DTF_DEFINED))
+				{
+					dec = pdec;
+				}
+				else
+				{
+					mErrors->Error(mScanner->mLocation, EERR_DUPLICATE_DEFINITION, "Error duplicate struct declaration", structName->mString);
+				}
 			}
 		}
 	}
@@ -745,7 +753,7 @@ Declaration* Parser::ParseDeclaration(bool variable)
 			if (ndec->mIdent)
 			{
 				Declaration* pdec = mScope->Insert(ndec->mIdent, ndec->mBase);
-				if (pdec)
+				if (pdec && pdec != ndec->mBase)
 					mErrors->Error(ndec->mLocation, EERR_DUPLICATE_DEFINITION, "Duplicate type declaration", ndec->mIdent->mString);
 			}
 		}