diff --git a/src/Common/Types.hpp b/src/Common/Types.hpp
index 837df46..fac6d36 100644
--- a/src/Common/Types.hpp
+++ b/src/Common/Types.hpp
@@ -15,6 +15,7 @@
 #ifndef sw_Types_hpp
 #define sw_Types_hpp
 
+#include <assert.h>
 #include <limits>
 #include <type_traits>
 
@@ -151,6 +152,46 @@
 		return v;
 	}
 
+	template <int limit> class BoundedIndex
+	{
+	public:
+		BoundedIndex(int index) : index(index) {}
+
+		inline int operator++(int) { return index++; }
+		inline int operator--(int) { return index--; }
+		inline void operator=(int i) { index = i; }
+
+		inline bool operator==(int i) { return index == i; }
+		inline bool operator!=(int i) { return index != i; }
+		inline bool operator<(int i) { return index < i; }
+		inline bool operator>(int i) { return index > i; }
+		inline bool operator<=(int i) { return index <= i; }
+		inline bool operator>=(int i) { return index >= i; }
+
+		inline operator int()
+		{
+			if(index < 0)
+			{
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+				assert(false);
+#endif
+				return 0;
+			}
+			else if(index >= limit)
+			{
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+				assert(false);
+#endif
+				return limit - 1;
+			}
+
+			return index;
+		}
+
+	private:
+		int index = 0;
+	};
+
 	// The OFFSET macro is a generalization of the offsetof() macro defined in <cstddef>.
 	// It allows e.g. getting the offset of array elements, even when indexed dynamically.
 	// We cast the address '32' and subtract it again, because null-dereference is undefined behavior.
diff --git a/src/Main/Config.hpp b/src/Main/Config.hpp
index 017e38b..d2ba6ff 100644
--- a/src/Main/Config.hpp
+++ b/src/Main/Config.hpp
@@ -97,6 +97,11 @@
 		MAX_TEXTURE_LOD = MIPMAP_LEVELS - 2,   // Trilinear accesses lod+1
 		RENDERTARGETS = 8,
 		NUM_TEMPORARY_REGISTERS = 4096,
+		MAX_SHADER_CALL_SITES = 2048,
+		MAX_SHADER_NESTED_LOOPS = 4,
+		MAX_SHADER_NESTED_IFS = 24 + 24,
+		MAX_SHADER_CALL_STACK_SIZE = 16,
+		MAX_SHADER_ENABLE_STACK_SIZE = 1 + 24,
 	};
 }
 
diff --git a/src/Shader/PixelProgram.cpp b/src/Shader/PixelProgram.cpp
index 671b0ef..bc879a3 100644
--- a/src/Shader/PixelProgram.cpp
+++ b/src/Shader/PixelProgram.cpp
@@ -838,7 +838,7 @@
 			return Int4(0xFFFFFFFF);
 		}
 
-		Int4 enable = instruction->analysisBranch ? Int4(enableStack[enableIndex]) : Int4(0xFFFFFFFF);
+		Int4 enable = instruction->analysisBranch ? Int4(enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))]) : Int4(0xFFFFFFFF);
 
 		if(shader->containsBreakInstruction() && instruction->analysisBreak)
 		{
@@ -1353,7 +1353,7 @@
 
 	void PixelProgram::BREAK()
 	{
-		enableBreak = enableBreak & ~enableStack[enableIndex];
+		enableBreak = enableBreak & ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 	}
 
 	void PixelProgram::BREAKC(Vector4f &src0, Vector4f &src1, Control control)
@@ -1389,14 +1389,14 @@
 
 	void PixelProgram::BREAK(Int4 &condition)
 	{
-		condition &= enableStack[enableIndex];
+		condition &= enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		enableBreak = enableBreak & ~condition;
 	}
 
 	void PixelProgram::CONTINUE()
 	{
-		enableContinue = enableContinue & ~enableStack[enableIndex];
+		enableContinue = enableContinue & ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 	}
 
 	void PixelProgram::TEST()
@@ -1419,7 +1419,7 @@
 
 		if(callRetBlock[labelIndex].size() > 1)
 		{
-			callStack[stackIndex++] = UInt(callSiteIndex);
+			callStack[Min(stackIndex++, Int(MAX_SHADER_CALL_STACK_SIZE))] = UInt(callSiteIndex);
 		}
 
 		Int4 restoreLeave = enableLeave;
@@ -1459,7 +1459,7 @@
 
 		if(callRetBlock[labelIndex].size() > 1)
 		{
-			callStack[stackIndex++] = UInt(callSiteIndex);
+			callStack[Min(stackIndex++, Int(MAX_SHADER_CALL_STACK_SIZE))] = UInt(callSiteIndex);
 		}
 
 		Int4 restoreLeave = enableLeave;
@@ -1479,7 +1479,7 @@
 			condition = ~condition;
 		}
 
-		condition &= enableStack[enableIndex];
+		condition &= enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		if(!labelBlock[labelIndex])
 		{
@@ -1488,11 +1488,11 @@
 
 		if(callRetBlock[labelIndex].size() > 1)
 		{
-			callStack[stackIndex++] = UInt(callSiteIndex);
+			callStack[Min(stackIndex++, Int(MAX_SHADER_CALL_STACK_SIZE))] = UInt(callSiteIndex);
 		}
 
 		enableIndex++;
-		enableStack[enableIndex] = condition;
+		enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = condition;
 		Int4 restoreLeave = enableLeave;
 
 		Bool notAllFalse = SignMask(condition) != 0;
@@ -1512,12 +1512,12 @@
 
 		if(isConditionalIf[ifDepth])
 		{
-			Int4 condition = ~enableStack[enableIndex] & enableStack[enableIndex - 1];
+			Int4 condition = ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] & enableStack[Min(enableIndex - 1, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 			Bool notAllFalse = SignMask(condition) != 0;
 
 			branch(notAllFalse, falseBlock, endBlock);
 
-			enableStack[enableIndex] = ~enableStack[enableIndex] & enableStack[enableIndex - 1];
+			enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] & enableStack[Min(enableIndex - 1, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 		}
 		else
 		{
@@ -1671,10 +1671,10 @@
 
 	void PixelProgram::IF(Int4 &condition)
 	{
-		condition &= enableStack[enableIndex];
+		condition &= enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		enableIndex++;
-		enableStack[enableIndex] = condition;
+		enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = condition;
 
 		BasicBlock *trueBlock = Nucleus::createBasicBlock();
 		BasicBlock *falseBlock = Nucleus::createBasicBlock();
@@ -1778,10 +1778,10 @@
 
 		const Vector4f &src = fetchRegister(temporaryRegister);
 		Int4 condition = As<Int4>(src.x);
-		condition &= enableStack[enableIndex - 1];
+		condition &= enableStack[Min(enableIndex - 1, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 		if(shader->containsLeaveInstruction()) condition &= enableLeave;
 		if(shader->containsBreakInstruction()) condition &= enableBreak;
-		enableStack[enableIndex] = condition;
+		enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = condition;
 
 		Bool notAllFalse = SignMask(condition) != 0;
 		branch(notAllFalse, loopBlock, endBlock);
@@ -1854,7 +1854,7 @@
 
 	void PixelProgram::LEAVE()
 	{
-		enableLeave = enableLeave & ~enableStack[enableIndex];
+		enableLeave = enableLeave & ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		// FIXME: Return from function if all instances left
 		// FIXME: Use enableLeave in other control-flow constructs
diff --git a/src/Shader/PixelProgram.hpp b/src/Shader/PixelProgram.hpp
index 3c3a06f..b8548d7 100644
--- a/src/Shader/PixelProgram.hpp
+++ b/src/Shader/PixelProgram.hpp
@@ -26,7 +26,7 @@
 		PixelProgram(const PixelProcessor::State &state, const PixelShader *shader) :
 			PixelRoutine(state, shader), r(shader->indirectAddressableTemporaries)
 		{
-			for(int i = 0; i < 2048; ++i)
+			for(int i = 0; i < MAX_SHADER_CALL_SITES; ++i)
 			{
 				labelBlock[i] = 0;
 			}
@@ -67,17 +67,17 @@
 
 		// DX9 specific variables
 		Vector4f p0;
-		Array<Int, 4> aL;
-		Array<Int, 4> increment;
-		Array<Int, 4> iteration;
+		Array<Int, MAX_SHADER_NESTED_LOOPS> aL;
+		Array<Int, MAX_SHADER_NESTED_LOOPS> increment;
+		Array<Int, MAX_SHADER_NESTED_LOOPS> iteration;
 
 		Int loopDepth;    // FIXME: Add support for switch
 		Int stackIndex;   // FIXME: Inc/decrement callStack
-		Array<UInt, 16> callStack;
+		Array<UInt, MAX_SHADER_CALL_STACK_SIZE> callStack;
 
 		// Per pixel based on conditions reached
 		Int enableIndex;
-		Array<Int4, 1 + 24> enableStack;
+		Array<Int4, MAX_SHADER_ENABLE_STACK_SIZE> enableStack;
 		Int4 enableBreak;
 		Int4 enableContinue;
 		Int4 enableLeave;
@@ -153,18 +153,18 @@
 		void RET();
 		void LEAVE();
 
-		int ifDepth = 0;
-		int loopRepDepth = 0;
-		int currentLabel = -1;
+		BoundedIndex<MAX_SHADER_NESTED_IFS> ifDepth = 0;
+		BoundedIndex<MAX_SHADER_NESTED_LOOPS> loopRepDepth = 0;
+		BoundedIndex<MAX_SHADER_CALL_SITES> currentLabel = -1;
 		bool scalar = false;
 
-		BasicBlock *ifFalseBlock[24 + 24];
-		BasicBlock *loopRepTestBlock[4];
-		BasicBlock *loopRepEndBlock[4];
-		BasicBlock *labelBlock[2048];
-		std::vector<BasicBlock*> callRetBlock[2048];
+		BasicBlock *ifFalseBlock[MAX_SHADER_NESTED_IFS];
+		BasicBlock *loopRepTestBlock[MAX_SHADER_NESTED_LOOPS];
+		BasicBlock *loopRepEndBlock[MAX_SHADER_NESTED_LOOPS];
+		BasicBlock *labelBlock[MAX_SHADER_CALL_SITES];
+		std::vector<BasicBlock*> callRetBlock[MAX_SHADER_CALL_SITES];
 		BasicBlock *returnBlock;
-		bool isConditionalIf[24 + 24];
+		bool isConditionalIf[MAX_SHADER_NESTED_IFS];
 		std::vector<Int4> restoreContinue;
 	};
 }
diff --git a/src/Shader/Shader.cpp b/src/Shader/Shader.cpp
index 36192c9..0e06703 100644
--- a/src/Shader/Shader.cpp
+++ b/src/Shader/Shader.cpp
@@ -1877,13 +1877,13 @@
 	// This is used to know what basic block to return to.
 	void Shader::analyzeCallSites()
 	{
-		int callSiteIndex[2048] = {0};
+		int callSiteIndex[MAX_SHADER_CALL_SITES] = {0};
 
 		for(auto &inst : instruction)
 		{
 			if(inst->opcode == OPCODE_CALL || inst->opcode == OPCODE_CALLNZ)
 			{
-				int label = inst->dst.label;
+				int label = sw::min(inst->dst.label, unsigned int(MAX_SHADER_CALL_SITES));
 
 				inst->dst.callSite = callSiteIndex[label]++;
 			}
diff --git a/src/Shader/VertexProgram.cpp b/src/Shader/VertexProgram.cpp
index bde7531..05f8dfb 100644
--- a/src/Shader/VertexProgram.cpp
+++ b/src/Shader/VertexProgram.cpp
@@ -26,7 +26,7 @@
 	VertexProgram::VertexProgram(const VertexProcessor::State &state, const VertexShader *shader)
 		: VertexRoutine(state, shader), shader(shader), r(shader->indirectAddressableTemporaries)
 	{
-		for(int i = 0; i < 2048; i++)
+		for(int i = 0; i < MAX_SHADER_CALL_SITES; i++)
 		{
 			labelBlock[i] = 0;
 		}
@@ -979,7 +979,7 @@
 			return Int4(0xFFFFFFFF);
 		}
 
-		Int4 enable = instruction->analysisBranch ? Int4(enableStack[enableIndex]) : Int4(0xFFFFFFFF);
+		Int4 enable = instruction->analysisBranch ? Int4(enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))]) : Int4(0xFFFFFFFF);
 
 		if(shader->containsBreakInstruction() && instruction->analysisBreak)
 		{
@@ -1058,7 +1058,7 @@
 
 	void VertexProgram::BREAK()
 	{
-		enableBreak = enableBreak & ~enableStack[enableIndex];
+		enableBreak = enableBreak & ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 	}
 
 	void VertexProgram::BREAKC(Vector4f &src0, Vector4f &src1, Control control)
@@ -1094,14 +1094,14 @@
 
 	void VertexProgram::BREAK(Int4 &condition)
 	{
-		condition &= enableStack[enableIndex];
+		condition &= enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		enableBreak = enableBreak & ~condition;
 	}
 
 	void VertexProgram::CONTINUE()
 	{
-		enableContinue = enableContinue & ~enableStack[enableIndex];
+		enableContinue = enableContinue & ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 	}
 
 	void VertexProgram::TEST()
@@ -1124,7 +1124,7 @@
 
 		if(callRetBlock[labelIndex].size() > 1)
 		{
-			callStack[stackIndex++] = UInt(callSiteIndex);
+			callStack[Min(stackIndex++, Int(MAX_SHADER_CALL_STACK_SIZE))] = UInt(callSiteIndex);
 		}
 
 		Int4 restoreLeave = enableLeave;
@@ -1164,7 +1164,7 @@
 
 		if(callRetBlock[labelIndex].size() > 1)
 		{
-			callStack[stackIndex++] = UInt(callSiteIndex);
+			callStack[Min(stackIndex++, Int(MAX_SHADER_CALL_STACK_SIZE))] = UInt(callSiteIndex);
 		}
 
 		Int4 restoreLeave = enableLeave;
@@ -1184,7 +1184,7 @@
 			condition = ~condition;
 		}
 
-		condition &= enableStack[enableIndex];
+		condition &= enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		if(!labelBlock[labelIndex])
 		{
@@ -1193,11 +1193,11 @@
 
 		if(callRetBlock[labelIndex].size() > 1)
 		{
-			callStack[stackIndex++] = UInt(callSiteIndex);
+			callStack[Min(stackIndex++, Int(MAX_SHADER_CALL_STACK_SIZE))] = UInt(callSiteIndex);
 		}
 
 		enableIndex++;
-		enableStack[enableIndex] = condition;
+		enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = condition;
 		Int4 restoreLeave = enableLeave;
 
 		Bool notAllFalse = SignMask(condition) != 0;
@@ -1217,12 +1217,12 @@
 
 		if(isConditionalIf[ifDepth])
 		{
-			Int4 condition = ~enableStack[enableIndex] & enableStack[enableIndex - 1];
+			Int4 condition = ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] & enableStack[Min(enableIndex - 1, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 			Bool notAllFalse = SignMask(condition) != 0;
 
 			branch(notAllFalse, falseBlock, endBlock);
 
-			enableStack[enableIndex] = ~enableStack[enableIndex] & enableStack[enableIndex - 1];
+			enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] & enableStack[Min(enableIndex - 1, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 		}
 		else
 		{
@@ -1376,10 +1376,10 @@
 
 	void VertexProgram::IF(Int4 &condition)
 	{
-		condition &= enableStack[enableIndex];
+		condition &= enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		enableIndex++;
-		enableStack[enableIndex] = condition;
+		enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = condition;
 
 		BasicBlock *trueBlock = Nucleus::createBasicBlock();
 		BasicBlock *falseBlock = Nucleus::createBasicBlock();
@@ -1484,10 +1484,10 @@
 
 		const Vector4f &src = fetchRegister(temporaryRegister);
 		Int4 condition = As<Int4>(src.x);
-		condition &= enableStack[enableIndex - 1];
+		condition &= enableStack[Min(enableIndex - 1, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 		if(shader->containsLeaveInstruction()) condition &= enableLeave;
 		if(shader->containsBreakInstruction()) condition &= enableBreak;
-		enableStack[enableIndex] = condition;
+		enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))] = condition;
 
 		Bool notAllFalse = SignMask(condition) != 0;
 		branch(notAllFalse, loopBlock, endBlock);
@@ -1560,7 +1560,7 @@
 
 	void VertexProgram::LEAVE()
 	{
-		enableLeave = enableLeave & ~enableStack[enableIndex];
+		enableLeave = enableLeave & ~enableStack[Min(enableIndex, Int(MAX_SHADER_ENABLE_STACK_SIZE))];
 
 		// FIXME: Return from function if all instances left
 		// FIXME: Use enableLeave in other control-flow constructs
diff --git a/src/Shader/VertexProgram.hpp b/src/Shader/VertexProgram.hpp
index 33f3c5c..379abce 100644
--- a/src/Shader/VertexProgram.hpp
+++ b/src/Shader/VertexProgram.hpp
@@ -39,18 +39,18 @@
 
 		RegisterArray<NUM_TEMPORARY_REGISTERS> r;   // Temporary registers
 		Vector4f a0;
-		Array<Int, 4> aL;
+		Array<Int, MAX_SHADER_NESTED_LOOPS> aL;
 		Vector4f p0;
 
-		Array<Int, 4> increment;
-		Array<Int, 4> iteration;
+		Array<Int, MAX_SHADER_NESTED_LOOPS> increment;
+		Array<Int, MAX_SHADER_NESTED_LOOPS> iteration;
 
 		Int loopDepth;
 		Int stackIndex;   // FIXME: Inc/decrement callStack
-		Array<UInt, 16> callStack;
+		Array<UInt, MAX_SHADER_CALL_STACK_SIZE> callStack;
 
 		Int enableIndex;
-		Array<Int4, 1 + 24> enableStack;
+		Array<Int4, MAX_SHADER_ENABLE_STACK_SIZE> enableStack;
 		Int4 enableBreak;
 		Int4 enableContinue;
 		Int4 enableLeave;
@@ -122,18 +122,18 @@
 		Vector4f sampleTexture(const Src &s, Vector4f &uvwq, Float4 &lod, Vector4f &dsx, Vector4f &dsy, Vector4f &offset, SamplerFunction function);
 		Vector4f sampleTexture(int sampler, Vector4f &uvwq, Float4 &lod, Vector4f &dsx, Vector4f &dsy, Vector4f &offset, SamplerFunction function);
 
-		int ifDepth = 0;
-		int loopRepDepth = 0;
-		int currentLabel = -1;
+		BoundedIndex<MAX_SHADER_NESTED_IFS> ifDepth = 0;
+		BoundedIndex<MAX_SHADER_NESTED_LOOPS> loopRepDepth = 0;
+		BoundedIndex<MAX_SHADER_CALL_SITES> currentLabel = -1;
 		bool scalar = false;
 
-		BasicBlock *ifFalseBlock[24 + 24];
-		BasicBlock *loopRepTestBlock[4];
-		BasicBlock *loopRepEndBlock[4];
-		BasicBlock *labelBlock[2048];
-		std::vector<BasicBlock*> callRetBlock[2048];
+		BasicBlock *ifFalseBlock[MAX_SHADER_NESTED_IFS];
+		BasicBlock *loopRepTestBlock[MAX_SHADER_NESTED_LOOPS];
+		BasicBlock *loopRepEndBlock[MAX_SHADER_NESTED_LOOPS];
+		BasicBlock *labelBlock[MAX_SHADER_CALL_SITES];
+		std::vector<BasicBlock*> callRetBlock[MAX_SHADER_CALL_SITES];
 		BasicBlock *returnBlock;
-		bool isConditionalIf[24 + 24];
+		bool isConditionalIf[MAX_SHADER_NESTED_IFS];
 		std::vector<Int4> restoreContinue;
 	};
 }