diff --git a/builtins.cpp b/builtins.cpp
index 65f31856..9cc36fc0 100644
--- a/builtins.cpp
+++ b/builtins.cpp
@@ -47,10 +47,10 @@
 
 #include <math.h>
 #include <stdlib.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/Attributes.h>
 #endif
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/LLVMContext.h>
   #include <llvm/Module.h>
   #include <llvm/Type.h>
@@ -66,7 +66,7 @@
   #include <llvm/IR/Intrinsics.h>
   #include <llvm/IR/DerivedTypes.h>
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5
     #include <llvm/Linker/Linker.h>
 #else
     #include <llvm/Linker.h>
@@ -784,13 +784,13 @@ void
 AddBitcodeToModule(const unsigned char *bitcode, int length,
                    llvm::Module *module, SymbolTable *symbolTable, bool warn) {
     llvm::StringRef sb = llvm::StringRef((char *)bitcode, length);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     llvm::MemoryBuffer *bcBuf = llvm::MemoryBuffer::getMemBuffer(sb);
 #else // LLVM 3.6+
     llvm::MemoryBufferRef bcBuf = llvm::MemoryBuffer::getMemBuffer(sb)->getMemBufferRef();
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5
     llvm::ErrorOr<llvm::Module *> ModuleOrErr = llvm::parseBitcodeFile(bcBuf, *g->ctx);
     if (std::error_code EC = ModuleOrErr.getError())
         Error(SourcePos(), "Error parsing stdlib bitcode: %s", EC.message().c_str());
@@ -850,7 +850,7 @@ AddBitcodeToModule(const unsigned char *bitcode, int length,
             // architecture and investigate what happened.
             // Generally we allow library DataLayout to be subset of module
             // DataLayout or library DataLayout to be empty.
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5
             if (!VerifyDataLayoutCompatibility(module->getDataLayoutStr(),
                                                bcModule->getDataLayoutStr())
                 && warn) {
@@ -880,7 +880,7 @@ AddBitcodeToModule(const unsigned char *bitcode, int length,
 
         std::string(linkError);
         if (llvm::Linker::LinkModules(module, bcModule
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) 
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
                                       , llvm::Linker::DestroySource,
                                       &linkError))
             Error(SourcePos(), "Error linking stdlib bitcode: %s", linkError.c_str());
@@ -917,7 +917,7 @@ lDefineConstantInt(const char *name, int val, llvm::Module *module,
     symbolTable->AddVariable(sym);
 
     if (m->diBuilder != NULL) {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIFile file;
         llvm::DIType diType = sym->type->GetDIType(file);
         Assert(diType.Verify());
@@ -932,7 +932,7 @@ lDefineConstantInt(const char *name, int val, llvm::Module *module,
         // have the DW_AT_artifical attribute.  It's not clear if this
         // matters for anything though.
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::DIGlobalVariable var = m->diBuilder->createGlobalVariable(
                                                name,
                                                file,
@@ -940,7 +940,7 @@ lDefineConstantInt(const char *name, int val, llvm::Module *module,
                                                diType,
                                                true /* static */,
                                                sym->storagePtr);
-#elif defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* i.e., 3.6 */
         llvm::Constant *sym_const_storagePtr = llvm::dyn_cast<llvm::Constant>(sym->storagePtr);
         Assert(sym_const_storagePtr);
         llvm::DIGlobalVariable var = m->diBuilder->createGlobalVariable(
@@ -965,10 +965,10 @@ lDefineConstantInt(const char *name, int val, llvm::Module *module,
               true /* static */,
               sym_const_storagePtr);
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         Assert(var.Verify());
 #else // LLVM 3.7+
-    //comming soon
+    //coming soon
 #endif
     }
 }
@@ -984,7 +984,7 @@ lDefineConstantIntFunc(const char *name, int val, llvm::Module *module,
 
     llvm::Function *func = module->getFunction(name);
     Assert(func != NULL); // it should be declared already...
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
     func->addFnAttr(llvm::Attributes::AlwaysInline);
 #else // LLVM 3.3+
     func->addFnAttr(llvm::Attribute::AlwaysInline);
@@ -1019,7 +1019,7 @@ lDefineProgramIndex(llvm::Module *module, SymbolTable *symbolTable) {
     symbolTable->AddVariable(sym);
 
     if (m->diBuilder != NULL) {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIFile file;
         llvm::DIType diType = sym->type->GetDIType(file);
         Assert(diType.Verify());
@@ -1030,10 +1030,13 @@ lDefineProgramIndex(llvm::Module *module, SymbolTable *symbolTable) {
         llvm::DIType *diType = sym->type->GetDIType(file);
 //        Assert(diType.Verify());
 #endif
-#if defined(LLVM_3_6)// LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6
         llvm::Constant *sym_const_storagePtr = llvm::dyn_cast<llvm::Constant>(sym->storagePtr);
         Assert(sym_const_storagePtr);
-        llvm::DIGlobalVariable var = m->diBuilder->createGlobalVariable(
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
+        llvm::DIGlobalVariable var =
+#endif
+                                     m->diBuilder->createGlobalVariable(
                                                file,
                                                sym->name.c_str(),
                                                sym->name.c_str(),
@@ -1042,7 +1045,7 @@ lDefineProgramIndex(llvm::Module *module, SymbolTable *symbolTable) {
                                                diType,
                                                false /* static */,
                                                sym_const_storagePtr);
-#elif defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#elif ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 /* && ISPC_LLVM_VERSION < ISPC_LLVM_3_6 */
         llvm::DIGlobalVariable var = m->diBuilder->createGlobalVariable(
                                                sym->name.c_str(),
                                                file,
@@ -1063,10 +1066,10 @@ lDefineProgramIndex(llvm::Module *module, SymbolTable *symbolTable) {
                                                false /* static */,
                                                sym_const_storagePtr);
 #endif    
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         Assert(var.Verify());
 #else // LLVM 3.7+
-    //comming soon
+    //coming soon
 #endif
     }
 }
diff --git a/cbackend.cpp b/cbackend.cpp
index ad0ba32a..aa2385eb 100644
--- a/cbackend.cpp
+++ b/cbackend.cpp
@@ -32,7 +32,7 @@
 
 #include "llvmutil.h"
 
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include "llvm/Constants.h"
   #include "llvm/DerivedTypes.h"
   #include "llvm/CallingConv.h"
@@ -41,7 +41,7 @@
   #include "llvm/Intrinsics.h"
   #include "llvm/IntrinsicInst.h"
   #include "llvm/InlineAsm.h"
-#else
+#else /* LLVM 3.3+ */
   #include "llvm/IR/Constants.h"
   #include "llvm/IR/DerivedTypes.h"
   #include "llvm/IR/CallingConv.h"
@@ -52,29 +52,29 @@
   #include "llvm/IR/InlineAsm.h"
 #endif
 #include "llvm/Pass.h"
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* <= 3.6 */
   #include "llvm/PassManager.h"
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
   #include "llvm/IR/LegacyPassManager.h"
 #endif
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include "llvm/TypeFinder.h"
-#else // LLVM_3_3 +
+#else /* LLVM_3_3+ */
   #include "llvm/IR/TypeFinder.h"
 #endif
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/STLExtras.h"
-#if defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.2, 3.3, 3.4 */
   #include "llvm/Support/InstIterator.h"
-#else
+#else /* 3.5+ */
   #include "llvm/IR/InstIterator.h"
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
   #include "llvm/Analysis/FindUsedTypes.h"
 #endif
 #include "llvm/Analysis/LoopInfo.h"
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5
     #include "llvm/IR/Verifier.h"
     #include <llvm/IR/IRPrintingPasses.h>
     #include "llvm/IR/CallSite.h"
@@ -100,18 +100,18 @@
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3 /* 3.2 */
   #include "llvm/DataLayout.h"
-#else // LLVM 3.3+
+#else /* LLVM 3.3+ */
   #include "llvm/IR/DataLayout.h"
 #endif
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormattedStream.h"
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3 /* 3.2 */
   #include "llvm/Support/InstVisitor.h"
-#elif defined (LLVM_3_3) || defined (LLVM_3_4)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.3, 3.4 */
   #include "llvm/InstVisitor.h"
-#else // LLVM 3.5+
+#else /* LLVM 3.5+ */
   #include "llvm/IR/InstVisitor.h"
 #endif
 #include "llvm/Support/MathExtras.h"
@@ -119,7 +119,7 @@
 #include "llvm/Support/Host.h"
 #include "llvm/Target/TargetMachine.h"
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.2, 3.3, 3.4 */
     #include "llvm/Config/config.h"
 #endif
 
@@ -139,7 +139,7 @@
 namespace constant_scanner {
 class constant_iterator : public std::iterator<std::forward_iterator_tag,
                                                const llvm::Constant, ptrdiff_t> {
-  llvm::const_inst_iterator InstI;                // Method instruction iterator
+  llvm::const_inst_iterator InstI;         // Method instruction iterator
   unsigned OpIdx;                           // Operand index
 
   bool isAtConstant() const {
@@ -206,7 +206,7 @@ namespace {
     // To avoid walking constant expressions multiple times and other IR
     // objects, we keep several helper maps.
     llvm::DenseSet<const llvm::Value*> VisitedConstants;
-#if !defined (LLVM_3_2) && !defined (LLVM_3_3) && !defined (LLVM_3_4) && !defined (LLVM_3_5)// LLVN 3.6++
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 // LLVM 3.6+
     llvm::DenseSet<const llvm::Metadata*> VisitedMDNodes;
 #endif
     llvm::DenseSet<llvm::Type*> VisitedTypes;
@@ -312,12 +312,12 @@ namespace {
     /// walked in other ways.  GlobalValues, basic blocks, instructions, and
     /// inst operands are all explicitly enumerated.
     void incorporateValue(const llvm::Value *V) {
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 // 3.2, 3.3, 3.4, 3.5 */
       if (const llvm::MDNode *M = llvm::dyn_cast<llvm::MDNode>(V)) {
         incorporateMDNode(M);
         return;
       }
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
       if (const llvm::MetadataAsValue *MV = llvm::dyn_cast<llvm::MetadataAsValue>(V)) {
         incorporateMDNode(MV->getMetadata());
         return;
@@ -339,7 +339,7 @@ namespace {
         incorporateValue(*I);
     }
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 // 3.2, 3.3, 3.4, 3.5 */
     void incorporateMDNode(const llvm::MDNode *V) {
 
       // Already visited?
@@ -351,7 +351,7 @@ namespace {
         if (llvm::Value *Op = V->getOperand(i))
           incorporateValue(Op);
     }
-#else // LLVM 3.6+
+#else /* LLVM 3.6+ */
     void incorporateMDNode(const llvm::Metadata *M) {
 
       // Already visited?
@@ -397,7 +397,7 @@ namespace {
   public:
     CBEMCAsmInfo() {
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.2, 3.3, 3.4 */
       GlobalPrefix = "";
 #endif
       PrivateGlobalPrefix = "";
@@ -449,9 +449,9 @@ namespace {
         OpaqueCounter(0), NextAnonValueNumber(0),
         includeName(incname ? incname : "generic_defs.h"),
         vectorWidth(vecwidth) {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* < 3.6 */
       initializeLoopInfoPass(*llvm::PassRegistry::getPassRegistry());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
       initializeLoopInfoWrapperPassPass(*llvm::PassRegistry::getPassRegistry());
 #endif
       FPCounter = 0;
@@ -461,9 +461,9 @@ namespace {
     virtual const char *getPassName() const { return "C backend"; }
 
     void getAnalysisUsage(llvm::AnalysisUsage &AU) const {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* < 3.6 */
       AU.addRequired<llvm::LoopInfo>();
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
       AU.addRequired<llvm::LoopInfoWrapperPass>();
 #endif
       AU.setPreservesAll();
@@ -477,9 +477,9 @@ namespace {
      if (F.hasAvailableExternallyLinkage())
        return false;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* < 3.6 */
      LI = &getAnalysis<llvm::LoopInfo>();
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
      LI = &getAnalysis<llvm::LoopInfoWrapperPass>().getLoopInfo();
 #endif
 
@@ -519,9 +519,9 @@ namespace {
                            bool isSigned = false,
                            const std::string &VariableName = "",
                            bool IgnoreName = false,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                            const llvm::AttrListPtr &PAL = llvm::AttrListPtr()
-#else
+#else /* LLVM 3.3+ */
                            const llvm::AttributeSet &PAL = llvm::AttributeSet()
 #endif
                                  );
@@ -530,9 +530,9 @@ namespace {
                            const std::string &NameSoFar = "");
 
     void printStructReturnPointerFunctionType(llvm::raw_ostream &Out,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                                               const llvm::AttrListPtr &PAL,
-#else
+#else /* LLVM 3.3+ */
                                               const llvm::AttributeSet &PAL,
 #endif
                                               llvm::PointerType *Ty);
@@ -610,7 +610,7 @@ namespace {
       if (llvm::isa<llvm::CmpInst>(I) && llvm::isa<llvm::VectorType>(I.getType()) == false)
         return true;
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 // 3.5+
       // This instruction returns a struct on LLVM older than 3.4, and can not be inlined
       if (llvm::isa<llvm::AtomicCmpXchgInst>(I))
         return false;
@@ -628,7 +628,7 @@ namespace {
       // Must not be used in inline asm, extractelement, or shufflevector.
       if (I.hasOneUse()) {
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 // 3.5+
         const llvm::Instruction &User = llvm::cast<llvm::Instruction>(*I.user_back());
 #else
         const llvm::Instruction &User = llvm::cast<llvm::Instruction>(*I.use_back());
@@ -640,7 +640,7 @@ namespace {
       }
 
       // Only inline instruction it if it's use is in the same BB as the inst.
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 // 3.5+
       return I.getParent() == llvm::cast<llvm::Instruction>(I.user_back())->getParent();
 #else
       return I.getParent() == llvm::cast<llvm::Instruction>(I.use_back())->getParent();
@@ -776,9 +776,9 @@ std::string CWriter::getArrayName(llvm::ArrayType *AT) {
 /// return type, except, instead of printing the type as void (*)(Struct*, ...)
 /// print it as "Struct (*)(...)", for struct return functions.
 void CWriter::printStructReturnPointerFunctionType(llvm::raw_ostream &Out,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                                                    const llvm::AttrListPtr &PAL,
-#else
+#else /* LLVM 3.3+ */
                                                    const llvm::AttributeSet &PAL,
 #endif
                                                    llvm::PointerType *TheTy) {
@@ -795,18 +795,18 @@ void CWriter::printStructReturnPointerFunctionType(llvm::raw_ostream &Out,
     if (PrintedType)
       FunctionInnards << ", ";
     llvm::Type *ArgTy = *I;
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
     if (PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::ByVal)) {
-#else
+#else /* LLVM 3.3+ */
         if (PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::ByVal)) {
 #endif
       assert(ArgTy->isPointerTy());
       ArgTy = llvm::cast<llvm::PointerType>(ArgTy)->getElementType();
     }
     printType(FunctionInnards, ArgTy,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
               PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::SExt),
-#else
+#else /* LLVM 3.3+ */
               PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::SExt),
 #endif
               "");
@@ -821,9 +821,9 @@ void CWriter::printStructReturnPointerFunctionType(llvm::raw_ostream &Out,
   }
   FunctionInnards << ')';
   printType(Out, RetTy,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
             PAL.getParamAttributes(0).hasAttribute(llvm::Attributes::SExt),
-#else
+#else /* LLVM 3.3+ */
             PAL.getParamAttributes(0).hasAttribute(llvm::AttributeSet::ReturnIndex, llvm::Attribute::SExt),
 #endif
             FunctionInnards.str());
@@ -919,9 +919,9 @@ CWriter::printSimpleType(llvm::raw_ostream &Out, llvm::Type *Ty, bool isSigned,
 llvm::raw_ostream &CWriter::printType(llvm::raw_ostream &Out, llvm::Type *Ty,
                                 bool isSigned, const std::string &NameSoFar,
                                 bool IgnoreName,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                                 const llvm::AttrListPtr &PAL
-#else
+#else /* LLVM 3.3+ */
                                 const llvm::AttributeSet &PAL
 #endif
                                       ) {
@@ -941,9 +941,9 @@ llvm::raw_ostream &CWriter::printType(llvm::raw_ostream &Out, llvm::Type *Ty,
     for (llvm::FunctionType::param_iterator I = FTy->param_begin(),
            E = FTy->param_end(); I != E; ++I) {
       llvm::Type *ArgTy = *I;
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
       if (PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::ByVal)) {
-#else
+#else /* LLVM 3.3+ */
           if (PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::ByVal)) {
 #endif
         assert(ArgTy->isPointerTy());
@@ -952,9 +952,9 @@ llvm::raw_ostream &CWriter::printType(llvm::raw_ostream &Out, llvm::Type *Ty,
       if (I != FTy->param_begin())
         FunctionInnards << ", ";
       printType(FunctionInnards, ArgTy,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                 PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::SExt),
-#else
+#else /* LLVM 3.3+ */
                 PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::SExt),
 #endif
                 "");
@@ -969,9 +969,9 @@ llvm::raw_ostream &CWriter::printType(llvm::raw_ostream &Out, llvm::Type *Ty,
     }
     FunctionInnards << ')';
     printType(Out, FTy->getReturnType(),
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
               PAL.getParamAttributes(0).hasAttribute(llvm::Attributes::SExt),
-#else
+#else /* LLVM 3.3+ */
               PAL.getParamAttributes(0).hasAttribute(llvm::AttributeSet::ReturnIndex, llvm::Attribute::SExt),
 #endif
               FunctionInnards.str());
@@ -1585,7 +1585,8 @@ void CWriter::printConstant(llvm::Constant *CPV, bool Static) {
       Out << CI->getZExtValue() << "ull";
     else if (Ty->getPrimitiveSizeInBits() > 64) {
       Out << "\"";
-      const uint64_t *Ptr64 = CPV->getUniqueInteger().getRawData();
+      //const uint64_t *Ptr64 = CPV->getUniqueInteger().getRawData();
+      const uint64_t *Ptr64 = CI->getValue().getRawData();
       for (int i = 0; i < Ty->getPrimitiveSizeInBits(); i++) {
         Out << ((Ptr64[i / (sizeof (uint64_t) * 8)] >> (i % (sizeof (uint64_t) * 8))) & 1);
       }
@@ -1956,9 +1957,9 @@ std::string CWriter::GetValueName(const llvm::Value *Operand) {
 
   // Resolve potential alias.
   if (const llvm::GlobalAlias *GA = llvm::dyn_cast<llvm::GlobalAlias>(Operand)) {
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
     if (const llvm::Value *V = GA->getAliasee())
-#else
+#else /* <= LLVM 3.4 */
     if (const llvm::Value *V = GA->resolveAliasedGlobal(false))
 #endif
       Operand = V;
@@ -2332,7 +2333,7 @@ static SpecialGlobalClass getGlobalVariableClass(const llvm::GlobalVariable *GV)
 
   // Otherwise, if it is other metadata, don't print it.  This catches things
   // like debug information.
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
   // Here we compare char *
   if (!strcmp(GV->getSection(), "llvm.metadata"))
 #else
@@ -2390,7 +2391,7 @@ bool CWriter::doInitialization(llvm::Module &M) {
 #endif
   TAsm = new CBEMCAsmInfo();
   MRI  = new llvm::MCRegisterInfo();
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 /* LLVM 3.4+ */
   TCtx = new llvm::MCContext(TAsm, MRI, NULL);
 #else
   TCtx = new llvm::MCContext(*TAsm, *MRI, NULL);
@@ -2514,7 +2515,7 @@ bool CWriter::doInitialization(llvm::Module &M) {
       if (I->hasExternalLinkage() || I->hasExternalWeakLinkage() ||
           I->hasCommonLinkage())
         Out << "extern ";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
       else if (I->hasDLLImportStorageClass())
 #else
       else if (I->hasDLLImportLinkage())
@@ -2691,7 +2692,7 @@ bool CWriter::doInitialization(llvm::Module &M) {
 
         if (I->hasLocalLinkage())
           Out << "static ";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
         else if (I->hasDLLImportStorageClass()) Out << "__declspec(dllimport) ";
         else if (I->hasDLLExportStorageClass()) Out << "__declspec(dllexport) ";
 #else
@@ -3040,7 +3041,7 @@ void CWriter::printContainedStructs(llvm::Type *Ty,
 
   if (llvm::StructType *ST = llvm::dyn_cast<llvm::StructType>(Ty)) {
     // Check to see if we have already printed this struct.
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 /* LLVM 3.6+ */
     if (!Printed.insert(Ty).second) return;
 #else
     if (!Printed.insert(Ty)) return;
@@ -3051,7 +3052,7 @@ void CWriter::printContainedStructs(llvm::Type *Ty,
     Out << ";\n\n";
   }
   if (llvm::ArrayType *AT = llvm::dyn_cast<llvm::ArrayType>(Ty)) {
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 /* LLVM 3.6+ */
       if (!Printed.insert(Ty).second) return;
 #else
       if (!Printed.insert(Ty)) return;
@@ -3065,7 +3066,7 @@ void CWriter::printContainedStructs(llvm::Type *Ty,
 
 void CWriter::printContainedArrays(llvm::ArrayType *ATy,
                                    llvm::SmallPtrSet<llvm::Type *, 16> &Printed) {
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 /* LLVM 3.6+ */
   if (!Printed.insert(ATy).second)
       return;
 #else
@@ -3086,7 +3087,7 @@ void CWriter::printFunctionSignature(const llvm::Function *F, bool Prototype) {
   bool isStructReturn = F->hasStructRetAttr();
 
   if (F->hasLocalLinkage()) Out << "static ";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
   if (F->hasDLLImportStorageClass()) Out << "__declspec(dllimport) ";
   if (F->hasDLLExportStorageClass()) Out << "__declspec(dllexport) ";
 #else
@@ -3109,9 +3110,9 @@ void CWriter::printFunctionSignature(const llvm::Function *F, bool Prototype) {
 
   // Loop over the arguments, printing them...
   llvm::FunctionType *FT = llvm::cast<llvm::FunctionType>(F->getFunctionType());
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   const llvm::AttrListPtr &PAL = F->getAttributes();
-#else
+#else /* LLVM 3.3+ */
   const llvm::AttributeSet &PAL = F->getAttributes();
 #endif
 
@@ -3143,18 +3144,18 @@ void CWriter::printFunctionSignature(const llvm::Function *F, bool Prototype) {
         else
           ArgName = "";
         llvm::Type *ArgTy = I->getType();
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
         if (PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::ByVal)) {
-#else
+#else /* LLVM 3.3+ */
             if (PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::ByVal)) {
 #endif
           ArgTy = llvm::cast<llvm::PointerType>(ArgTy)->getElementType();
           ByValParams.insert(I);
         }
         printType(FunctionInnards, ArgTy,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                   PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::SExt),
-#else
+#else /* LLVM 3.3+ */
                   PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::SExt),
 #endif
                   ArgName);
@@ -3178,18 +3179,18 @@ void CWriter::printFunctionSignature(const llvm::Function *F, bool Prototype) {
     for (; I != E; ++I) {
       if (PrintedArg) FunctionInnards << ", ";
       llvm::Type *ArgTy = *I;
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
       if (PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::ByVal)) {
-#else
+#else /* LLVM 3.3+ */
           if (PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::ByVal)) {
 #endif
         assert(ArgTy->isPointerTy());
         ArgTy = llvm::cast<llvm::PointerType>(ArgTy)->getElementType();
       }
       printType(FunctionInnards, ArgTy,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                 PAL.getParamAttributes(Idx).hasAttribute(llvm::Attributes::SExt)
-#else
+#else /* LLVM 3.3+ */
                 PAL.getParamAttributes(Idx).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::SExt)
 #endif
                 );
@@ -3224,9 +3225,9 @@ void CWriter::printFunctionSignature(const llvm::Function *F, bool Prototype) {
 
   // Print out the return type and the signature built above.
   printType(Out, RetTy,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
             PAL.getParamAttributes(0).hasAttribute(llvm::Attributes::SExt),
-#else
+#else /* LLVM 3.3+ */
             PAL.getParamAttributes(0).hasAttribute(llvm::AttributeSet::ReturnIndex, llvm::Attribute::SExt),
 #endif
             FunctionInnards.str());
@@ -3412,7 +3413,7 @@ void CWriter::visitSwitchInst(llvm::SwitchInst &SI) {
     printPHICopiesForSuccessor (SI.getParent(), Succ, 2);
     printBranchToBlock(SI.getParent(), Succ, 2);
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
     if (llvm::Function::iterator(Succ) == std::next(llvm::Function::iterator(SI.getParent())))
 #else
     if (llvm::Function::iterator(Succ) == llvm::next(llvm::Function::iterator(SI.getParent())))
@@ -3437,7 +3438,7 @@ bool CWriter::isGotoCodeNecessary(llvm::BasicBlock *From, llvm::BasicBlock *To)
   /// FIXME: This should be reenabled, but loop reordering safe!!
   return true;
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
   if (std::next(llvm::Function::iterator(From)) != llvm::Function::iterator(To))
 #else
   if (llvm::next(llvm::Function::iterator(From)) != llvm::Function::iterator(To))
@@ -4079,9 +4080,9 @@ void CWriter::lowerIntrinsics(llvm::Function &F) {
             const char *BuiltinName = "";
 #define GET_GCC_BUILTIN_NAME
 #define Intrinsic llvm::Intrinsic
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include "llvm/Intrinsics.gen"
-#else
+#else /* LLVM 3.3+ */
   #include "llvm/IR/Intrinsics.gen"
 #endif
 #undef Intrinsic
@@ -4092,7 +4093,7 @@ void CWriter::lowerIntrinsics(llvm::Function &F) {
             // All other intrinsic calls we must lower.
             llvm::Instruction *Before = 0;
             if (CI != &BB->front())
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
               Before = std::prev(llvm::BasicBlock::iterator(CI));
 #else
               Before = prior(llvm::BasicBlock::iterator(CI));
@@ -4148,9 +4149,9 @@ void CWriter::visitCallInst(llvm::CallInst &I) {
 
   // If this is a call to a struct-return function, assign to the first
   // parameter instead of passing it to the call.
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   const llvm::AttrListPtr &PAL = I.getAttributes();
-#else
+#else /* LLVM 3.3+ */
   const llvm::AttributeSet &PAL = I.getAttributes();
 #endif
   bool hasByVal = I.hasByValArgument();
@@ -4258,9 +4259,9 @@ void CWriter::visitCallInst(llvm::CallInst &I) {
         (*AI)->getType() != FTy->getParamType(ArgNo)) {
       Out << '(';
       printType(Out, FTy->getParamType(ArgNo),
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                 PAL.getParamAttributes(ArgNo+1).hasAttribute(llvm::Attributes::SExt)
-#else
+#else /* LLVM 3.3+ */
                 PAL.getParamAttributes(ArgNo+1).hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::SExt)
 #endif
                 );
@@ -4268,9 +4269,9 @@ void CWriter::visitCallInst(llvm::CallInst &I) {
     }
     // Check if the argument is expected to be passed by value.
     if (I.paramHasAttr(ArgNo+1,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                        llvm::Attributes::ByVal
-#else
+#else /* LLVM 3.3+ */
                        llvm::Attribute::ByVal
 #endif
                        )) {
@@ -4296,9 +4297,9 @@ bool CWriter::visitBuiltinCall(llvm::CallInst &I, llvm::Intrinsic::ID ID,
     const char *BuiltinName = "";
 #define GET_GCC_BUILTIN_NAME
 #define Intrinsic llvm::Intrinsic
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include "llvm/Intrinsics.gen"
-#else
+#else /* LLVM 3.3+ */
   #include "llvm/IR/Intrinsics.gen"
 #endif
 #undef Intrinsic
@@ -4817,7 +4818,7 @@ void CWriter::visitAtomicRMWInst(llvm::AtomicRMWInst &AI) {
 
 void CWriter::visitAtomicCmpXchgInst(llvm::AtomicCmpXchgInst &ACXI) {
     Out << "(";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
     printType(Out, ACXI.getType(), false);
     Out << "::init("; // LLVM cmpxchg returns a struct, so we need make an assighment properly
 #endif
@@ -4828,7 +4829,7 @@ void CWriter::visitAtomicCmpXchgInst(llvm::AtomicCmpXchgInst &ACXI) {
     Out << ", ";
     writeOperand(ACXI.getNewValOperand());
     Out << ")";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* LLVM 3.5+ */
     Out << ", true /* There is no way to learn the value of this bit inside ISPC, so making it constant */)";
 #endif
     Out << ")";
@@ -4932,7 +4933,11 @@ SmearCleanupPass::getShuffleSmearValue(llvm::Instruction* inst) const {
     // Check that the shuffle is a broadcast of the element of the first vector,
     // i.e. mask vector is vector with equal elements of expected size.     
     if (!(mask &&
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
+         (mask->isNullValue() || (shuffleInst->getMask()->getType()->isVectorTy() && llvm::dyn_cast<llvm::ConstantVector>(shuffleInst->getMask())->getSplatValue() != 0 ) ) &&
+#else
          (mask->isNullValue() || (shuffleInst->getMask()->getSplatValue() != 0))&&
+#endif
           llvm::dyn_cast<llvm::VectorType>(mask->getType())->getNumElements() == vectorWidth)) {
         return NULL;
     }
@@ -4973,8 +4978,14 @@ SmearCleanupPass::getShuffleSmearValue(llvm::Instruction* inst) const {
             return NULL;
         }
         llvm::Instruction *extractCall = 
-              llvm::ExtractElementInst::Create(shuffleInst->getOperand(0), mask->getSplatValue(),  
-                                               "__extract_element", inst);
+              llvm::ExtractElementInst::Create(shuffleInst->getOperand(0), 
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
+                         // mask is of VectorType
+                         llvm::dyn_cast<llvm::ConstantVector>(mask)->getSplatValue(),  
+#else
+                         mask->getSplatValue(),  
+#endif
+                         "__extract_element", inst);
         return extractCall;
     }
 
@@ -5150,10 +5161,10 @@ public:
         notFunc =
             llvm::dyn_cast<llvm::Function>(m->getOrInsertFunction("__not", mt, mt, NULL));
         assert(notFunc != NULL);
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
         notFunc->addFnAttr(llvm::Attributes::NoUnwind);
         notFunc->addFnAttr(llvm::Attributes::ReadNone);
-#else
+#else /* LLVM 3.3+ */
         notFunc->addFnAttr(llvm::Attribute::NoUnwind);
         notFunc->addFnAttr(llvm::Attribute::ReadNone);
 #endif
@@ -5162,10 +5173,10 @@ public:
             llvm::dyn_cast<llvm::Function>(m->getOrInsertFunction("__and_not1", mt, mt, mt,
                                                       NULL));
         assert(andNotFuncs[0] != NULL);
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
         andNotFuncs[0]->addFnAttr(llvm::Attributes::NoUnwind);
         andNotFuncs[0]->addFnAttr(llvm::Attributes::ReadNone);
-#else
+#else /* LLVM 3.3+ */
         andNotFuncs[0]->addFnAttr(llvm::Attribute::NoUnwind);
         andNotFuncs[0]->addFnAttr(llvm::Attribute::ReadNone);
 #endif
@@ -5173,10 +5184,10 @@ public:
             llvm::dyn_cast<llvm::Function>(m->getOrInsertFunction("__and_not2", mt, mt, mt,
                                                       NULL));
         assert(andNotFuncs[1] != NULL);
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
         andNotFuncs[1]->addFnAttr(llvm::Attributes::NoUnwind);
         andNotFuncs[1]->addFnAttr(llvm::Attributes::ReadNone);
-#else
+#else /* LLVM 3.3+ */
         andNotFuncs[1]->addFnAttr(llvm::Attribute::NoUnwind);
         andNotFuncs[1]->addFnAttr(llvm::Attribute::ReadNone);
 #endif
@@ -5304,9 +5315,9 @@ bool
 WriteCXXFile(llvm::Module *module, const char *fn, int vectorWidth,
              const char *includeName) {
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
     llvm::PassManager pm;
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::legacy::PassManager pm;
 #endif
 #if 0
@@ -5316,23 +5327,23 @@ WriteCXXFile(llvm::Module *module, const char *fn, int vectorWidth,
         pm.add(new llvm::TargetData(module));
 #endif
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_4 /* 3.2, 3.3 */
     int flags = 0;
-#else
+#else /* LLVM 3.4+ */
     llvm::sys::fs::OpenFlags flags = llvm::sys::fs::F_None;
 #endif
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     std::string error;
-#else // LLVM 3.6+
+#else /* LLVM 3.6+ */
     std::error_code error;
 #endif
 
     llvm::tool_output_file *of = new llvm::tool_output_file(fn, error, flags);
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     if (error.size()) {
-#else // LLVM 3.6+
+#else /* LLVM 3.6+ */
     if (error) {
 #endif
         fprintf(stderr, "Error opening output file \"%s\".\n", fn);
@@ -5350,7 +5361,7 @@ WriteCXXFile(llvm::Module *module, const char *fn, int vectorWidth,
     pm.add(llvm::createDeadCodeEliminationPass()); // clean up after smear pass
 //CO    pm.add(llvm::createPrintModulePass(&fos));
     pm.add(new CWriter(fos, includeName, vectorWidth));
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
     // This interface is depricated for 3.3+
     pm.add(llvm::createGCInfoDeleter());
 #endif
diff --git a/ctx.cpp b/ctx.cpp
index 082759b9..fdf80c56 100644
--- a/ctx.cpp
+++ b/ctx.cpp
@@ -46,7 +46,7 @@
 #include "sym.h"
 #include <map>
 #include <llvm/Support/Dwarf.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/Metadata.h>
   #include <llvm/Module.h>
   #include <llvm/Instructions.h>
@@ -337,25 +337,27 @@ FunctionEmitContext::FunctionEmitContext(Function *func, Symbol *funSym,
 
         /* If debugging is enabled, tell the debug information emission
            code about this new function */
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         diFile = funcStartPos.GetDIFile();
         AssertPos(currentPos, diFile.Verify());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         diFile = funcStartPos.GetDIFile();
 #endif
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_4 /* 3.2, 3.3 */
         llvm::DIScope scope = llvm::DIScope(m->diBuilder->getCU());
-#elif defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.4, 3.5, 3.6 */
         llvm::DIScope scope = llvm::DIScope(m->diCompileUnit);
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         llvm::DIScope *scope = m->diCompileUnit;
+        //llvm::MDScope *scope = m->diCompileUnit;
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         llvm::DIType diSubprogramType;
         AssertPos(currentPos, scope.Verify());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         llvm::DIType *diSubprogramType = NULL;
+        //llvm::MDType *diSubprogramType = NULL;
 #endif
 
         const FunctionType *functionType = function->GetType();
@@ -363,21 +365,22 @@ FunctionEmitContext::FunctionEmitContext(Function *func, Symbol *funSym,
             AssertPos(currentPos, m->errorCount > 0);
         else {
             diSubprogramType = functionType->GetDIType(scope);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
             AssertPos(currentPos, diSubprogramType.Verify());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     //comming soon
 #endif
         }
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_4 /* 3.2, 3.3 */
         llvm::DIType diSubprogramType_n = diSubprogramType;
-#elif defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+        int flags = llvm::DIDescriptor::FlagPrototyped;
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.4, 3.5, 3.6 */
         Assert(diSubprogramType.isCompositeType());
         llvm::DICompositeType diSubprogramType_n =
             static_cast<llvm::DICompositeType>(diSubprogramType);
         int flags = llvm::DIDescriptor::FlagPrototyped;
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         Assert(llvm::isa<llvm::DICompositeTypeBase>(diSubprogramType));
         llvm::DISubroutineType *diSubprogramType_n =
             llvm::cast<llvm::DISubroutineType>(getDICompositeType(diSubprogramType));
@@ -392,7 +395,7 @@ FunctionEmitContext::FunctionEmitContext(Function *func, Symbol *funSym,
         bool isOptimized = (g->opt.level > 0);
         int firstLine = funcStartPos.first_line;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         diSubprogram =
             m->diBuilder->createFunction(diFile /* scope */, funSym->name,
                                          mangledName,        diFile,
@@ -401,7 +404,7 @@ FunctionEmitContext::FunctionEmitContext(Function *func, Symbol *funSym,
                                          firstLine,          flags,
                                          isOptimized,        llvmFunction);
         AssertPos(currentPos, diSubprogram.Verify());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         diSubprogram =
             m->diBuilder->createFunction(diFile /* scope */, funSym->name,
                                          mangledName,        diFile,
@@ -1610,9 +1613,9 @@ lGetStringAsValue(llvm::BasicBlock *bblock, const char *s) {
                                                  sConstant, var_name.c_str());
     llvm::Value *indices[2] = { LLVMInt32(0), LLVMInt32(0) };
     llvm::ArrayRef<llvm::Value *> arrayRef(&indices[0], &indices[2]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
     return llvm::GetElementPtrInst::Create(sPtr, arrayRef, "sptr", bblock);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
     return llvm::GetElementPtrInst::Create(PTYPE(sPtr),
                                            sPtr, arrayRef, "sptr", bblock);
 #endif
@@ -1654,10 +1657,11 @@ FunctionEmitContext::GetDebugPos() const {
 
 void
 FunctionEmitContext::AddDebugPos(llvm::Value *value, const SourcePos *pos,
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
                                  llvm::DIScope *scope) {
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
                                  llvm::DIScope *scope) {
+                                 //llvm::MDScope *scope) {
 #endif
     llvm::Instruction *inst = llvm::dyn_cast<llvm::Instruction>(value);
     if (inst != NULL && m->diBuilder) {
@@ -1668,9 +1672,9 @@ FunctionEmitContext::AddDebugPos(llvm::Value *value, const SourcePos *pos,
             // for those functions
             inst->setDebugLoc(llvm::DebugLoc::get(p.first_line, p.first_column,
                                                   scope ?
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
                                                   *scope
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
                                                   scope
 #endif
                                                   : GetDIScope()));
@@ -1681,12 +1685,14 @@ FunctionEmitContext::AddDebugPos(llvm::Value *value, const SourcePos *pos,
 void
 FunctionEmitContext::StartScope() {
     if (m->diBuilder != NULL) {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         llvm::DIScope parentScope;
         llvm::DILexicalBlock lexicalBlock;
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
         llvm::DIScope *parentScope;
         llvm::DILexicalBlock *lexicalBlock;
+        //llvm::MDScope *parentScope;
+        //llvm::MDLexicalBlock *lexicalBlock;
 #endif
         if (debugScopes.size() > 0)
             parentScope = debugScopes.back();
@@ -1696,7 +1702,7 @@ FunctionEmitContext::StartScope() {
         lexicalBlock =
             m->diBuilder->createLexicalBlock(parentScope, diFile,
                                              currentPos.first_line,
-#if defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_5
         // Revision 202736 in LLVM adds support of DWARF discriminator
         // to the last argument and revision 202737 in clang adds 0
         // for the last argument by default.
@@ -1706,11 +1712,12 @@ FunctionEmitContext::StartScope() {
         // as the last argument
                                              currentPos.first_column);
 #endif // LLVM 3.2, 3.3, 3.4 and 3.6+
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         AssertPos(currentPos, lexicalBlock.Verify());
         debugScopes.push_back(lexicalBlock);
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         debugScopes.push_back(llvm::cast<llvm::DILexicalBlockBase>(lexicalBlock));
+        //debugScopes.push_back(llvm::cast<llvm::MDLexicalBlockBase>(lexicalBlock));
 #endif
     }
 }
@@ -1725,10 +1732,11 @@ FunctionEmitContext::EndScope() {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
 llvm::DIScope
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
 llvm::DIScope*
+//llvm::MDScope*
 #endif
 FunctionEmitContext::GetDIScope() const {
     AssertPos(currentPos, debugScopes.size() > 0);
@@ -1741,15 +1749,18 @@ FunctionEmitContext::EmitVariableDebugInfo(Symbol *sym) {
     if (m->diBuilder == NULL)
         return;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
     llvm::DIScope scope = GetDIScope();
     llvm::DIType diType = sym->type->GetDIType(scope);
     AssertPos(currentPos, diType.Verify());
     llvm::DIVariable var =
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::DIScope *scope = GetDIScope();
     llvm::DIType *diType = sym->type->GetDIType(scope);
     llvm::DILocalVariable *var =
+    //llvm::MDScope *scope = GetDIScope();
+    //llvm::MDType *diType = sym->type->GetDIType(scope);
+    //llvm::MDLocalVariable *var =
 #endif
         m->diBuilder->createLocalVariable(llvm::dwarf::DW_TAG_auto_variable,
                                           scope,
@@ -1758,16 +1769,16 @@ FunctionEmitContext::EmitVariableDebugInfo(Symbol *sym) {
                                           sym->pos.first_line,
                                           diType,
                                           true /* preserve through opts */);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
     AssertPos(currentPos, var.Verify());
     llvm::Instruction *declareInst =
         m->diBuilder->insertDeclare(sym->storagePtr, var,
-    #if defined(LLVM_3_6)
+    #if ISPC_LLVM_VERSION == ISPC_LLVM_3_6
                                     m->diBuilder->createExpression(),
     #endif
                                     bblock);
     AddDebugPos(declareInst, &sym->pos, &scope);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
     llvm::Instruction *declareInst =
         m->diBuilder->insertDeclare(sym->storagePtr, var,
                                     m->diBuilder->createExpression(),
@@ -1785,15 +1796,18 @@ FunctionEmitContext::EmitFunctionParameterDebugInfo(Symbol *sym, int argNum) {
         return;
 
     int flags = 0;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
     llvm::DIScope scope = diSubprogram;
     llvm::DIType diType = sym->type->GetDIType(scope);
     AssertPos(currentPos, diType.Verify());
     llvm::DIVariable var =
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::DIScope *scope = diSubprogram;
     llvm::DIType *diType = sym->type->GetDIType(scope);
     llvm::DILocalVariable *var =
+    //llvm::MDScope *scope = diSubprogram;
+    //llvm::MDType *diType = sym->type->GetDIType(scope);
+    //llvm::MDLocalVariable *var =
 #endif
         m->diBuilder->createLocalVariable(llvm::dwarf::DW_TAG_arg_variable,
                                           scope,
@@ -1804,16 +1818,16 @@ FunctionEmitContext::EmitFunctionParameterDebugInfo(Symbol *sym, int argNum) {
                                           true /* preserve through opts */,
                                           flags,
                                           argNum + 1);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
     AssertPos(currentPos, var.Verify());
     llvm::Instruction *declareInst =
         m->diBuilder->insertDeclare(sym->storagePtr, var,
-    #if defined(LLVM_3_6)
+    #if ISPC_LLVM_VERSION == ISPC_LLVM_3_6
                                     m->diBuilder->createExpression(),
     #endif
                                     bblock);
     AddDebugPos(declareInst, &sym->pos, &scope);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
     llvm::Instruction *declareInst =
         m->diBuilder->insertDeclare(sym->storagePtr, var,
                                     m->diBuilder->createExpression(),
@@ -2430,11 +2444,11 @@ FunctionEmitContext::GetElementPtrInst(llvm::Value *basePtr, llvm::Value *index,
         // uniform, so just emit the regular LLVM GEP instruction
         llvm::Value *ind[1] = { index };
         llvm::ArrayRef<llvm::Value *> arrayRef(&ind[0], &ind[1]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         llvm::Instruction *inst =
             llvm::GetElementPtrInst::Create(basePtr, arrayRef,
                                             name ? name : "gep", bblock);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
         llvm::Instruction *inst =
             llvm::GetElementPtrInst::Create(PTYPE(basePtr),
                                             basePtr, arrayRef,
@@ -2497,11 +2511,11 @@ FunctionEmitContext::GetElementPtrInst(llvm::Value *basePtr, llvm::Value *index0
         // uniform, so just emit the regular LLVM GEP instruction
         llvm::Value *indices[2] = { index0, index1 };
         llvm::ArrayRef<llvm::Value *> arrayRef(&indices[0], &indices[2]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         llvm::Instruction *inst =
             llvm::GetElementPtrInst::Create(basePtr, arrayRef,
                                             name ? name : "gep", bblock);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
         llvm::Instruction *inst =
             llvm::GetElementPtrInst::Create(PTYPE(basePtr),
                                             basePtr, arrayRef,
@@ -2598,11 +2612,11 @@ FunctionEmitContext::AddElementOffset(llvm::Value *fullBasePtr, int elementNum,
         // If the pointer is uniform, we can use the regular LLVM GEP.
         llvm::Value *offsets[2] = { LLVMInt32(0), LLVMInt32(elementNum) };
         llvm::ArrayRef<llvm::Value *> arrayRef(&offsets[0], &offsets[2]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.2, 3.3, 3.4, 3.5, 3.6 */
         resultPtr =
             llvm::GetElementPtrInst::Create(basePtr, arrayRef,
                                             name ? name : "struct_offset", bblock);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
         resultPtr =
             llvm::GetElementPtrInst::Create(PTYPE(basePtr), basePtr, arrayRef,
                                             name ? name : "struct_offset", bblock);
@@ -2909,41 +2923,41 @@ FunctionEmitContext::addGSMetadata(llvm::Value *v, SourcePos pos) {
     llvm::Instruction *inst = llvm::dyn_cast<llvm::Instruction>(v);
     if (inst == NULL)
         return;
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     llvm::Value *str = llvm::MDString::get(*g->ctx, pos.name);
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
     llvm::MDString *str = llvm::MDString::get(*g->ctx, pos.name);
 #endif
     llvm::MDNode *md = llvm::MDNode::get(*g->ctx, str);
     inst->setMetadata("filename", md);
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     llvm::Value *first_line = LLVMInt32(pos.first_line);
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
     llvm::Metadata *first_line = llvm::ConstantAsMetadata::get(LLVMInt32(pos.first_line));
 #endif
     md = llvm::MDNode::get(*g->ctx, first_line);
     inst->setMetadata("first_line", md);
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     llvm::Value *first_column = LLVMInt32(pos.first_column);
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
     llvm::Metadata *first_column = llvm::ConstantAsMetadata::get(LLVMInt32(pos.first_column));
 #endif
     md = llvm::MDNode::get(*g->ctx, first_column);
     inst->setMetadata("first_column", md);
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     llvm::Value *last_line = LLVMInt32(pos.last_line);
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
     llvm::Metadata *last_line = llvm::ConstantAsMetadata::get(LLVMInt32(pos.last_line));
 #endif
     md = llvm::MDNode::get(*g->ctx, last_line);
     inst->setMetadata("last_line", md);
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
     llvm::Value *last_column = LLVMInt32(pos.last_column);
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
     llvm::Metadata *last_column = llvm::ConstantAsMetadata::get(LLVMInt32(pos.last_column));
 #endif
     md = llvm::MDNode::get(*g->ctx, last_column);
@@ -3577,7 +3591,7 @@ FunctionEmitContext::CallInst(llvm::Value *func, const FunctionType *funcType,
         // alias analysis.
         // TODO: what other attributes needs to be copied?
         // TODO: do the same for varing path.
-#if !defined (LLVM_3_2) // LLVM 3.3+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3 // LLVM 3.3+
         llvm::CallInst *cc = llvm::dyn_cast<llvm::CallInst>(ci);
         if (cc &&
             cc->getCalledFunction() &&
diff --git a/ctx.h b/ctx.h
index edc51ce4..7b2184ca 100644
--- a/ctx.h
+++ b/ctx.h
@@ -40,19 +40,19 @@
 
 #include "ispc.h"
 #include <map>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/InstrTypes.h>
   #include <llvm/Instructions.h>
-#else
+#else /* >= 3.3 */
   #include <llvm/IR/InstrTypes.h>
   #include <llvm/IR/Instructions.h>
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
-  #include <llvm/IR/DebugInfo.h>
-  #include <llvm/IR/DIBuilder.h>
-#else
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_5
   #include <llvm/DebugInfo.h>
   #include <llvm/DIBuilder.h>
+#else /* >= 3.5 */
+  #include <llvm/IR/DebugInfo.h>
+  #include <llvm/IR/DIBuilder.h>
 #endif
 
 struct CFInfo;
@@ -352,10 +352,11 @@ public:
         Instructions stored using Value pointers; the code here returns
         silently if it's not actually given an instruction. */
     void AddDebugPos(llvm::Value *instruction, const SourcePos *pos = NULL,
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
                      llvm::DIScope *scope = NULL);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
                      llvm::DIScope *scope = NULL);
+                     //llvm::MDScope *scope = NULL );
 #endif
 
     /** Inform the debugging information generation code that a new scope
@@ -368,7 +369,7 @@ public:
 
     /** Returns the llvm::DIScope corresponding to the current program
         scope. */
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIScope GetDIScope() const;
 #else // LLVM 3.7++
     llvm::DIScope *GetDIScope() const;
@@ -683,7 +684,7 @@ private:
         emitted. */
     std::vector<CFInfo *> controlFlowInfo;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     /** DIFile object corresponding to the source file where the current
         function was defined (used for debugging info). */
     llvm::DIFile diFile;
diff --git a/expr.cpp b/expr.cpp
index e829f578..411628ab 100644
--- a/expr.cpp
+++ b/expr.cpp
@@ -56,7 +56,7 @@
 #include <list>
 #include <set>
 #include <stdio.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/Module.h>
   #include <llvm/Type.h>
   #include <llvm/Instructions.h>
@@ -74,7 +74,7 @@
   #include <llvm/IR/CallingConv.h>
 #endif
 #include <llvm/ExecutionEngine/GenericValue.h>
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* 3.5+ */
   #include <llvm/IR/InstIterator.h>
 #else
   #include <llvm/Support/InstIterator.h>
diff --git a/func.cpp b/func.cpp
index 13aa09ee..9be935f4 100644
--- a/func.cpp
+++ b/func.cpp
@@ -46,7 +46,7 @@
 #include "util.h"
 #include <stdio.h>
 
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3 /* 3.2 */
 #ifdef ISPC_NVPTX_ENABLED
   #include <llvm/Metadata.h>
 #endif /* ISPC_NVPTX_ENABLED */
@@ -67,9 +67,9 @@
   #include <llvm/IR/Intrinsics.h>
   #include <llvm/IR/DerivedTypes.h>
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* < 3.6 */
   #include "llvm/PassManager.h"
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
   #include "llvm/IR/LegacyPassManager.h"
 #endif
 #include <llvm/PassRegistry.h>
@@ -78,7 +78,7 @@
 #include <llvm/Support/FileUtilities.h>
 #include <llvm/Target/TargetMachine.h>
 #include <llvm/Target/TargetOptions.h>
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* 3.5+ */
     #include <llvm/IR/Verifier.h>
     #include <llvm/IR/IRPrintingPasses.h>
     #include <llvm/IR/CFG.h>
@@ -360,11 +360,19 @@ Function::emitCode(FunctionEmitContext *ctx, llvm::Function *function,
         {
           llvm::NamedMDNode* annotations =
             m->module->getOrInsertNamedMetadata("nvvm.annotations");
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 /* 3.6+ */
+          llvm::SmallVector<llvm::Metadata*, 3> av;
+          av.push_back(llvm::ValueAsMetadata::get(function));
+          av.push_back(llvm::MDString::get(*g->ctx, "kernel"));
+          av.push_back(llvm::ConstantAsMetadata::get(LLVMInt32(1)));
+          annotations->addOperand(llvm::MDNode::get(*g->ctx, llvm::ArrayRef<llvm::Metadata*>(av)));
+#else
           llvm::SmallVector<llvm::Value*, 3> av;
           av.push_back(function);
           av.push_back(llvm::MDString::get(*g->ctx, "kernel"));
           av.push_back(LLVMInt32(1));
           annotations->addOperand(llvm::MDNode::get(*g->ctx, av));
+#endif
         }
 #endif /* ISPC_NVPTX_ENABLED */
     }
@@ -384,9 +392,9 @@ Function::emitCode(FunctionEmitContext *ctx, llvm::Function *function,
         // isn't worth the code bloat / overhead.
         bool checkMask = (type->isTask == true) ||
             (
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3 /* 3.2 */
               (function->getFnAttributes().hasAttribute(llvm::Attributes::AlwaysInline) == false)
-#else // LLVM 3.3+
+#else /* LLVM 3.3+ */
               (function->getAttributes().getFnAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::AlwaysInline) == false)
 #endif
              &&
@@ -569,11 +577,21 @@ Function::GenerateIR() {
                     {
                       llvm::NamedMDNode* annotations =
                         m->module->getOrInsertNamedMetadata("nvvm.annotations");
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 /* 3.6+ */
+
+                      llvm::SmallVector<llvm::Metadata*, 3> av;
+                      av.push_back(llvm::ValueAsMetadata::get(function));
+                      av.push_back(llvm::MDString::get(*g->ctx, "kernel"));
+                      av.push_back(llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(llvm::IntegerType::get(*g->ctx,32), 1)));
+                      annotations->addOperand(llvm::MDNode::get(*g->ctx, llvm::ArrayRef<llvm::Metadata*>(av))); 
+#else
                       llvm::SmallVector<llvm::Value*, 3> av;
-                      av.push_back(appFunction);
+                      av.push_back(function);
                       av.push_back(llvm::MDString::get(*g->ctx, "kernel"));
                       av.push_back(llvm::ConstantInt::get(llvm::IntegerType::get(*g->ctx,32), 1));
-                      annotations->addOperand(llvm::MDNode::get(*g->ctx, av)); 
+                      annotations->addOperand(llvm::MDNode::get(*g->ctx, av));
+#endif
+
                     }
 #endif /* ISPC_NVPTX_ENABLED */
                 }
diff --git a/ispc.cpp b/ispc.cpp
index fd1459cc..6d5ff527 100644
--- a/ispc.cpp
+++ b/ispc.cpp
@@ -50,22 +50,22 @@
   #include <sys/types.h>
   #include <unistd.h>
 #endif
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/LLVMContext.h>
   #include <llvm/Module.h>
   #include <llvm/Instructions.h>
-#else
+#else /* 3.3+ */
   #include <llvm/IR/LLVMContext.h>
   #include <llvm/IR/Module.h>
   #include <llvm/IR/Instructions.h>
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 // LLVM 3.6+
   #include <llvm/Target/TargetSubtargetInfo.h>
-  #if !defined(LLVM_3_6) // LLVM 3.7+
+  #if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
     #include <llvm/Target/TargetLowering.h>
   #endif
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 // LLVM 3.5+
   #include <llvm/IR/DebugInfo.h>
   #include <llvm/IR/DIBuilder.h>
 #else // LLVM 3.2, 3.3, 3.4
@@ -75,7 +75,7 @@
 #include <llvm/Support/Dwarf.h>
 #include <llvm/Target/TargetMachine.h>
 #include <llvm/Target/TargetOptions.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/DataLayout.h>
 #else // LLVM 3.3+
   #include <llvm/IR/DataLayout.h>
@@ -233,17 +233,17 @@ typedef enum {
     // Haswell. Supports AVX 2.
     CPU_Haswell,
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 // LLVM 3.6+
     // Broadwell. Supports AVX 2 + ADX/RDSEED/SMAP.
     CPU_Broadwell,
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
     // KNL. Supports AVX512.
     CPU_KNL,
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) // LLVM 3.4+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 // LLVM 3.4+
     // Late Atom-like design. Supports SSE 4.2 + POPCNT/LZCNT.
     CPU_Silvermont,
 #endif
@@ -302,7 +302,7 @@ public:
 
         names[CPU_Penryn].push_back("penryn");
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) // LLVM 3.4+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 // LLVM 3.4+
         names[CPU_Silvermont].push_back("slm");
         names[CPU_Silvermont].push_back("silvermont");
 #endif
@@ -319,11 +319,11 @@ public:
         names[CPU_Haswell].push_back("core-avx2");
         names[CPU_Haswell].push_back("haswell");
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6 // LLVM 3.6+
         names[CPU_Broadwell].push_back("broadwell");
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
          names[CPU_KNL].push_back("knl");
 #endif
 
@@ -338,24 +338,24 @@ public:
 #endif
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) // LLVM 3.4+
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_4 // LLVM 3.2 or 3.3
         #define CPU_Silvermont CPU_Nehalem
-#else
+#else /* LLVM 3.4+ */
         compat[CPU_Silvermont]  = Set(CPU_Generic, CPU_Bonnell, CPU_Penryn,
                                       CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                                       CPU_None);
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
         compat[CPU_KNL]         = Set(CPU_KNL, CPU_Generic, CPU_Bonnell, CPU_Penryn,
                                       CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                                       CPU_SandyBridge, CPU_IvyBridge,
                                       CPU_Haswell, CPU_Broadwell, CPU_None);
 #endif
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) // LLVM 3.6+
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 // LLVM 3.2, 3.3, 3.4 or 3.5
         #define CPU_Broadwell CPU_Haswell
-#else
+#else /* LLVM 3.6+ */
         compat[CPU_Broadwell]   = Set(CPU_Generic, CPU_Bonnell, CPU_Penryn,
                                       CPU_Core2, CPU_Nehalem, CPU_Silvermont,
                                       CPU_SandyBridge, CPU_IvyBridge,
@@ -446,7 +446,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
     m_is32Bit(true),
     m_cpu(""),
     m_attributes(""),
-#if !defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3 /* ! 3.2 */
     m_tf_attributes(NULL),
 #endif
     m_nativeVectorWidth(-1),
@@ -507,13 +507,13 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
                 break;
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
             case CPU_KNL:
                 isa = "avx512knl-i32x16";
                 break;
 #endif
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6
             case CPU_Broadwell:
 #endif
             case CPU_Haswell:
@@ -531,7 +531,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
             // Penryn is here because ISPC does not use SSE 4.2
             case CPU_Penryn:
             case CPU_Nehalem:
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4
             case CPU_Silvermont:
 #endif
                 isa = "sse4-i32x4";
@@ -569,7 +569,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
 
     // Make sure the target architecture is a known one; print an error
     // with the valid ones otherwise.
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6) // 3.7 +
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
     for (llvm::TargetRegistry::iterator iter = llvm::TargetRegistry::targets().begin();
          iter != llvm::TargetRegistry::targets().end(); ++iter) {
 #else
@@ -584,7 +584,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
     if (this->m_target == NULL) {
         fprintf(stderr, "Invalid architecture \"%s\"\nOptions: ", arch);
         llvm::TargetRegistry::iterator iter;
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6) // 3.7 +
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
         for (iter = llvm::TargetRegistry::targets().begin();
              iter != llvm::TargetRegistry::targets().end(); ++iter)
 #else
@@ -891,7 +891,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
         this->m_hasGather = true;
         CPUfromISA = CPU_Haswell;
     }
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
     else if (!strcasecmp(isa, "avx512knl-i32x16")) {
         this->m_isa = Target::KNL_AVX512;
         this->m_nativeVectorWidth = 16;
@@ -1020,7 +1020,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
 #endif
         if (g->opt.disableFMA == false)
             options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 #ifdef ISPC_IS_WINDOWS
         if (strcmp("x86", arch) == 0) {
             // Workaround for issue #503 (LLVM issue 14646).
@@ -1034,18 +1034,17 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
                     relocModel);
         Assert(m_targetMachine != NULL);
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         m_targetMachine->setAsmVerbosityDefault(true);
-#else
+#else /* LLVM 3.7+ */
         m_targetMachine->Options.MCOptions.AsmVerbose = true;
 #endif
         // Initialize TargetData/DataLayout in 3 steps.
         // 1. Get default data layout first
         std::string dl_string;
-
-#if defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_6
         dl_string = m_targetMachine->getSubtargetImpl()->getDataLayout()->getStringRepresentation();
-#else // LLVM 3.5- and LLVM 3.7+
+#else // LLVM 3.5- or LLVM 3.7+
         dl_string = m_targetMachine->getDataLayout()->getStringRepresentation();
 #endif
         // 2. Adjust for generic
@@ -1076,7 +1075,7 @@ Target::Target(const char *arch, const char *cpu, const char *isa, bool pic, boo
 
         this->m_is32Bit = (getDataLayout()->getPointerSize() == 4);
 
-#if !defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3
         // This is LLVM 3.3+ feature.
         // Initialize target-specific "target-feature" attribute.
         if (!m_attributes.empty()) {
@@ -1135,11 +1134,11 @@ Target::SupportedTargets() {
         "avx1-i32x8, avx1-i32x16, avx1-i64x4, "
         "avx1.1-i32x8, avx1.1-i32x16, avx1.1-i64x4, "
         "avx2-i32x8, avx2-i32x16, avx2-i64x4, "
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
         "avx512knl-i32x16, "
 #endif
         "generic-x1, generic-x4, generic-x8, generic-x16, "
-        "generic-x32, generic-x64, *-generic-x16"
+        "generic-x32, generic-x64, *-generic-x16, "
 #ifdef ISPC_ARM_ENABLED
         ", neon-i8x16, neon-i16x8, neon-i32x4"
 #endif
@@ -1208,7 +1207,7 @@ Target::ISAToString(ISA isa) {
         return "avx11";
     case Target::AVX2:
         return "avx2";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
     case Target::KNL_AVX512:
         return "avx512knl-i32x16";
 #endif
@@ -1256,7 +1255,7 @@ Target::ISAToTargetString(ISA isa) {
         return "avx1.1-i32x8";
     case Target::AVX2:
         return "avx2-i32x8";
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6)// LLVM 3.7+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7+
     case Target::KNL_AVX512:
         return "avx512knl-i32x16";
 #endif
@@ -1325,11 +1324,11 @@ Target::SizeOf(llvm::Type *type,
         llvm::PointerType *ptrType = llvm::PointerType::get(type, 0);
         llvm::Value *voidPtr = llvm::ConstantPointerNull::get(ptrType);
         llvm::ArrayRef<llvm::Value *> arrayRef(&index[0], &index[1]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::Instruction *gep =
             llvm::GetElementPtrInst::Create(voidPtr, arrayRef, "sizeof_gep",
                                             insertAtEnd);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
         llvm::Instruction *gep =
             llvm::GetElementPtrInst::Create(PTYPE(voidPtr), voidPtr,
                                             arrayRef, "sizeof_gep",
@@ -1363,11 +1362,11 @@ Target::StructOffset(llvm::Type *type, int element,
         llvm::PointerType *ptrType = llvm::PointerType::get(type, 0);
         llvm::Value *voidPtr = llvm::ConstantPointerNull::get(ptrType);
         llvm::ArrayRef<llvm::Value *> arrayRef(&indices[0], &indices[2]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::Instruction *gep =
             llvm::GetElementPtrInst::Create(voidPtr, arrayRef, "offset_gep",
                                             insertAtEnd);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
         llvm::Instruction *gep =
             llvm::GetElementPtrInst::Create(PTYPE(voidPtr), voidPtr,
                                             arrayRef, "offset_gep",
@@ -1399,7 +1398,7 @@ Target::StructOffset(llvm::Type *type, int element,
 }
 
 void Target::markFuncWithTargetAttr(llvm::Function* func) {
-#if !defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3
     if (m_tf_attributes) {
         func->addAttributes(llvm::AttributeSet::FunctionIndex, *m_tf_attributes);
     }
@@ -1484,19 +1483,21 @@ SourcePos::SourcePos(const char *n, int fl, int fc, int ll, int lc) {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIFile
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
 llvm::DIFile*
+//llvm::MDFile*
 #endif
 SourcePos::GetDIFile() const {
     std::string directory, filename;
     GetDirectoryAndFileName(g->currentDirectory, name, &directory, &filename);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIFile ret = m->diBuilder->createFile(filename, directory);
     Assert(ret.Verify());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::DIFile *ret = m->diBuilder->createFile(filename, directory);
+    //llvm::MDFile *ret = m->diBuilder->createFile(filename, directory);
 #endif
     return ret;
 }
diff --git a/ispc.h b/ispc.h
index 584c0242..31c0bd9d 100644
--- a/ispc.h
+++ b/ispc.h
@@ -38,9 +38,9 @@
 #ifndef ISPC_H
 #define ISPC_H
 
-#define ISPC_VERSION "1.8.3dev"
+#include "ispc_version.h"
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5) && !defined(LLVM_3_6) && !defined(LLVM_3_7)
+#if ISPC_LLVM_VERSION < OLDEST_SUPPORTED_LLVM || ISPC_LLVM_VERSION > LATEST_SUPPORTED_LLVM
 #error "Only LLVM 3.2, 3.3, 3.4, 3.5, 3.6 and 3.7 development branch are supported"
 #endif
 
@@ -86,7 +86,7 @@ namespace llvm {
     class TargetMachine;
     class Type;
     class Value;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     class DIFile;
     class DIType;
     class DIDescriptor;
@@ -144,7 +144,7 @@ struct SourcePos {
     /** Prints the filename and line/column range to standard output. */
     void Print() const;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     /** Returns a LLVM DIFile object that represents the SourcePos's file */
     llvm::DIFile GetDIFile() const;
 #else
@@ -259,7 +259,7 @@ public:
 
     // Note the same name of method for 3.1 and 3.2+, this allows
     // to reduce number ifdefs on client side.
-    llvm::DataLayout *getDataLayout() const {return m_dataLayout;}
+    const llvm::DataLayout *getDataLayout() const {return m_dataLayout;}
 
     /** Reports if Target object has valid state. */
     bool isValid() const {return m_valid;}
@@ -344,7 +344,7 @@ private:
     /** Target-specific attribute string to pass along to the LLVM backend */
     std::string m_attributes;
 
-#if !defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3
     /** Target-specific LLVM attribute, which has to be attached to every
         function to ensure that it is generated for correct target architecture.
         This is requirement was introduced in LLVM 3.3 */
diff --git a/ispc_version.h b/ispc_version.h
new file mode 100644
index 00000000..fe438e76
--- /dev/null
+++ b/ispc_version.h
@@ -0,0 +1,64 @@
+/*
+  Copyright (c) 2015, Intel Corporation
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are
+  met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+
+    * Neither the name of Intel Corporation nor the names of its
+      contributors may be used to endorse or promote products derived from
+      this software without specific prior written permission.
+
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+   IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+   TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+   PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/** @file ispc_version.h
+    @brief defines the ISPC version
+*/
+
+#ifndef ISPC_VERSION_H
+#define ISPC_VERSION_H
+
+#define ISPC_VERSION "1.8.3dev"
+#include "llvm/Config/llvm-config.h"
+
+#define ISPC_LLVM_VERSION ( LLVM_VERSION_MAJOR * 10000 + LLVM_VERSION_MINOR * 100 )
+
+#define ISPC_LLVM_3_2 30200
+#define ISPC_LLVM_3_3 30300
+#define ISPC_LLVM_3_4 30400
+#define ISPC_LLVM_3_5 30500
+#define ISPC_LLVM_3_6 30600
+#define ISPC_LLVM_3_7 30700
+
+#define OLDEST_SUPPORTED_LLVM ISPC_LLVM_3_2
+#define LATEST_SUPPORTED_LLVM ISPC_LLVM_3_7
+
+#ifdef __ispc__xstr
+#undef __ispc__xstr
+#endif
+#define __ispc__xstr(s) __ispc__str(s)
+#define __ispc__str(s) #s
+
+#define ISPC_LLVM_VERSION_STRING __ispc__xstr(LLVM_VERSION_MAJOR) "." __ispc__xstr(LLVM_VERSION_MINOR)
+
+#endif // ISPC_VERSION_H
diff --git a/llvmutil.cpp b/llvmutil.cpp
index 3ec5ebef..9b2b3573 100644
--- a/llvmutil.cpp
+++ b/llvmutil.cpp
@@ -38,7 +38,7 @@
 #include "llvmutil.h"
 #include "ispc.h"
 #include "type.h"
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2 
   #include <llvm/Instructions.h>
   #include <llvm/BasicBlock.h>
 #else
diff --git a/llvmutil.h b/llvmutil.h
index eb8ea49e..f65bf638 100644
--- a/llvmutil.h
+++ b/llvmutil.h
@@ -38,12 +38,13 @@
 #ifndef ISPC_LLVMUTIL_H
 #define ISPC_LLVMUTIL_H 1
 
-#if defined(LLVM_3_2)
+#include "ispc_version.h"
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/LLVMContext.h>
   #include <llvm/Type.h>
   #include <llvm/DerivedTypes.h>
   #include <llvm/Constants.h>
-#else
+#else /* >= 3.3 */
   #include <llvm/IR/LLVMContext.h>
   #include <llvm/IR/Type.h>
   #include <llvm/IR/DerivedTypes.h>
diff --git a/main.cpp b/main.cpp
index 60965317..7937dfcb 100644
--- a/main.cpp
+++ b/main.cpp
@@ -62,21 +62,7 @@ static void
 lPrintVersion() {
     printf("Intel(r) SPMD Program Compiler (ispc), %s (build %s @ %s, LLVM %s)\n",
            ISPC_VERSION, BUILD_VERSION, BUILD_DATE,
-#if defined(LLVM_3_2)
-           "3.2"
-#elif defined(LLVM_3_3)
-           "3.3"
-#elif defined(LLVM_3_4)
-           "3.4"
-#elif defined(LLVM_3_5)
-           "3.5"
-#elif defined(LLVM_3_6)
-           "3.6"
-#elif defined(LLVM_3_7)
-           "3.7"
-#else
-#error "Unhandled LLVM version"
-#endif
+           ISPC_LLVM_VERSION_STRING
            );
 }
 
@@ -173,7 +159,7 @@ devUsage(int ret) {
     printf("    [--yydebug]\t\t\t\tPrint debugging information during parsing\n");
     printf("    [--debug-phase=<value>]\t\tSet optimization phases to dump. --debug-phase=first,210:220,300,305,310:last\n");
 
-#if defined(LLVM_3_4) || defined(LLVM_3_5) // only 3.4 and 3.5
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.4, 3.5 */
     printf("    [--debug-ir=<value>]\t\tSet optimization phase to generate debugIR after it\n");
 #endif
     printf("    [--off-phase=<value>]\t\tSwitch off optimization phases. --off-phase=first,210:220,300,305,310:last\n");
@@ -570,7 +556,7 @@ int main(int Argc, char *Argv[]) {
             g->debug_stages = ParsingPhases(argv[i] + strlen("--debug-phase="));
         }
 
-#if defined(LLVM_3_4) || defined(LLVM_3_5) // only 3.4 and 3.5
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.4, 3.5 */
         else if (strncmp(argv[i], "--debug-ir=", 11) == 0) {
             g->debugIR = ParsingPhaseName(argv[i] + strlen("--debug-ir="));
         }
diff --git a/module.cpp b/module.cpp
index 28480488..a0412edf 100644
--- a/module.cpp
+++ b/module.cpp
@@ -66,8 +66,7 @@
 #include <io.h>
 #define strcasecmp stricmp
 #endif
-
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/LLVMContext.h>
   #include <llvm/Module.h>
   #include <llvm/Type.h>
@@ -85,16 +84,16 @@
   #include <llvm/IR/Intrinsics.h>
   #include <llvm/IR/DerivedTypes.h>
 #ifdef ISPC_NVPTX_ENABLED
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* 3.5+ */
   #include <llvm/IR/AssemblyAnnotationWriter.h>
 #else
   #include <llvm/Assembly/AssemblyAnnotationWriter.h>
 #endif
 #endif /* ISPC_NVPTX_ENABLED */
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
   #include "llvm/PassManager.h"
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
   #include "llvm/IR/LegacyPassManager.h"
 #endif
 #include <llvm/PassRegistry.h>
@@ -103,14 +102,14 @@
 #include <llvm/Support/FileUtilities.h>
 #include <llvm/Target/TargetMachine.h>
 #include <llvm/Target/TargetOptions.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/DataLayout.h>
   #include <llvm/TargetTransformInfo.h>
 #else // LLVM 3.3+
   #include <llvm/IR/DataLayout.h>
   #include <llvm/Analysis/TargetTransformInfo.h>
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5
     #include <llvm/IR/Verifier.h>
     #include <llvm/IR/IRPrintingPasses.h>
     #include <llvm/IR/InstIterator.h>
@@ -170,9 +169,9 @@ static void
 lStripUnusedDebugInfo(llvm::Module *module) {
     if (g->generateDebuggingSymbols == false)
         return;
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* <= 3.5 */
     std::set<llvm::Value *> SPall;
-#else // LLVM 3.6++
+#else /* LLVM 3.6+ */
     std::set<llvm::Metadata *> SPall;
 #endif
     // OK, now we are to determine which functions actually survived the
@@ -191,7 +190,7 @@ lStripUnusedDebugInfo(llvm::Module *module) {
             while (node) {
                 // get the scope of the current instruction`s location
                 // node becomes NULL if this was the original location
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5) || (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* <= 3.6 */
                 llvm::DILocation dloc(node);
                 llvm::DIScope scope = dloc.getScope();
                 node = dloc.getOrigLocation();
@@ -206,9 +205,11 @@ lStripUnusedDebugInfo(llvm::Module *module) {
                     else break;
                 }
                 if (scope.isSubprogram()) {
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
                 llvm::DILocation *dloc = llvm::cast<llvm::DILocation>(node);
                 llvm::DIScope *scope = dloc->getScope();
+                //llvm::MDLocation *dloc = llvm::cast<llvm::MDLocation>(node);
+                //llvm::MDScope *scope = dloc->getScope();
                 node = dloc->getInlinedAt();
                 // now following a chain of nested scopes
                 while (!0) {
@@ -232,36 +233,38 @@ lStripUnusedDebugInfo(llvm::Module *module) {
     if (llvm::NamedMDNode *cuNodes = module->getNamedMetadata("llvm.dbg.cu")) {
         for (unsigned i = 0, ie = cuNodes->getNumOperands(); i != ie; ++i) {
             llvm::MDNode *cuNode = cuNodes->getOperand(i);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
             llvm::DICompileUnit cu(cuNode);
             llvm::DIArray subprograms = cu.getSubprograms();
             if (subprograms.getNumElements() == 0) {
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
             llvm::DICompileUnit *cu = llvm::cast<llvm::DICompileUnit>(cuNode);
             llvm::DISubprogramArray subprograms = cu->getSubprograms();
+            //llvm::MDCompileUnit *cu = llvm::cast<llvm::MDCompileUnit>(cuNode);
+            //llvm::MDSubprogramArray subprograms = cu->getSubprograms();
             if (subprograms.size() == 0) {
 #endif
                 continue;
             }
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
             std::set<llvm::Value *> SPset;
             std::vector<llvm::Value *> usedSubprograms;
-#else // LLVM 3.6+
+#else /* LLVM 3.6+ */
             std::set<llvm::Metadata *> SPset;
             std::vector<llvm::Metadata *> usedSubprograms;
 #endif
 
             // determine what functions of those extracted belong to the unit
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
             for (unsigned j = 0, je = subprograms.getNumElements(); j != je; ++j)
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
             for (unsigned j = 0, je = subprograms.size(); j != je; ++j)
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
                 SPset.insert(subprograms->getOperand(j));
-#elif defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7
                 SPset.insert(subprograms.getElement(j));
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
                 SPset.insert(subprograms [j]);
 #endif
 
@@ -271,9 +274,9 @@ lStripUnusedDebugInfo(llvm::Module *module) {
 
             Debug(SourcePos(), "%d / %d functions left in module with debug "
                   "info.", (int)usedSubprograms.size(),
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
                   (int)subprograms.getNumElements());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
                   (int)subprograms.size());
 #endif
 
@@ -296,7 +299,7 @@ lStripUnusedDebugInfo(llvm::Module *module) {
             // stuff and remove it later on. Removing it is useful, as it
             // reduces size of the binary significantly (manyfold for small
             // programs).
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3 /* 3.2 */
             llvm::MDNode *nodeSPMD =
                 llvm::dyn_cast<llvm::MDNode>(cuNode->getOperand(12));
             Assert(nodeSPMD != NULL);
@@ -314,7 +317,7 @@ lStripUnusedDebugInfo(llvm::Module *module) {
             llvm::MDNode *replNode =
                 llvm::MDNode::get(*g->ctx, llvm::ArrayRef<llvm::Value *>(usedSubprogramsArray));
             cuNode->replaceOperandWith(12, replNode);
-#elif defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.3, 3.4, 3.5 */
             llvm::MDNode *nodeSPMDArray =
                 llvm::dyn_cast<llvm::MDNode>(cuNode->getOperand(9));
             Assert(nodeSPMDArray != NULL);
@@ -328,8 +331,7 @@ lStripUnusedDebugInfo(llvm::Module *module) {
             llvm::MDNode *replNode =
                 m->diBuilder->getOrCreateArray(llvm::ArrayRef<llvm::Value *>(usedSubprograms));
             cuNode->replaceOperandWith(9, replNode);
-#else // LLVM 3.6+
-  #if defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.6 */
             llvm::DIArray nodeSPs = cu.getSubprograms();
             Assert(nodeSPs.getNumElements() == subprograms.getNumElements());
             for (int i = 0; i < (int)nodeSPs.getNumElements(); ++i)
@@ -340,8 +342,9 @@ lStripUnusedDebugInfo(llvm::Module *module) {
             llvm::MDNode *replNode = llvm::MDNode::get(module->getContext(), 
                                                        llvm::ArrayRef<llvm::Metadata *>(usedSubprograms));
             cu.replaceSubprograms(llvm::DIArray(replNode));
-  #else // LLVM 3.7+
+#else /* LLVM 3.7+ */
             llvm::DISubprogramArray nodeSPs = cu->getSubprograms();
+            //llvm::MDSubprogramArray nodeSPs = cu->getSubprograms();
             Assert(nodeSPs.size() == subprograms.size());
             for (int i = 0; i < (int)nodeSPs.size(); ++i)
                  Assert(nodeSPs [i] == subprograms [i]);
@@ -350,7 +353,6 @@ lStripUnusedDebugInfo(llvm::Module *module) {
             // confidence...
             cu->replaceSubprograms(llvm::MDTuple::get(cu->getContext(),
                                                       llvm::ArrayRef<llvm::Metadata *>(usedSubprograms)));
-  #endif
 #endif
         }
     }
@@ -418,7 +420,7 @@ Module::Module(const char *fn) {
             sprintf(producerString, "ispc version %s (built on %s)",
                     ISPC_VERSION, __DATE__);
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 /* 3.4+ */
             diCompileUnit = 
 #endif // LLVM_3_4+            
             diBuilder->createCompileUnit(llvm::dwarf::DW_LANG_C99,  /* lang */
@@ -698,7 +700,7 @@ Module::AddGlobalVariable(const std::string &name, const Type *type, Expr *initE
     }
 
     if (diBuilder) {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.2, 3.3, 3.4, 3.5 */
         llvm::DIFile file = pos.GetDIFile();
         llvm::DIGlobalVariable var = diBuilder->createGlobalVariable(
                                             name,
@@ -707,7 +709,7 @@ Module::AddGlobalVariable(const std::string &name, const Type *type, Expr *initE
                                             sym->type->GetDIType(file),
                                             (sym->storageClass == SC_STATIC),
                                             sym->storagePtr);
-#elif defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.6 */
         llvm::DIFile file = pos.GetDIFile();
         llvm::Constant *sym_const_storagePtr = llvm::dyn_cast<llvm::Constant>(sym->storagePtr);
         Assert(sym_const_storagePtr);
@@ -720,8 +722,9 @@ Module::AddGlobalVariable(const std::string &name, const Type *type, Expr *initE
                                             sym->type->GetDIType(file),
                                             (sym->storageClass == SC_STATIC),
                                             sym_const_storagePtr);
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
         llvm::DIFile *file = pos.GetDIFile();
+        //llvm::MDFile *file = pos.GetDIFile();
         llvm::Constant *sym_const_storagePtr = llvm::dyn_cast<llvm::Constant>(sym->storagePtr);
         Assert(sym_const_storagePtr);
         diBuilder->createGlobalVariable(
@@ -734,9 +737,9 @@ Module::AddGlobalVariable(const std::string &name, const Type *type, Expr *initE
                                             (sym->storageClass == SC_STATIC),
                                             sym_const_storagePtr);
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         Assert(var.Verify());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     //comming soon
 #endif
     }
@@ -1159,7 +1162,7 @@ Module::writeOutput(OutputType outputType, const char *outFileName,
     if (diBuilder && (outputType != Header) && (outputType != Deps))
         lStripUnusedDebugInfo(module);
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) // LLVM 3.4+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 /* 3.4+ */
     // In LLVM_3_4 after r195494 and r195504 revisions we should pass
     // "Debug Info Version" constant to the module. LLVM will ignore
     // our Debug Info metadata without it.
@@ -1393,7 +1396,7 @@ Module::writeBitcode(llvm::Module *module, const char *outFileName) {
 
       std::string s;
       llvm::raw_string_ostream out(s);
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* 3.5+ */
       std::unique_ptr<llvm::AssemblyAnnotationWriter> Annotator;
 #else
       llvm::OwningPtr<llvm::AssemblyAnnotationWriter> Annotator;
@@ -1406,7 +1409,7 @@ Module::writeBitcode(llvm::Module *module, const char *outFileName) {
         input.push_back(s);
       output = input;
 
-#if !(defined(LLVM_3_1) || defined(LLVM_3_2))
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3 /* 3.3+ */
       /* do not fix attributed with LLVM 3.2, everything is fine there */
       lFixAttributes(input,output);
 #endif
@@ -1442,28 +1445,28 @@ Module::writeObjectFileOrAssembly(llvm::TargetMachine *targetMachine,
     llvm::TargetMachine::CodeGenFileType fileType = (outputType == Object) ?
         llvm::TargetMachine::CGFT_ObjectFile : llvm::TargetMachine::CGFT_AssemblyFile;
     bool binary = (fileType == llvm::TargetMachine::CGFT_ObjectFile);
-#if defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_4 /* 3.2, 3.3 */
     unsigned int flags = binary ? llvm::raw_fd_ostream::F_Binary : 0;
-#elif defined(LLVM_3_4)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.4 */
     llvm::sys::fs::OpenFlags flags = binary ? llvm::sys::fs::F_Binary :
         llvm::sys::fs::F_None;
-#else
+#else /* 3.5+ */
     llvm::sys::fs::OpenFlags flags = binary ? llvm::sys::fs::F_None :
         llvm::sys::fs::F_Text;
 
 #endif
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     std::string error;
-#else // LLVM 3.6+
+#else /* LLVM 3.6+ */
     std::error_code error;
 #endif
 
     llvm::tool_output_file *of = new llvm::tool_output_file(outFileName, error, flags);
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     if (error.size()) {
-#else // LLVM 3.6+
+#else /* LLVM 3.6+ */
     if (error) {
 #endif
 
@@ -1471,25 +1474,25 @@ Module::writeObjectFileOrAssembly(llvm::TargetMachine *targetMachine,
         return false;
     }
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::PassManager pm;
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::legacy::PassManager pm;
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.2, 3.3, 3.4 */
     pm.add(new llvm::DataLayout(*g->target->getDataLayout()));
-#elif defined(LLVM_3_5)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_6 /* 3.5 */
     pm.add(new llvm::DataLayoutPass(*g->target->getDataLayout()));
-#elif defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7 /* 3.6 */
     llvm::DataLayoutPass *dlp= new llvm::DataLayoutPass();
     dlp->doInitialization(*module);
     pm.add(dlp);
 #endif // LLVM 3.7+ doesn't have DataLayoutPass anymore.
 
     {
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::formatted_raw_ostream fos(of->os());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::raw_fd_ostream &fos(of->os());
 #endif
     if (targetMachine->addPassesToEmitFile(pm, fos, fileType)) {
@@ -1578,7 +1581,7 @@ lEmitStructDecl(const StructType *st, std::vector<const StructType *> *emittedSt
     char sSOA[48];
     bool pack, needsAlign = false;
     llvm::Type *stype = st->LLVMType(g->ctx);
-    llvm::DataLayout *DL = g->target->getDataLayout();
+    const llvm::DataLayout *DL = g->target->getDataLayout();
 
     if (!(pack = llvm::dyn_cast<llvm::StructType>(stype)->isPacked()))
         for (int i = 0; !needsAlign && (i < st->GetElementCount()); ++i) {
@@ -2431,9 +2434,9 @@ Module::execPreprocessor(const char *infilename, llvm::raw_string_ostream *ostre
     
     inst.setDiagnostics(diagEngine);
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.2, 3.3, 3.4 */
     clang::TargetOptions &options = inst.getTargetOpts();
-#else // LLVM 3.5+
+#else /* LLVM 3.5+ */
     const std::shared_ptr< clang::TargetOptions > &options = 
           std::make_shared< clang::TargetOptions >(inst.getTargetOpts());
 #endif
@@ -2443,19 +2446,19 @@ Module::execPreprocessor(const char *infilename, llvm::raw_string_ostream *ostre
         triple.setTriple(llvm::sys::getDefaultTargetTriple());
     }
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.2, 3.3, 3.4 */
     options.Triple = triple.getTriple();
-#else // LLVM 3.5+
+#else /* LLVM 3.5+ */
    options->Triple = triple.getTriple();
 #endif
 
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3 /* 3.2 */
     clang::TargetInfo *target =
         clang::TargetInfo::CreateTargetInfo(inst.getDiagnostics(), options);
-#elif defined(LLVM_3_3) || defined(LLVM_3_4)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_5 /* 3.3, 3.4 */
     clang::TargetInfo *target =
         clang::TargetInfo::CreateTargetInfo(inst.getDiagnostics(), &options);
-#else // LLVM 3.5+
+#else /* LLVM 3.5+ */
     clang::TargetInfo *target =
         clang::TargetInfo::CreateTargetInfo(inst.getDiagnostics(), options);
 #endif
@@ -2469,7 +2472,7 @@ Module::execPreprocessor(const char *infilename, llvm::raw_string_ostream *ostre
     // track the source file position by handling them ourselves.
     inst.getPreprocessorOutputOpts().ShowComments = 1;
 
-#if !defined(LLVM_3_2) // LLVM 3.3+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3 // LLVM 3.3+
     inst.getPreprocessorOutputOpts().ShowCPP = 1;
 #endif
 
@@ -2481,7 +2484,7 @@ Module::execPreprocessor(const char *infilename, llvm::raw_string_ostream *ostre
         headerOpts.Verbose = 1;
     for (int i = 0; i < (int)g->includePath.size(); ++i) {
         headerOpts.AddPath(g->includePath[i], clang::frontend::Angled,
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
                            true /* is user supplied */,
 #endif
                            false /* not a framework */,
@@ -2560,7 +2563,7 @@ Module::execPreprocessor(const char *infilename, llvm::raw_string_ostream *ostre
 
     inst.getLangOpts().LineComment = 1;
 
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 /* 3.5+ */
     inst.createPreprocessor(clang::TU_Complete);
 #else
     inst.createPreprocessor();
@@ -2905,9 +2908,9 @@ static void lEmitDispatchModule(llvm::Module *module,
 
     // Do some rudimentary cleanup of the final result and make sure that
     // the module is all ok.
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::PassManager optPM;
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::legacy::PassManager optPM;
 #endif
     optPM.add(llvm::createGlobalDCEPass());
diff --git a/module.h b/module.h
index fb84122d..f6a82646 100644
--- a/module.h
+++ b/module.h
@@ -41,10 +41,9 @@
 
 #include "ispc.h"
 #include "ast.h"
-#if defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 && ISPC_LLVM_VERSION < ISPC_LLVM_3_5
   #include <llvm/DebugInfo.h>
-#endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#elif ISPC_LLVM_VERSION >= ISPC_LLVM_3_5
   #include <llvm/IR/DebugInfo.h>
 #endif
 
@@ -161,10 +160,10 @@ public:
     /** The diBuilder manages generating debugging information */
     llvm::DIBuilder *diBuilder;
 
-#if defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DICompileUnit diCompileUnit;
-#elif !defined(LLVM_3_2) && !defined(LLVM_3_3) // LLVM 3.7++
-    llvm::DICompileUnit *diCompileUnit;
+#elif ISPC_LLVM_VERSION >= ISPC_LLVM_3_7
+    llvm::DICompileUnit* diCompileUnit;
 #endif // LLVM_3_4+
 
 private:
diff --git a/opt.cpp b/opt.cpp
index ac9d2e2b..47918c78 100644
--- a/opt.cpp
+++ b/opt.cpp
@@ -48,7 +48,7 @@
 #include <set>
 
 #include <llvm/Pass.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/Module.h>
   #include <llvm/Instructions.h>
   #include <llvm/Intrinsics.h>
@@ -58,7 +58,7 @@
 #ifdef ISPC_NVPTX_ENABLED
   #include <llvm/InlineAsm.h>
 #endif /* ISPC_NVPTX_ENABLED */
-#else
+#else /* >= 3.3 */
   #include <llvm/IR/Module.h>
   #include <llvm/IR/Instructions.h>
   #include <llvm/IR/Intrinsics.h>
@@ -69,30 +69,30 @@
   #include <llvm/IR/InlineAsm.h>
 #endif /* ISPC_NVPTX_ENABLED */
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) // LLVM 3.4+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 // LLVM 3.4+
   #include <llvm/Transforms/Instrumentation.h>
 #endif
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
   #include "llvm/PassManager.h"
-#else // LLVM 3.7+
+#else /* >= 3.7 */
   #include "llvm/IR/LegacyPassManager.h"
 #endif
 #include <llvm/PassRegistry.h>
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 // LLVM 3.5+
     #include <llvm/IR/Verifier.h>
     #include <llvm/IR/IRPrintingPasses.h>
     #include <llvm/IR/PatternMatch.h>
     #include <llvm/IR/DebugInfo.h>
-#else
+#else /* < 3.5 */
     #include <llvm/Analysis/Verifier.h>
     #include <llvm/Assembly/PrintModulePass.h>
     #include <llvm/Support/PatternMatch.h>
     #include <llvm/DebugInfo.h>
 #endif
 #include <llvm/Analysis/ConstantFolding.h>
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     #include <llvm/Target/TargetLibraryInfo.h>
-#else // LLVM 3.7+
+#else /* >= 3.7 */
     #include <llvm/Analysis/TargetLibraryInfo.h>
 #endif
 #include <llvm/ADT/Triple.h>
@@ -101,9 +101,9 @@
 #include <llvm/Transforms/IPO.h>
 #include <llvm/Transforms/Utils/BasicBlockUtils.h>
 #include <llvm/Target/TargetOptions.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/DataLayout.h>
-#else // LLVM 3.3+
+#else /* LLVM 3.3+ */
   #include <llvm/IR/DataLayout.h>
   #include <llvm/Analysis/TargetTransformInfo.h>
 #endif
@@ -111,7 +111,7 @@
 #include <llvm/Analysis/Passes.h>
 #include <llvm/Support/raw_ostream.h>
 #include <llvm/Support/Dwarf.h>
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) && !defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_6
   #include <llvm/IR/IntrinsicInst.h>
 #endif
 #ifdef ISPC_IS_LINUX
@@ -238,33 +238,33 @@ lGetSourcePosFromMetadata(const llvm::Instruction *inst, SourcePos *pos) {
     llvm::MDString *str = llvm::dyn_cast<llvm::MDString>(filename->getOperand(0));
     Assert(str);
     llvm::ConstantInt *first_lnum =
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::dyn_cast<llvm::ConstantInt>(first_line->getOperand(0));
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
         llvm::mdconst::extract<llvm::ConstantInt>(first_line->getOperand(0));
 #endif
     Assert(first_lnum);
 
     llvm::ConstantInt *first_colnum =
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::dyn_cast<llvm::ConstantInt>(first_column->getOperand(0));
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
         llvm::mdconst::extract<llvm::ConstantInt>(first_column->getOperand(0));
 #endif
     Assert(first_column);
 
     llvm::ConstantInt *last_lnum =
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::dyn_cast<llvm::ConstantInt>(last_line->getOperand(0));
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
         llvm::mdconst::extract<llvm::ConstantInt>(last_line->getOperand(0));
 #endif
     Assert(last_lnum);
 
     llvm::ConstantInt *last_colnum =
-#if defined (LLVM_3_2) || defined (LLVM_3_3)|| defined (LLVM_3_4)|| defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::dyn_cast<llvm::ConstantInt>(last_column->getOperand(0));
-#else // LLVN 3.6++
+#else /* LLVN 3.6+ */
         llvm::mdconst::extract<llvm::ConstantInt>(last_column->getOperand(0));
 #endif
     Assert(last_column);
@@ -330,10 +330,10 @@ lGEPInst(llvm::Value *ptr, llvm::Value *offset, const char *name,
          llvm::Instruction *insertBefore) {
     llvm::Value *index[1] = { offset };
     llvm::ArrayRef<llvm::Value *> arrayRef(&index[0], &index[1]);
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     return llvm::GetElementPtrInst::Create(ptr, arrayRef, name,
                                            insertBefore);
-#else // LLVM 3.7++
+#else /* LLVM 3.7+ */
     return llvm::GetElementPtrInst::Create(PTYPE(ptr), ptr, arrayRef,
                                            name, insertBefore);
 #endif
@@ -466,15 +466,15 @@ public:
     DebugPassManager():number(0){}
     void add(llvm::Pass * P, int stage);
     bool run(llvm::Module& M) {return PM.run(M);}
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::PassManager& getPM() {return PM;}
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::legacy::PassManager& getPM() {return PM;}
 #endif
 private:
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::PassManager PM;
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     llvm::legacy::PassManager PM;
 #endif
     int number;
@@ -500,7 +500,7 @@ DebugPassManager::add(llvm::Pass * P, int stage = -1) {
             PM.add(CreateDebugPass(buf));
         }
 
-#if defined(LLVM_3_4) || defined(LLVM_3_5) // only 3.4 and 3.5
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_4 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6 // only 3.4 and 3.5
         if (g->debugIR == number) {
             // adding generating of LLVM IR debug after optimization
             char buf[100];
@@ -521,19 +521,19 @@ Optimize(llvm::Module *module, int optLevel) {
     DebugPassManager optPM;
     optPM.add(llvm::createVerifierPass(),0);
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::TargetLibraryInfo *targetLibraryInfo =
         new llvm::TargetLibraryInfo(llvm::Triple(module->getTargetTriple()));
     optPM.add(targetLibraryInfo);
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     optPM.add(new llvm::TargetLibraryInfoWrapperPass(llvm::Triple(module->getTargetTriple())));
 #endif
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_5
     optPM.add(new llvm::DataLayout(*g->target->getDataLayout()));
-#elif defined(LLVM_3_5)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     optPM.add(new llvm::DataLayoutPass(*g->target->getDataLayout()));
-#elif defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DataLayoutPass *dlp= new llvm::DataLayoutPass();
     dlp->doInitialization(*module);
     optPM.add(dlp);
@@ -541,12 +541,12 @@ Optimize(llvm::Module *module, int optLevel) {
 
     llvm::TargetMachine *targetMachine = g->target->GetTargetMachine();
 
-#ifdef LLVM_3_2
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_3
     optPM.add(new llvm::TargetTransformInfo(targetMachine->getScalarTargetTransformInfo(),
                                             targetMachine->getVectorTargetTransformInfo()));
-#elif defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6) // LLVM 3.3 - 3.6
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     targetMachine->addAnalysisPasses(optPM.getPM());
-#else // LLVM 3.7+
+#else /* LLVM 3.7+ */
     optPM.getPM().add(createTargetTransformInfoWrapperPass(targetMachine->getTargetIRAnalysis()));
 #endif
 
@@ -660,7 +660,7 @@ Optimize(llvm::Module *module, int optLevel) {
         optPM.add(llvm::createCFGSimplificationPass());
 
         optPM.add(llvm::createArgumentPromotionPass());
-#if defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_4 
         // Starting from 3.4 this functionality was moved to
         // InstructionCombiningPass. See r184459 for details.
         optPM.add(llvm::createSimplifyLibCallsPass(), 240);
@@ -810,7 +810,7 @@ Optimize(llvm::Module *module, int optLevel) {
           optPM.add(llvm::createCFGSimplificationPass());
 
           optPM.add(llvm::createArgumentPromotionPass());
-#if defined(LLVM_3_1) || defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_2 && ISPC_LLVM_VERSION < ISPC_LLVM_3_4 
           // Starting from 3.4 this functionality was moved to
           // InstructionCombiningPass. See r184459 for details.
           optPM.add(llvm::createSimplifyLibCallsPass());
@@ -4924,7 +4924,7 @@ PeepholePass::PeepholePass()
     : BasicBlockPass(ID) {
 }
 
-#if !defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION > ISPC_LLVM_3_2
 
 using namespace llvm::PatternMatch;
 
@@ -5258,7 +5258,7 @@ PeepholePass::runOnBasicBlock(llvm::BasicBlock &bb) {
         llvm::Instruction *inst = &*iter;
 
         llvm::Instruction *builtinCall = NULL;
-#if !defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION > ISPC_LLVM_3_2
         if (!builtinCall)
           builtinCall = lMatchAvgUpUInt8(inst);
         if (!builtinCall)
@@ -5471,9 +5471,7 @@ llvm::Instruction* FixBooleanSelectPass::fixSelect(llvm::SelectInst* sel, llvm::
 bool
 FixBooleanSelectPass::runOnFunction(llvm::Function &F) {
     bool modifiedAny = false;
-
-    // LLVM 3.3 only
-#if defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_3 // LLVM 3.3 only
 
     // Don't optimize generic targets.
     if (g->target->getISA() == Target::GENERIC) {
diff --git a/parse.yy b/parse.yy
index daa41e54..703e12d1 100644
--- a/parse.yy
+++ b/parse.yy
@@ -83,7 +83,7 @@ struct ForeachDimension;
 #include "util.h"
 
 #include <stdio.h>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/Constants.h>
 #else
   #include <llvm/IR/Constants.h>
diff --git a/stmt.cpp b/stmt.cpp
index 586cb0fe..3b70c364 100644
--- a/stmt.cpp
+++ b/stmt.cpp
@@ -48,7 +48,7 @@
 #include <stdio.h>
 #include <map>
 
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/Module.h>
   #include <llvm/Type.h>
   #include <llvm/Instructions.h>
@@ -190,7 +190,11 @@ static llvm::Value* lConvertToGenericPtr(FunctionEmitContext *ctx, llvm::Value *
     llvm::Function *func_warp_index    = m->module->getFunction("__warp_index");
     llvm::Value *warpId = ctx->CallInst(func_warp_index, NULL, std::vector<llvm::Value*>(),  "gep2gen_warp_index");
     llvm::Value *offset = ctx->BinaryOperator(llvm::Instruction::Mul, warpId, LLVMInt32(numEl), "gep2gen_offset");
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     value = llvm::GetElementPtrInst::Create(value, offset, "gep2gen_offset", ctx->GetCurrentBasicBlock());
+#else
+    value = llvm::GetElementPtrInst::Create(NULL, value, offset, "gep2gen_offset", ctx->GetCurrentBasicBlock());
+#endif
   }
 
   /* convert arrElTy* to elTy* */
@@ -1535,7 +1539,11 @@ lUpdateVaryingCounter(int dim, int nDims, FunctionEmitContext *ctx,
       ptr_arrayidx_indices.push_back(LLVMInt32(0));
       ptr_arrayidx_indices.push_back(laneIdx);
 #if 1
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
       llvm::Instruction* ptr_arrayidx = llvm::GetElementPtrInst::Create(globalDelta, ptr_arrayidx_indices, "arrayidx", ctx->GetCurrentBasicBlock());
+#else
+      llvm::Instruction* ptr_arrayidx = llvm::GetElementPtrInst::Create(NULL, globalDelta, ptr_arrayidx_indices, "arrayidx", ctx->GetCurrentBasicBlock());
+#endif
       llvm::LoadInst* int8_39 = new llvm::LoadInst(ptr_arrayidx, "", false, ctx->GetCurrentBasicBlock());
       llvm::Value * int32_39 = ctx->ZExtInst(int8_39, LLVMTypes::Int32Type);
 
diff --git a/type.cpp b/type.cpp
index 2f7b3546..6d48bca4 100644
--- a/type.cpp
+++ b/type.cpp
@@ -43,14 +43,14 @@
 
 #include <stdio.h>
 #include <map>
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
   #include <llvm/Value.h>
   #include <llvm/Module.h>
 #else
   #include <llvm/IR/Value.h>
   #include <llvm/IR/Module.h>
 #endif
-#if !defined(LLVM_3_2) && !defined(LLVM_3_3) && !defined(LLVM_3_4) // LLVM 3.5+
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_5 // LLVM 3.5+
   #include <llvm/IR/DebugInfo.h>
   #include <llvm/IR/DIBuilder.h>
 #else
@@ -79,12 +79,13 @@ lShouldPrintName(const std::string &name) {
 
 /** Utility routine to create a llvm array type of the given number of
     the given element type. */
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 static llvm::DIType lCreateDIArray(llvm::DIType eltType, int count) {
 #else // LLVM 3.7++
 static llvm::DIType *lCreateDIArray(llvm::DIType *eltType, int count) {
 #endif
-#ifdef LLVM_3_2
+
+#if ISPC_LLVM_VERSION == ISPC_LLVM_3_2
     int lowerBound = 0, upperBound = count-1;
 
     if (count == 0) {
@@ -94,11 +95,11 @@ static llvm::DIType *lCreateDIArray(llvm::DIType *eltType, int count) {
     }
 
     llvm::Value *sub = m->diBuilder->getOrCreateSubrange(lowerBound, upperBound);
-#elif defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, count);
 #endif
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     std::vector<llvm::Value *> subs;
 #else // LLVM 3.6++
     llvm::Metadata *sub = m->diBuilder->getOrCreateSubrange(0, count);
@@ -106,7 +107,7 @@ static llvm::DIType *lCreateDIArray(llvm::DIType *eltType, int count) {
 #endif
     subs.push_back(sub);
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIArray subArray = m->diBuilder->getOrCreateArray(subs);
     uint64_t size = eltType.getSizeInBits() * count;
     uint64_t align = eltType.getAlignInBits();
@@ -525,7 +526,7 @@ AtomicType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType AtomicType::GetDIType(llvm::DIDescriptor scope) const {
 #else //LLVM 3.7++
 llvm::DIType *AtomicType::GetDIType(llvm::DIScope *scope) const {
@@ -535,7 +536,7 @@ llvm::DIType *AtomicType::GetDIType(llvm::DIScope *scope) const {
     if (variability.type == Variability::Uniform) {
         switch (basicType) {
         case TYPE_VOID:
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
             return llvm::DIType();
 #else //LLVM 3.7++
             return NULL;
@@ -586,7 +587,7 @@ llvm::DIType *AtomicType::GetDIType(llvm::DIScope *scope) const {
             break;
         default:
             FATAL("unhandled basic type in AtomicType::GetDIType()");
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
             return llvm::DIType();
 #else //LLVM 3.7++
             return NULL;
@@ -594,21 +595,23 @@ llvm::DIType *AtomicType::GetDIType(llvm::DIScope *scope) const {
         }
     }
     else if (variability == Variability::Varying) {
-#ifdef LLVM_3_2
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
         llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, g->target->getVectorWidth()-1);
-#elif defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5)
+#elif ISPC_LLVM_VERSION >= ISPC_VERSION_3_3 && ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, g->target->getVectorWidth());
 #else // LLVM 3.6++
         llvm::Metadata *sub = m->diBuilder->getOrCreateSubrange(0, g->target->getVectorWidth());
 #endif
-#if defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_VERSION_3_3 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIArray subArray = m->diBuilder->getOrCreateArray(sub);
         llvm::DIType unifType = GetAsUniformType()->GetDIType(scope);
         uint64_t size =  unifType.getSizeInBits()  * g->target->getVectorWidth();
         uint64_t align = unifType.getAlignInBits() * g->target->getVectorWidth();
-#else // LLVM 3.7++
+#elif ISPC_LLVM_VERSION >= ISPC_VERSION_3_7 // LLVM 3.7+
         llvm::DINodeArray subArray = m->diBuilder->getOrCreateArray(sub);
         llvm::DIType *unifType = GetAsUniformType()->GetDIType(scope);
+        //llvm::DebugNodeArray subArray = m->diBuilder->getOrCreateArray(sub);
+        //llvm::MDType *unifType = GetAsUniformType()->GetDIType(scope);
         uint64_t size =  unifType->getSizeInBits() * g->target->getVectorWidth();
         uint64_t align = unifType->getAlignInBits()* g->target->getVectorWidth();
 #endif
@@ -844,13 +847,13 @@ EnumType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType EnumType::GetDIType(llvm::DIDescriptor scope) const {
 #else // LLVM 3.7++
 llvm::DIType *EnumType::GetDIType(llvm::DIScope *scope) const {
 #endif
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     std::vector<llvm::Value *> enumeratorDescriptors;
 #else // LLVM 3.6++
     std::vector<llvm::Metadata *> enumeratorDescriptors;
@@ -860,7 +863,7 @@ llvm::DIType *EnumType::GetDIType(llvm::DIScope *scope) const {
         Assert(enumerators[i]->constValue != NULL);
         int count = enumerators[i]->constValue->GetValues(&enumeratorValue);
         Assert(count == 1);
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::Value *descriptor =
 #else // LLVM 3.6++
         llvm::Metadata *descriptor =
@@ -868,7 +871,7 @@ llvm::DIType *EnumType::GetDIType(llvm::DIScope *scope) const {
             m->diBuilder->createEnumerator(enumerators[i]->name, enumeratorValue);
         enumeratorDescriptors.push_back(descriptor);
     }
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIArray elementArray =
         m->diBuilder->getOrCreateArray(enumeratorDescriptors);
     llvm::DIFile diFile = pos.GetDIFile();
@@ -891,19 +894,20 @@ llvm::DIType *EnumType::GetDIType(llvm::DIScope *scope) const {
     case Variability::Uniform:
         return diType;
     case Variability::Varying: {
-#ifdef LLVM_3_2
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
         llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, g->target->getVectorWidth()-1);
-#elif defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5)        
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_6
         llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, g->target->getVectorWidth());
 #else // LLVM 3.6++
         llvm::Metadata *sub = m->diBuilder->getOrCreateSubrange(0, g->target->getVectorWidth());
 #endif
-#if defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIArray subArray = m->diBuilder->getOrCreateArray(sub);
-        uint64_t size =  diType.getSizeInBits()  * g->target->getVectorWidth();
+        uint64_t size  =  diType.getSizeInBits() * g->target->getVectorWidth();
         uint64_t align = diType.getAlignInBits() * g->target->getVectorWidth();
-#else // LLVM 3.7++
+#elif ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7++
         llvm::DINodeArray subArray = m->diBuilder->getOrCreateArray(sub);
+        //llvm::DebugNodeArray subArray = m->diBuilder->getOrCreateArray(sub);
         uint64_t size =  diType->getSizeInBits() * g->target->getVectorWidth();
         uint64_t align = diType->getAlignInBits()* g->target->getVectorWidth();
 #endif
@@ -914,7 +918,7 @@ llvm::DIType *EnumType::GetDIType(llvm::DIScope *scope) const {
     }
     default:
         FATAL("Unexpected variability in EnumType::GetDIType()");
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         return llvm::DIType();
 #else //LLVM 3.7++
         return NULL;
@@ -1252,7 +1256,7 @@ PointerType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType PointerType::GetDIType(llvm::DIDescriptor scope) const {
     if (baseType == NULL) {
         Assert(m->errorCount > 0);
@@ -1275,7 +1279,7 @@ llvm::DIType *PointerType::GetDIType(llvm::DIScope *scope) const {
                                                ptrAlignBits);
     case Variability::Varying: {
         // emit them as an array of pointers
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIType eltType =
 #else //LLVM 3.7++
         llvm::DIDerivedType *eltType =
@@ -1289,7 +1293,7 @@ llvm::DIType *PointerType::GetDIType(llvm::DIScope *scope) const {
     }
     default:
         FATAL("Unexpected variability in PointerType::GetDIType()");
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         return llvm::DIType();
 #else //LLVM 3.7++
         return NULL;
@@ -1567,7 +1571,7 @@ ArrayType::TotalElementCount() const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType ArrayType::GetDIType(llvm::DIDescriptor scope) const {
     if (child == NULL) {
         Assert(m->errorCount > 0);
@@ -1816,16 +1820,16 @@ VectorType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType VectorType::GetDIType(llvm::DIDescriptor scope) const {
     llvm::DIType eltType = base->GetDIType(scope);
 #else //LLVM 3.7++
 llvm::DIType *VectorType::GetDIType(llvm::DIScope *scope) const {
     llvm::DIType *eltType = base->GetDIType(scope);
 #endif
-#ifdef LLVM_3_2
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
     llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, numElements-1);
-#elif defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     llvm::Value *sub = m->diBuilder->getOrCreateSubrange(0, numElements);
 #else // LLVM 3.6++
     llvm::Metadata *sub = m->diBuilder->getOrCreateSubrange(0, numElements);
@@ -1834,7 +1838,7 @@ llvm::DIType *VectorType::GetDIType(llvm::DIScope *scope) const {
     // vectors of varying types are already naturally aligned to the
     // machine's vector width, but arrays of uniform types need to be
     // explicitly aligned to the machines natural vector alignment.
-#if defined (LLVM_3_3)|| defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIArray subArray = m->diBuilder->getOrCreateArray(sub);
     uint64_t sizeBits = eltType.getSizeInBits() * numElements;
     uint64_t align = eltType.getAlignInBits();
@@ -1855,7 +1859,7 @@ llvm::DIType *VectorType::GetDIType(llvm::DIScope *scope) const {
     }
     else {
         FATAL("Unexpected variability in VectorType::GetDIType()");
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         return llvm::DIType();
 #else // LLVM 3.7++
         return NULL;
@@ -2259,13 +2263,13 @@ StructType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType StructType::GetDIType(llvm::DIDescriptor scope) const {
 #else //LLVM 3.7++
 llvm::DIType *StructType::GetDIType(llvm::DIScope *scope) const {
 #endif
     uint64_t currentSize = 0, align = 0;
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     std::vector<llvm::Value *> elementLLVMTypes;
 #else // LLVM 3.6++
     std::vector<llvm::Metadata *> elementLLVMTypes;
@@ -2274,7 +2278,7 @@ llvm::DIType *StructType::GetDIType(llvm::DIScope *scope) const {
     // alignment and size, using that to figure out its offset w.r.t. the
     // start of the structure.
     for (unsigned int i = 0; i < elementTypes.size(); ++i) {
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIType eltType = GetElementType(i)->GetDIType(scope);
         uint64_t eltAlign = eltType.getAlignInBits();
         uint64_t eltSize = eltType.getSizeInBits();
@@ -2296,7 +2300,7 @@ llvm::DIType *StructType::GetDIType(llvm::DIScope *scope) const {
         Assert((currentSize == 0) || (currentSize % eltAlign) == 0);
 
         int line = elementPositions[i].first_line;
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIFile diFile = elementPositions[i].GetDIFile();
         llvm::DIType fieldType =
 #else // LLVM 3.7++
@@ -2316,7 +2320,7 @@ llvm::DIType *StructType::GetDIType(llvm::DIScope *scope) const {
     if (currentSize > 0 && (currentSize % align))
         currentSize += align - (currentSize % align);
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5) || defined (LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIArray elements = m->diBuilder->getOrCreateArray(elementLLVMTypes);
     llvm::DIFile diFile = pos.GetDIFile();
 #else // LLVM 3.7++
@@ -2331,9 +2335,9 @@ llvm::DIType *StructType::GetDIType(llvm::DIScope *scope) const {
         currentSize,    // Size in bits
         align,          // Alignment in bits
         0,              // Flags
-#if defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIType(), // DerivedFrom
-#elif !defined(LLVM_3_2) // LLVM 3.7++
+#elif ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7++
         NULL,
 #endif
         elements);
@@ -2564,7 +2568,7 @@ UndefinedStructType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType UndefinedStructType::GetDIType(llvm::DIDescriptor scope) const {
     llvm::DIFile diFile = pos.GetDIFile();
     llvm::DIArray elements;
@@ -2581,9 +2585,9 @@ llvm::DIType *UndefinedStructType::GetDIType(llvm::DIScope *scope) const {
         0,              // Size
         0,              // Align
         0,              // Flags
-#if defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION >= ISPC_LLVM_3_3 && ISPC_LLVM_VERSION < ISPC_LLVM_3_7
         llvm::DIType(), // DerivedFrom
-#elif !defined(LLVM_3_2) // LLVM 3.7++
+#elif ISPC_LLVM_VERSION >= ISPC_LLVM_3_7 // LLVM 3.7++
         NULL,
 #endif
         elements);
@@ -2838,7 +2842,7 @@ ReferenceType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType ReferenceType::GetDIType(llvm::DIDescriptor scope) const {
     if (targetType == NULL) {
         Assert(m->errorCount > 0);
@@ -3117,13 +3121,13 @@ FunctionType::LLVMType(llvm::LLVMContext *ctx) const {
 }
 
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
 llvm::DIType FunctionType::GetDIType(llvm::DIDescriptor scope) const {
 #else //LLVM 3.7++
 llvm::DIType *FunctionType::GetDIType(llvm::DIScope *scope) const {
 #endif
 
-#if defined (LLVM_3_2) || defined (LLVM_3_3) || defined (LLVM_3_4) || defined (LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     std::vector<llvm::Value *> retArgTypes;
 #else // LLVM 3.6++
     std::vector<llvm::Metadata *> retArgTypes;
@@ -3133,22 +3137,22 @@ llvm::DIType *FunctionType::GetDIType(llvm::DIScope *scope) const {
         const Type *t = GetParameterType(i);
         if (t == NULL)
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_4
             return llvm::DIType();
-#elif defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7
             return llvm::DICompositeType();
 #else // LLVM 3.7++
             return NULL;
 #endif
         retArgTypes.push_back(t->GetDIType(scope));
     }
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_6
     llvm::DIArray retArgTypesArray =
         m->diBuilder->getOrCreateArray(llvm::ArrayRef<llvm::Value *>(retArgTypes));
     llvm::DIType diType =
         // FIXME: DIFile
         m->diBuilder->createSubroutineType(llvm::DIFile(), retArgTypesArray);
-#elif defined(LLVM_3_6)
+#elif ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DITypeArray retArgTypesArray =
         m->diBuilder->getOrCreateTypeArray(retArgTypes);
     llvm::DIType diType =
diff --git a/type.h b/type.h
index 91b318bf..a8c70512 100644
--- a/type.h
+++ b/type.h
@@ -40,10 +40,10 @@
 
 #include "ispc.h"
 #include "util.h"
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/Type.h>
   #include <llvm/DerivedTypes.h>
-#else
+#else /* >= 3.3 */
   #include <llvm/IR/Type.h>
   #include <llvm/IR/DerivedTypes.h>
 #endif
@@ -222,7 +222,7 @@ public:
     /** Returns the LLVM type corresponding to this ispc type */
     virtual llvm::Type *LLVMType(llvm::LLVMContext *ctx) const = 0;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     /** Returns the DIType (LLVM's debugging information structure),
         corresponding to this type. */
     virtual llvm::DIType GetDIType(llvm::DIDescriptor scope) const = 0;
@@ -317,7 +317,7 @@ public:
     std::string GetCDeclaration(const std::string &name) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -400,7 +400,7 @@ public:
     const std::string &GetEnumName() const { return name; }
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -485,7 +485,7 @@ public:
     std::string GetCDeclaration(const std::string &name) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -591,7 +591,7 @@ public:
     std::string Mangle() const;
     std::string GetCDeclaration(const std::string &name) const;
 
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -663,7 +663,7 @@ public:
     std::string GetCDeclaration(const std::string &name) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -718,7 +718,7 @@ public:
     std::string GetCDeclaration(const std::string &name) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -810,7 +810,7 @@ public:
     std::string GetCDeclaration(const std::string &name) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -857,7 +857,7 @@ public:
     std::string GetCDeclaration(const std::string &name) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
@@ -915,7 +915,7 @@ public:
     std::string GetCDeclarationForDispatch(const std::string &fname) const;
 
     llvm::Type *LLVMType(llvm::LLVMContext *ctx) const;
-#if defined(LLVM_3_2) || defined(LLVM_3_3) || defined(LLVM_3_4) || defined(LLVM_3_5) || defined(LLVM_3_6)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_7
     llvm::DIType GetDIType(llvm::DIDescriptor scope) const;
 #else // LLVM 3.7++
     llvm::DIType *GetDIType(llvm::DIScope *scope) const;
diff --git a/util.cpp b/util.cpp
index ba4249c3..fd076ade 100644
--- a/util.cpp
+++ b/util.cpp
@@ -65,7 +65,7 @@
 #include <set>
 #include <algorithm>
 
-#if defined(LLVM_3_2)
+#if ISPC_LLVM_VERSION < ISPC_LLVM_3_3
   #include <llvm/DataLayout.h>
 #else // LLVM 3.3+
   #include <llvm/IR/DataLayout.h>