diff --git a/opts/ClassIMPCache.cpp b/opts/ClassIMPCache.cpp
index f0beb45..493e969 100644
--- a/opts/ClassIMPCache.cpp
+++ b/opts/ClassIMPCache.cpp
@@ -38,7 +38,6 @@ namespace
         if (F->isDeclaration()) { continue; }
 
         SmallVector<std::pair<CallSite, bool>, 16> Lookups;
-        BasicBlock *entry = &F->getEntryBlock();
 
         for (Function::iterator i=F->begin(), end=F->end() ;
             i != end ; ++i) {
@@ -62,7 +61,6 @@ namespace
             }
           }
         }
-        IRBuilder<> B = IRBuilder<>(entry);
         for (SmallVectorImpl<std::pair<CallSite, bool> >::iterator
             i=Lookups.begin(), e=Lookups.end() ; e!=i ; i++) {
           Instruction *call = i->first.getInstruction();
diff --git a/opts/ClassLookupCache.cpp b/opts/ClassLookupCache.cpp
index 7d34c11..6068357 100644
--- a/opts/ClassLookupCache.cpp
+++ b/opts/ClassLookupCache.cpp
@@ -11,6 +11,7 @@
 #include <string>
 
 #include "IMPCacher.h"
+#include "LLVMCompat.h"
 
 using namespace llvm;
 using namespace GNUstep;
@@ -98,8 +99,7 @@ namespace
           removeTerminator(beforeLookupBB);
           removeTerminator(lookupBB);
 
-          PHINode *phi =
-            PHINode::Create(clsTy, 2, cls, afterLookupBB->begin());
+		  PHINode *phi = CreatePHI(clsTy, 2, cls, afterLookupBB->begin());
           // We replace all of the existing uses with the PHI node now, because
           // we're going to add some more uses later that we don't want
           // replaced.
diff --git a/opts/IMPCacher.cpp b/opts/IMPCacher.cpp
index bcc48a3..0638eb3 100644
--- a/opts/IMPCacher.cpp
+++ b/opts/IMPCacher.cpp
@@ -11,6 +11,8 @@
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 
+#include "LLVMCompat.h"
+
 GNUstep::IMPCacher::IMPCacher(LLVMContext &C, Pass *owner) : Context(C),
   Owner(owner) {
 
@@ -19,7 +21,7 @@ GNUstep::IMPCacher::IMPCacher(LLVMContext &C, Pass *owner) : Context(C),
   IntTy = Type::getInt32Ty(Context);
   IdTy = PointerType::getUnqual(PtrTy);
   Value *AlreadyCachedFlagValue = MDString::get(C, "IMPCached");
-  AlreadyCachedFlag = MDNode::get(C, &AlreadyCachedFlagValue, 1);
+  AlreadyCachedFlag = CreateMDNode(C, AlreadyCachedFlagValue);
   IMPCacheFlagKind = Context.getMDKindID("IMPCache");
 }
 
@@ -171,8 +173,7 @@ void GNUstep::IMPCacher::SpeculativelyInline(Instruction *call, Function
 
   // Unify the return values
   if (call->getType() != Type::getVoidTy(Context)) {
-    B.SetInsertPoint(afterCallBB, afterCallBB->begin());
-    PHINode *phi = B.CreatePHI(call->getType(), 2);
+    PHINode *phi = CreatePHI(call->getType(), 2, 0, afterCallBB->begin());
     call->replaceAllUsesWith(phi);
     phi->addIncoming(call, callBB);
     phi->addIncoming(inlineResult, inlineBB);
diff --git a/opts/LLVMCompat.h b/opts/LLVMCompat.h
new file mode 100644
index 0000000..d7df502
--- /dev/null
+++ b/opts/LLVMCompat.h
@@ -0,0 +1,29 @@
+/**
+ * Compatibility header that wraps LLVM API breakage and lets us compile with
+ * old and new versions of LLVM.
+ */
+
+__attribute((unused)) static inline 
+PHINode* CreatePHI(const Type *Ty,
+                   unsigned NumReservedValues,
+                   const Twine &NameStr="",
+                   Instruction *InsertBefore=0) {
+#if LLVM_MAJOR < 3
+    PHINode *phi = PHINode::Create(Ty, NameStr, InsertBefore);
+    phi->reserveOperandSpace(NumReservedValues);
+    return phi;
+#else
+    return PHINode::Create(Ty, NumReservedValues, NameStr, InsertBefore);
+#endif
+}
+
+__attribute((unused)) static inline 
+MDNode* CreateMDNode(LLVMContext &C,
+                     Value *V) {
+#if LLVM_MAJOR < 3
+  return MDNode::get(C, &V, 1);
+#else
+  ArrayRef<Value*> val(V);
+  return MDNode::get(C, val);
+#endif
+}
diff --git a/opts/Makefile b/opts/Makefile
index fcef1b5..46e15e0 100644
--- a/opts/Makefile
+++ b/opts/Makefile
@@ -2,6 +2,7 @@ LEVEL = ../../../
 LIBRARYNAME = libGNUObjCRuntime
 LOADABLE_MODULE = 1
 USEDLIBS =
+CPPFLAGS += `llvm-config --version | sed 's/\([0-9]*\).\([0-9]*\).*/-DLLVM_MAJOR=\1 -DLLVM_MINOR=\2/'`
 
 include $(LEVEL)/Makefile.common
 
diff --git a/opts/TypeFeedbackDrivenInliner.cpp b/opts/TypeFeedbackDrivenInliner.cpp
index 77702b5..2658b65 100644
--- a/opts/TypeFeedbackDrivenInliner.cpp
+++ b/opts/TypeFeedbackDrivenInliner.cpp
@@ -65,7 +65,6 @@ namespace {
 
         if (Entry->size() == 1) {
 
-          TypeInfoProvider::CallSiteEntry::iterator iterator = Entry->begin();
           Function *method = M.getFunction(Entry->begin()->getKey());
           if (0 == method || method->isDeclaration()) { continue; }