diff --git a/ctx.cpp b/ctx.cpp
index 95840aab..a3702d7a 100644
--- a/ctx.cpp
+++ b/ctx.cpp
@@ -1156,19 +1156,62 @@ FunctionEmitContext::PtrToIntInst(llvm::Value *value, const char *name) {
 
 
 llvm::Value *
-FunctionEmitContext::IntToPtrInst(llvm::Value *value, LLVM_TYPE_CONST llvm::Type *type,
+FunctionEmitContext::PtrToIntInst(llvm::Value *value, 
+                                  LLVM_TYPE_CONST llvm::Type *toType,
                                   const char *name) {
     if (value == NULL) {
         assert(m->errorCount > 0);
         return NULL;
     }
 
-    if (llvm::isa<LLVM_TYPE_CONST llvm::VectorType>(value->getType()))
-        // no-op for varying pointers; they're already vectors of ints
-        return value;
+    LLVM_TYPE_CONST llvm::Type *fromType = value->getType();
+    if (llvm::isa<LLVM_TYPE_CONST llvm::VectorType>(fromType)) {
+        // varying pointer
+        if (fromType == toType)
+            // already the right type--done
+            return value;
+        else if (fromType->getScalarSizeInBits() > toType->getScalarSizeInBits())
+            return TruncInst(value, toType, "ptr_to_int");
+        else {
+            assert(fromType->getScalarSizeInBits() <
+                   toType->getScalarSizeInBits());
+            return ZExtInst(value, toType, "ptr_to_int");
+        }
+    }
 
     llvm::Instruction *inst = 
-        new llvm::IntToPtrInst(value, type, name ? name : "int2ptr", bblock);
+        new llvm::PtrToIntInst(value, toType, name ? name : "ptr2int", bblock);
+    AddDebugPos(inst);
+    return inst;
+}
+
+
+llvm::Value *
+FunctionEmitContext::IntToPtrInst(llvm::Value *value, 
+                                  LLVM_TYPE_CONST llvm::Type *toType,
+                                  const char *name) {
+    if (value == NULL) {
+        assert(m->errorCount > 0);
+        return NULL;
+    }
+
+    LLVM_TYPE_CONST llvm::Type *fromType = value->getType();
+    if (llvm::isa<LLVM_TYPE_CONST llvm::VectorType>(fromType)) {
+        // varying pointer
+        if (fromType == toType)
+            // done
+            return value;
+        else if (fromType->getScalarSizeInBits() > toType->getScalarSizeInBits())
+            return TruncInst(value, toType, "int_to_ptr");
+        else {
+            assert(fromType->getScalarSizeInBits() <
+                   toType->getScalarSizeInBits());
+            return ZExtInst(value, toType, "int_to_ptr");
+        }
+    }
+
+    llvm::Instruction *inst = 
+        new llvm::IntToPtrInst(value, toType, name ? name : "int2ptr", bblock);
     AddDebugPos(inst);
     return inst;
 }
diff --git a/ctx.h b/ctx.h
index b4472f1c..298167a5 100644
--- a/ctx.h
+++ b/ctx.h
@@ -41,9 +41,7 @@
 #include "ispc.h"
 #include <llvm/InstrTypes.h>
 #include <llvm/Instructions.h>
-#ifndef LLVM_2_8
 #include <llvm/Analysis/DIBuilder.h>
-#endif
 #include <llvm/Analysis/DebugInfo.h>
 
 struct CFInfo;
@@ -316,6 +314,8 @@ public:
     llvm::Value *BitCastInst(llvm::Value *value, LLVM_TYPE_CONST llvm::Type *type,
                              const char *name = NULL);
     llvm::Value *PtrToIntInst(llvm::Value *value, const char *name = NULL);
+    llvm::Value *PtrToIntInst(llvm::Value *value, LLVM_TYPE_CONST llvm::Type *type,
+                              const char *name = NULL);
     llvm::Value *IntToPtrInst(llvm::Value *value, LLVM_TYPE_CONST llvm::Type *type,
                               const char *name = NULL);
 
diff --git a/expr.cpp b/expr.cpp
index f6800b3d..c8c8bdfc 100644
--- a/expr.cpp
+++ b/expr.cpp
@@ -1294,8 +1294,9 @@ BinaryExpr::GetType() const {
                 // ptr - int -> ptr
                 return type0;
         }
-        // otherwise fall through for these two...
-        assert(op == Equal || op == NotEqual);
+        // otherwise fall through for these...
+        assert(op == Lt || op == Gt || op == Le || op == Ge ||
+               op == Equal || op == NotEqual);
     }
 
     const Type *exprType = Type::MoreGeneralType(type0, type1, pos, lOpString(op));
@@ -1648,6 +1649,7 @@ BinaryExpr::TypeCheck() {
             // put in canonical order with the pointer as the first operand
             // for GetValue()
             std::swap(arg0, arg1);
+            std::swap(type0, type1);
             std::swap(pt0, pt1);
         }
 
@@ -1726,11 +1728,7 @@ BinaryExpr::TypeCheck() {
     case Sub:
     case Mul:
     case Div:
-    case Mod:
-    case Lt:
-    case Gt:
-    case Le:
-    case Ge: {
+    case Mod: {
         // Must be numeric type for these.  (And mod is special--can't be float)
         if (!type0->IsNumericType() || (op == Mod && type0->IsFloatType())) {
             Error(arg0->pos, "First operand to binary operator \"%s\" is of "
@@ -1756,6 +1754,10 @@ BinaryExpr::TypeCheck() {
             return NULL;
         return this;
     }
+    case Lt:
+    case Gt:
+    case Le:
+    case Ge:
     case Equal:
     case NotEqual: {
         const PointerType *pt0 = dynamic_cast<const PointerType *>(type0);
@@ -1763,14 +1765,14 @@ BinaryExpr::TypeCheck() {
         if (pt0 == NULL && pt1 == NULL) {
             if (!type0->IsBoolType() && !type0->IsNumericType()) {
                 Error(arg0->pos,
-                      "First operand to equality operator \"%s\" is of "
+                      "First operand to operator \"%s\" is of "
                       "non-comparable type \"%s\".", lOpString(op), 
                       type0->GetString().c_str());
                 return NULL;
             }
             if (!type1->IsBoolType() && !type1->IsNumericType()) {
                 Error(arg1->pos,
-                      "Second operand to equality operator \"%s\" is of "
+                      "Second operand to operator \"%s\" is of "
                       "non-comparable type \"%s\".", lOpString(op), 
                       type1->GetString().c_str());
                 return NULL;
@@ -5132,30 +5134,46 @@ TypeCastExpr::GetValue(FunctionEmitContext *ctx) const {
             }
         }
         else {
-            // convert pointer to bool
-            assert(dynamic_cast<const AtomicType *>(toType) &&
-                   toType->IsBoolType());
-            LLVM_TYPE_CONST llvm::Type *lfu = 
-                fromType->GetAsUniformType()->LLVMType(g->ctx);
-            LLVM_TYPE_CONST llvm::PointerType *llvmFromUnifType = 
-                llvm::dyn_cast<LLVM_TYPE_CONST llvm::PointerType>(lfu);
+            assert(dynamic_cast<const AtomicType *>(toType) != NULL);
+            if (toType->IsBoolType()) {
+                // convert pointer to bool
+                LLVM_TYPE_CONST llvm::Type *lfu = 
+                    fromType->GetAsUniformType()->LLVMType(g->ctx);
+                LLVM_TYPE_CONST llvm::PointerType *llvmFromUnifType = 
+                    llvm::dyn_cast<LLVM_TYPE_CONST llvm::PointerType>(lfu);
 
-            llvm::Value *nullPtrValue = llvm::ConstantPointerNull::get(llvmFromUnifType);
-            if (fromType->IsVaryingType())
-                nullPtrValue = ctx->SmearUniform(nullPtrValue);
+                llvm::Value *nullPtrValue = 
+                    llvm::ConstantPointerNull::get(llvmFromUnifType);
+                if (fromType->IsVaryingType())
+                    nullPtrValue = ctx->SmearUniform(nullPtrValue);
 
-            llvm::Value *exprVal = expr->GetValue(ctx);
-            llvm::Value *cmp = ctx->CmpInst(llvm::Instruction::ICmp, 
-                                            llvm::CmpInst::ICMP_NE,
-                                            exprVal, nullPtrValue, "ptr_ne_NULL");
+                llvm::Value *exprVal = expr->GetValue(ctx);
+                llvm::Value *cmp = 
+                    ctx->CmpInst(llvm::Instruction::ICmp, llvm::CmpInst::ICMP_NE,
+                                 exprVal, nullPtrValue, "ptr_ne_NULL");
 
-            if (toType->IsVaryingType()) {
-                if (fromType->IsUniformType())
-                    cmp = ctx->SmearUniform(cmp);
-                cmp = ctx->I1VecToBoolVec(cmp);
+                if (toType->IsVaryingType()) {
+                    if (fromType->IsUniformType())
+                        cmp = ctx->SmearUniform(cmp);
+                    cmp = ctx->I1VecToBoolVec(cmp);
+                }
+
+                return cmp;
             }
+            else {
+                // ptr -> int
+                llvm::Value *value = expr->GetValue(ctx);
+                if (value == NULL)
+                    return NULL;
 
-            return cmp;
+                if (toType->IsVaryingType() && fromType->IsUniformType())
+                    value = ctx->SmearUniform(value);
+
+                LLVM_TYPE_CONST llvm::Type *llvmToType = toType->LLVMType(g->ctx);
+                if (llvmToType == NULL)
+                    return NULL;
+                return ctx->PtrToIntInst(value, llvmToType, "ptr_typecast");
+            }
         }
     }
 
@@ -5304,6 +5322,17 @@ TypeCastExpr::GetValue(FunctionEmitContext *ctx) const {
             cast = ctx->InsertInst(cast, conv, i);
         return cast;
     }
+    else if (toPointerType != NULL) {
+        // int -> ptr
+        if (toType->IsVaryingType() && fromType->IsUniformType())
+            exprVal = ctx->SmearUniform(exprVal);
+
+        LLVM_TYPE_CONST llvm::Type *llvmToType = toType->LLVMType(g->ctx);
+        if (llvmToType == NULL)
+            return NULL;
+
+        return ctx->IntToPtrInst(exprVal, llvmToType, "int_to_ptr");
+    }
     else {
         const AtomicType *toAtomic = dynamic_cast<const AtomicType *>(toType);
         // typechecking should ensure this is the case
@@ -5352,10 +5381,17 @@ TypeCastExpr::TypeCheck() {
     fromType = lDeconstifyType(fromType);
     toType = lDeconstifyType(toType);
 
+    if (fromType->IsVaryingType() && toType->IsUniformType()) {
+        Error(pos, "Can't type cast from varying type \"%s\" to uniform "
+              "type \"%s\"", fromType->GetString().c_str(),
+              toType->GetString().c_str());
+        return NULL;
+    }
+
     // First some special cases that we allow only with an explicit type cast
-    const PointerType *ptFrom = dynamic_cast<const PointerType *>(fromType);
-    const PointerType *ptTo = dynamic_cast<const PointerType *>(toType);
-    if (ptFrom != NULL && ptTo != NULL)
+    const PointerType *fromPtr = dynamic_cast<const PointerType *>(fromType);
+    const PointerType *toPtr = dynamic_cast<const PointerType *>(toType);
+    if (fromPtr != NULL && toPtr != NULL)
         // allow explicit typecasts between any two different pointer types
         return this;
 
@@ -5367,6 +5403,25 @@ TypeCastExpr::TypeCheck() {
         // Allow explicit casts between all of these
         return this;
 
+    // ptr -> int type casts
+    if (fromPtr != NULL && toAtomic != NULL && toAtomic->IsIntType()) {
+        bool safeCast = (toAtomic->basicType == AtomicType::TYPE_INT64 ||
+                         toAtomic->basicType == AtomicType::TYPE_UINT64);
+        if (g->target.is32Bit)
+            safeCast |= (toAtomic->basicType == AtomicType::TYPE_INT32 ||
+                         toAtomic->basicType == AtomicType::TYPE_UINT32);
+        if (safeCast == false)
+            Warning(pos, "Pointer type cast of type \"%s\" to integer type "
+                    "\"%s\" may lose information.", 
+                    fromType->GetString().c_str(), 
+                    toType->GetString().c_str());
+        return this;
+    }
+
+    // int -> ptr
+    if (fromAtomic != NULL && fromAtomic->IsIntType() && toPtr != NULL)
+        return this;
+
     // And otherwise see if it's one of the conversions allowed to happen
     // implicitly.
     if (CanConvertTypes(fromType, toType, "type cast expression", pos) == false)
@@ -5483,6 +5538,12 @@ TypeCastExpr::Print() const {
 }
 
 
+Symbol *
+TypeCastExpr::GetBaseSymbol() const {
+    return expr ? expr->GetBaseSymbol() : NULL;
+}
+
+
 llvm::Constant *
 TypeCastExpr::GetConstant(const Type *constType) const {
     // We don't need to worry about most the basic cases where the type
diff --git a/expr.h b/expr.h
index a6720c03..4de7ddb1 100644
--- a/expr.h
+++ b/expr.h
@@ -502,6 +502,7 @@ public:
     Expr *TypeCheck();
     Expr *Optimize();
     int EstimateCost() const;
+    Symbol *GetBaseSymbol() const;
     llvm::Constant *GetConstant(const Type *type) const;
 
     const Type *type;
diff --git a/opt.cpp b/opt.cpp
index 9999a469..fade6563 100644
--- a/opt.cpp
+++ b/opt.cpp
@@ -63,7 +63,7 @@
     #include <llvm/Support/StandardPasses.h>
 #else
     #include <llvm/Transforms/IPO/PassManagerBuilder.h>
-#endif // LLVM_2_8
+#endif // LLVM_2_9
 #include <llvm/ADT/Triple.h>
 #include <llvm/Transforms/Scalar.h>
 #include <llvm/Transforms/IPO.h>
diff --git a/run_tests.py b/run_tests.py
index 7bc7ebdf..058b10b8 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -107,7 +107,7 @@ def run_tasks_from_queue(queue):
         # is this a test to make sure an error is issued?
         want_error = (filename.find("tests_errors") != -1)
         if want_error == True:
-            ispc_cmd = "ispc --nowrap --woff %s --arch=%s --target=%s" % \
+            ispc_cmd = "ispc --nowrap %s --arch=%s --target=%s" % \
                 ( filename, options.arch, options.target)
             sp = subprocess.Popen(shlex.split(ispc_cmd), stdin=None, stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE)
diff --git a/tests/ptr-cmp-1.ispc b/tests/ptr-cmp-1.ispc
new file mode 100644
index 00000000..2c32e156
--- /dev/null
+++ b/tests/ptr-cmp-1.ispc
@@ -0,0 +1,12 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float * varying b = &aFOO[10];
+    uniform float * uniform c = aFOO;
+    RET[programIndex] = (b > c) ? 10 : 0;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 10;
+}
diff --git a/tests/ptr-cmp-2.ispc b/tests/ptr-cmp-2.ispc
new file mode 100644
index 00000000..0633011e
--- /dev/null
+++ b/tests/ptr-cmp-2.ispc
@@ -0,0 +1,12 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float * uniform b = aFOO;
+    uniform float * uniform c = aFOO;
+    RET[programIndex] = (c <= b) ? 10 : 0;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 10;
+}
diff --git a/tests/ptr-diff-4.ispc b/tests/ptr-diff-4.ispc
new file mode 100644
index 00000000..89b37813
--- /dev/null
+++ b/tests/ptr-diff-4.ispc
@@ -0,0 +1,12 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float * varying b = aFOO;
+    b = 5 + b;
+    RET[programIndex] = b - aFOO;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 5;
+}
diff --git a/tests/ptr-diff-5.ispc b/tests/ptr-diff-5.ispc
new file mode 100644
index 00000000..4fb649aa
--- /dev/null
+++ b/tests/ptr-diff-5.ispc
@@ -0,0 +1,12 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float * varying b = aFOO;
+    uniform float * uniform c = &aFOO[10];
+    RET[programIndex] = c - b;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 10;
+}
diff --git a/tests/ptr-diff-6.ispc b/tests/ptr-diff-6.ispc
new file mode 100644
index 00000000..48d8b25f
--- /dev/null
+++ b/tests/ptr-diff-6.ispc
@@ -0,0 +1,12 @@
+
+export uniform int width() { return programCount; }
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform float * varying b = &aFOO[10];
+    uniform float * uniform c = aFOO;
+    RET[programIndex] = b - c;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 10;
+}
diff --git a/tests/ptr-int-1.ispc b/tests/ptr-int-1.ispc
new file mode 100644
index 00000000..1ffbc02f
--- /dev/null
+++ b/tests/ptr-int-1.ispc
@@ -0,0 +1,14 @@
+
+export uniform int width() { return programCount; }
+
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    uniform int a = 1;
+    uniform int * uniform b = &a;
+    int64 pi = (int64)b;
+    RET[programIndex] = *((uniform int * varying)pi);
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 1;
+}
diff --git a/tests_errors/func-export-task.ispc b/tests_errors/func-export-task.ispc
new file mode 100644
index 00000000..d6796b73
--- /dev/null
+++ b/tests_errors/func-export-task.ispc
@@ -0,0 +1,4 @@
+// Function can't have both "task" and "export" qualifiers 
+
+export task void foo() {
+}
diff --git a/tests_errors/ptrcast-lose-info.ispc b/tests_errors/ptrcast-lose-info.ispc
new file mode 100644
index 00000000..fdaac83b
--- /dev/null
+++ b/tests_errors/ptrcast-lose-info.ispc
@@ -0,0 +1,6 @@
+// Pointer type cast of type "int32 * uniform" to integer type "uniform int32" may lose information.
+
+int32 foo(int * uniform x)  {
+    return (int32) x;
+}
+
diff --git a/tests_errors/vary-to-unif-typecast.ispc b/tests_errors/vary-to-unif-typecast.ispc
new file mode 100644
index 00000000..ca60749a
--- /dev/null
+++ b/tests_errors/vary-to-unif-typecast.ispc
@@ -0,0 +1,6 @@
+// Can't type cast from varying type "int32" to uniform type "uniform int32"
+
+uniform int foo(int x)  {
+    return (uniform int) x;
+}
+