diff --git a/SingleSource/UnitTests/Vectorizer/common.h b/SingleSource/UnitTests/Vectorizer/common.h
new file mode 100644
--- /dev/null
+++ b/SingleSource/UnitTests/Vectorizer/common.h
@@ -0,0 +1,38 @@
+#include <memory>
+#include <random>
+
+#define DEFINE_SCALAR_AND_VECTOR_FN2(Init, Loop)                               \
+  auto ScalarFn = [](auto *A, auto *B, unsigned TC) {                          \
+    Init _Pragma("clang loop vectorize(disable) interleave_count(1)") Loop     \
+  };                                                                           \
+  auto VectorFn = [](auto *A, auto *B, unsigned TC) {                          \
+    Init _Pragma("clang loop vectorize(enable)") Loop                          \
+  };
+
+#define DEFINE_SCALAR_AND_VECTOR_FN3(Loop)                                     \
+  auto ScalarFn = [](auto *A, auto *B, auto *C, unsigned TC) {                 \
+    _Pragma("clang loop vectorize(disable) interleave_count(1)") Loop          \
+  };                                                                           \
+  auto VectorFn = [](auto *A, auto *B, auto *C, unsigned TC) {                 \
+    _Pragma("clang loop vectorize(enable)") Loop                               \
+  };
+
+static std::mt19937 rng;
+
+// Initialize arrays A with random numbers.
+template <typename Ty>
+static void init_data(const std::unique_ptr<Ty[]> &A, unsigned N) {
+  std::uniform_int_distribution<uint64_t> distrib(
+      std::numeric_limits<Ty>::min(), std::numeric_limits<Ty>::max());
+  for (unsigned i = 0; i < N; i++)
+    A[i] = distrib(rng);
+}
+
+template <typename Ty>
+static void check(const std::unique_ptr<Ty[]> &Reference,
+                  const std::unique_ptr<Ty[]> &Tmp, unsigned NumElements) {
+  if (!std::equal(&Reference[0], &Reference[0] + NumElements, &Tmp[0])) {
+    std::cerr << "Miscompare\n";
+    exit(1);
+  }
+}
diff --git a/SingleSource/UnitTests/Vectorizer/recurrences.cpp b/SingleSource/UnitTests/Vectorizer/recurrences.cpp
--- a/SingleSource/UnitTests/Vectorizer/recurrences.cpp
+++ b/SingleSource/UnitTests/Vectorizer/recurrences.cpp
@@ -2,38 +2,11 @@
 #include <iostream>
 #include <limits>
 #include <memory>
-#include <random>
 #include <stdint.h>
 
-// Tests for vectorizing loops with recurrences.
-
-static std::mt19937 rng;
-
-// Initialize arrays A with random numbers.
-template <typename Ty>
-static void init_data(const std::unique_ptr<Ty[]> &A, unsigned N) {
-  std::uniform_int_distribution<uint64_t> distrib(
-      std::numeric_limits<Ty>::min(), std::numeric_limits<Ty>::max());
-  for (unsigned i = 0; i < N; i++)
-    A[i] = distrib(rng);
-}
+#include "common.h"
 
-template <typename Ty>
-static void check(const std::unique_ptr<Ty[]> &Reference,
-                  const std::unique_ptr<Ty[]> &Tmp, unsigned NumElements) {
-  if (!std::equal(&Reference[0], &Reference[0] + NumElements, &Tmp[0])) {
-    std::cerr << "Miscompare\n";
-    exit(1);
-  }
-}
-
-#define DEFINE_SCALAR_AND_VECTOR_FN2(Init, Loop)                               \
-  auto ScalarFn = [](auto *A, auto *B, unsigned TC) {                          \
-    Init _Pragma("clang loop vectorize(disable)") Loop                         \
-  };                                                                           \
-  auto VectorFn = [](auto *A, auto *B, unsigned TC) {                          \
-    Init _Pragma("clang loop vectorize(enable)") Loop                          \
-  };
+// Tests for vectorizing loops with recurrences.
 
 template <typename Ty> using Fn2Ty = std::function<void(Ty *, Ty *, unsigned)>;
 template <typename Ty>
diff --git a/SingleSource/UnitTests/Vectorizer/runtime-checks.cpp b/SingleSource/UnitTests/Vectorizer/runtime-checks.cpp
--- a/SingleSource/UnitTests/Vectorizer/runtime-checks.cpp
+++ b/SingleSource/UnitTests/Vectorizer/runtime-checks.cpp
@@ -5,22 +5,13 @@
 #include <random>
 #include <stdint.h>
 
+#include "common.h"
+
 // Tests for memory runtime checks generated by the vectorizer. Runs scalar and
 // vectorized versions of a loop requiring runtime checks on the same inputs
 // with pointers to the same buffer using various offsets between reads and
 // writes. Fails if they do not produce the same results.
 
-static std::mt19937 rng;
-
-// Initialize arrays A with random numbers.
-template <typename Ty>
-static void init_data(const std::unique_ptr<Ty[]> &A, unsigned N) {
-  std::uniform_int_distribution<uint64_t> distrib(std::numeric_limits<Ty>::min(),
-                                            std::numeric_limits<Ty>::max());
-  for (unsigned i = 0; i < N; i++)
-    A[i] = distrib(rng);
-}
-
 template <typename Ty>
 static void check(const std::unique_ptr<Ty[]> &Reference,
                   const std::unique_ptr<Ty[]> &Tmp, unsigned NumElements,
@@ -31,22 +22,6 @@
   }
 }
 
-#define DEFINE_SCALAR_AND_VECTOR_FN2(Loop)                                     \
-  auto ScalarFn = [](auto *A, auto *B, unsigned TC) {                          \
-    _Pragma("clang loop vectorize(disable)") Loop                              \
-  };                                                                           \
-  auto VectorFn = [](auto *A, auto *B, unsigned TC) {                          \
-    _Pragma("clang loop vectorize(enable)") Loop                               \
-  };
-
-#define DEFINE_SCALAR_AND_VECTOR_FN3(Loop)                                     \
-  auto ScalarFn = [](auto *A, auto *B, auto *C, unsigned TC) {                 \
-    _Pragma("clang loop vectorize(disable)") Loop                              \
-  };                                                                           \
-  auto VectorFn = [](auto *A, auto *B, auto *C, unsigned TC) {                 \
-    _Pragma("clang loop vectorize(enable)") Loop                               \
-  };
-
 // Helper to call \p f with \p args and acts as optimization barrier for \p f.
 template <typename F, typename... Args>
 __attribute__((optnone)) static void callThroughOptnone(F &&f, Args &&...args) {
@@ -137,7 +112,7 @@
   rng = std::mt19937(15);
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = 0; i < TC; i++)
         A[i] = B[i] + 10;
     );
@@ -151,7 +126,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = 0; i < TC; i++)
         A[i] = B[i + 3] + 10;
     );
@@ -165,7 +140,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = 3; i < TC; i++)
         A[i] = B[i - 3] + 10;
     );
@@ -179,7 +154,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = TC; i > 0; i--)
         A[i] = B[i] + 10;);
 
@@ -192,7 +167,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = TC; i > 2; i -= 2)
         A[i] = B[i] + 10;
     );
@@ -206,7 +181,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = 0, j = 0; i < TC; i++) {
         A[i] = B[j] + 10;
         j += 2;
@@ -224,7 +199,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       _Pragma("clang loop unroll(disable)")
       for (unsigned i = 0; i < TC; i += 2)
         A[i] = B[i] + 10;
@@ -240,7 +215,7 @@
   }
 
   {
-    DEFINE_SCALAR_AND_VECTOR_FN2(
+    DEFINE_SCALAR_AND_VECTOR_FN2(,
       for (unsigned i = 0, sum = 0; i < TC; i++) {
         sum += A[i] + 10;
         B[TC / 2] = sum;