diff --git a/crypto/CMakeLists.txt b/crypto/CMakeLists.txt
index be36c4b..56ce7eb 100644
--- a/crypto/CMakeLists.txt
+++ b/crypto/CMakeLists.txt
@@ -238,6 +238,7 @@
   bio/bio_test.cc
   bytestring/bytestring_test.cc
   chacha/chacha_test.cc
+  compiler_test.cc
   constant_time_test.cc
   curve25519/x25519_test.cc
   dh/dh_test.cc
diff --git a/crypto/compiler_test.cc b/crypto/compiler_test.cc
new file mode 100644
index 0000000..5b1c014
--- /dev/null
+++ b/crypto/compiler_test.cc
@@ -0,0 +1,168 @@
+/* Copyright (c) 2017, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <limits.h>
+#include <stdint.h>
+
+#include <type_traits>
+
+#include <gtest/gtest.h>
+
+#include "test/test_util.h"
+
+
+template <typename T>
+static void CheckRepresentation(T value) {
+  SCOPED_TRACE(value);
+
+  // Convert to the corresponding two's-complement unsigned value. We use an
+  // unsigned value so the right-shift below has defined value. Right-shifts of
+  // negative numbers in C are implementation defined.
+  //
+  // If |T| is already unsigned, this is a no-op, as desired.
+  //
+  // If |T| is signed, conversion to unsigned is defined to repeatedly add or
+  // subtract (numerically, not within |T|) one more than the unsigned type's
+  // maximum value until it fits (this must be a power of two). This is the
+  // conversion we want.
+  using UnsignedT = typename std::make_unsigned<T>::type;
+  UnsignedT value_u = static_cast<UnsignedT>(value);
+  EXPECT_EQ(sizeof(UnsignedT), sizeof(T));
+
+  // Integers must be little-endian.
+  uint8_t expected[sizeof(UnsignedT)];
+  for (size_t i = 0; i < sizeof(UnsignedT); i++) {
+    expected[i] = static_cast<uint8_t>(value_u);
+    // Divide instead of right-shift to appease compilers that warn if |T| is a
+    // char. The explicit cast is also needed to appease MSVC if integer
+    // promotion happened.
+    value_u = static_cast<UnsignedT>(value_u / 256);
+  }
+  EXPECT_EQ(0u, value_u);
+
+  // Check that |value| has the expected representation.
+  EXPECT_EQ(Bytes(expected),
+            Bytes(reinterpret_cast<const uint8_t *>(&value), sizeof(value)));
+}
+
+TEST(CompilerTest, IntegerRepresentation) {
+  EXPECT_EQ(8, CHAR_BIT);
+  EXPECT_EQ(0xff, UCHAR_MAX);
+
+  // uint8_t is assumed to be unsigned char. I.e., casting to uint8_t should be
+  // as good as unsigned char for strict aliasing purposes.
+  uint8_t u8 = 0;
+  unsigned char *ptr = &u8;
+  (void)ptr;
+
+  // Sized integers have the expected size.
+  EXPECT_EQ(1u, sizeof(uint8_t));
+  EXPECT_EQ(2u, sizeof(uint16_t));
+  EXPECT_EQ(4u, sizeof(uint32_t));
+  EXPECT_EQ(8u, sizeof(uint64_t));
+
+  // size_t does not exceed uint64_t.
+  EXPECT_LE(sizeof(size_t), 8u);
+
+  // int must be 32-bit or larger.
+  EXPECT_LE(0x7fffffff, INT_MAX);
+  EXPECT_LE(0xffffffffu, UINT_MAX);
+
+  CheckRepresentation(static_cast<signed char>(127));
+  CheckRepresentation(static_cast<signed char>(1));
+  CheckRepresentation(static_cast<signed char>(0));
+  CheckRepresentation(static_cast<signed char>(-1));
+  CheckRepresentation(static_cast<signed char>(-42));
+  CheckRepresentation(static_cast<signed char>(-128));
+
+  CheckRepresentation(static_cast<int>(INT_MAX));
+  CheckRepresentation(static_cast<int>(0x12345678));
+  CheckRepresentation(static_cast<int>(1));
+  CheckRepresentation(static_cast<int>(0));
+  CheckRepresentation(static_cast<int>(-1));
+  CheckRepresentation(static_cast<int>(-0x12345678));
+  CheckRepresentation(static_cast<int>(INT_MIN));
+
+  CheckRepresentation(static_cast<unsigned>(UINT_MAX));
+  CheckRepresentation(static_cast<unsigned>(0x12345678));
+  CheckRepresentation(static_cast<unsigned>(1));
+  CheckRepresentation(static_cast<unsigned>(0));
+
+  CheckRepresentation(static_cast<long>(LONG_MAX));
+  CheckRepresentation(static_cast<long>(0x12345678));
+  CheckRepresentation(static_cast<long>(1));
+  CheckRepresentation(static_cast<long>(0));
+  CheckRepresentation(static_cast<long>(-1));
+  CheckRepresentation(static_cast<long>(-0x12345678));
+  CheckRepresentation(static_cast<long>(LONG_MIN));
+
+  CheckRepresentation(static_cast<unsigned long>(ULONG_MAX));
+  CheckRepresentation(static_cast<unsigned long>(0x12345678));
+  CheckRepresentation(static_cast<unsigned long>(1));
+  CheckRepresentation(static_cast<unsigned long>(0));
+
+  CheckRepresentation(static_cast<int16_t>(0x7fff));
+  CheckRepresentation(static_cast<int16_t>(0x1234));
+  CheckRepresentation(static_cast<int16_t>(1));
+  CheckRepresentation(static_cast<int16_t>(0));
+  CheckRepresentation(static_cast<int16_t>(-1));
+  CheckRepresentation(static_cast<int16_t>(-0x7fff - 1));
+
+  CheckRepresentation(static_cast<uint16_t>(0xffff));
+  CheckRepresentation(static_cast<uint16_t>(0x1234));
+  CheckRepresentation(static_cast<uint16_t>(1));
+  CheckRepresentation(static_cast<uint16_t>(0));
+
+  CheckRepresentation(static_cast<int32_t>(0x7fffffff));
+  CheckRepresentation(static_cast<int32_t>(0x12345678));
+  CheckRepresentation(static_cast<int32_t>(1));
+  CheckRepresentation(static_cast<int32_t>(0));
+  CheckRepresentation(static_cast<int32_t>(-1));
+  CheckRepresentation(static_cast<int32_t>(-0x7fffffff - 1));
+
+  CheckRepresentation(static_cast<uint32_t>(0xffffffff));
+  CheckRepresentation(static_cast<uint32_t>(0x12345678));
+  CheckRepresentation(static_cast<uint32_t>(1));
+  CheckRepresentation(static_cast<uint32_t>(0));
+
+  CheckRepresentation(static_cast<int64_t>(0x7fffffffffffffff));
+  CheckRepresentation(static_cast<int64_t>(0x123456789abcdef0));
+  CheckRepresentation(static_cast<int64_t>(1));
+  CheckRepresentation(static_cast<int64_t>(0));
+  CheckRepresentation(static_cast<int64_t>(-1));
+  CheckRepresentation(static_cast<int64_t>(-0x7fffffffffffffff - 1));
+
+  CheckRepresentation(static_cast<uint64_t>(0xffffffffffffffff));
+  CheckRepresentation(static_cast<uint64_t>(0x12345678abcdef0));
+  CheckRepresentation(static_cast<uint64_t>(1));
+  CheckRepresentation(static_cast<uint64_t>(0));
+}
+
+// Converting pointers to integers and doing arithmetic on those values are both
+// defined. Converting those values back into pointers is undefined, but, for
+// aliasing checks, we require that the implementation-defined result of that
+// computation commutes with pointer arithmetic.
+TEST(CompilerTest, PointerRepresentation) {
+  char chars[256];
+  for (size_t i = 0; i < sizeof(chars); i++) {
+    EXPECT_EQ(reinterpret_cast<uintptr_t>(chars) + i,
+              reinterpret_cast<uintptr_t>(chars + i));
+  }
+
+  int ints[256];
+  for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(ints); i++) {
+    EXPECT_EQ(reinterpret_cast<uintptr_t>(ints) + i * sizeof(int),
+              reinterpret_cast<uintptr_t>(ints + i));
+  }
+}