diff --git a/compiler-rt/lib/xray/xray_AArch64.cc b/compiler-rt/lib/xray/xray_AArch64.cc
index c2d33a2..8f24610 100644
--- a/compiler-rt/lib/xray/xray_AArch64.cc
+++ b/compiler-rt/lib/xray/xray_AArch64.cc
@@ -14,12 +14,26 @@
 //===----------------------------------------------------------------------===//
 #include "sanitizer_common/sanitizer_common.h"
 #include "xray_defs.h"
+#include "xray_emulate_tsc.h"
 #include "xray_interface_internal.h"
 #include <atomic>
 #include <cassert>
 
 namespace __xray {
 
+uint64_t cycleFrequency() XRAY_NEVER_INSTRUMENT {
+  // There is no instruction like RDTSCP in user mode on ARM.  ARM's CP15 does
+  //   not have a constant frequency like TSC on x86[_64]; it may go faster or
+  //   slower depending on CPU's turbo or power saving modes.  Furthermore, to
+  //   read from CP15 on ARM a kernel modification or a driver is needed.
+  //   We can not require this from users of compiler-rt.
+  // So on ARM we use clock_gettime(2) which gives the result in nanoseconds.
+  //   To get the measurements per second, we scale this by the number of
+  //   nanoseconds per second, pretending that the TSC frequency is 1GHz and
+  //   one TSC tick is 1 nanosecond.
+  return NanosecondsPerSecond;
+}
+
 // The machine codes for some instructions used in runtime patching.
 enum class PatchOpcodes : uint32_t {
   PO_StpX0X30SP_m16e = 0xA9BF7BE0, // STP X0, X30, [SP, #-16]!
diff --git a/compiler-rt/lib/xray/xray_arm.cc b/compiler-rt/lib/xray/xray_arm.cc
index 9ce8451..d89322e 100644
--- a/compiler-rt/lib/xray/xray_arm.cc
+++ b/compiler-rt/lib/xray/xray_arm.cc
@@ -14,12 +14,26 @@
 //===----------------------------------------------------------------------===//
 #include "sanitizer_common/sanitizer_common.h"
 #include "xray_defs.h"
+#include "xray_emulate_tsc.h"
 #include "xray_interface_internal.h"
 #include <atomic>
 #include <cassert>
 
 namespace __xray {
 
+uint64_t cycleFrequency() XRAY_NEVER_INSTRUMENT {
+  // There is no instruction like RDTSCP in user mode on ARM.  ARM's CP15 does
+  //   not have a constant frequency like TSC on x86[_64]; it may go faster or
+  //   slower depending on CPU's turbo or power saving modes.  Furthermore, to
+  //   read from CP15 on ARM a kernel modification or a driver is needed.
+  //   We can not require this from users of compiler-rt.
+  // So on ARM we use clock_gettime(2) which gives the result in nanoseconds.
+  //   To get the measurements per second, we scale this by the number of
+  //   nanoseconds per second, pretending that the TSC frequency is 1GHz and
+  //   one TSC tick is 1 nanosecond.
+  return NanosecondsPerSecond;
+}
+
 // The machine codes for some instructions used in runtime patching.
 enum class PatchOpcodes : uint32_t {
   PO_PushR0Lr = 0xE92D4001, // PUSH {r0, lr}
diff --git a/compiler-rt/lib/xray/xray_emulate_tsc.h b/compiler-rt/lib/xray/xray_emulate_tsc.h
new file mode 100644
index 0000000..a3e8b1c
--- /dev/null
+++ b/compiler-rt/lib/xray/xray_emulate_tsc.h
@@ -0,0 +1,40 @@
+//===-- xray_emulate_tsc.h --------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of XRay, a dynamic runtime instrumentation system.
+//
+//===----------------------------------------------------------------------===//
+#ifndef XRAY_EMULATE_TSC_H
+#define XRAY_EMULATE_TSC_H
+
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "xray_defs.h"
+#include <cerrno>
+#include <cstdint>
+#include <time.h>
+
+namespace __xray {
+
+static constexpr uint64_t NanosecondsPerSecond = 1000ULL * 1000 * 1000;
+
+ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
+  timespec TS;
+  int result = clock_gettime(CLOCK_REALTIME, &TS);
+  if (result != 0) {
+    Report("clock_gettime(2) returned %d, errno=%d.", result, int(errno));
+    TS.tv_sec = 0;
+    TS.tv_nsec = 0;
+  }
+  CPU = 0;
+  return TS.tv_sec * NanosecondsPerSecond + TS.tv_nsec;
+}
+}
+
+#endif // XRAY_EMULATE_TSC_H
diff --git a/compiler-rt/lib/xray/xray_inmemory_log.cc b/compiler-rt/lib/xray/xray_inmemory_log.cc
index a93972d..7ec56f4 100644
--- a/compiler-rt/lib/xray/xray_inmemory_log.cc
+++ b/compiler-rt/lib/xray/xray_inmemory_log.cc
@@ -16,6 +16,7 @@
 //===----------------------------------------------------------------------===//
 
 #include <cassert>
+#include <cstdint>
 #include <cstdio>
 #include <fcntl.h>
 #include <mutex>
@@ -26,12 +27,12 @@
 #include <unistd.h>
 
 #if defined(__x86_64__)
-#include <x86intrin.h>
+#include "xray_x86_64.h"
 #elif defined(__arm__) || defined(__aarch64__)
-static const int64_t NanosecondsPerSecond = 1000LL * 1000 * 1000;
+#include "xray_emulate_tsc.h"
 #else
 #error "Unsupported CPU Architecture"
-#endif /* CPU architecture */
+#endif /* Architecture-specific inline intrinsics */
 
 #include "sanitizer_common/sanitizer_libc.h"
 #include "xray/xray_records.h"
@@ -71,52 +72,6 @@
   }
 }
 
-#if defined(__x86_64__)
-static std::pair<ssize_t, bool>
-retryingReadSome(int Fd, char *Begin, char *End) XRAY_NEVER_INSTRUMENT {
-  auto BytesToRead = std::distance(Begin, End);
-  ssize_t BytesRead;
-  ssize_t TotalBytesRead = 0;
-  while (BytesToRead && (BytesRead = read(Fd, Begin, BytesToRead))) {
-    if (BytesRead == -1) {
-      if (errno == EINTR)
-        continue;
-      Report("Read error; errno = %d\n", errno);
-      return std::make_pair(TotalBytesRead, false);
-    }
-
-    TotalBytesRead += BytesRead;
-    BytesToRead -= BytesRead;
-    Begin += BytesRead;
-  }
-  return std::make_pair(TotalBytesRead, true);
-}
-
-static bool readValueFromFile(const char *Filename,
-                              long long *Value) XRAY_NEVER_INSTRUMENT {
-  int Fd = open(Filename, O_RDONLY | O_CLOEXEC);
-  if (Fd == -1)
-    return false;
-  static constexpr size_t BufSize = 256;
-  char Line[BufSize] = {};
-  ssize_t BytesRead;
-  bool Success;
-  std::tie(BytesRead, Success) = retryingReadSome(Fd, Line, Line + BufSize);
-  if (!Success)
-    return false;
-  close(Fd);
-  char *End = nullptr;
-  long long Tmp = internal_simple_strtoll(Line, &End, 10);
-  bool Result = false;
-  if (Line[0] != '\0' && (*End == '\n' || *End == '\0')) {
-    *Value = Tmp;
-    Result = true;
-  }
-  return Result;
-}
-
-#endif /* CPU architecture */
-
 class ThreadExitFlusher {
   int Fd;
   XRayRecord *Start;
@@ -151,6 +106,46 @@
   fprintf(stderr, "%s", Buffer);
 }
 
+static int __xray_OpenLogFile() XRAY_NEVER_INSTRUMENT {
+  // FIXME: Figure out how to make this less stderr-dependent.
+  SetPrintfAndReportCallback(PrintToStdErr);
+  // Open a temporary file once for the log.
+  static char TmpFilename[256] = {};
+  static char TmpWildcardPattern[] = "XXXXXX";
+  auto E = internal_strncat(TmpFilename, flags()->xray_logfile_base,
+                            sizeof(TmpFilename) - 10);
+  if (static_cast<size_t>((E + 6) - TmpFilename) > (sizeof(TmpFilename) - 1)) {
+    Report("XRay log file base too long: %s\n", flags()->xray_logfile_base);
+    return -1;
+  }
+  internal_strncat(TmpFilename, TmpWildcardPattern,
+                   sizeof(TmpWildcardPattern) - 1);
+  int Fd = mkstemp(TmpFilename);
+  if (Fd == -1) {
+    Report("XRay: Failed opening temporary file '%s'; not logging events.\n",
+           TmpFilename);
+    return -1;
+  }
+  if (Verbosity())
+    fprintf(stderr, "XRay: Log file in '%s'\n", TmpFilename);
+
+  // Since we're here, we get to write the header. We set it up so that the
+  // header will only be written once, at the start, and let the threads
+  // logging do writes which just append.
+  XRayFileHeader Header;
+  Header.Version = 1;
+  Header.Type = FileTypes::NAIVE_LOG;
+  Header.CycleFrequency = __xray::cycleFrequency();
+
+  // FIXME: Actually check whether we have 'constant_tsc' and 'nonstop_tsc'
+  // before setting the values in the header.
+  Header.ConstantTSC = 1;
+  Header.NonstopTSC = 1;
+  retryingWriteAll(Fd, reinterpret_cast<char *>(&Header),
+                   reinterpret_cast<char *>(&Header) + sizeof(Header));
+  return Fd;
+}
+
 void __xray_InMemoryRawLog(int32_t FuncId,
                            XRayEntryType Type) XRAY_NEVER_INSTRUMENT {
   using Buffer =
@@ -158,75 +153,7 @@
   static constexpr size_t BuffLen = 1024;
   thread_local static Buffer InMemoryBuffer[BuffLen] = {};
   thread_local static size_t Offset = 0;
-  static int Fd = [] {
-    // FIXME: Figure out how to make this less stderr-dependent.
-    SetPrintfAndReportCallback(PrintToStdErr);
-    // Open a temporary file once for the log.
-    static char TmpFilename[256] = {};
-    static char TmpWildcardPattern[] = "XXXXXX";
-    auto E = internal_strncat(TmpFilename, flags()->xray_logfile_base,
-                              sizeof(TmpFilename) - 10);
-    if (static_cast<size_t>((E + 6) - TmpFilename) >
-        (sizeof(TmpFilename) - 1)) {
-      Report("XRay log file base too long: %s\n", flags()->xray_logfile_base);
-      return -1;
-    }
-    internal_strncat(TmpFilename, TmpWildcardPattern,
-                     sizeof(TmpWildcardPattern) - 1);
-    int Fd = mkstemp(TmpFilename);
-    if (Fd == -1) {
-      Report("XRay: Failed opening temporary file '%s'; not logging events.\n",
-             TmpFilename);
-      return -1;
-    }
-    if (Verbosity())
-      fprintf(stderr, "XRay: Log file in '%s'\n", TmpFilename);
-
-    // Get the cycle frequency from SysFS on Linux.
-    long long CPUFrequency = -1;
-#if defined(__x86_64__)
-    if (readValueFromFile("/sys/devices/system/cpu/cpu0/tsc_freq_khz",
-                          &CPUFrequency)) {
-      CPUFrequency *= 1000;
-    } else if (readValueFromFile(
-                   "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq",
-                   &CPUFrequency)) {
-      CPUFrequency *= 1000;
-    } else {
-      Report("Unable to determine CPU frequency for TSC accounting.\n");
-    }
-#elif defined(__arm__) || defined(__aarch64__)
-    // There is no instruction like RDTSCP in user mode on ARM. ARM's CP15 does
-    //   not have a constant frequency like TSC on x86(_64), it may go faster
-    //   or slower depending on CPU turbo or power saving mode. Furthermore,
-    //   to read from CP15 on ARM a kernel modification or a driver is needed.
-    //   We can not require this from users of compiler-rt.
-    // So on ARM we use clock_gettime() which gives the result in nanoseconds.
-    //   To get the measurements per second, we scale this by the number of
-    //   nanoseconds per second, pretending that the TSC frequency is 1GHz and
-    //   one TSC tick is 1 nanosecond.
-    CPUFrequency = NanosecondsPerSecond;
-#else
-#error "Unsupported CPU Architecture"
-#endif /* CPU architecture */
-
-    // Since we're here, we get to write the header. We set it up so that the
-    // header will only be written once, at the start, and let the threads
-    // logging do writes which just append.
-    XRayFileHeader Header;
-    Header.Version = 1;
-    Header.Type = FileTypes::NAIVE_LOG;
-    Header.CycleFrequency =
-        CPUFrequency == -1 ? 0 : static_cast<uint64_t>(CPUFrequency);
-
-    // FIXME: Actually check whether we have 'constant_tsc' and 'nonstop_tsc'
-    // before setting the values in the header.
-    Header.ConstantTSC = 1;
-    Header.NonstopTSC = 1;
-    retryingWriteAll(Fd, reinterpret_cast<char *>(&Header),
-                     reinterpret_cast<char *>(&Header) + sizeof(Header));
-    return Fd;
-  }();
+  static int Fd = __xray_OpenLogFile();
   if (Fd == -1)
     return;
   thread_local __xray::ThreadExitFlusher Flusher(
@@ -237,27 +164,7 @@
   // through a pointer offset.
   auto &R = reinterpret_cast<__xray::XRayRecord *>(InMemoryBuffer)[Offset];
   R.RecordType = RecordTypes::NORMAL;
-#if defined(__x86_64__)
-  {
-    unsigned CPU;
-    R.TSC = __rdtscp(&CPU);
-    R.CPU = CPU;
-  }
-#elif defined(__arm__) || defined(__aarch64__)
-  {
-    timespec TS;
-    int result = clock_gettime(CLOCK_REALTIME, &TS);
-    if (result != 0) {
-      Report("clock_gettime() returned %d, errno=%d.\n", result, int(errno));
-      TS.tv_sec = 0;
-      TS.tv_nsec = 0;
-    }
-    R.TSC = TS.tv_sec * NanosecondsPerSecond + TS.tv_nsec;
-    R.CPU = 0;
-  }
-#else
-#error "Unsupported CPU Architecture"
-#endif /* CPU architecture */
+  R.TSC = __xray::readTSC(R.CPU);
   R.TId = TId;
   R.Type = Type;
   R.FuncId = FuncId;
diff --git a/compiler-rt/lib/xray/xray_interface_internal.h b/compiler-rt/lib/xray/xray_interface_internal.h
index c4f7243..a8434a6 100644
--- a/compiler-rt/lib/xray/xray_interface_internal.h
+++ b/compiler-rt/lib/xray/xray_interface_internal.h
@@ -48,6 +48,8 @@
   size_t Entries;
 };
 
+uint64_t cycleFrequency();
+
 bool patchFunctionEntry(bool Enable, uint32_t FuncId,
                         const XRaySledEntry &Sled);
 bool patchFunctionExit(bool Enable, uint32_t FuncId, const XRaySledEntry &Sled);
diff --git a/compiler-rt/lib/xray/xray_x86_64.cc b/compiler-rt/lib/xray/xray_x86_64.cc
index 09ca34c..74bd9cf 100644
--- a/compiler-rt/lib/xray/xray_x86_64.cc
+++ b/compiler-rt/lib/xray/xray_x86_64.cc
@@ -3,10 +3,71 @@
 #include "xray_interface_internal.h"
 #include <atomic>
 #include <cstdint>
+#include <fcntl.h>
 #include <limits>
+#include <tuple>
+#include <unistd.h>
 
 namespace __xray {
 
+static std::pair<ssize_t, bool>
+retryingReadSome(int Fd, char *Begin, char *End) XRAY_NEVER_INSTRUMENT {
+  auto BytesToRead = std::distance(Begin, End);
+  ssize_t BytesRead;
+  ssize_t TotalBytesRead = 0;
+  while (BytesToRead && (BytesRead = read(Fd, Begin, BytesToRead))) {
+    if (BytesRead == -1) {
+      if (errno == EINTR)
+        continue;
+      Report("Read error; errno = %d\n", errno);
+      return std::make_pair(TotalBytesRead, false);
+    }
+
+    TotalBytesRead += BytesRead;
+    BytesToRead -= BytesRead;
+    Begin += BytesRead;
+  }
+  return std::make_pair(TotalBytesRead, true);
+}
+
+static bool readValueFromFile(const char *Filename,
+                              long long *Value) XRAY_NEVER_INSTRUMENT {
+  int Fd = open(Filename, O_RDONLY | O_CLOEXEC);
+  if (Fd == -1)
+    return false;
+  static constexpr size_t BufSize = 256;
+  char Line[BufSize] = {};
+  ssize_t BytesRead;
+  bool Success;
+  std::tie(BytesRead, Success) = retryingReadSome(Fd, Line, Line + BufSize);
+  if (!Success)
+    return false;
+  close(Fd);
+  char *End = nullptr;
+  long long Tmp = internal_simple_strtoll(Line, &End, 10);
+  bool Result = false;
+  if (Line[0] != '\0' && (*End == '\n' || *End == '\0')) {
+    *Value = Tmp;
+    Result = true;
+  }
+  return Result;
+}
+
+uint64_t cycleFrequency() XRAY_NEVER_INSTRUMENT {
+  long long CPUFrequency = -1;
+  if (readValueFromFile("/sys/devices/system/cpu/cpu0/tsc_freq_khz",
+                        &CPUFrequency)) {
+    CPUFrequency *= 1000;
+  } else if (readValueFromFile(
+      "/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq",
+      &CPUFrequency)) {
+    CPUFrequency *= 1000;
+  } else {
+    Report("Unable to determine CPU frequency for TSC accounting.\n");
+  }
+  return CPUFrequency == -1 ? 0 : static_cast<uint64_t>(CPUFrequency);
+}
+
 static constexpr uint8_t CallOpCode = 0xe8;
 static constexpr uint16_t MovR10Seq = 0xba41;
 static constexpr uint16_t Jmp9Seq = 0x09eb;
diff --git a/compiler-rt/lib/xray/xray_x86_64.h b/compiler-rt/lib/xray/xray_x86_64.h
new file mode 100644
index 0000000..52d2dea
--- /dev/null
+++ b/compiler-rt/lib/xray/xray_x86_64.h
@@ -0,0 +1,32 @@
+//===-- xray_x86_64.h -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of XRay, a dynamic runtime instrumentation system.
+//
+//===----------------------------------------------------------------------===//
+#ifndef XRAY_X86_64_H
+#define XRAY_X86_64_H
+
+#include <cstdint>
+#include <x86intrin.h>
+
+#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "xray_defs.h"
+
+namespace __xray {
+
+ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
+  unsigned LongCPU;
+  uint64_t TSC = __rdtscp(&LongCPU);
+  CPU = LongCPU;
+  return TSC;
+}
+}
+
+#endif // XRAY_X86_64_H