compiler-rt/lib/xray/xray_tsc.h

   1 //===-- xray_tsc.h ----------------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of XRay, a dynamic runtime instrumentation system.
  10 //
  11 //===----------------------------------------------------------------------===//
  12 #ifndef XRAY_EMULATE_TSC_H
  13 #define XRAY_EMULATE_TSC_H
  14
  15 #include "sanitizer_common/sanitizer_common.h"
  16
  17 namespace __xray {
  18 static constexpr uint64_t NanosecondsPerSecond = 1000ULL * 1000 * 1000;
  19 }
  20
  21 #if SANITIZER_FUCHSIA
  22 #include <zircon/syscalls.h>
  23
  24 namespace __xray {
  25
  26 inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
  27
  28 ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
  29   CPU = 0;
  30   return _zx_ticks_get();
  31 }
  32
  33 inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT {
  34   return _zx_ticks_per_second();
  35 }
  36
  37 } // namespace __xray
  38
  39 #else // SANITIZER_FUCHSIA
  40
  41 #if defined(__x86_64__)
  42 #include "xray_x86_64.inc"
  43 #elif defined(__powerpc64__)
  44 #include "xray_powerpc64.inc"
  45 #elif defined(__arm__) || defined(__aarch64__) || defined(__mips__) ||         \
  46     defined(__hexagon__)
  47 // Emulated TSC.
  48 // There is no instruction like RDTSCP in user mode on ARM. ARM's CP15 does
  49 //   not have a constant frequency like TSC on x86(_64), it may go faster
  50 //   or slower depending on CPU turbo or power saving mode. Furthermore,
  51 //   to read from CP15 on ARM a kernel modification or a driver is needed.
  52 //   We can not require this from users of compiler-rt.
  53 // So on ARM we use clock_gettime() which gives the result in nanoseconds.
  54 //   To get the measurements per second, we scale this by the number of
  55 //   nanoseconds per second, pretending that the TSC frequency is 1GHz and
  56 //   one TSC tick is 1 nanosecond.
  57 #include "sanitizer_common/sanitizer_common.h"
  58 #include "sanitizer_common/sanitizer_internal_defs.h"
  59 #include "xray_defs.h"
  60 #include <cerrno>
  61 #include <cstdint>
  62 #include <time.h>
  63
  64 namespace __xray {
  65
  66 inline bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; }
  67
  68 ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
  69   timespec TS;
  70   int result = clock_gettime(CLOCK_REALTIME, &TS);
  71   if (result != 0) {
  72     Report("clock_gettime(2) returned %d, errno=%d.", result, int(errno));
  73     TS.tv_sec = 0;
  74     TS.tv_nsec = 0;
  75   }
  76   CPU = 0;
  77   return TS.tv_sec * NanosecondsPerSecond + TS.tv_nsec;
  78 }
  79
  80 inline uint64_t getTSCFrequency() XRAY_NEVER_INSTRUMENT {
  81   return NanosecondsPerSecond;
  82 }
  83
  84 } // namespace __xray
  85
  86 #else
  87 #error Target architecture is not supported.
  88 #endif // CPU architecture
  89 #endif // SANITIZER_FUCHSIA
  90
  91 #endif // XRAY_EMULATE_TSC_H