Add MSVC ARM64 support for reading clocks (#1052)

Lacks CMake support, see https://github.com/google/benchmark/pull/1090
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Michał Janiszewski 2021-02-12 11:30:26 +01:00 committed by GitHub
parent 8df87f6c87
commit ea5a5bbff4
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1 changed files with 7 additions and 1 deletions

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@ -36,7 +36,7 @@
// declarations of some other intrinsics, breaking compilation.
// Therefore, we simply declare __rdtsc ourselves. See also
// http://connect.microsoft.com/VisualStudio/feedback/details/262047
#if defined(COMPILER_MSVC) && !defined(_M_IX86)
#if defined(COMPILER_MSVC) && !defined(_M_IX86) && !defined(_M_ARM64)
extern "C" uint64_t __rdtsc();
#pragma intrinsic(__rdtsc)
#endif
@ -114,6 +114,12 @@ inline BENCHMARK_ALWAYS_INLINE int64_t Now() {
// when I know it will work. Otherwise, I'll use __rdtsc and hope
// the code is being compiled with a non-ancient compiler.
_asm rdtsc
#elif defined(COMPILER_MSVC) && defined(_M_ARM64)
// See https://docs.microsoft.com/en-us/cpp/intrinsics/arm64-intrinsics?view=vs-2019
// and https://reviews.llvm.org/D53115
int64_t virtual_timer_value;
virtual_timer_value = _ReadStatusReg(ARM64_CNTVCT);
return virtual_timer_value;
#elif defined(COMPILER_MSVC)
return __rdtsc();
#elif defined(BENCHMARK_OS_NACL)