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// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/base/internal/unscaledcycleclock.h"
#if ABSL_USE_UNSCALED_CYCLECLOCK
#if defined(_WIN32)
#include <intrin.h>
#endif
#if defined(__powerpc__) || defined(__ppc__)
#include <sys/platform/ppc.h>
#endif
#include "absl/base/internal/sysinfo.h"
namespace absl {
namespace base_internal {
#if defined(__i386__)
int64_t UnscaledCycleClock::Now() {
int64_t ret;
__asm__ volatile("rdtsc" : "=A"(ret));
return ret;
}
double UnscaledCycleClock::Frequency() {
return base_internal::NominalCPUFrequency();
}
#elif defined(__x86_64__)
int64_t UnscaledCycleClock::Now() {
uint64_t low, high;
__asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
return (high << 32) | low;
}
double UnscaledCycleClock::Frequency() {
return base_internal::NominalCPUFrequency();
}
#elif defined(__powerpc__) || defined(__ppc__)
int64_t UnscaledCycleClock::Now() {
return __ppc_get_timebase();
}
double UnscaledCycleClock::Frequency() {
return __ppc_get_timebase_freq();
}
#elif defined(__aarch64__)
// System timer of ARMv8 runs at a different frequency than the CPU's.
// The frequency is fixed, typically in the range 1-50MHz. It can be
// read at CNTFRQ special register. We assume the OS has set up
// the virtual timer properly.
int64_t UnscaledCycleClock::Now() {
int64_t virtual_timer_value;
asm volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value));
return virtual_timer_value;
}
double UnscaledCycleClock::Frequency() {
uint64_t aarch64_timer_frequency;
asm volatile("mrs %0, cntfrq_el0" : "=r"(aarch64_timer_frequency));
return aarch64_timer_frequency;
}
#elif defined(_M_IX86) || defined(_M_X64)
#pragma intrinsic(__rdtsc)
int64_t UnscaledCycleClock::Now() {
return __rdtsc();
}
double UnscaledCycleClock::Frequency() {
return base_internal::NominalCPUFrequency();
}
#endif
} // namespace base_internal
} // namespace absl
#endif // ABSL_USE_UNSCALED_CYCLECLOCK
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