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Diffstat (limited to 'abseil-cpp/absl/base/internal/unscaledcycleclock_config.h')
| -rw-r--r-- | abseil-cpp/absl/base/internal/unscaledcycleclock_config.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/abseil-cpp/absl/base/internal/unscaledcycleclock_config.h b/abseil-cpp/absl/base/internal/unscaledcycleclock_config.h new file mode 100644 index 0000000..24b324a --- /dev/null +++ b/abseil-cpp/absl/base/internal/unscaledcycleclock_config.h @@ -0,0 +1,62 @@ +// Copyright 2022 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. + +#ifndef ABSL_BASE_INTERNAL_UNSCALEDCYCLECLOCK_CONFIG_H_ +#define ABSL_BASE_INTERNAL_UNSCALEDCYCLECLOCK_CONFIG_H_ + +#if defined(__APPLE__) +#include <TargetConditionals.h> +#endif + +// The following platforms have an implementation of a hardware counter. +#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) || \ + defined(__powerpc__) || defined(__ppc__) || defined(__riscv) || \ + defined(_M_IX86) || (defined(_M_X64) && !defined(_M_ARM64EC)) +#define ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION 1 +#else +#define ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION 0 +#endif + +// The following platforms often disable access to the hardware +// counter (through a sandbox) even if the underlying hardware has a +// usable counter. The CycleTimer interface also requires a *scaled* +// CycleClock that runs at atleast 1 MHz. We've found some Android +// ARM64 devices where this is not the case, so we disable it by +// default on Android ARM64. +#if defined(__native_client__) || (defined(__APPLE__)) || \ + (defined(__ANDROID__) && defined(__aarch64__)) +#define ABSL_USE_UNSCALED_CYCLECLOCK_DEFAULT 0 +#else +#define ABSL_USE_UNSCALED_CYCLECLOCK_DEFAULT 1 +#endif + +// UnscaledCycleClock is an optional internal feature. +// Use "#if ABSL_USE_UNSCALED_CYCLECLOCK" to test for its presence. +// Can be overridden at compile-time via -DABSL_USE_UNSCALED_CYCLECLOCK=0|1 +#if !defined(ABSL_USE_UNSCALED_CYCLECLOCK) +#define ABSL_USE_UNSCALED_CYCLECLOCK \ + (ABSL_HAVE_UNSCALED_CYCLECLOCK_IMPLEMENTATION && \ + ABSL_USE_UNSCALED_CYCLECLOCK_DEFAULT) +#endif + +#if ABSL_USE_UNSCALED_CYCLECLOCK +// This macro can be used to test if UnscaledCycleClock::Frequency() +// is NominalCPUFrequency() on a particular platform. +#if (defined(__i386__) || defined(__x86_64__) || defined(__riscv) || \ + defined(_M_IX86) || defined(_M_X64)) +#define ABSL_INTERNAL_UNSCALED_CYCLECLOCK_FREQUENCY_IS_CPU_FREQUENCY +#endif +#endif + +#endif // ABSL_BASE_INTERNAL_UNSCALEDCYCLECLOCK_CONFIG_H_ |