libc/src/time/gpu/time_utils.h

   1 //===-- Generic utilities for GPU timing ----------------------------------===//
   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 #ifndef LLVM_LIBC_SRC_TIME_GPU_TIME_UTILS_H
  10 #define LLVM_LIBC_SRC_TIME_GPU_TIME_UTILS_H
  11
  12 #include "src/__support/GPU/utils.h"
  13
  14 namespace LIBC_NAMESPACE {
  15
  16 #if defined(LIBC_TARGET_ARCH_IS_AMDGPU)
  17 // AMDGPU does not have a single set frequency. Different architectures and
  18 // cards can have vary values. Here we default to a few known values, but for
  19 // complete support the frequency needs to be read from the kernel driver.
  20 #if defined(__gfx1010__) || defined(__gfx1011__) || defined(__gfx1012__) ||    \
  21     defined(__gfx1013__) || defined(__gfx1030__) || defined(__gfx1031__) ||    \
  22     defined(__gfx1032__) || defined(__gfx1033__) || defined(__gfx1034__) ||    \
  23     defined(__gfx1035__) || defined(__gfx1036__) || defined(__gfx1100__) ||    \
  24     defined(__gfx1101__) || defined(__gfx1102__) || defined(__gfx1103__) ||    \
  25     defined(__gfx1150__) || defined(__gfx1151__)
  26 // These architectures use a 100 MHz fixed frequency clock.
  27 constexpr uint64_t clock_freq = 100000000;
  28 #elif defined(__gfx900__) || defined(__gfx902__) || defined(__gfx904__) ||     \
  29     defined(__gfx906__) || defined(__gfx908__) || defined(__gfx909__) ||       \
  30     defined(__gfx90a__) || defined(__gfx90c__) || defined(__gfx940__)
  31 // These architectures use a 25 MHz fixed frequency clock expect for Vega 10
  32 // which is actually 27 Mhz. We default to 25 MHz in all cases anyway.
  33 constexpr uint64_t clock_freq = 25000000;
  34 #else
  35 // The frequency for these architecture is unknown. We simply default to zero.
  36 constexpr uint64_t clock_freq = 0;
  37 #endif
  38
  39 // We provide an externally visible symbol such that the runtime can set this to
  40 // the correct value. If it is not set we try to default to the known values.
  41 extern "C" [[gnu::visibility("protected")]] uint64_t
  42     [[clang::address_space(4)]] __llvm_libc_clock_freq;
  43 #define GPU_CLOCKS_PER_SEC static_cast<clock_t>(__llvm_libc_clock_freq)
  44
  45 #elif defined(LIBC_TARGET_ARCH_IS_NVPTX)
  46 // NPVTX uses a single 1 GHz fixed frequency clock for all target architectures.
  47 #define GPU_CLOCKS_PER_SEC static_cast<clock_t>(1000000000UL)
  48 #else
  49 #error "Unsupported target"
  50 #endif
  51
  52 } // namespace LIBC_NAMESPACE
  53
  54 #endif // LLVM_LIBC_SRC_TIME_GPU_TIME_UTILS_H