libc/src/assert/gpu/__assert_fail.cpp

   1 //===-- GPU definition of a libc internal assert macro ----------*- 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 #include "src/assert/__assert_fail.h"
  10
  11 #include "src/__support/CPP/atomic.h"
  12 #include "src/__support/GPU/utils.h"
  13 #include "src/__support/libc_assert.h"
  14 #include "src/__support/macros/config.h"
  15 #include "src/stdlib/abort.h"
  16
  17 namespace LIBC_NAMESPACE_DECL {
  18
  19 // A single-use lock to allow only a single thread to print the assertion.
  20 static cpp::Atomic<uint32_t> lock = 0;
  21
  22 LLVM_LIBC_FUNCTION(void, __assert_fail,
  23                    (const char *assertion, const char *file, unsigned line,
  24                     const char *function)) {
  25   uint64_t mask = gpu::get_lane_mask();
  26   // We only want a single work group or warp to handle the assertion. Each
  27   // group attempts to claim the lock, if it is already claimed we simply exit.
  28   uint32_t claimed = gpu::is_first_lane(mask)
  29                          ? !lock.fetch_or(1, cpp::MemoryOrder::ACQUIRE)
  30                          : 0;
  31   if (!gpu::broadcast_value(mask, claimed))
  32     gpu::end_program();
  33
  34   // Only a single line should be printed if an assertion is hit.
  35   if (gpu::is_first_lane(mask))
  36     LIBC_NAMESPACE::report_assertion_failure(assertion, file, line, function);
  37   gpu::sync_lane(mask);
  38   LIBC_NAMESPACE::abort();
  39 }
  40
  41 } // namespace LIBC_NAMESPACE_DECL