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