xref: /llvm-project/libc/src/assert/gpu/__assert_fail.cpp (revision b6bc9d72f65a5086f310f321e969d96e9a559e75)
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   LIBC_NAMESPACE::abort();
37 }
38 
39 } // namespace LIBC_NAMESPACE
40