[clang] [libc] [Clang] Implement resource directory headers for common GPU intrinsics (PR #110179)

[Johannes Doerfert via cfe-commits]

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@@ -0,0 +1,154 @@
+//===-- amdgpuintrin.h - AMDPGU intrinsic functions -----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __AMDGPUINTRIN_H
+#define __AMDGPUINTRIN_H
+
+#ifndef __AMDGPU__
+#error "This file is intended for AMDGPU targets or offloading to AMDGPU"
+#endif
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#if defined(__HIP__) || defined(__CUDA__)
+#define _DEFAULT_ATTRS __attribute__((device))
+#elif !defined(_DEFAULT_ATTRS)
+#define _DEFAULT_ATTRS
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jdoerfert wrote:

Oddly, you define it in one case and then test if it is not defined already.
That implies on non-hip/cuda it might be defined but otherwise it shouldn't be?
If the above is not true, e.g., if it should not be defined at all, make that clearer plz. 

https://github.com/llvm/llvm-project/pull/110179