[clang] Add clang atomic control options and attribute (PR #114841)

[Matt Arsenault via cfe-commits]

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@@ -0,0 +1,30 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -verify -fcuda-is-device %s
+// RUN: %clang_cc1 -fsyntax-only -verify -fcuda-is-device %s \
+// RUN:   -fatomic=no_fine_grained_memory:off,no_remote_memory:on,ignore_denormal_mode:on
+
+#include "Inputs/cuda.h"
+
+[[clang::atomic(!no_remote_memory)]] // expected-error {{'atomic' attribute cannot be applied to a declaration}}
+__device__ __host__ void test_location(float *a) {
+  __scoped_atomic_fetch_add(a, 1, __ATOMIC_RELAXED, __MEMORY_SCOPE_SYSTEM);
+  [[clang::atomic(!no_remote_memory)]] int x; // expected-error {{'atomic' attribute cannot be applied to a declaration}}
+}
+
+__device__ __host__ void test_invalid_option(float *a) {
+  [[clang::atomic(fast)]] { // expected-error {{invalid argument 'fast' to atomic attribute; valid options are: 'no_remote_memory', 'no_fine_grained_memory', 'ignore_denormal_mode' (optionally prefixed with '!')}}
+    __scoped_atomic_fetch_add(a, 1, __ATOMIC_RELAXED, __MEMORY_SCOPE_SYSTEM);
+  }
+}
+
+__device__ __host__ void test_invalid_value(float *a) {
+  [[clang::atomic(no_remote_memory(default))]] { // expected-error {{expected ')'}} expected-note {{to match this '('}}
+    __scoped_atomic_fetch_add(a, 1, __ATOMIC_RELAXED, __MEMORY_SCOPE_SYSTEM);
+  }
+}
+
+__device__ __host__ void test_invalid_format(float *a) {
+  [[clang::atomic(no_remote_memory=on)]] { // expected-error {{expected ')'}} expected-note {{to match this '('}}
+    __scoped_atomic_fetch_add(a, 1, __ATOMIC_RELAXED, __MEMORY_SCOPE_SYSTEM);
+  }
+}
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arsenm wrote:

Missing newline 

https://github.com/llvm/llvm-project/pull/114841