[libcxx-commits] [libcxx] [libcxx] Adjust inline assembly constraints for the AMDGPU target (PR #101747)

[Matt Arsenault via libcxx-commits]

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@@ -291,17 +291,27 @@ struct is_same<T, T> { enum {value = 1}; };
 // when optimizations are enabled.
 template <class Tp>
 inline Tp const& DoNotOptimize(Tp const& value) {
-    asm volatile("" : : "r,m"(value) : "memory");
-    return value;
+  // The `m` constraint is invalid in the AMDGPU backend.
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arsenm wrote:

That's stuff they went and implemented on their own without telling us 

https://github.com/llvm/llvm-project/pull/101747