[llvm] [LLVM] Add a C API for creating instructions with custom syncscopes. (PR #104775)

[Tim Besard via llvm-commits]

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@@ -4611,6 +4629,22 @@ int LLVMGetMaskValue(LLVMValueRef ShuffleVectorInst, unsigned Elt);
 LLVMBool LLVMIsAtomicSingleThread(LLVMValueRef AtomicInst);
 void LLVMSetAtomicSingleThread(LLVMValueRef AtomicInst, LLVMBool SingleThread);
 
+/**
+ * Returns whether an instruction is an atomic instruction, e.g., atomicrmw,
+ * cmpxchg, fence, or loads and stores with atomic ordering.
+ */
+LLVMBool LLVMIsAtomic(LLVMValueRef Inst);
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maleadt wrote:

Maybe this should be `LLVMInstructionIsAtomic`? The API isn't consequent on this.

https://github.com/llvm/llvm-project/pull/104775