[llvm-branch-commits] [clang] [HLSL] Add `InterlockedCompareExchange` function and resource methods (PR #222165)

[via llvm-branch-commits]

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+// RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -triple \
+// RUN:   dxil-pc-shadermodel6.6-library %s -emit-llvm -disable-llvm-passes -o - | \
+// RUN:   FileCheck %s --check-prefixes=CHECK,DXCHECK
+
+// RUN: %clang_cc1 -std=hlsl2021 -finclude-default-header -triple \
+// RUN:   spirv-pc-vulkan-library %s -emit-llvm -disable-llvm-passes -o - | \
+// RUN:   FileCheck %s --check-prefixes=CHECK,SPVCHECK
+
+// Test basic lowering of HLSL InterlockedCompareExchange to `cmpxchg
+// monotonic`. The operation reports the value that was in the destination
+// before the operation, so the first element of the `cmpxchg` result goes to
+// the out parameter.
+
+groupshared int  gs_i32;
+groupshared uint gs_u32;
+groupshared int64_t  gs_i64;
+groupshared uint64_t gs_u64;
+
+// CHECK-LABEL: define {{.*}}void @{{.*}}test_int
+// DXCHECK:  [[PAIR:%.*]] = cmpxchg ptr addrspace(3) {{.*}}@gs_i32{{.*}}, i32 %{{.*}}, i32 %{{.*}} syncscope("workgroup") monotonic monotonic
+// SPVCHECK: [[PAIR:%.*]] = cmpxchg ptr addrspace(3) {{.*}}@gs_i32{{.*}}, i32 %{{.*}}, i32 %{{.*}} syncscope("workgroup") monotonic monotonic
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joaosaffran wrote:

```suggestion
// CHECK:  [[PAIR:%.*]] = cmpxchg ptr addrspace(3) {{.*}}@gs_i32{{.*}}, i32 %{{.*}}, i32 %{{.*}} syncscope("workgroup") monotonic monotonic
```

https://github.com/llvm/llvm-project/pull/222165