[clang] [AMDGPU][SPIRV] Use SPIR-V syncscopes for some AMDGCN BIs (PR #154867)

[Alex Voicu via cfe-commits]

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@@ -238,13 +248,19 @@ void CodeGenFunction::ProcessOrderScopeAMDGCN(Value *Order, Value *Scope,
     SSID = llvm::SyncScope::System;
     break;
   case 1: // __MEMORY_SCOPE_DEVICE
-    SSID = getLLVMContext().getOrInsertSyncScopeID("agent");
+    if (getTarget().getTriple().isSPIRV())
+      SSID = getLLVMContext().getOrInsertSyncScopeID("device");
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AlexVlx wrote:

Yes, reverse translation maps from SPIR-V to AMDGPU; we don't test this in LLVM yet because we don't use the BE, yet, reverse translation is done in the OOT translator.

https://github.com/llvm/llvm-project/pull/154867