[llvm] [AMDGPU] Insert waitcnt for non-global fence release in GFX12 (PR #159282)

[Fabian Ritter via llvm-commits]

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@@ -2521,45 +2521,41 @@ bool SIGfx12CacheControl::insertRelease(MachineBasicBlock::iterator &MI,
   // writeback as all memory operations by the same thread are
   // sequentially consistent, and no other thread can access scratch
   // memory.
+  if ((AddrSpace & SIAtomicAddrSpace::GLOBAL) != SIAtomicAddrSpace::NONE) {
+    if (Pos == Position::AFTER)
+      ++MI;
 
-  // Other address spaces do not have a cache.
-  if ((AddrSpace & SIAtomicAddrSpace::GLOBAL) == SIAtomicAddrSpace::NONE)
-    return false;
-
-  if (Pos == Position::AFTER)
-    ++MI;
-
-  // global_wb is only necessary at system scope for GFX12.0,
-  // they're also necessary at device scope for GFX12.5.
-  //
-  // Emitting it for lower scopes is a slow no-op, so we omit it
-  // for performance.
-  switch (Scope) {
-  case SIAtomicScope::SYSTEM:
-    BuildMI(MBB, MI, DL, TII->get(AMDGPU::GLOBAL_WB))
-        .addImm(AMDGPU::CPol::SCOPE_SYS);
-    break;
-  case SIAtomicScope::AGENT:
-    // TODO DOCS
-    if (ST.hasGFX1250Insts()) {
+    // global_wb is only necessary at system scope for GFX12.0,
+    // they're also necessary at device scope for GFX12.5.
+    //
+    // Emitting it for lower scopes is a slow no-op, so we omit it
+    // for performance.
+    switch (Scope) {
+    case SIAtomicScope::SYSTEM:
       BuildMI(MBB, MI, DL, TII->get(AMDGPU::GLOBAL_WB))
-          .addImm(AMDGPU::CPol::SCOPE_DEV);
+          .addImm(AMDGPU::CPol::SCOPE_SYS);
+      break;
+    case SIAtomicScope::AGENT:
+      // TODO DOCS
+      if (ST.hasGFX1250Insts()) {
+        BuildMI(MBB, MI, DL, TII->get(AMDGPU::GLOBAL_WB))
+            .addImm(AMDGPU::CPol::SCOPE_DEV);
+      }
+      break;
+    case SIAtomicScope::CLUSTER:
+    case SIAtomicScope::WORKGROUP:
+      // No WB necessary, but we still have to wait.
+    case SIAtomicScope::WAVEFRONT:
+    case SIAtomicScope::SINGLETHREAD:
+      // No WB or wait necessary here, but insertWait takes care of that.
+      break;
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ritter-x2a wrote:

Done.

https://github.com/llvm/llvm-project/pull/159282