[AMDGPU] Cluster export instruction in PostRA Scheduler

[perlfu]

DAG mutation needs to be applied post-RA to maintain order established during pre-RA scheduler.

[llvmbot]

@llvm/pr-subscribers-backend-amdgpu

Author: Carl Ritson (perlfu)

Changes

DAG mutation needs to be applied post-RA to maintain order established during pre-RA scheduler.

---

Full diff: https://github.com/llvm/llvm-project/pull/141399.diff

1 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp (+1)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index e24d8481408ad..7479703ce353a 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -1129,6 +1129,7 @@ GCNTargetMachine::createPostMachineScheduler(MachineSchedContext *C) const {
        getOptLevel() >= CodeGenOptLevel::Less) &&
       EnableVOPD)
     DAG->addMutation(createVOPDPairingMutation());
+  DAG->addMutation(createAMDGPUExportClusteringDAGMutation());
   return DAG;
 }
 //===----------------------------------------------------------------------===//

[arsenm]

Maybe this can only apply post-RA?