[PATCH] D29452: AMDGPU/SI: DAGMutation for removing deps between CSEs

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: lib/Target/AMDGPU/GCNSchedStrategy.cpp:409-410
+
+      // Try to schedule the two SCEs together so MachineCSE can more easily
+      // remove them.
+      IdenticalSU->addPred(SDep(SU, SDep::Cluster));
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I thought MachineCSE ran well before the scheduler?


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Comment at: test/CodeGen/AMDGPU/init-m0-sched-deps.mir:21-25
+    %m0 = S_MOV_B32 -1
+    %0 = V_MOV_B32_e32 0, implicit %exec
+    %1 = DS_READ_B32 %0, 0, 0, implicit %m0, implicit %exec :: (load 4 from %ir.lds0)
+    %m0 = S_MOV_B32 -1
+    %2 = DS_READ_B32 %0, 4, 0, implicit %m0, implicit %exec :: (load 4 from %ir.lds1)
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Can you add a few more complex cases, like multiple operations using the same def of m0


https://reviews.llvm.org/D29452