[PATCH] D92645: [X86] Add X86ISD::SUBV_BROADCAST_LOAD and begin removing X86ISD::SUBV_BROADCAST (PR38969)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:44573
+        Extract = DAG.getBitcast(RegVT, Extract);
+        return DCI.CombineTo(N, Extract, SDValue(User, 1));
+      }
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yubing wrote:
> Hi, Simon. If we have a load and subv_broadcast_load which has the same SRC, the load will be combined into a extract_subv from subv_broadcast_load. But If some optimization delete subv_broadcast_load's other users and make it has only one user i.e. extract_subv, will extract_subv(subv_broadcast_load) roll back to a simple load?
Yes the new SimplifyDemandedVectorElts code at line 38024 should handle that.


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  https://reviews.llvm.org/D92645/new/

https://reviews.llvm.org/D92645