[PATCH] D42067: [SelectionDAG] Teach computeKnownBits about ATOMIC_CMP_SWAP_WITH_SUCCESS boolean return value

[Ulrich Weigand via Phabricator via llvm-commits]

uweigand created this revision.
uweigand added reviewers: RKSimon, craig.topper.

The second return value of ATOMIC_CMP_SWAP_WITH_SUCCESS is known to be a boolean, and should therefore be treated by computeKnownBits just like the second return values of SMULO / UMULO.

(I don't have a stand-alone test case for this, but this patch is required to make a test case pass that I'll be adding with a follow-on SystemZ back-end patch.)


Repository:
  rL LLVM

https://reviews.llvm.org/D42067

Files:
  lib/CodeGen/SelectionDAG/SelectionDAG.cpp


Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2442,6 +2442,7 @@
     break;
   case ISD::SMULO:
   case ISD::UMULO:
+  case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS:
     if (Op.getResNo() != 1)
       break;
     // The boolean result conforms to getBooleanContents.


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