[PATCH] D33787: [IR] BasicBlock updatePHIs function for updating predecessors

[Daniel Berlin via Phabricator via llvm-commits]

dberlin added inline comments.


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Comment at: lib/IR/BasicBlock.cpp:464
+    int incoming = PHI.getBasicBlockIndex(IncomingOld);
+    if (incoming >= 0) {
+      if (oldPredecessor) {
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It should be an assert that the old predecessor existed in the phi


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Comment at: lib/IR/BasicBlock.cpp:468
+        // need to insert another value with the same incoming value.
+        PHI.addIncoming(PHI.getIncomingValue(incoming), IncomingNew);
+      } else {
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This will put the phi arguments out of order with the predecessors, which is smoethign we would like to avoid.


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Comment at: lib/IR/BasicBlock.cpp:470
+      } else {
+        PHI.setIncomingBlock(incoming, IncomingNew);
+      }
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I looked at the code for this function, and i don't see why it would fail.
Can you explain?



https://reviews.llvm.org/D33787