don't break phis with switch legalization

1 files changed, 16 insertions, 0 deletions

diff --git a/lib/Transforms/NaCl/ExpandI64.cpp b/lib/Transforms/NaCl/ExpandI64.cpp
index 63c2328cb2..d224e48659 100644
--- a/lib/Transforms/NaCl/ExpandI64.cpp
+++ b/lib/Transforms/NaCl/ExpandI64.cpp
@@ -122,6 +122,20 @@ INITIALIZE_PASS(ExpandI64, "expand-i64",
 
 // Utilities
 
+static void updateEdge(BasicBlock *Dest, // from PNaClSjLjEH.cpp
+                       BasicBlock *OldIncoming,
+                       BasicBlock *NewIncoming) {
+  for (BasicBlock::iterator Inst = Dest->begin(); Inst != Dest->end(); ++Inst) {
+    PHINode *Phi = dyn_cast<PHINode>(Inst);
+    if (!Phi)
+      break;
+    for (unsigned I = 0, E = Phi->getNumIncomingValues(); I < E; ++I) {
+      if (Phi->getIncomingBlock(I) == OldIncoming)
+        Phi->setIncomingBlock(I, NewIncoming);
+    }
+  }
+}
+
 static bool isIllegal(Type *T) {
   return T->isIntegerTy() && T->getIntegerBitWidth() == 64;
 }
@@ -565,6 +579,8 @@ void ExpandI64::splitInst(Instruction *I, DataLayout& DL) {
           CopyDebug(BranchInst::Create(BB, DD, CheckHigh, NewBB), I);
 
           LowSI->addCase(cast<ConstantInt>(ConstantInt::get(i32, LowBits)), NewBB);
+
+          updateEdge(BB, SwitchBB, NewBB); // make sure phis work properly
         }
       }
       break;