Fix the crash in this test. This is basically the same

problem addressed in 31284, but the patch there only
addressed the case where an invoke is the first thing in
a block.

llvm-svn: 73416

1 files changed, 27 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index bcc6b819013..ee0f6a65de4 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -859,6 +859,26 @@ static bool FoldValueComparisonIntoPredecessors(TerminatorInst *TI) {
   return Changed;
 }
 
+// isSafeToHoistInvoke - If we would need to insert a select that uses the
+// value of this invoke (comments in HoistThenElseCodeToIf explain why we
+// would need to do this), we can't hoist the invoke, as there is nowhere
+// to put the select in this case.
+static bool isSafeToHoistInvoke(BasicBlock *BB1, BasicBlock *BB2,
+                                Instruction *I1, Instruction *I2) {
+  for (succ_iterator SI = succ_begin(BB1), E = succ_end(BB1); SI != E; ++SI) {
+    PHINode *PN;
+    for (BasicBlock::iterator BBI = SI->begin();
+         (PN = dyn_cast<PHINode>(BBI)); ++BBI) {
+      Value *BB1V = PN->getIncomingValueForBlock(BB1);
+      Value *BB2V = PN->getIncomingValueForBlock(BB2);
+      if (BB1V != BB2V && (BB1V==I1 || BB2V==I2)) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
 /// HoistThenElseCodeToIf - Given a conditional branch that goes to BB1 and
 /// BB2, hoist any common code in the two blocks up into the branch block.  The
 /// caller of this function guarantees that BI's block dominates BB1 and BB2.
@@ -879,8 +899,9 @@ static bool HoistThenElseCodeToIf(BranchInst *BI) {
     I1 = BB1_Itr++;
   while (isa<DbgInfoIntrinsic>(I2))
     I2 = BB2_Itr++;
-  if (I1->getOpcode() != I2->getOpcode() || isa<PHINode>(I1) || 
-      isa<InvokeInst>(I1) || !I1->isIdenticalTo(I2))
+  if (I1->getOpcode() != I2->getOpcode() || isa<PHINode>(I1) ||
+      !I1->isIdenticalTo(I2) ||
+      (isa<InvokeInst>(I1) && !isSafeToHoistInvoke(BB1, BB2, I1, I2)))
     return false;
 
   // If we get here, we can hoist at least one instruction.
@@ -911,6 +932,10 @@ static bool HoistThenElseCodeToIf(BranchInst *BI) {
   return true;
 
 HoistTerminator:
+  // It may not be possible to hoist an invoke.
+  if (isa<InvokeInst>(I1) && !isSafeToHoistInvoke(BB1, BB2, I1, I2))
+    return true;
+
   // Okay, it is safe to hoist the terminator.
   Instruction *NT = I1->clone();
   BIParent->getInstList().insert(BI, NT);