Don't crash when trying to constant fold a vector with some elements that can't

be folded. Instead, fail to fold the entire vector.

We could also return a vector with some elements folded and some not. If anyone
thinks that's a better approach, please speak up!

llvm-svn: 55689

1 files changed, 12 insertions, 6 deletions

diff --git a/llvm/lib/VMCore/ConstantFold.cpp b/llvm/lib/VMCore/ConstantFold.cpp
index 5167c12d49b..25c756ab6e5 100644
--- a/llvm/lib/VMCore/ConstantFold.cpp
+++ b/llvm/lib/VMCore/ConstantFold.cpp
@@ -238,9 +238,12 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
       std::vector<Constant*> res;
       const VectorType *DestVecTy = cast<VectorType>(DestTy);
       const Type *DstEltTy = DestVecTy->getElementType();
-      for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
-        res.push_back(ConstantFoldCastInstruction(opc, V->getOperand(i),
-                                                  DstEltTy));
+      for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) {
+        Constant *C = ConstantFoldCastInstruction(opc, CV->getOperand(i),
+                                                  DstEltTy);
+        if (!C) return 0;       // Can't fold operand.
+        res.push_back(C);
+      }
       return ConstantVector::get(DestVecTy, res);
     }
     return 0; // Can't fold.
@@ -268,9 +271,12 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, const Constant *V,
       std::vector<Constant*> res;
       const VectorType *DestVecTy = cast<VectorType>(DestTy);
       const Type *DstEltTy = DestVecTy->getElementType();
-      for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
-        res.push_back(ConstantFoldCastInstruction(opc, V->getOperand(i),
-                                                  DstEltTy));
+      for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) {
+        Constant *C = ConstantFoldCastInstruction(opc, CV->getOperand(i),
+                                                  DstEltTy);
+        if (!C) return 0;       // Can't fold operand.
+        res.push_back(C);
+      }
       return ConstantVector::get(DestVecTy, res);
     }
     return 0;