Fix crash when when do lto on Bullet. Dynamic GEPs in SROA were incorrectly being applied to all accesses to an alloca, not just the ones which read from the GEP. Thanks to Evan for reducing the test. rdar://11861001

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161654 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 3 deletions

diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index ec835b1..6637126 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -612,11 +612,16 @@ void ConvertToScalarInfo::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI,
     if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
       // Compute the offset that this GEP adds to the pointer.
       SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end());
-      if (!GEP->hasAllConstantIndices())
-        NonConstantIdx = Indices.pop_back_val();
+      Value* GEPNonConstantIdx = 0;
+      if (!GEP->hasAllConstantIndices()) {
+        assert(!NonConstantIdx &&
+               "Dynamic GEP reading from dynamic GEP unsupported");
+        GEPNonConstantIdx = Indices.pop_back_val();
+      } else
+        GEPNonConstantIdx = NonConstantIdx;
       uint64_t GEPOffset = TD.getIndexedOffset(GEP->getPointerOperandType(),
                                                Indices);
-      ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8, NonConstantIdx);
+      ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8, GEPNonConstantIdx);
       GEP->eraseFromParent();
       continue;
     }