1 files changed, 16 insertions, 9 deletions
diff --git a/lib/CodeGen/Analysis.cpp b/lib/CodeGen/Analysis.cpp
index 9a3b790..e50b846 100644
--- a/lib/CodeGen/Analysis.cpp
+++ b/lib/CodeGen/Analysis.cpp
@@ -30,10 +30,9 @@
 
 using namespace llvm;
 
-/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence
-/// of insertvalue or extractvalue indices that identify a member, return
-/// the linearized index of the start of the member.
-///
+/// Compute the linearized index of a member in a nested aggregate/struct/array
+/// by recursing and accumulating CurIndex as long as there are indices in the
+/// index list.
 unsigned llvm::ComputeLinearIndex(Type *Ty,
                                   const unsigned *Indices,
                                   const unsigned *IndicesEnd,
@@ -52,16 +51,23 @@ unsigned llvm::ComputeLinearIndex(Type *Ty,
         return ComputeLinearIndex(*EI, Indices+1, IndicesEnd, CurIndex);
       CurIndex = ComputeLinearIndex(*EI, nullptr, nullptr, CurIndex);
     }
+    assert(!Indices && "Unexpected out of bound");
     return CurIndex;
   }
   // Given an array type, recursively traverse the elements.
   else if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
     Type *EltTy = ATy->getElementType();
-    for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
-      if (Indices && *Indices == i)
-        return ComputeLinearIndex(EltTy, Indices+1, IndicesEnd, CurIndex);
-      CurIndex = ComputeLinearIndex(EltTy, nullptr, nullptr, CurIndex);
+    unsigned NumElts = ATy->getNumElements();
+    // Compute the Linear offset when jumping one element of the array
+    unsigned EltLinearOffset = ComputeLinearIndex(EltTy, nullptr, nullptr, 0);
+    if (Indices) {
+      assert(*Indices < NumElts && "Unexpected out of bound");
+      // If the indice is inside the array, compute the index to the requested
+      // elt and recurse inside the element with the end of the indices list
+      CurIndex += EltLinearOffset* *Indices;
+      return ComputeLinearIndex(EltTy, Indices+1, IndicesEnd, CurIndex);
     }
+    CurIndex += EltLinearOffset*NumElts;
     return CurIndex;
   }
   // We haven't found the type we're looking for, so keep searching.
@@ -512,8 +518,9 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS, const TargetMachine &TM) {
         return false;
     }
 
+  const Function *F = ExitBB->getParent();
   return returnTypeIsEligibleForTailCall(
-      ExitBB->getParent(), I, Ret, *TM.getSubtargetImpl()->getTargetLowering());
+      F, I, Ret, *TM.getSubtargetImpl(*F)->getTargetLowering());
 }
 
 bool llvm::returnTypeIsEligibleForTailCall(const Function *F,