Convert InsertValueInst and ExtractValueInst APIs to use ArrayRef.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135040 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 130e3ce..455c910 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -1352,14 +1352,15 @@
   // we might be able to find the complete struct somewhere.
   
   // Find the value that is at that particular spot
-  Value *V = FindInsertedValue(From, Idxs.begin(), Idxs.end());
+  Value *V = FindInsertedValue(From, Idxs);
 
   if (!V)
     return NULL;
 
   // Insert the value in the new (sub) aggregrate
-  return llvm::InsertValueInst::Create(To, V, Idxs.begin() + IdxSkip,
-                                       Idxs.end(), "tmp", InsertBefore);
+  return llvm::InsertValueInst::Create(To, V,
+                                       ArrayRef<unsigned>(Idxs).slice(IdxSkip),
+                                       "tmp", InsertBefore);
 }
 
 // This helper takes a nested struct and extracts a part of it (which is again a
@@ -1374,15 +1375,13 @@
 // insertvalue instruction somewhere).
 //
 // All inserted insertvalue instructions are inserted before InsertBefore
-static Value *BuildSubAggregate(Value *From, const unsigned *idx_begin,
-                                const unsigned *idx_end,
+static Value *BuildSubAggregate(Value *From, ArrayRef<unsigned> idx_range,
                                 Instruction *InsertBefore) {
   assert(InsertBefore && "Must have someplace to insert!");
   const Type *IndexedType = ExtractValueInst::getIndexedType(From->getType(),
-                                                             idx_begin,
-                                                             idx_end);
+                                                             idx_range);
   Value *To = UndefValue::get(IndexedType);
-  SmallVector<unsigned, 10> Idxs(idx_begin, idx_end);
+  SmallVector<unsigned, 10> Idxs(idx_range.begin(), idx_range.end());
   unsigned IdxSkip = Idxs.size();
 
   return BuildSubAggregate(From, To, IndexedType, Idxs, IdxSkip, InsertBefore);
@@ -1394,39 +1393,37 @@
 ///
 /// If InsertBefore is not null, this function will duplicate (modified)
 /// insertvalues when a part of a nested struct is extracted.
-Value *llvm::FindInsertedValue(Value *V, const unsigned *idx_begin,
-                         const unsigned *idx_end, Instruction *InsertBefore) {
+Value *llvm::FindInsertedValue(Value *V, ArrayRef<unsigned> idx_range,
+                               Instruction *InsertBefore) {
   // Nothing to index? Just return V then (this is useful at the end of our
   // recursion)
-  if (idx_begin == idx_end)
+  if (idx_range.empty())
     return V;
   // We have indices, so V should have an indexable type
   assert((V->getType()->isStructTy() || V->getType()->isArrayTy())
          && "Not looking at a struct or array?");
-  assert(ExtractValueInst::getIndexedType(V->getType(), idx_begin, idx_end)
+  assert(ExtractValueInst::getIndexedType(V->getType(), idx_range)
          && "Invalid indices for type?");
   const CompositeType *PTy = cast<CompositeType>(V->getType());
 
   if (isa<UndefValue>(V))
     return UndefValue::get(ExtractValueInst::getIndexedType(PTy,
-                                                              idx_begin,
-                                                              idx_end));
+                                                              idx_range));
   else if (isa<ConstantAggregateZero>(V))
     return Constant::getNullValue(ExtractValueInst::getIndexedType(PTy, 
-                                                                  idx_begin,
-                                                                  idx_end));
+                                                                  idx_range));
   else if (Constant *C = dyn_cast<Constant>(V)) {
     if (isa<ConstantArray>(C) || isa<ConstantStruct>(C))
       // Recursively process this constant
-      return FindInsertedValue(C->getOperand(*idx_begin), idx_begin + 1,
-                               idx_end, InsertBefore);
+      return FindInsertedValue(C->getOperand(idx_range[0]), idx_range.slice(1),
+                               InsertBefore);
   } else if (InsertValueInst *I = dyn_cast<InsertValueInst>(V)) {
     // Loop the indices for the insertvalue instruction in parallel with the
     // requested indices
-    const unsigned *req_idx = idx_begin;
+    const unsigned *req_idx = idx_range.begin();
     for (const unsigned *i = I->idx_begin(), *e = I->idx_end();
          i != e; ++i, ++req_idx) {
-      if (req_idx == idx_end) {
+      if (req_idx == idx_range.end()) {
         if (InsertBefore)
           // The requested index identifies a part of a nested aggregate. Handle
           // this specially. For example,
@@ -1438,7 +1435,10 @@
           // %C = insertvalue {i32, i32 } %A, i32 11, 1
           // which allows the unused 0,0 element from the nested struct to be
           // removed.
-          return BuildSubAggregate(V, idx_begin, req_idx, InsertBefore);
+          return BuildSubAggregate(V,
+                                   ArrayRef<unsigned>(idx_range.begin(),
+                                                      req_idx),
+                                   InsertBefore);
         else
           // We can't handle this without inserting insertvalues
           return 0;
@@ -1448,13 +1448,14 @@
       // See if the (aggregrate) value inserted into has the value we are
       // looking for, then.
       if (*req_idx != *i)
-        return FindInsertedValue(I->getAggregateOperand(), idx_begin, idx_end,
+        return FindInsertedValue(I->getAggregateOperand(), idx_range,
                                  InsertBefore);
     }
     // If we end up here, the indices of the insertvalue match with those
     // requested (though possibly only partially). Now we recursively look at
     // the inserted value, passing any remaining indices.
-    return FindInsertedValue(I->getInsertedValueOperand(), req_idx, idx_end,
+    return FindInsertedValue(I->getInsertedValueOperand(),
+                             ArrayRef<unsigned>(req_idx, idx_range.end()),
                              InsertBefore);
   } else if (ExtractValueInst *I = dyn_cast<ExtractValueInst>(V)) {
     // If we're extracting a value from an aggregrate that was extracted from
@@ -1462,24 +1463,20 @@
     // However, we will need to chain I's indices with the requested indices.
    
     // Calculate the number of indices required 
-    unsigned size = I->getNumIndices() + (idx_end - idx_begin);
+    unsigned size = I->getNumIndices() + idx_range.size();
     // Allocate some space to put the new indices in
     SmallVector<unsigned, 5> Idxs;
     Idxs.reserve(size);
     // Add indices from the extract value instruction
-    for (const unsigned *i = I->idx_begin(), *e = I->idx_end();
-         i != e; ++i)
-      Idxs.push_back(*i);
+    Idxs.append(I->idx_begin(), I->idx_end());
     
     // Add requested indices
-    for (const unsigned *i = idx_begin, *e = idx_end; i != e; ++i)
-      Idxs.push_back(*i);
+    Idxs.append(idx_range.begin(), idx_range.end());
 
     assert(Idxs.size() == size 
            && "Number of indices added not correct?");
     
-    return FindInsertedValue(I->getAggregateOperand(), Idxs.begin(), Idxs.end(),
-                             InsertBefore);
+    return FindInsertedValue(I->getAggregateOperand(), Idxs, InsertBefore);
   }
   // Otherwise, we don't know (such as, extracting from a function return value
   // or load instruction)