1 files changed, 19 insertions, 10 deletions
diff --git a/llvm/lib/Support/SmallVector.cpp b/llvm/lib/Support/SmallVector.cpp
index 9ece0c5..776b098 100644
--- a/llvm/lib/Support/SmallVector.cpp
+++ b/llvm/lib/Support/SmallVector.cpp
@@ -37,24 +37,30 @@ static_assert(sizeof(SmallVector<void *, 1>) ==
                   sizeof(unsigned) * 2 + sizeof(void *) * 2,
               "wasted space in SmallVector size 1");
 
-/// grow_pod - This is an implementation of the grow() method which only works
-/// on POD-like datatypes and is out of line to reduce code duplication.
-/// This function will report a fatal error if it cannot increase capacity.
-void SmallVectorBase::grow_pod(void *FirstEl, size_t MinCapacity,
-                               size_t TSize) {
-  // Ensure we can fit the new capacity in 32 bits.
-  if (MinCapacity > UINT32_MAX)
+static_assert(sizeof(SmallVector<char, 0>) ==
+                  sizeof(void *) * 2 + sizeof(void *),
+              "1 byte elements have word-sized type for size and capacity");
+
+// Note: Moving this function into the header may cause performance regression.
+template <class Size_T>
+void SmallVectorBase<Size_T>::grow_pod(void *FirstEl, size_t MinCapacity,
+                                       size_t TSize) {
+  // Ensure we can fit the new capacity.
+  // This is only going to be applicable when the capacity is 32 bit.
+  if (MinCapacity > SizeTypeMax())
     report_bad_alloc_error("SmallVector capacity overflow during allocation");
 
   // Ensure we can meet the guarantee of space for at least one more element.
   // The above check alone will not catch the case where grow is called with a
   // default MinCapacity of 0, but the current capacity cannot be increased.
-  if (capacity() == size_t(UINT32_MAX))
+  // This is only going to be applicable when the capacity is 32 bit.
+  if (capacity() == SizeTypeMax())
     report_bad_alloc_error("SmallVector capacity unable to grow");
 
+  // In theory 2*capacity can overflow if the capacity is 64 bit, but the
+  // original capacity would never be large enough for this to be a problem.
   size_t NewCapacity = 2 * capacity() + 1; // Always grow.
-  NewCapacity =
-      std::min(std::max(NewCapacity, MinCapacity), size_t(UINT32_MAX));
+  NewCapacity = std::min(std::max(NewCapacity, MinCapacity), SizeTypeMax());
 
   void *NewElts;
   if (BeginX == FirstEl) {
@@ -70,3 +76,6 @@ void SmallVectorBase::grow_pod(void *FirstEl, size_t MinCapacity,
   this->BeginX = NewElts;
   this->Capacity = NewCapacity;
 }
+
+template class llvm::SmallVectorBase<uint32_t>;
+template class llvm::SmallVectorBase<uint64_t>;