Revert "ADT: SmallVector size/capacity use word-size integers when elements are small"

This reverts commit b8d08e961df1d229872c785ebdbc8367432e9752.

This change causes a 1% compile-time and 1% memory usage regression:

http://llvm-compile-time-tracker.com/compare.php?from=73b7dd1fb3c17a4ac4b1f1e603f26fa708009649&to=b8d08e961df1d229872c785ebdbc8367432e9752&stat=instructions
http://llvm-compile-time-tracker.com/compare.php?from=73b7dd1fb3c17a4ac4b1f1e603f26fa708009649&to=b8d08e961df1d229872c785ebdbc8367432e9752&stat=max-rss

1 files changed, 27 insertions, 3 deletions

diff --git a/llvm/lib/Support/SmallVector.cpp b/llvm/lib/Support/SmallVector.cpp
index 0d1765a..36f0a81 100644
--- a/llvm/lib/Support/SmallVector.cpp
+++ b/llvm/lib/Support/SmallVector.cpp
@@ -36,6 +36,30 @@ static_assert(sizeof(SmallVector<Struct32B, 0>) >= alignof(Struct32B),
 static_assert(sizeof(SmallVector<void *, 1>) ==
                   sizeof(unsigned) * 2 + sizeof(void *) * 2,
               "wasted space in SmallVector size 1");
-static_assert(sizeof(SmallVector<char, 0>) ==
-                  sizeof(void *) * 2 + sizeof(void *),
-              "1 byte elements have word-sized type for size and capacity");
+
+/// 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.
+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)
+    report_bad_alloc_error("SmallVector capacity overflow during allocation");
+
+  size_t NewCapacity = 2 * capacity() + 1; // Always grow.
+  NewCapacity =
+      std::min(std::max(NewCapacity, MinCapacity), size_t(UINT32_MAX));
+
+  void *NewElts;
+  if (BeginX == FirstEl) {
+    NewElts = safe_malloc(NewCapacity * TSize);
+
+    // Copy the elements over.  No need to run dtors on PODs.
+    memcpy(NewElts, this->BeginX, size() * TSize);
+  } else {
+    // If this wasn't grown from the inline copy, grow the allocated space.
+    NewElts = safe_realloc(this->BeginX, NewCapacity * TSize);
+  }
+
+  this->BeginX = NewElts;
+  this->Capacity = NewCapacity;
+}