allwpilib/upstream_utils/llvm_patches/0010-Detemplatize-SmallVectorBase.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: PJ Reiniger <pj.reiniger@gmail.com>
Date: Thu, 5 May 2022 23:18:34 -0400
Subject: [PATCH 10/35] Detemplatize SmallVectorBase

---
 llvm/include/llvm/ADT/SmallVector.h | 35 ++++++++++-------------------
 llvm/lib/Support/SmallVector.cpp    | 34 +++++-----------------------
 2 files changed, 17 insertions(+), 52 deletions(-)

diff --git a/llvm/include/llvm/ADT/SmallVector.h b/llvm/include/llvm/ADT/SmallVector.h
index 3cab284f5b6105956d6fff49a27d37482a3c321d..b8981ab67322f7888ad63d953ba72dbfa53b2939 100644
--- a/llvm/include/llvm/ADT/SmallVector.h
+++ b/llvm/include/llvm/ADT/SmallVector.h
@@ -56,19 +56,19 @@ using EnableIfConvertibleToInputIterator = std::enable_if_t<std::is_convertible<
 /// Using 64 bit size is desirable for cases like SmallVector<char>, where a
 /// 32 bit size would limit the vector to ~4GB. SmallVectors are used for
 /// buffering bitcode output - which can exceed 4GB.
-template <class Size_T> class SmallVectorBase {
+class SmallVectorBase {
 protected:
   void *BeginX;
-  Size_T Size = 0, Capacity;
+  unsigned Size = 0, Capacity;
 
-  /// The maximum value of the Size_T used.
+  /// The maximum value of the unsigned used.
   static constexpr size_t SizeTypeMax() {
-    return (std::numeric_limits<Size_T>::max)();
+    return (std::numeric_limits<unsigned>::max)();
   }
 
   SmallVectorBase() = delete;
   SmallVectorBase(void *FirstEl, size_t TotalCapacity)
-      : BeginX(FirstEl), Capacity(static_cast<Size_T>(TotalCapacity)) {}
+      : BeginX(FirstEl), Capacity(static_cast<unsigned>(TotalCapacity)) {}
 
   /// This is a helper for \a grow() that's out of line to reduce code
   /// duplication.  This function will report a fatal error if it can't grow at
@@ -94,7 +94,7 @@ protected:
   /// This does not construct or destroy any elements in the vector.
   void set_size(size_t N) {
     assert(N <= capacity()); // implies no overflow in assignment
-    Size = static_cast<Size_T>(N);
+    Size = static_cast<unsigned>(N);
   }
 
   /// Set the array data pointer to \p Begin and capacity to \p N.
@@ -104,19 +104,14 @@ protected:
   void set_allocation_range(void *Begin, size_t N) {
     assert(N <= SizeTypeMax());
     BeginX = Begin;
-    Capacity = static_cast<Size_T>(N);
+    Capacity = static_cast<unsigned>(N);
   }
 };
 
-template <class T>
-using SmallVectorSizeType =
-    std::conditional_t<sizeof(T) < 4 && sizeof(void *) >= 8, uint64_t,
-                       uint32_t>;
-
 /// Figure out the offset of the first element.
 template <class T, typename = void> struct SmallVectorAlignmentAndSize {
-  alignas(SmallVectorBase<SmallVectorSizeType<T>>) char Base[sizeof(
-      SmallVectorBase<SmallVectorSizeType<T>>)];
+  alignas(SmallVectorBase) char Base[sizeof(
+      SmallVectorBase)];
   alignas(T) char FirstEl[sizeof(T)];
 };
 
@@ -125,8 +120,8 @@ template <class T, typename = void> struct SmallVectorAlignmentAndSize {
 /// to avoid unnecessarily requiring T to be complete.
 template <typename T, typename = void>
 class SmallVectorTemplateCommon
-    : public SmallVectorBase<SmallVectorSizeType<T>> {
-  using Base = SmallVectorBase<SmallVectorSizeType<T>>;
+    : public SmallVectorBase {
+  using Base = SmallVectorBase;
 
 protected:
   /// Find the address of the first element.  For this pointer math to be valid
@@ -448,7 +443,7 @@ template <typename T, bool TriviallyCopyable>
 T *SmallVectorTemplateBase<T, TriviallyCopyable>::mallocForGrow(
     size_t MinSize, size_t &NewCapacity) {
   return static_cast<T *>(
-      SmallVectorBase<SmallVectorSizeType<T>>::mallocForGrow(
+      SmallVectorBase::mallocForGrow(
           this->getFirstEl(), MinSize, sizeof(T), NewCapacity));
 }
 
@@ -1320,12 +1315,6 @@ template <typename Out, typename R> SmallVector<Out> to_vector_of(R &&Range) {
   return {std::begin(Range), std::end(Range)};
 }
 
-// Explicit instantiations
-extern template class llvm::SmallVectorBase<uint32_t>;
-#if SIZE_MAX > UINT32_MAX
-extern template class llvm::SmallVectorBase<uint64_t>;
-#endif
-
 } // end namespace llvm
 
 namespace std {
diff --git a/llvm/lib/Support/SmallVector.cpp b/llvm/lib/Support/SmallVector.cpp
index fba8fcb7cf56f4914e6ab6ede78eb8d8c8bf3424..5fe82c223193e7353d0576b84897422bed26186b 100644
--- a/llvm/lib/Support/SmallVector.cpp
+++ b/llvm/lib/Support/SmallVector.cpp
@@ -51,10 +51,6 @@ 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");
-
 /// Report that MinSize doesn't fit into this vector's size type. Throws
 /// std::length_error or calls report_fatal_error.
 [[noreturn]] static void report_size_overflow(size_t MinSize, size_t MaxSize);
@@ -85,9 +81,8 @@ static void report_at_maximum_capacity(size_t MaxSize) {
 }
 
 // Note: Moving this function into the header may cause performance regression.
-template <class Size_T>
 static size_t getNewCapacity(size_t MinSize, size_t TSize, size_t OldCapacity) {
-  constexpr size_t MaxSize = std::numeric_limits<Size_T>::max();
+  constexpr size_t MaxSize = std::numeric_limits<unsigned>::max();
 
   // Ensure we can fit the new capacity.
   // This is only going to be applicable when the capacity is 32 bit.
@@ -127,11 +122,10 @@ static void *replaceAllocation(void *NewElts, size_t TSize, size_t NewCapacity,
 }
 
 // Note: Moving this function into the header may cause performance regression.
-template <class Size_T>
-void *SmallVectorBase<Size_T>::mallocForGrow(void *FirstEl, size_t MinSize,
+void *SmallVectorBase::mallocForGrow(void *FirstEl, size_t MinSize,
                                              size_t TSize,
                                              size_t &NewCapacity) {
-  NewCapacity = getNewCapacity<Size_T>(MinSize, TSize, this->capacity());
+  NewCapacity = getNewCapacity(MinSize, TSize, this->capacity());
   // Even if capacity is not 0 now, if the vector was originally created with
   // capacity 0, it's possible for the malloc to return FirstEl.
   void *NewElts = llvm::safe_malloc(NewCapacity * TSize);
@@ -141,10 +135,9 @@ void *SmallVectorBase<Size_T>::mallocForGrow(void *FirstEl, size_t MinSize,
 }
 
 // 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 MinSize,
+void SmallVectorBase::grow_pod(void *FirstEl, size_t MinSize,
                                        size_t TSize) {
-  size_t NewCapacity = getNewCapacity<Size_T>(MinSize, TSize, this->capacity());
+  size_t NewCapacity = getNewCapacity(MinSize, TSize, this->capacity());
   void *NewElts;
   if (BeginX == FirstEl) {
     NewElts = llvm::safe_malloc(NewCapacity * TSize);
@@ -162,20 +155,3 @@ void SmallVectorBase<Size_T>::grow_pod(void *FirstEl, size_t MinSize,
 
   this->set_allocation_range(NewElts, NewCapacity);
 }
-
-template class llvm::SmallVectorBase<uint32_t>;
-
-// Disable the uint64_t instantiation for 32-bit builds.
-// Both uint32_t and uint64_t instantiations are needed for 64-bit builds.
-// This instantiation will never be used in 32-bit builds, and will cause
-// warnings when sizeof(Size_T) > sizeof(size_t).
-#if SIZE_MAX > UINT32_MAX
-template class llvm::SmallVectorBase<uint64_t>;
-
-// Assertions to ensure this #if stays in sync with SmallVectorSizeType.
-static_assert(sizeof(SmallVectorSizeType<char>) == sizeof(uint64_t),
-              "Expected SmallVectorBase<uint64_t> variant to be in use.");
-#else
-static_assert(sizeof(SmallVectorSizeType<char>) == sizeof(uint32_t),
-              "Expected SmallVectorBase<uint32_t> variant to be in use.");
-#endif