1 files changed, 64 insertions, 4 deletions

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index 1ca509472b5f..ebd528bc8ec1 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -1037,17 +1037,15 @@ unsigned llvm::getOrEnforceKnownAlignment(Value *V, unsigned PrefAlign,
                                           const DominatorTree *DT) {
   assert(V->getType()->isPointerTy() &&
          "getOrEnforceKnownAlignment expects a pointer!");
-  unsigned BitWidth = DL.getPointerTypeSizeInBits(V->getType());
 
-  KnownBits Known(BitWidth);
-  computeKnownBits(V, Known, DL, 0, AC, CxtI, DT);
+  KnownBits Known = computeKnownBits(V, DL, 0, AC, CxtI, DT);
   unsigned TrailZ = Known.countMinTrailingZeros();
 
   // Avoid trouble with ridiculously large TrailZ values, such as
   // those computed from a null pointer.
   TrailZ = std::min(TrailZ, unsigned(sizeof(unsigned) * CHAR_BIT - 1));
 
-  unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
+  unsigned Align = 1u << std::min(Known.getBitWidth() - 1, TrailZ);
 
   // LLVM doesn't support alignments larger than this currently.
   Align = std::min(Align, +Value::MaximumAlignment);
@@ -1796,6 +1794,23 @@ static unsigned replaceDominatedUsesWith(Value *From, Value *To,
   return Count;
 }
 
+unsigned llvm::replaceNonLocalUsesWith(Instruction *From, Value *To) {
+   assert(From->getType() == To->getType());
+   auto *BB = From->getParent();
+   unsigned Count = 0;
+
+  for (Value::use_iterator UI = From->use_begin(), UE = From->use_end();
+       UI != UE;) {
+    Use &U = *UI++;
+    auto *I = cast<Instruction>(U.getUser());
+    if (I->getParent() == BB)
+      continue;
+    U.set(To);
+    ++Count;
+  }
+  return Count;
+}
+
 unsigned llvm::replaceDominatedUsesWith(Value *From, Value *To,
                                         DominatorTree &DT,
                                         const BasicBlockEdge &Root) {
@@ -2094,3 +2109,48 @@ void llvm::maybeMarkSanitizerLibraryCallNoBuiltin(
       !F->doesNotAccessMemory())
     CI->addAttribute(AttributeList::FunctionIndex, Attribute::NoBuiltin);
 }
+
+bool llvm::canReplaceOperandWithVariable(const Instruction *I, unsigned OpIdx) {
+  // We can't have a PHI with a metadata type.
+  if (I->getOperand(OpIdx)->getType()->isMetadataTy())
+    return false;
+
+  // Early exit.
+  if (!isa<Constant>(I->getOperand(OpIdx)))
+    return true;
+
+  switch (I->getOpcode()) {
+  default:
+    return true;
+  case Instruction::Call:
+  case Instruction::Invoke:
+    // Many arithmetic intrinsics have no issue taking a
+    // variable, however it's hard to distingish these from
+    // specials such as @llvm.frameaddress that require a constant.
+    if (isa<IntrinsicInst>(I))
+      return false;
+
+    // Constant bundle operands may need to retain their constant-ness for
+    // correctness.
+    if (ImmutableCallSite(I).isBundleOperand(OpIdx))
+      return false;
+    return true;
+  case Instruction::ShuffleVector:
+    // Shufflevector masks are constant.
+    return OpIdx != 2;
+  case Instruction::ExtractValue:
+  case Instruction::InsertValue:
+    // All operands apart from the first are constant.
+    return OpIdx == 0;
+  case Instruction::Alloca:
+    return false;
+  case Instruction::GetElementPtr:
+    if (OpIdx == 0)
+      return true;
+    gep_type_iterator It = gep_type_begin(I);
+    for (auto E = std::next(It, OpIdx); It != E; ++It)
+      if (It.isStruct())
+        return false;
+    return true;
+  }
+}