[canonicalization] Refactor how we create new stores into a helper

function. This is a bit tidier anyways and will make a subsquent patch
simpler as I want to add another case to this combine.

llvm-svn: 226746

1 files changed, 48 insertions, 38 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index af1694d3453..2ee04c1272e 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -489,6 +489,53 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
   return nullptr;
 }
 
+/// \brief Combine a store to a new type.
+///
+/// Returns the newly created store instruction.
+static StoreInst *combineStoreToNewValue(InstCombiner &IC, StoreInst &SI, Value *V) {
+  Value *Ptr = SI.getPointerOperand();
+  unsigned AS = SI.getPointerAddressSpace();
+  SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
+  SI.getAllMetadata(MD);
+
+  StoreInst *NewStore = IC.Builder->CreateAlignedStore(
+      V, IC.Builder->CreateBitCast(Ptr, V->getType()->getPointerTo(AS)),
+      SI.getAlignment());
+  for (const auto &MDPair : MD) {
+    unsigned ID = MDPair.first;
+    MDNode *N = MDPair.second;
+    // Note, essentially every kind of metadata should be preserved here! This
+    // routine is supposed to clone a store instruction changing *only its
+    // type*. The only metadata it makes sense to drop is metadata which is
+    // invalidated when the pointer type changes. This should essentially
+    // never be the case in LLVM, but we explicitly switch over only known
+    // metadata to be conservatively correct. If you are adding metadata to
+    // LLVM which pertains to stores, you almost certainly want to add it
+    // here.
+    switch (ID) {
+    case LLVMContext::MD_dbg:
+    case LLVMContext::MD_tbaa:
+    case LLVMContext::MD_prof:
+    case LLVMContext::MD_fpmath:
+    case LLVMContext::MD_tbaa_struct:
+    case LLVMContext::MD_alias_scope:
+    case LLVMContext::MD_noalias:
+    case LLVMContext::MD_nontemporal:
+    case LLVMContext::MD_mem_parallel_loop_access:
+    case LLVMContext::MD_nonnull:
+      // All of these directly apply.
+      NewStore->setMetadata(ID, N);
+      break;
+
+    case LLVMContext::MD_invariant_load:
+    case LLVMContext::MD_range:
+      break;
+    }
+  }
+
+  return NewStore;
+}
+
 /// \brief Combine stores to match the type of value being stored.
 ///
 /// The core idea here is that the memory does not have any intrinsic type and
@@ -515,49 +562,12 @@ static bool combineStoreToValueType(InstCombiner &IC, StoreInst &SI) {
   if (!SI.isSimple())
     return false;
 
-  Value *Ptr = SI.getPointerOperand();
   Value *V = SI.getValueOperand();
-  unsigned AS = SI.getPointerAddressSpace();
-  SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
-  SI.getAllMetadata(MD);
 
   // Fold away bit casts of the stored value by storing the original type.
   if (auto *BC = dyn_cast<BitCastInst>(V)) {
     V = BC->getOperand(0);
-    StoreInst *NewStore = IC.Builder->CreateAlignedStore(
-        V, IC.Builder->CreateBitCast(Ptr, V->getType()->getPointerTo(AS)),
-        SI.getAlignment());
-    for (const auto &MDPair : MD) {
-      unsigned ID = MDPair.first;
-      MDNode *N = MDPair.second;
-      // Note, essentially every kind of metadata should be preserved here! This
-      // routine is supposed to clone a store instruction changing *only its
-      // type*. The only metadata it makes sense to drop is metadata which is
-      // invalidated when the pointer type changes. This should essentially
-      // never be the case in LLVM, but we explicitly switch over only known
-      // metadata to be conservatively correct. If you are adding metadata to
-      // LLVM which pertains to stores, you almost certainly want to add it
-      // here.
-      switch (ID) {
-      case LLVMContext::MD_dbg:
-      case LLVMContext::MD_tbaa:
-      case LLVMContext::MD_prof:
-      case LLVMContext::MD_fpmath:
-      case LLVMContext::MD_tbaa_struct:
-      case LLVMContext::MD_alias_scope:
-      case LLVMContext::MD_noalias:
-      case LLVMContext::MD_nontemporal:
-      case LLVMContext::MD_mem_parallel_loop_access:
-      case LLVMContext::MD_nonnull:
-        // All of these directly apply.
-        NewStore->setMetadata(ID, N);
-        break;
-
-      case LLVMContext::MD_invariant_load:
-      case LLVMContext::MD_range:
-        break;
-      }
-    }
+    combineStoreToNewValue(IC, SI, V);
     return true;
   }