Migrate metadata information from scalar to vector instructions during

SLP vectorization. Based on the code in BBVectorizer.

Fixes PR17741.

Patch by Raul Silvera, reviewed by Hal and Nadav. Reformatted by my
driving of clang-format. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195528 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 68a7f64e7af58cd7742f24bf50a274c7f634b24c..f2a099ac691bfb800f5eb041e766b9a7d2d1fcb8 100644 (file)
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -163,6 +163,37 @@ static unsigned getSameOpcode(ArrayRef<Value *> VL) {
   return Opcode;
 }
 
   return Opcode;
 }
 

+/// \returns \p I after propagating metadata from \p VL.
+static Instruction *propagateMetadata(Instruction *I, ArrayRef<Value *> VL) {
+  Instruction *I0 = cast<Instruction>(VL[0]);
+  SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata;
+  I0->getAllMetadataOtherThanDebugLoc(Metadata);
+
+  for (unsigned i = 0, n = Metadata.size(); i != n; ++i) {
+    unsigned Kind = Metadata[i].first;
+    MDNode *MD = Metadata[i].second;
+
+    for (int i = 1, e = VL.size(); MD && i != e; i++) {
+      Instruction *I = cast<Instruction>(VL[i]);
+      MDNode *IMD = I->getMetadata(Kind);
+
+      switch (Kind) {
+      default:
+        MD = 0; // Remove unknown metadata
+        break;
+      case LLVMContext::MD_tbaa:
+        MD = MDNode::getMostGenericTBAA(MD, IMD);
+        break;
+      case LLVMContext::MD_fpmath:
+        MD = MDNode::getMostGenericFPMath(MD, IMD);
+        break;
+      }
+    }
+    I->setMetadata(Kind, MD);
+  }
+  return I;
+}
+

 /// \returns The type that all of the values in \p VL have or null if there
 /// are different types.
 static Type* getSameType(ArrayRef<Value *> VL) {
 /// \returns The type that all of the values in \p VL have or null if there
 /// are different types.
 static Type* getSameType(ArrayRef<Value *> VL) {


@@ -1481,6 +1512,10 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       BinaryOperator *BinOp = cast<BinaryOperator>(VL0);
       Value *V = Builder.CreateBinOp(BinOp->getOpcode(), LHS, RHS);
       E->VectorizedValue = V;
       BinaryOperator *BinOp = cast<BinaryOperator>(VL0);
       Value *V = Builder.CreateBinOp(BinOp->getOpcode(), LHS, RHS);
       E->VectorizedValue = V;

+
+      if (Instruction *I = dyn_cast<Instruction>(V))
+        return propagateMetadata(I, E->Scalars);
+

       return V;
     }
     case Instruction::Load: {
       return V;
     }
     case Instruction::Load: {


@@ -1497,7 +1532,7 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       LI = Builder.CreateLoad(VecPtr);
       LI->setAlignment(Alignment);
       E->VectorizedValue = LI;
       LI = Builder.CreateLoad(VecPtr);
       LI->setAlignment(Alignment);
       E->VectorizedValue = LI;

-      return LI;
+      return propagateMetadata(LI, E->Scalars);

     }
     case Instruction::Store: {
       StoreInst *SI = cast<StoreInst>(VL0);
     }
     case Instruction::Store: {
       StoreInst *SI = cast<StoreInst>(VL0);


@@ -1516,7 +1551,7 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       StoreInst *S = Builder.CreateStore(VecValue, VecPtr);
       S->setAlignment(Alignment);
       E->VectorizedValue = S;
       StoreInst *S = Builder.CreateStore(VecValue, VecPtr);
       S->setAlignment(Alignment);
       E->VectorizedValue = S;

-      return S;
+      return propagateMetadata(S, E->Scalars);

     }
     default:
     llvm_unreachable("unknown inst");
     }
     default:
     llvm_unreachable("unknown inst");