[llvm] r195528 - Migrate metadata information from scalar to vector instructions during

[Chandler Carruth]

Author: chandlerc
Date: Fri Nov 22 18:48:34 2013
New Revision: 195528

URL: http://llvm.org/viewvc/llvm-project?rev=195528&view=rev
Log:
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. =]

Modified:
    llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp

Modified: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp?rev=195528&r1=195527&r2=195528&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Fri Nov 22 18:48:34 2013
@@ -163,6 +163,37 @@ static unsigned getSameOpcode(ArrayRef<V
   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) {
@@ -1481,6 +1512,10 @@ Value *BoUpSLP::vectorizeTree(TreeEntry
       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: {
@@ -1497,7 +1532,7 @@ Value *BoUpSLP::vectorizeTree(TreeEntry
       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);
@@ -1516,7 +1551,7 @@ Value *BoUpSLP::vectorizeTree(TreeEntry
       StoreInst *S = Builder.CreateStore(VecValue, VecPtr);
       S->setAlignment(Alignment);
       E->VectorizedValue = S;
-      return S;
+      return propagateMetadata(S, E->Scalars);
     }
     default:
     llvm_unreachable("unknown inst");