[SLPV] Recognize vectorizable intrinsics during SLP vectorization and

transform accordingly. Based on similar code from Loop vectorization.
Subsequent commits will include vectorization of function calls to
vector intrinsics and form function calls to vector library calls.

Patch by Raul Silvera! (Much delayed due to my not running dcommit)

llvm-svn: 200576

1 files changed, 86 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 80d9ffccafb..0dec4b05f95 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -947,6 +947,39 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth) {
       buildTree_rec(Operands, Depth + 1);
       return;
     }
+    case Instruction::Call: {
+      // Check if the calls are all to the same vectorizable intrinsic.
+      IntrinsicInst *II = dyn_cast<IntrinsicInst>(VL[0]);
+      if (II==NULL) {
+        newTreeEntry(VL, false);
+        DEBUG(dbgs() << "SLP: Non-vectorizable call.\n");
+        return;
+      }
+
+      Intrinsic::ID ID = II->getIntrinsicID();
+
+      for (unsigned i = 1, e = VL.size(); i != e; ++i) {
+        IntrinsicInst *II2 = dyn_cast<IntrinsicInst>(VL[i]);
+        if (!II2 || II2->getIntrinsicID() != ID) {
+          newTreeEntry(VL, false);
+          DEBUG(dbgs() << "SLP: mismatched calls:" << *II << "!=" << *VL[i]
+                       << "\n");
+          return;
+        }
+      }
+
+      newTreeEntry(VL, true);
+      for (unsigned i = 0, e = II->getNumArgOperands(); i != e; ++i) {
+        ValueList Operands;
+        // Prepare the operand vector.
+        for (unsigned j = 0; j < VL.size(); ++j) {
+          IntrinsicInst *II2 = dyn_cast<IntrinsicInst>(VL[j]);
+          Operands.push_back(II2->getArgOperand(i));
+        }
+        buildTree_rec(Operands, Depth + 1);
+      }
+      return;
+    }
     default:
       newTreeEntry(VL, false);
       DEBUG(dbgs() << "SLP: Gathering unknown instruction.\n");
@@ -1072,6 +1105,30 @@ int BoUpSLP::getEntryCost(TreeEntry *E) {
       int VecStCost = TTI->getMemoryOpCost(Instruction::Store, VecTy, 1, 0);
       return VecStCost - ScalarStCost;
     }
+    case Instruction::Call: {
+      CallInst *CI = cast<CallInst>(VL0);
+      IntrinsicInst *II = cast<IntrinsicInst>(CI);
+      Intrinsic::ID ID = II->getIntrinsicID();
+
+      // Calculate the cost of the scalar and vector calls.
+      SmallVector<Type*, 4> ScalarTys, VecTys;
+      for (unsigned op = 0, opc = II->getNumArgOperands(); op!= opc; ++op) {
+        ScalarTys.push_back(CI->getArgOperand(op)->getType());
+        VecTys.push_back(VectorType::get(CI->getArgOperand(op)->getType(),
+                                         VecTy->getNumElements()));
+      }
+
+      int ScalarCallCost = VecTy->getNumElements() *
+          TTI->getIntrinsicInstrCost(ID, ScalarTy, ScalarTys);
+
+      int VecCallCost = TTI->getIntrinsicInstrCost(ID, VecTy, VecTys);
+
+      DEBUG(dbgs() << "SLP: Call cost "<< VecCallCost - ScalarCallCost
+            << " (" << VecCallCost  << "-" <<  ScalarCallCost << ")"
+            << " for " << *II << "\n");
+
+      return VecCallCost - ScalarCallCost;
+    }
     default:
       llvm_unreachable("Unknown instruction");
   }
@@ -1086,10 +1143,10 @@ bool BoUpSLP::isFullyVectorizableTinyTree() {
     return false;
 
   // Gathering cost would be too much for tiny trees.
-  if (VectorizableTree[0].NeedToGather || VectorizableTree[1].NeedToGather) 
-    return false; 
+  if (VectorizableTree[0].NeedToGather || VectorizableTree[1].NeedToGather)
+    return false;
 
-  return true; 
+  return true;
 }
 
 int BoUpSLP::getTreeCost() {
@@ -1555,6 +1612,32 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       E->VectorizedValue = S;
       return propagateMetadata(S, E->Scalars);
     }
+    case Instruction::Call: {
+      CallInst *CI = cast<CallInst>(VL0);
+
+      setInsertPointAfterBundle(E->Scalars);
+      std::vector<Value *> OpVecs;
+      for (int j = 0, e = CI->getNumArgOperands(); j < e; ++j) {
+        ValueList OpVL;
+        for (int i = 0, e = E->Scalars.size(); i < e; ++i) {
+          CallInst *CEI = cast<CallInst>(E->Scalars[i]);
+          OpVL.push_back(CEI->getArgOperand(j));
+        }
+
+        Value *OpVec = vectorizeTree(OpVL);
+        DEBUG(dbgs() << "SLP: OpVec[" << j << "]: " << *OpVec << "\n");
+        OpVecs.push_back(OpVec);
+      }
+
+      Module *M = F->getParent();
+      IntrinsicInst *II = cast<IntrinsicInst>(CI);
+      Intrinsic::ID ID = II->getIntrinsicID();
+      Type *Tys[] = { VectorType::get(CI->getType(), E->Scalars.size()) };
+      Function *CF = Intrinsic::getDeclaration(M, ID, Tys);
+      Value *V = Builder.CreateCall(CF, OpVecs);
+      E->VectorizedValue = V;
+      return V;
+    }
     default:
     llvm_unreachable("unknown inst");
   }