[DAG] make isConstantSplatVector() available to the rest of lowering

llvm-svn: 275025

3 files changed, 29 insertions, 32 deletions

diff --git a/llvm/include/llvm/CodeGen/SelectionDAGNodes.h b/llvm/include/llvm/CodeGen/SelectionDAGNodes.h
index 8fd558602e7..cfcc4117f93 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -66,6 +66,10 @@ struct SDVTList {
 namespace ISD {
   /// Node predicates
 
+  /// If N is a BUILD_VECTOR node whose elements are all the same constant or
+  /// undefined, return true and return the constant value in \p SplatValue.
+  bool isConstantSplatVector(const SDNode *N, APInt &SplatValue);
+
   /// Return true if the specified node is a BUILD_VECTOR where all of the
   /// elements are ~0 or undef.
   bool isBuildVectorAllOnes(const SDNode *N);
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index acb25a36d29..3ca224e4fa6 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -765,22 +765,6 @@ bool DAGCombiner::isOneUseSetCC(SDValue N) const {
   return false;
 }
 
-/// Returns true if N is a BUILD_VECTOR node whose
-/// elements are all the same constant or undefined.
-static bool isConstantSplatVector(SDNode *N, APInt& SplatValue) {
-  BuildVectorSDNode *C = dyn_cast<BuildVectorSDNode>(N);
-  if (!C)
-    return false;
-
-  APInt SplatUndef;
-  unsigned SplatBitSize;
-  bool HasAnyUndefs;
-  EVT EltVT = N->getValueType(0).getVectorElementType();
-  return (C->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
-                             HasAnyUndefs) &&
-          EltVT.getSizeInBits() >= SplatBitSize);
-}
-
 // \brief Returns the SDNode if it is a constant float BuildVector
 // or constant float.
 static SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N) {
@@ -2034,8 +2018,8 @@ SDValue DAGCombiner::visitMUL(SDNode *N) {
     if (SDValue FoldedVOp = SimplifyVBinOp(N))
       return FoldedVOp;
 
-    N0IsConst = isConstantSplatVector(N0.getNode(), ConstValue0);
-    N1IsConst = isConstantSplatVector(N1.getNode(), ConstValue1);
+    N0IsConst = ISD::isConstantSplatVector(N0.getNode(), ConstValue0);
+    N1IsConst = ISD::isConstantSplatVector(N1.getNode(), ConstValue1);
   } else {
     N0IsConst = isa<ConstantSDNode>(N0);
     if (N0IsConst) {
@@ -2099,23 +2083,21 @@ SDValue DAGCombiner::visitMUL(SDNode *N) {
   APInt Val;
   // (mul (shl X, c1), c2) -> (mul X, c2 << c1)
   if (N1IsConst && N0.getOpcode() == ISD::SHL &&
-      (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
-                     isa<ConstantSDNode>(N0.getOperand(1)))) {
-    SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT,
-                             N1, N0.getOperand(1));
+      (ISD::isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
+       isa<ConstantSDNode>(N0.getOperand(1)))) {
+    SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT, N1, N0.getOperand(1));
     AddToWorklist(C3.getNode());
-    return DAG.getNode(ISD::MUL, SDLoc(N), VT,
-                       N0.getOperand(0), C3);
+    return DAG.getNode(ISD::MUL, SDLoc(N), VT, N0.getOperand(0), C3);
   }
 
   // Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
   // use.
   {
-    SDValue Sh(nullptr,0), Y(nullptr,0);
+    SDValue Sh(nullptr, 0), Y(nullptr, 0);
     // Check for both (mul (shl X, C), Y)  and  (mul Y, (shl X, C)).
     if (N0.getOpcode() == ISD::SHL &&
-        (isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
-                       isa<ConstantSDNode>(N0.getOperand(1))) &&
+        (ISD::isConstantSplatVector(N0.getOperand(1).getNode(), Val) ||
+         isa<ConstantSDNode>(N0.getOperand(1))) &&
         N0.getNode()->hasOneUse()) {
       Sh = N0; Y = N1;
     } else if (N1.getOpcode() == ISD::SHL &&
@@ -2125,10 +2107,8 @@ SDValue DAGCombiner::visitMUL(SDNode *N) {
     }
 
     if (Sh.getNode()) {
-      SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT,
-                                Sh.getOperand(0), Y);
-      return DAG.getNode(ISD::SHL, SDLoc(N), VT,
-                         Mul, Sh.getOperand(1));
+      SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT, Sh.getOperand(0), Y);
+      return DAG.getNode(ISD::SHL, SDLoc(N), VT, Mul, Sh.getOperand(1));
     }
   }
 
@@ -4609,7 +4589,7 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
   APInt Val;
   if (N1C && N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse() &&
       (isa<ConstantSDNode>(N0.getOperand(1)) ||
-       isConstantSplatVector(N0.getOperand(1).getNode(), Val))) {
+       ISD::isConstantSplatVector(N0.getOperand(1).getNode(), Val))) {
     SDValue Shl0 = DAG.getNode(ISD::SHL, SDLoc(N0), VT, N0.getOperand(0), N1);
     SDValue Shl1 = DAG.getNode(ISD::SHL, SDLoc(N1), VT, N0.getOperand(1), N1);
     return DAG.getNode(ISD::ADD, SDLoc(N), VT, Shl0, Shl1);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index e3aeffbc2ef..c3dfd431ff0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -93,6 +93,19 @@ bool ConstantFPSDNode::isValueValidForType(EVT VT,
 //                              ISD Namespace
 //===----------------------------------------------------------------------===//
 
+bool ISD::isConstantSplatVector(const SDNode *N, APInt &SplatVal) {
+  auto *BV = dyn_cast<BuildVectorSDNode>(N);
+  if (!BV)
+    return false;
+
+  APInt SplatUndef;
+  unsigned SplatBitSize;
+  bool HasUndefs;
+  EVT EltVT = N->getValueType(0).getVectorElementType();
+  return BV->isConstantSplat(SplatVal, SplatUndef, SplatBitSize, HasUndefs) &&
+         EltVT.getSizeInBits() >= SplatBitSize;
+}
+
 // FIXME: AllOnes and AllZeros duplicate a lot of code. Could these be
 // specializations of the more general isConstantSplatVector()?