[SelectionDAG] move constant or splat functions to common location

rL347502 moved the null sibling, so we should group all of these
together. I'm not sure why these aren't methods of the SDValue
class itself, but that's another patch if that's possible.

llvm-svn: 347523

2 files changed, 28 insertions, 39 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 246222f8806..bce188e399a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -911,29 +911,6 @@ static bool isConstantOrConstantVector(SDValue N, bool NoOpaques = false) {
   return true;
 }
 
-// Determines if it is a constant integer of one or a splatted vector of a
-// constant integer of one (with no undefs).
-// Do not permit build vector implicit truncation.
-static bool isOneConstantOrOneSplatConstant(SDValue N) {
-  // TODO: may want to use peekThroughBitcast() here.
-  unsigned BitWidth = N.getScalarValueSizeInBits();
-  if (ConstantSDNode *Splat = isConstOrConstSplat(N))
-    return Splat->isOne() && Splat->getAPIntValue().getBitWidth() == BitWidth;
-  return false;
-}
-
-// Determines if it is a constant integer of all ones or a splatted vector of a
-// constant integer of all ones (with no undefs).
-// Do not permit build vector implicit truncation.
-static bool isAllOnesConstantOrAllOnesSplatConstant(SDValue N) {
-  N = peekThroughBitcasts(N);
-  unsigned BitWidth = N.getScalarValueSizeInBits();
-  if (ConstantSDNode *Splat = isConstOrConstSplat(N))
-    return Splat->isAllOnesValue() &&
-           Splat->getAPIntValue().getBitWidth() == BitWidth;
-  return false;
-}
-
 // Determines if a BUILD_VECTOR is composed of all-constants possibly mixed with
 // undef's.
 static bool isAnyConstantBuildVector(const SDNode *N) {
@@ -1911,11 +1888,10 @@ SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) {
   // and (select Cond, 0, -1), X --> select Cond, 0, X
   // or X, (select Cond, -1, 0) --> select Cond, -1, X
   auto BinOpcode = BO->getOpcode();
-  bool CanFoldNonConst = (BinOpcode == ISD::AND || BinOpcode == ISD::OR) &&
-                         (isNullOrNullSplat(CT) ||
-                          isAllOnesConstantOrAllOnesSplatConstant(CT)) &&
-                         (isNullOrNullSplat(CF) ||
-                          isAllOnesConstantOrAllOnesSplatConstant(CF));
+  bool CanFoldNonConst =
+      (BinOpcode == ISD::AND || BinOpcode == ISD::OR) &&
+      (isNullOrNullSplat(CT) || isAllOnesOrAllOnesSplat(CT)) &&
+      (isNullOrNullSplat(CF) || isAllOnesOrAllOnesSplat(CF));
 
   SDValue CBO = BO->getOperand(SelOpNo ^ 1);
   if (!CanFoldNonConst &&
@@ -2084,7 +2060,7 @@ SDValue DAGCombiner::visitADD(SDNode *N) {
     //   add (zext i1 X), -1 -> sext (not i1 X)
     // because most (?) targets generate better code for the zext form.
     if (N0.getOpcode() == ISD::SIGN_EXTEND && N0.hasOneUse() &&
-        isOneConstantOrOneSplatConstant(N1)) {
+        isOneOrOneSplat(N1)) {
       SDValue X = N0.getOperand(0);
       if ((!LegalOperations ||
            (TLI.isOperationLegal(ISD::XOR, X.getValueType()) &&
@@ -2175,7 +2151,7 @@ SDValue DAGCombiner::visitADD(SDNode *N) {
     return DAG.getNode(ISD::OR, DL, VT, N0, N1);
 
   // fold (add (xor a, -1), 1) -> (sub 0, a)
-  if (isBitwiseNot(N0) && isOneConstantOrOneSplatConstant(N1))
+  if (isBitwiseNot(N0) && isOneOrOneSplat(N1))
     return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
                        N0.getOperand(0));
 
@@ -2245,8 +2221,7 @@ SDValue DAGCombiner::visitADDLike(SDValue N0, SDValue N1, SDNode *LocReference)
 
     // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
     // and similar xforms where the inner op is either ~0 or 0.
-    if (NumSignBits == DestBits &&
-        isOneConstantOrOneSplatConstant(N1->getOperand(1)))
+    if (NumSignBits == DestBits && isOneOrOneSplat(N1->getOperand(1)))
       return DAG.getNode(ISD::SUB, DL, VT, N0, AndOp0);
   }
 
@@ -2377,7 +2352,7 @@ SDValue DAGCombiner::visitUADDO(SDNode *N) {
                      DAG.getConstant(0, DL, CarryVT));
 
   // fold (uaddo (xor a, -1), 1) -> (usub 0, a) and flip carry.
-  if (isBitwiseNot(N0) && isOneConstantOrOneSplatConstant(N1)) {
+  if (isBitwiseNot(N0) && isOneOrOneSplat(N1)) {
     SDValue Sub = DAG.getNode(ISD::USUBO, DL, N->getVTList(),
                               DAG.getConstant(0, DL, VT),
                               N0.getOperand(0));
@@ -2613,7 +2588,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
   }
 
   // Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
-  if (isAllOnesConstantOrAllOnesSplatConstant(N0))
+  if (isAllOnesOrAllOnesSplat(N0))
     return DAG.getNode(ISD::XOR, DL, VT, N1, N0);
 
   // fold (A - (0-B)) -> A+B
@@ -3899,7 +3874,7 @@ SDValue DAGCombiner::foldLogicOfSetCCs(bool IsAnd, SDValue N0, SDValue N1,
   bool IsInteger = OpVT.isInteger();
   if (LR == RR && CC0 == CC1 && IsInteger) {
     bool IsZero = isNullOrNullSplat(LR);
-    bool IsNeg1 = isAllOnesConstantOrAllOnesSplatConstant(LR);
+    bool IsNeg1 = isAllOnesOrAllOnesSplat(LR);
 
     // All bits clear?
     bool AndEqZero = IsAnd && CC1 == ISD::SETEQ && IsZero;
@@ -5946,7 +5921,7 @@ SDValue DAGCombiner::unfoldMaskedMerge(SDNode *N) {
   assert(N->getOpcode() == ISD::XOR);
 
   // Don't touch 'not' (i.e. where y = -1).
-  if (isAllOnesConstantOrAllOnesSplatConstant(N->getOperand(1)))
+  if (isAllOnesOrAllOnesSplat(N->getOperand(1)))
     return SDValue();
 
   EVT VT = N->getValueType(0);
@@ -5963,7 +5938,7 @@ SDValue DAGCombiner::unfoldMaskedMerge(SDNode *N) {
     SDValue Xor0 = Xor.getOperand(0);
     SDValue Xor1 = Xor.getOperand(1);
     // Don't touch 'not' (i.e. where y = -1).
-    if (isAllOnesConstantOrAllOnesSplatConstant(Xor1))
+    if (isAllOnesOrAllOnesSplat(Xor1))
       return false;
     if (Other == Xor0)
       std::swap(Xor0, Xor1);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index a2b5c9ffd96..502e5c71429 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -8381,8 +8381,22 @@ ConstantFPSDNode *llvm::isConstOrConstSplatFP(SDValue N, bool AllowUndefs) {
 
 bool llvm::isNullOrNullSplat(SDValue N) {
   // TODO: may want to use peekThroughBitcast() here.
-  ConstantSDNode *Splat = isConstOrConstSplat(N);
-  return Splat && Splat->isNullValue();
+  ConstantSDNode *C = isConstOrConstSplat(N);
+  return C && C->isNullValue();
+}
+
+bool llvm::isOneOrOneSplat(SDValue N) {
+  // TODO: may want to use peekThroughBitcast() here.
+  unsigned BitWidth = N.getScalarValueSizeInBits();
+  ConstantSDNode *C = isConstOrConstSplat(N);
+  return C && C->isOne() && C->getValueSizeInBits(0) == BitWidth;
+}
+
+bool llvm::isAllOnesOrAllOnesSplat(SDValue N) {
+  N = peekThroughBitcasts(N);
+  unsigned BitWidth = N.getScalarValueSizeInBits();
+  ConstantSDNode *C = isConstOrConstSplat(N);
+  return C && C->isAllOnesValue() && C->getValueSizeInBits(0) == BitWidth;
 }
 
 HandleSDNode::~HandleSDNode() {