[DAG] make isConstOrConstSplat and isConstOrConstSplatFP more accessible; NFC

As noted in:
https://reviews.llvm.org/D25685

This is the next-to-smallest step needed to enable the ComputeNumSignBits fix in that patch.
In a minor attempt to keep some structure, we're pulling the FP helper over along with its
integer sibling, but clearly we can and should do more refactoring of the similar helper
functions in DAGCombiner and SelectionDAG to simplify and not duplicate functionality.

llvm-svn: 284421

diff --git a/llvm/include/llvm/CodeGen/SelectionDAGNodes.h b/llvm/include/llvm/CodeGen/SelectionDAGNodes.h
index c70acb2..fa4fc4d 100644 (file)
--- a/llvm/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1401,16 +1401,27 @@ public:
 
 /// Returns true if \p V is a constant integer zero.
 bool isNullConstant(SDValue V);
+
 /// Returns true if \p V is an FP constant with a value of positive zero.
 bool isNullFPConstant(SDValue V);
+
 /// Returns true if \p V is an integer constant with all bits set.
 bool isAllOnesConstant(SDValue V);
+
 /// Returns true if \p V is a constant integer one.
 bool isOneConstant(SDValue V);
+
 /// Returns true if \p V is a bitwise not operation. Assumes that an all ones
 /// constant is canonicalized to be operand 1.
 bool isBitwiseNot(SDValue V);
 
+/// Returns the SDNode if it is a constant splat BuildVector or constant int.
+ConstantSDNode *isConstOrConstSplat(SDValue V);
+
+/// Returns the SDNode if it is a constant splat BuildVector or constant float.
+ConstantFPSDNode *isConstOrConstSplatFP(SDValue V);
+
+
 class GlobalAddressSDNode : public SDNode {
   const GlobalValue *TheGlobal;
   int64_t Offset;

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f460d52..5984ceb 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -786,44 +786,6 @@ static SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N) {
   return nullptr;
 }
 
-// \brief Returns the SDNode if it is a constant splat BuildVector or constant
-// int.
-static ConstantSDNode *isConstOrConstSplat(SDValue N) {
-  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
-    return CN;
-
-  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
-    BitVector UndefElements;
-    ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
-
-    // BuildVectors can truncate their operands. Ignore that case here.
-    // FIXME: We blindly ignore splats which include undef which is overly
-    // pessimistic.
-    if (CN && UndefElements.none() &&
-        CN->getValueType(0) == N.getValueType().getScalarType())
-      return CN;
-  }
-
-  return nullptr;
-}
-
-// \brief Returns the SDNode if it is a constant splat BuildVector or constant
-// float.
-static ConstantFPSDNode *isConstOrConstSplatFP(SDValue N) {
-  if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N))
-    return CN;
-
-  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
-    BitVector UndefElements;
-    ConstantFPSDNode *CN = BV->getConstantFPSplatNode(&UndefElements);
-
-    if (CN && UndefElements.none())
-      return CN;
-  }
-
-  return nullptr;
-}
-
 // Determines if it is a constant integer or a build vector of constant
 // integers (and undefs).
 // Do not permit build vector implicit truncation.

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 7cca214..776b0ea 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6653,6 +6653,40 @@ bool llvm::isBitwiseNot(SDValue V) {
   return V.getOpcode() == ISD::XOR && isAllOnesConstant(V.getOperand(1));
 }
 
+ConstantSDNode *llvm::isConstOrConstSplat(SDValue N) {
+  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
+    return CN;
+
+  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
+    BitVector UndefElements;
+    ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
+
+    // BuildVectors can truncate their operands. Ignore that case here.
+    // FIXME: We blindly ignore splats which include undef which is overly
+    // pessimistic.
+    if (CN && UndefElements.none() &&
+        CN->getValueType(0) == N.getValueType().getScalarType())
+      return CN;
+  }
+
+  return nullptr;
+}
+
+ConstantFPSDNode *llvm::isConstOrConstSplatFP(SDValue N) {
+  if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N))
+    return CN;
+
+  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
+    BitVector UndefElements;
+    ConstantFPSDNode *CN = BV->getConstantFPSplatNode(&UndefElements);
+
+    if (CN && UndefElements.none())
+      return CN;
+  }
+
+  return nullptr;
+}
+
 HandleSDNode::~HandleSDNode() {
   DropOperands();
 }