[PATCH] D99428: [SelDag] Add isIntOrFPConstant helper function.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: david-arm, dmgreen, spatel, RKSimon, arsenm.
Herald added subscribers: ecnelises, hiraditya.
fhahn requested review of this revision.
Herald added a subscriber: wdng.
Herald added a project: LLVM.

This patch adds a new isIntOrFPConstant  helper function to check if a
SDValue is a integer of FP constant. This pattern is used in various
places.

There also are places that incorrectly just check for integer constants,
e.g. D99384 <https://reviews.llvm.org/D99384>, so hopefully this helper will help people avoid that issue.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D99428

Files:
  llvm/include/llvm/CodeGen/SelectionDAGNodes.h
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/lib/Target/AArch64/AArch64ISelLowering.cpp


Index: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -9680,10 +9680,10 @@
     }
     if (i > 0)
       isOnlyLowElement = false;
-    if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
+    if (!isIntOrFPConstant(V))
       isConstant = false;
 
-    if (isa<ConstantSDNode>(V) || isa<ConstantFPSDNode>(V)) {
+    if (isIntOrFPConstant(V)) {
       ++NumConstantLanes;
       if (!ConstantValue.getNode())
         ConstantValue = V;
@@ -9849,7 +9849,7 @@
     for (unsigned i = 0; i < NumElts; ++i) {
       SDValue V = Op.getOperand(i);
       SDValue LaneIdx = DAG.getConstant(i, dl, MVT::i64);
-      if (!isa<ConstantSDNode>(V) && !isa<ConstantFPSDNode>(V))
+      if (!isIntOrFPConstant(V))
         // Note that type legalization likely mucked about with the VT of the
         // source operand, so we may have to convert it here before inserting.
         Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Val, V, LaneIdx);
Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -12413,7 +12413,7 @@
                                              VT.getVectorElementType());
 
   // If the input is a constant, let getNode fold it.
-  if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
+  if (isIntOrFPConstant(N0)) {
     // If we can't allow illegal operations, we need to check that this is just
     // a fp -> int or int -> conversion and that the resulting operation will
     // be legal.
@@ -12651,7 +12651,7 @@
     return N0;
 
   // If the input is a constant, return it.
-  if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0))
+  if (isIntOrFPConstant(N0))
     return N0;
 
   return SDValue();
@@ -16912,7 +16912,7 @@
     case StoreSource::Constant:
       if (NoTypeMatch)
         return false;
-      if (!(isa<ConstantSDNode>(OtherBC) || isa<ConstantFPSDNode>(OtherBC)))
+      if (!isIntOrFPConstant(OtherBC))
         return false;
       break;
     case StoreSource::Extract:
@@ -20492,7 +20492,7 @@
     // generating a splat; semantically, this is fine, but it's likely to
     // generate low-quality code if the target can't reconstruct an appropriate
     // shuffle.
-    if (!Op.isUndef() && !isa<ConstantSDNode>(Op) && !isa<ConstantFPSDNode>(Op))
+    if (!Op.isUndef() && !isIntOrFPConstant(Op))
       if (!IsSplat && !DuplicateOps.insert(Op).second)
         return SDValue();
 
Index: llvm/include/llvm/CodeGen/SelectionDAGNodes.h
===================================================================
--- llvm/include/llvm/CodeGen/SelectionDAGNodes.h
+++ llvm/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1684,6 +1684,11 @@
 /// Does not permit build vector implicit truncation.
 bool isAllOnesOrAllOnesSplat(SDValue V, bool AllowUndefs = false);
 
+/// Return true if \p V is either a integer or FP constant.
+inline bool isIntOrFPConstant(SDValue V) {
+  return isa<ConstantSDNode>(V) || isa<ConstantFPSDNode>(V);
+}
+
 class GlobalAddressSDNode : public SDNode {
   friend class SelectionDAG;
 


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