[AArch64][DAG] Allow fptos/ui.sat to scalarized. (#126799)

We we previously running into problems with fp128 types and certain
integer sizes.

Fixes an issue reported on #124984

2 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index f13f70e..b58c160 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -880,6 +880,7 @@ private:
   bool ScalarizeVectorOperand(SDNode *N, unsigned OpNo);
   SDValue ScalarizeVecOp_BITCAST(SDNode *N);
   SDValue ScalarizeVecOp_UnaryOp(SDNode *N);
+  SDValue ScalarizeVecOp_UnaryOpWithExtraInput(SDNode *N);
   SDValue ScalarizeVecOp_UnaryOp_StrictFP(SDNode *N);
   SDValue ScalarizeVecOp_CONCAT_VECTORS(SDNode *N);
   SDValue ScalarizeVecOp_INSERT_SUBVECTOR(SDNode *N, unsigned OpNo);
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
index 915ee2d..1d8bf54 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
@@ -775,6 +775,10 @@ bool DAGTypeLegalizer::ScalarizeVectorOperand(SDNode *N, unsigned OpNo) {
   case ISD::LLRINT:
     Res = ScalarizeVecOp_UnaryOp(N);
     break;
+  case ISD::FP_TO_SINT_SAT:
+  case ISD::FP_TO_UINT_SAT:
+    Res = ScalarizeVecOp_UnaryOpWithExtraInput(N);
+    break;
   case ISD::STRICT_SINT_TO_FP:
   case ISD::STRICT_UINT_TO_FP:
   case ISD::STRICT_FP_TO_SINT:
@@ -882,6 +886,20 @@ SDValue DAGTypeLegalizer::ScalarizeVecOp_UnaryOp(SDNode *N) {
   return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(N), N->getValueType(0), Op);
 }
 
+/// Same as ScalarizeVecOp_UnaryOp with an extra operand (for example a
+/// typesize).
+SDValue DAGTypeLegalizer::ScalarizeVecOp_UnaryOpWithExtraInput(SDNode *N) {
+  assert(N->getValueType(0).getVectorNumElements() == 1 &&
+         "Unexpected vector type!");
+  SDValue Elt = GetScalarizedVector(N->getOperand(0));
+  SDValue Op =
+      DAG.getNode(N->getOpcode(), SDLoc(N), N->getValueType(0).getScalarType(),
+                  Elt, N->getOperand(1));
+  // Revectorize the result so the types line up with what the uses of this
+  // expression expect.
+  return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(N), N->getValueType(0), Op);
+}
+
 /// If the input is a vector that needs to be scalarized, it must be <1 x ty>.
 /// Do the strict FP operation on the element instead.
 SDValue DAGTypeLegalizer::ScalarizeVecOp_UnaryOp_StrictFP(SDNode *N) {