1 files changed, 26 insertions, 16 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index e123e814c66..a897fb562e7 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -10902,6 +10902,28 @@ SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
   return SDValue();
 }
 
+static SDValue foldFPToIntToFP(SDNode *N, SelectionDAG &DAG,
+                               const TargetLowering &TLI) {
+  // We only do this if the target has legal ftrunc. Otherwise, we'd likely be
+  // replacing casts with a libcall.
+  EVT VT = N->getValueType(0);
+  if (!TLI.isOperationLegal(ISD::FTRUNC, VT))
+    return SDValue();
+
+  // fptosi/fptoui round towards zero, so converting from FP to integer and
+  // back is the same as an 'ftrunc': [us]itofp (fpto[us]i X) --> ftrunc X
+  SDValue N0 = N->getOperand(0);
+  if (N->getOpcode() == ISD::SINT_TO_FP && N0.getOpcode() == ISD::FP_TO_SINT &&
+      N0.getOperand(0).getValueType() == VT)
+    return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0.getOperand(0));
+
+  if (N->getOpcode() == ISD::UINT_TO_FP && N0.getOpcode() == ISD::FP_TO_UINT &&
+      N0.getOperand(0).getValueType() == VT)
+    return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0.getOperand(0));
+
+  return SDValue();
+}
+
 SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
   SDValue N0 = N->getOperand(0);
   EVT VT = N->getValueType(0);
@@ -10953,14 +10975,8 @@ SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
     }
   }
 
-  // fptosi rounds towards zero, so converting from FP to integer and back is
-  // the same as an 'ftrunc': sitofp (fptosi X) --> ftrunc X
-  // We only do this if the target has legal ftrunc, otherwise we'd likely be
-  // replacing casts with a libcall.
-  if (N0.getOpcode() == ISD::FP_TO_SINT &&
-      N0.getOperand(0).getValueType() == VT &&
-      TLI.isOperationLegal(ISD::FTRUNC, VT))
-    return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0.getOperand(0));
+  if (SDValue FTrunc = foldFPToIntToFP(N, DAG, TLI))
+    return FTrunc;
 
   return SDValue();
 }
@@ -11001,14 +11017,8 @@ SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
     }
   }
 
-  // fptoui rounds towards zero, so converting from FP to integer and back is
-  // the same as an 'ftrunc': uitofp (fptoui X) --> ftrunc X
-  // We only do this if the target has legal ftrunc, otherwise we'd likely be
-  // replacing casts with a libcall.
-  if (N0.getOpcode() == ISD::FP_TO_UINT &&
-      N0.getOperand(0).getValueType() == VT &&
-      TLI.isOperationLegal(ISD::FTRUNC, VT))
-    return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0.getOperand(0));
+  if (SDValue FTrunc = foldFPToIntToFP(N, DAG, TLI))
+    return FTrunc;
 
   return SDValue();
 }