1 files changed, 17 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 6602ffed020..c3db6609f9d 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2805,12 +2805,18 @@ bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
     break;
   }
   case ISD::STRICT_FP_ROUND:
-    // This expansion does not honor the "strict" properties anyway,
-    // so prefer falling back to the non-strict operation if legal.
+    // When strict mode is enforced we can't do expansion because it
+    // does not honor the "strict" properties. Only libcall is allowed.
+    if (TLI.isStrictFPEnabled())
+      break;
+    // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
+    // since this operation is more efficient than stack operation.
     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
                                        Node->getValueType(0))
         == TargetLowering::Legal)
       break;
+    // We fall back to use stack operation when the FP_ROUND operation
+    // isn't available.
     Tmp1 = EmitStackConvert(Node->getOperand(1), 
                             Node->getValueType(0),
                             Node->getValueType(0), dl, Node->getOperand(0));
@@ -2825,12 +2831,18 @@ bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
     Results.push_back(Tmp1);
     break;
   case ISD::STRICT_FP_EXTEND:
-    // This expansion does not honor the "strict" properties anyway,
-    // so prefer falling back to the non-strict operation if legal.
+    // When strict mode is enforced we can't do expansion because it
+    // does not honor the "strict" properties. Only libcall is allowed.
+    if (TLI.isStrictFPEnabled())
+      break;
+    // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
+    // since this operation is more efficient than stack operation.
     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
                                        Node->getValueType(0))
         == TargetLowering::Legal)
       break;
+    // We fall back to use stack operation when the FP_EXTEND operation
+    // isn't available.
     Tmp1 = EmitStackConvert(Node->getOperand(1),
                             Node->getOperand(1).getValueType(),
                             Node->getValueType(0), dl, Node->getOperand(0));
@@ -3701,7 +3713,7 @@ bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
     break;
   }
 
-  if (Results.empty() && Node->isStrictFPOpcode()) {
+  if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
     // FIXME: We were asked to expand a strict floating-point operation,
     // but there is currently no expansion implemented that would preserve
     // the "strict" properties.  For now, we just fall back to the non-strict