diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 2974486..6d1fdd2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2402,15 +2402,22 @@
   case ISD::FMUL:
   case ISD::FDIV:
   case ISD::FREM:
-    if (UnsafeFPMath && Opcode == ISD::FADD) {
-      // 0+x --> x
-      if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1))
-        if (CFP->getValueAPF().isZero())
-          return N2;
-      // x+0 --> x
-      if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N2))
-        if (CFP->getValueAPF().isZero())
-          return N1;
+    if (UnsafeFPMath) {
+      if (Opcode == ISD::FADD) {
+        // 0+x --> x
+        if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1))
+          if (CFP->getValueAPF().isZero())
+            return N2;
+        // x+0 --> x
+        if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N2))
+          if (CFP->getValueAPF().isZero())
+            return N1;
+      } else if (Opcode == ISD::FSUB) {
+        // x-0 --> x
+        if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N2))
+          if (CFP->getValueAPF().isZero())
+            return N1;
+      }
     }
     assert(N1.getValueType() == N2.getValueType() &&
            N1.getValueType() == VT && "Binary operator types must match!");