1 files changed, 19 insertions, 2 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index e11522db79..df86064d28 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -10074,10 +10074,27 @@ SDValue X86TargetLowering::EmitTest(SDValue Op, unsigned X86CC, SDLoc dl,
     break;
   case X86::COND_G: case X86::COND_GE:
   case X86::COND_L: case X86::COND_LE:
-  case X86::COND_O: case X86::COND_NO:
-    NeedOF = true;
+  case X86::COND_O: case X86::COND_NO: {
+    // Check if we really need to set the
+    // Overflow flag. If NoSignedWrap is present
+    // that is not actually needed.
+    switch (Op->getOpcode()) {
+    case ISD::ADD:
+    case ISD::SUB:
+    case ISD::MUL:
+    case ISD::SHL: {
+      const BinaryWithFlagsSDNode *BinNode =
+          cast<BinaryWithFlagsSDNode>(Op.getNode());
+      if (BinNode->hasNoSignedWrap())
+        break;
+    }
+    default:
+      NeedOF = true;
+      break;
+    }
     break;
   }
+  }
   // See if we can use the EFLAGS value from the operand instead of
   // doing a separate TEST. TEST always sets OF and CF to 0, so unless
   // we prove that the arithmetic won't overflow, we can't use OF or CF.