Enable the SLP-vectorizer by default

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187596 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 20dbaad..3a23732 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -3452,9 +3452,9 @@
                    options::OPT_fno_vectorize, true))
     CmdArgs.push_back("-vectorize-loops");
 
-  // -fno-slp-vectorize is default.
+  // -fslp-vectorize is default.
   if (Args.hasFlag(options::OPT_fslp_vectorize,
-                   options::OPT_fno_slp_vectorize, false))
+                   options::OPT_fno_slp_vectorize, true))
     CmdArgs.push_back("-vectorize-slp");
 
   // -fno-slp-vectorize-aggressive is default.