Add -fslp-vectorize to enable bb-vectorize

Add -fslp-vectorize (with -ftree-slp-vectorize as an alias for gcc compatibility)
to provide a way to enable the basic-block vectorization pass. This uses the same
acronym as gcc, superword-level parallelism (SLP), also common in the literature,
to refer to basic-block vectorization.

Nadav suggested this as a follow-up to the adding of -fvectorize.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169909 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 9ae03fc8c6..25aab58660 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2935,6 +2935,13 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-vectorize-loops");
   }
 
+  // -fno-slp-vectorize is default.
+  if (Args.hasFlag(options::OPT_fslp_vectorize,
+                   options::OPT_fno_slp_vectorize, false)) {
+    CmdArgs.push_back("-backend-option");
+    CmdArgs.push_back("-vectorize");
+  }
+
   if (Arg *A = Args.getLastArg(options::OPT_fshow_overloads_EQ))
     A->render(Args, CmdArgs);