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

include/clang/Driver/Options.td

@@ -655,6 +655,11 @@ def fvectorize : Flag<["-"], "fvectorize">, Group<f_Group>,
 def fno_vectorize : Flag<["-"], "fno-vectorize">, Group<f_Group>;
 def ftree_vectorize : Flag<["-"], "ftree-vectorize">, Alias<fvectorize>;
 def fno_tree_vectorize : Flag<["-"], "fno-tree-vectorize">, Alias<fno_vectorize>;
+def fslp_vectorize : Flag<["-"], "fslp-vectorize">, Group<f_Group>,
+  HelpText<"Enable the superword-level parallelism vectorization passes">;
+def fno_slp_vectorize : Flag<["-"], "fno-slp-vectorize">, Group<f_Group>;
+def ftree_slp_vectorize : Flag<["-"], "ftree-slp-vectorize">, Alias<fslp_vectorize>;
+def fno_tree_slp_vectorize : Flag<["-"], "fno-tree-slp-vectorize">, Alias<fno_slp_vectorize>;
 def Wlarge_by_value_copy_def : Flag<["-"], "Wlarge-by-value-copy">,
   HelpText<"Warn if a function definition returns or accepts an object larger "
            "in bytes than a given value">, Flags<[HelpHidden]>;

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);
 

test/Driver/clang_f_opts.c

@@ -51,3 +51,16 @@
 // CHECK-VECTORIZE: "-vectorize-loops"
 // CHECK-NO-VECTORIZE-NOT: "-backend-option"
 // CHECK-NO-VECTORIZE-NOT: "-vectorize-loops"
+
+// RUN: %clang -### -S -fslp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
+// RUN: %clang -### -S -fno-slp-vectorize -fslp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
+// RUN: %clang -### -S -fno-slp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
+// RUN: %clang -### -S -fslp-vectorize -fno-slp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
+// RUN: %clang -### -S -ftree-slp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
+// RUN: %clang -### -S -ftree-no-slp-vectorize -fslp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
+// RUN: %clang -### -S -ftree-no-slp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
+// RUN: %clang -### -S -ftree-slp-vectorize -fno-slp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
+// CHECK-SLP-VECTORIZE: "-backend-option"
+// CHECK-SLP-VECTORIZE: "-vectorize"
+// CHECK-NO-SLP-VECTORIZE-NOT: "-backend-option"
+// CHECK-NO-SLP-VECTORIZE-NOT: "-vectorize"