From bea199a7054c516463d19cc99a7a3351a6e3de0e Mon Sep 17 00:00:00 2001
From: Chad Rosier <mcrosier@codeaurora.org>
Date: Fri, 2 May 2014 18:41:57 +0000
Subject: [PATCH] [driver] Enable the slp vectorizer at -Oz. PR19568

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207858 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Driver/Tools.cpp       | 14 ++++++++------
 test/Driver/clang_f_opts.c |  2 +-
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index bec557b4cb..fe0b727b1d 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2146,7 +2146,8 @@ static void SplitDebugInfo(const ToolChain &TC, Compilation &C,
 }
 
 /// \brief Vectorize at all optimization levels greater than 1 except for -Oz.
-static bool shouldEnableVectorizerAtOLevel(const ArgList &Args) {
+/// For -Oz the loop vectorizer is disable, while the slp vectorizer is enabled.
+static bool shouldEnableVectorizerAtOLevel(const ArgList &Args, bool isSlpVec) {
   if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
     if (A->getOption().matches(options::OPT_O4) ||
         A->getOption().matches(options::OPT_Ofast))
@@ -2162,9 +2163,9 @@ static bool shouldEnableVectorizerAtOLevel(const ArgList &Args) {
     if (S == "s")
       return true;
 
-    // Don't vectorize -Oz.
+    // Don't vectorize -Oz, unless it's the slp vectorizer.
     if (S == "z")
-      return false;
+      return isSlpVec;
 
     unsigned OptLevel = 0;
     if (S.getAsInteger(10, OptLevel))
@@ -3900,7 +3901,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   // Enable vectorization per default according to the optimization level
   // selected. For optimization levels that want vectorization we use the alias
   // option to simplify the hasFlag logic.
-  bool EnableVec = shouldEnableVectorizerAtOLevel(Args);
+  bool EnableVec = shouldEnableVectorizerAtOLevel(Args, false);
   OptSpecifier VectorizeAliasOption = EnableVec ? options::OPT_O_Group :
     options::OPT_fvectorize;
   if (Args.hasFlag(options::OPT_fvectorize, VectorizeAliasOption,
@@ -3908,10 +3909,11 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-vectorize-loops");
 
   // -fslp-vectorize is enabled based on the optimization level selected.
-  OptSpecifier SLPVectAliasOption = EnableVec ? options::OPT_O_Group :
+  bool EnableSLPVec = shouldEnableVectorizerAtOLevel(Args, true);
+  OptSpecifier SLPVectAliasOption = EnableSLPVec ? options::OPT_O_Group :
     options::OPT_fslp_vectorize;
   if (Args.hasFlag(options::OPT_fslp_vectorize, SLPVectAliasOption,
-                   options::OPT_fno_slp_vectorize, EnableVec))
+                   options::OPT_fno_slp_vectorize, EnableSLPVec))
     CmdArgs.push_back("-vectorize-slp");
 
   // -fno-slp-vectorize-aggressive is default.
diff --git a/test/Driver/clang_f_opts.c b/test/Driver/clang_f_opts.c
index 6e4fa72cb5..c88ced05ac 100644
--- a/test/Driver/clang_f_opts.c
+++ b/test/Driver/clang_f_opts.c
@@ -92,6 +92,7 @@
 // RUN: %clang -### -S -O %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
 // RUN: %clang -### -S -O2 %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
 // RUN: %clang -### -S -Os %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
+// RUN: %clang -### -S -Oz %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
 // RUN: %clang -### -S -O3 %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
 // RUN: %clang -### -S -fno-slp-vectorize -O3 %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
 // RUN: %clang -### -S -O1 -fslp-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-SLP-VECTORIZE %s
@@ -99,7 +100,6 @@
 // RUN: %clang -### -S %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
 // RUN: %clang -### -S -O0 %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
 // RUN: %clang -### -S -O1 %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
-// RUN: %clang -### -S -Oz %s 2>&1 | FileCheck -check-prefix=CHECK-NO-SLP-VECTORIZE %s
 // CHECK-SLP-VECTORIZE: "-vectorize-slp"
 // CHECK-NO-SLP-VECTORIZE-NOT: "-vectorize-slp"
 
-- 
2.50.1