commit 3ba81bdb45ad4a9ef603566a4ca222754649b43d
author Chad Rosier <mcrosier@codeaurora.org> Fri May 02 18:41:57 2014 +0000
committer Chad Rosier <mcrosier@codeaurora.org> Fri May 02 18:41:57 2014 +0000
tree 922ed94bcc24df5c37237e9b5ba4820675411ae3
parent 7cdc8a1f302994727150a08b2e7726e0063619a9

[driver] Enable the slp vectorizer at -Oz.
PR19568

llvm-svn: 207858

clang/lib/Driver/Tools.cpp

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index bec557b..fe0b727 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -2146,7 +2146,8 @@
 }
 
 /// \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 @@
     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 @@
   // 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 @@
     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.