Enable -fno-altivec, -mno-altivec for PowerPC.

Introduces these negation forms explicitly and uses them to control a new
"altivec" target feature for PowerPC.  This allows avoiding generating
Altivec instructions on processors that support Altivec.

The new test case verifies that the Altivec "lvx" instruction is not
used when -fno-altivec is present on the command line.

llvm-svn: 174140

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 4919508..a3dd71d 100644 (file)
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -291,6 +291,7 @@ def faccess_control : Flag<["-"], "faccess-control">, Group<f_Group>;
 def fallow_unsupported : Flag<["-"], "fallow-unsupported">, Group<f_Group>;
 def faltivec : Flag<["-"], "faltivec">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Enable AltiVec vector initializer syntax">;
+def fno_altivec : Flag<["-"], "fno-altivec">, Group<f_Group>, Flags<[CC1Option]>;
 def fapple_kext : Flag<["-"], "fapple-kext">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Use Apple's kernel extensions ABI">;
 def fapple_pragma_pack : Flag<["-"], "fapple-pragma-pack">, Group<f_Group>, Flags<[CC1Option]>,
@@ -809,6 +810,7 @@ def m64 : Flag<["-"], "m64">, Group<m_Group>, Flags<[DriverOption]>;
 def mabi_EQ : Joined<["-"], "mabi=">, Group<m_Group>;
 def march_EQ : Joined<["-"], "march=">, Group<m_Group>;
 def maltivec : Flag<["-"], "maltivec">, Alias<faltivec>;
+def mno_altivec : Flag<["-"], "mno-altivec">, Alias<fno_altivec>;
 def mcmodel_EQ : Joined<["-"], "mcmodel=">, Group<m_Group>;
 def mconstant_cfstrings : Flag<["-"], "mconstant-cfstrings">, Group<clang_ignored_m_Group>;
 def mcpu_EQ : Joined<["-"], "mcpu=">, Group<m_Group>;

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 27984df..4d0a833 100644 (file)
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -711,6 +711,12 @@ public:
   virtual void getTargetDefines(const LangOptions &Opts,
                                 MacroBuilder &Builder) const;
 
+  virtual void getDefaultFeatures(llvm::StringMap<bool> &Features) const;
+
+  virtual bool setFeatureEnabled(llvm::StringMap<bool> &Features,
+                                 StringRef Name,
+                                 bool Enabled) const;
+
   virtual bool hasFeature(StringRef Feature) const;
   
   virtual void getGCCRegNames(const char * const *&Names,
@@ -907,7 +913,32 @@ void PPCTargetInfo::getTargetDefines(const LangOptions &Opts,
   if (defs & ArchDefinePwr6) {
     Builder.defineMacro("_ARCH_PWR5");
     Builder.defineMacro("_ARCH_PWR6");
+  }  
+}
+
+void PPCTargetInfo::getDefaultFeatures(llvm::StringMap<bool> &Features) const {
+  Features["altivec"] = llvm::StringSwitch<bool>(CPU)
+    .Case("7400", true)
+    .Case("g4", true)
+    .Case("7450", true)
+    .Case("g4+", true)
+    .Case("970", true)
+    .Case("g5", true)
+    .Case("pwr6", true)
+    .Case("pwr7", true)
+    .Case("ppc64", true)
+    .Default(false);
+}
+
+bool PPCTargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
+                                         StringRef Name,
+                                         bool Enabled) const {
+  if (Name == "altivec") {
+    Features[Name] = Enabled;
+    return true;
   }
+
+  return false;
 }
 
 bool PPCTargetInfo::hasFeature(StringRef Feature) const {

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index cb7cc23..844367e 100644 (file)
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1084,6 +1084,12 @@ void Clang::AddPPCTargetArgs(const ArgList &Args,
     CmdArgs.push_back("-target-cpu");
     CmdArgs.push_back(Args.MakeArgString(TargetCPUName.c_str()));
   }
+
+  // Allow override of the Altivec feature.
+  if (Args.hasFlag(options::OPT_fno_altivec, options::OPT_faltivec, false)) {
+    CmdArgs.push_back("-target-feature");
+    CmdArgs.push_back("-altivec");
+  }
 }
 
 void Clang::AddSparcTargetArgs(const ArgList &Args,

diff --git a/clang/test/CodeGen/ppc-no-altivec.c b/clang/test/CodeGen/ppc-no-altivec.c
new file mode 100644 (file)
index 0000000..1830f26
--- /dev/null
+++ b/clang/test/CodeGen/ppc-no-altivec.c
@@ -0,0 +1,12 @@
+// REQUIRES: ppc64-registered-target
+// RUN: %clang_cc1 %s -triple=powerpc64-unknown-linux-gnu -S -o - | FileCheck %s
+
+typedef char v8qi  __attribute__((vector_size (8)));
+
+extern v8qi x, y;
+
+v8qi foo (void) {
+  return x + y;
+}
+
+// CHECK-NOT: lvx