Enable -mcpu=native and -march=native for arm targets.

This is only implemented on linux at the moment.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159232 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 53 insertions, 34 deletions

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 307856a1bb..c3ea22f888 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -422,16 +422,47 @@ void Clang::AddPreprocessingOptions(Compilation &C,
   getToolChain().AddClangSystemIncludeArgs(Args, CmdArgs);
 }
 
+/// getLLVMArchSuffixForARM - Get the LLVM arch name to use for a particular
+/// CPU.
+//
+// FIXME: This is redundant with -mcpu, why does LLVM use this.
+// FIXME: tblgen this, or kill it!
+static const char *getLLVMArchSuffixForARM(StringRef CPU) {
+  return llvm::StringSwitch<const char *>(CPU)
+    .Cases("arm7tdmi", "arm7tdmi-s", "arm710t", "v4t")
+    .Cases("arm720t", "arm9", "arm9tdmi", "v4t")
+    .Cases("arm920", "arm920t", "arm922t", "v4t")
+    .Cases("arm940t", "ep9312","v4t")
+    .Cases("arm10tdmi",  "arm1020t", "v5")
+    .Cases("arm9e",  "arm926ej-s",  "arm946e-s", "v5e")
+    .Cases("arm966e-s",  "arm968e-s",  "arm10e", "v5e")
+    .Cases("arm1020e",  "arm1022e",  "xscale", "iwmmxt", "v5e")
+    .Cases("arm1136j-s",  "arm1136jf-s",  "arm1176jz-s", "v6")
+    .Cases("arm1176jzf-s",  "mpcorenovfp",  "mpcore", "v6")
+    .Cases("arm1156t2-s",  "arm1156t2f-s", "v6t2")
+    .Cases("cortex-a8", "cortex-a9", "v7")
+    .Case("cortex-m3", "v7m")
+    .Case("cortex-m4", "v7m")
+    .Case("cortex-m0", "v6m")
+    .Default("");
+}
+
 /// getARMTargetCPU - Get the (LLVM) name of the ARM cpu we are targeting.
 //
 // FIXME: tblgen this.
-static const char *getARMTargetCPU(const ArgList &Args,
+static std::string getARMTargetCPU(const ArgList &Args,
                                    const llvm::Triple &Triple) {
   // FIXME: Warn on inconsistent use of -mcpu and -march.
 
   // If we have -mcpu=, use that.
-  if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
-    return A->getValue(Args);
+  if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
+    StringRef MCPU = A->getValue(Args);
+    // Handle -mcpu=native.
+    if (MCPU == "native")
+      return llvm::sys::getHostCPUName();
+    else
+      return MCPU;
+  }
 
   StringRef MArch;
   if (Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
@@ -442,6 +473,18 @@ static const char *getARMTargetCPU(const ArgList &Args,
     MArch = Triple.getArchName();
   }
 
+  // Handle -march=native.
+  std::string NativeMArch;
+  if (MArch == "native") {
+    std::string CPU = llvm::sys::getHostCPUName();
+    if (CPU != "generic") {
+      // Translate the native cpu into the architecture. The switch below will
+      // then chose the minimum cpu for that arch.
+      NativeMArch = std::string("arm") + getLLVMArchSuffixForARM(CPU);
+      MArch = NativeMArch;
+    }
+  }
+
   return llvm::StringSwitch<const char *>(MArch)
     .Cases("armv2", "armv2a","arm2")
     .Case("armv3", "arm6")
@@ -465,31 +508,6 @@ static const char *getARMTargetCPU(const ArgList &Args,
     .Default("arm7tdmi");
 }
 
-/// getLLVMArchSuffixForARM - Get the LLVM arch name to use for a particular
-/// CPU.
-//
-// FIXME: This is redundant with -mcpu, why does LLVM use this.
-// FIXME: tblgen this, or kill it!
-static const char *getLLVMArchSuffixForARM(StringRef CPU) {
-  return llvm::StringSwitch<const char *>(CPU)
-    .Cases("arm7tdmi", "arm7tdmi-s", "arm710t", "v4t")
-    .Cases("arm720t", "arm9", "arm9tdmi", "v4t")
-    .Cases("arm920", "arm920t", "arm922t", "v4t")
-    .Cases("arm940t", "ep9312","v4t")
-    .Cases("arm10tdmi",  "arm1020t", "v5")
-    .Cases("arm9e",  "arm926ej-s",  "arm946e-s", "v5e")
-    .Cases("arm966e-s",  "arm968e-s",  "arm10e", "v5e")
-    .Cases("arm1020e",  "arm1022e",  "xscale", "iwmmxt", "v5e")
-    .Cases("arm1136j-s",  "arm1136jf-s",  "arm1176jz-s", "v6")
-    .Cases("arm1176jzf-s",  "mpcorenovfp",  "mpcore", "v6")
-    .Cases("arm1156t2-s",  "arm1156t2f-s", "v6t2")
-    .Cases("cortex-a8", "cortex-a9", "v7")
-    .Case("cortex-m3", "v7m")
-    .Case("cortex-m4", "v7m")
-    .Case("cortex-m0", "v6m")
-    .Default("");
-}
-
 // FIXME: Move to target hook.
 static bool isSignedCharDefault(const llvm::Triple &Triple) {
   switch (Triple.getArch()) {
@@ -601,9 +619,10 @@ static StringRef getARMFloatABI(const Driver &D,
       // Darwin defaults to "softfp" for v6 and v7.
       //
       // FIXME: Factor out an ARM class so we can cache the arch somewhere.
-      StringRef ArchName =
+      std::string ArchName =
         getLLVMArchSuffixForARM(getARMTargetCPU(Args, Triple));
-      if (ArchName.startswith("v6") || ArchName.startswith("v7"))
+      if (StringRef(ArchName).startswith("v6") ||
+          StringRef(ArchName).startswith("v7"))
         FloatABI = "softfp";
       else
         FloatABI = "soft";
@@ -628,9 +647,9 @@ static StringRef getARMFloatABI(const Driver &D,
         FloatABI = "softfp";
         break;
       case llvm::Triple::ANDROIDEABI: {
-        StringRef ArchName =
+        std::string ArchName =
           getLLVMArchSuffixForARM(getARMTargetCPU(Args, Triple));
-        if (ArchName.startswith("v7"))
+        if (StringRef(ArchName).startswith("v7"))
           FloatABI = "softfp";
         else
           FloatABI = "soft";
@@ -680,7 +699,7 @@ void Clang::AddARMTargetArgs(const ArgList &Args,
 
   // Set the CPU based on -march= and -mcpu=.
   CmdArgs.push_back("-target-cpu");
-  CmdArgs.push_back(getARMTargetCPU(Args, Triple));
+  CmdArgs.push_back(Args.MakeArgString(getARMTargetCPU(Args, Triple)));
 
   // Determine floating point ABI from the options & target defaults.
   StringRef FloatABI = getARMFloatABI(D, Args, Triple);
@@ -2790,7 +2809,7 @@ void ClangAs::AddARMTargetArgs(const ArgList &Args,
 
   // Set the CPU based on -march= and -mcpu=.
   CmdArgs.push_back("-target-cpu");
-  CmdArgs.push_back(getARMTargetCPU(Args, Triple));
+  CmdArgs.push_back(Args.MakeArgString(getARMTargetCPU(Args, Triple)));
 
   // Honor -mfpu=.
   if (const Arg *A = Args.getLastArg(options::OPT_mfpu_EQ))