From 4dbaaa6f43adb0b80c9818d0b5f75ff04793bde3 Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Wed, 6 May 2009 03:16:41 +0000
Subject: Improve handling of (X86) target features.  - This is a WIP...

 - This adds -march= handling to the driver, and fixes the defaulting
   of -mcpu on Darwin (which was using the wrong test).

Instead of handling -m{sse, ...} in the driver, pass them to clang-cc as
 -target-feature [+-]name

In clang-cc, communicate with the (clang) target to discover the legal
features of a target, and the features which are enabled based on
-mcpu. This is currently hardcoded just enough to not be a feature
regression, we need to get this information from the backend's
TableGen information somehow.

This is used to construct the full list of features which are being
used, which is in turn used to initialize the predefines.

llvm-svn: 71061
---
 clang/lib/Driver/Tools.cpp | 98 ++++++++++++++++++++++------------------------
 1 file changed, 47 insertions(+), 51 deletions(-)

(limited to 'clang/lib/Driver/Tools.cpp')

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 2a959b3c55a..a52498dc950 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -31,6 +31,13 @@
 using namespace clang::driver;
 using namespace clang::driver::tools;
 
+static const char *MakeFormattedString(const ArgList &Args,
+                                       const llvm::format_object_base &Fmt) {
+  std::string Str;
+  llvm::raw_string_ostream(Str) << Fmt;
+  return Args.MakeArgString(Str.c_str());
+}
+
 void Clang::AddPreprocessingOptions(const Driver &D, 
                                     const ArgList &Args,
                                     ArgStringList &CmdArgs,
@@ -318,52 +325,48 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    false))
     CmdArgs.push_back("--soft-float");
 
-  // FIXME: Need target hooks.
-  if (memcmp(getToolChain().getPlatform().c_str(), "darwin", 6) == 0) {
-    if (getToolChain().getArchName() == "x86_64")
-      CmdArgs.push_back("--mcpu=core2");
-    else if (getToolChain().getArchName() == "i386")
-      CmdArgs.push_back("--mcpu=yonah");
-  }
-
-  // FIXME: Ignores ordering. Also, we need to find a realistic
-  // solution for this.
-  static const struct {
-    options::ID Pos, Neg;
-    const char *Name;
-  } FeatureOptions[] = {
-    { options::OPT_mmmx, options::OPT_mno_mmx, "mmx" },
-    { options::OPT_msse, options::OPT_mno_sse, "sse" },
-    { options::OPT_msse2, options::OPT_mno_sse2, "sse2" },
-    { options::OPT_msse3, options::OPT_mno_sse3, "sse3" },
-    { options::OPT_mssse3, options::OPT_mno_ssse3, "ssse3" },
-    { options::OPT_msse41, options::OPT_mno_sse41, "sse41" },
-    { options::OPT_msse42, options::OPT_mno_sse42, "sse42" },
-    { options::OPT_msse4a, options::OPT_mno_sse4a, "sse4a" },
-    { options::OPT_m3dnow, options::OPT_mno_3dnow, "3dnow" },
-    { options::OPT_m3dnowa, options::OPT_mno_3dnowa, "3dnowa" }
-  };
-  const unsigned NumFeatureOptions =
-    sizeof(FeatureOptions)/sizeof(FeatureOptions[0]);
-
-  // FIXME: Avoid std::string
-  std::string Attrs;
-  for (unsigned i=0; i < NumFeatureOptions; ++i) {
-    if (Args.hasArg(FeatureOptions[i].Pos)) {
-      if (!Attrs.empty())
-        Attrs += ',';
-      Attrs += '+';
-      Attrs += FeatureOptions[i].Name;
-    } else if (Args.hasArg(FeatureOptions[i].Neg)) {
-      if (!Attrs.empty())
-        Attrs += ',';
-      Attrs += '-';
-      Attrs += FeatureOptions[i].Name;
+  // FIXME: Handle -mtune=.
+  (void) Args.hasArg(options::OPT_mtune_EQ);
+
+  if (const Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
+    // FIXME: We made need some translation here from the options gcc
+    // takes to names the LLVM backend understand?
+    CmdArgs.push_back("-mcpu");
+    CmdArgs.push_back(A->getValue(Args));
+  } else {
+    // Select default CPU.
+    
+    // FIXME: Need target hooks.
+    if (memcmp(getToolChain().getOS().c_str(), "darwin", 6) == 0) {
+      if (getToolChain().getArchName() == "x86_64")
+        CmdArgs.push_back("--mcpu=core2");
+      else if (getToolChain().getArchName() == "i386")
+        CmdArgs.push_back("--mcpu=pentium4");
     }
   }
-  if (!Attrs.empty()) {
-    CmdArgs.push_back("--mattr");
-    CmdArgs.push_back(Args.MakeArgString(Attrs.c_str()));
+
+  // FIXME: Use iterator.
+  for (ArgList::const_iterator
+         it = Args.begin(), ie = Args.end(); it != ie; ++it) {
+    const Arg *A = *it;
+    if (A->getOption().matches(options::OPT_m_x86_Features_Group)) {
+      const char *Name = A->getOption().getName();
+
+      // Skip over "-m".
+      assert(Name[0] == '-' && Name[1] == 'm' && "Invalid feature name.");
+      Name += 2;
+      
+      bool IsNegative = memcmp(Name, "no-", 3) == 0;
+      if (IsNegative)
+        Name += 3;
+
+      A->claim();
+      CmdArgs.push_back("-target-feature");
+      CmdArgs.push_back(MakeFormattedString(Args,
+                                            llvm::format("%c%s", 
+                                                         IsNegative ? '-' : '+',
+                                                         Name)));
+    }
   }
 
   if (Args.hasFlag(options::OPT_fmath_errno,
@@ -1215,13 +1218,6 @@ void darwin::Assemble::ConstructJob(Compilation &C, const JobAction &JA,
   Dest.addCommand(new Command(Exec, CmdArgs));
 }
 
-static const char *MakeFormattedString(const ArgList &Args,
-                                       const llvm::format_object_base &Fmt) {
-  std::string Str;
-  llvm::raw_string_ostream(Str) << Fmt;
-  return Args.MakeArgString(Str.c_str());
-}
-
 /// Helper routine for seeing if we should use dsymutil; this is a
 /// gcc compatible hack, we should remove it and use the input
 /// type information.
-- 
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