Merge pull request #341 from klickverbot/default-target-cpu

Use generic target CPU by default

CMakeLists.txt

@@ -149,6 +149,7 @@ file(GLOB IR_HDR ir/*.h)
 set(DRV_SRC
     driver/cl_options.cpp
     driver/configfile.cpp
+    driver/target.cpp
     driver/toobj.cpp
     driver/tool.cpp
     driver/linker.cpp
@@ -158,6 +159,7 @@ set(DRV_HDR
     driver/linker.h
     driver/cl_options.h
     driver/configfile.h
+    driver/target.h
     driver/toobj.h
     driver/tool.h
 )

driver/main.cpp

@@ -17,23 +17,21 @@
 #include "driver/cl_options.h"
 #include "driver/configfile.h"
 #include "driver/linker.h"
+#include "driver/target.h"
 #include "driver/toobj.h"
 #include "gen/cl_helpers.h"
 #include "gen/irstate.h"
 #include "gen/linkage.h"
 #include "gen/llvm.h"
-#include "gen/llvmcompat.h"
 #include "gen/logger.h"
 #include "gen/metadata.h"
 #include "gen/optimizer.h"
 #include "gen/passes/Passes.h"
 #include "llvm/Linker.h"
-#include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetOptions.h"
 #if LDC_LLVM_VER >= 303
 #include "llvm/LinkAllIR.h"
 #include "llvm/IR/LLVMContext.h"
@@ -338,19 +336,10 @@ int main(int argc, char** argv)
         return EXIT_FAILURE;
     }
 
-#if LDC_LLVM_VER >= 301
-    llvm::TargetOptions targetOptions;
-#endif
-
     Array* libs;
     if (global.params.symdebug)
     {
         libs = global.params.debuglibnames;
-#if LDC_LLVM_VER == 300
-        llvm::NoFramePointerElim = true;
-#else
-        targetOptions.NoFramePointerElim = true;
-#endif
     }
     else
         libs = global.params.defaultlibnames;
@@ -452,120 +441,32 @@ int main(int argc, char** argv)
     // create a proper target
     Ir ir;
 
-    // check -m32/64 sanity
-    if (m32bits && m64bits)
-        error("cannot use both -m32 and -m64 options");
-    else if ((m32bits || m64bits) && (!mArch.empty() || !mTargetTriple.empty()))
+    // Set up the TargetMachine.
+    ExplicitBitness::Type bitness = ExplicitBitness::None;
+    if ((m32bits || m64bits) && (!mArch.empty() || !mTargetTriple.empty()))
         error("-m32 and -m64 switches cannot be used together with -march and -mtriple switches");
+
+    if (m32bits)
+        bitness = ExplicitBitness::M32;
+    if (m64bits)
+    {
+        if (bitness != ExplicitBitness::None)
+        {
+            error("cannot use both -m32 and -m64 options");
+        }
+    }
+
     if (global.errors)
         fatal();
 
-    // override triple if needed
-    std::string defaultTriple = llvm::sys::getDefaultTargetTriple();
-    if (sizeof(void*) == 4 && m64bits)
-    {
-#if LDC_LLVM_VER >= 301
-        defaultTriple = llvm::Triple(defaultTriple).get64BitArchVariant().str();
-#else
-        defaultTriple = llvm::Triple__get64BitArchVariant(defaultTriple).str();
-#endif
-    }
-    else if (sizeof(void*) == 8 && m32bits)
-    {
-#if LDC_LLVM_VER >= 301
-        defaultTriple = llvm::Triple(defaultTriple).get32BitArchVariant().str();
-#else
-        defaultTriple = llvm::Triple__get32BitArchVariant(defaultTriple).str();
-#endif
-    }
-
-    std::string triple;
-
-    // did the user override the target triple?
-    if (mTargetTriple.empty())
-    {
-        if (!mArch.empty())
-        {
-            error("you must specify a target triple as well with -mtriple when using the -march option");
-            fatal();
-        }
-        triple = defaultTriple;
-    }
-    else
-    {
-        triple = llvm::Triple::normalize(mTargetTriple);
-    }
-
-    global.params.targetTriple = llvm::Triple(triple);
-
-    // Allocate target machine.
-    const llvm::Target *theTarget = NULL;
-    // Check whether the user has explicitly specified an architecture to compile for.
-    if (mArch.empty())
-    {
-        std::string Err;
-        theTarget = llvm::TargetRegistry::lookupTarget(triple, Err);
-        if (theTarget == 0)
-        {
-            error("%s Please use the -march option.", Err.c_str());
-            fatal();
-        }
-    }
-    else
-    {
-        for (llvm::TargetRegistry::iterator it = llvm::TargetRegistry::begin(),
-             ie = llvm::TargetRegistry::end(); it != ie; ++it)
-        {
-            if (mArch == it->getName())
-            {
-                theTarget = &*it;
-                break;
-            }
-        }
-
-        if (!theTarget)
-        {
-            error("invalid target '%s'", mArch.c_str());
-            fatal();
-        }
-    }
-
-    // Package up features to be passed to target/subtarget
-    std::string FeaturesStr;
-    if (mCPU.size() || mAttrs.size())
-    {
-        llvm::SubtargetFeatures Features;
-        for (unsigned i = 0; i != mAttrs.size(); ++i)
-            Features.AddFeature(mAttrs[i]);
-        FeaturesStr = Features.getString();
-    }
-
-    // FIXME
-    //std::auto_ptr<llvm::TargetMachine> target(theTarget->createTargetMachine(triple, FeaturesStr));
-    //assert(target.get() && "Could not allocate target machine!");
-    //gTargetMachine = target.get();
-
-#if LDC_LLVM_VER == 300
-    llvm::TargetMachine* target = theTarget->createTargetMachine(triple, mCPU, FeaturesStr,
-                                                                 mRelocModel, mCodeModel);
-#else
-    llvm::TargetMachine * target = theTarget->createTargetMachine(
-        llvm::StringRef(triple),
-        llvm::StringRef(mCPU),
-        llvm::StringRef(FeaturesStr),
-        targetOptions,
-        mRelocModel,
-        mCodeModel,
-        codeGenOptLevel()
-    );
-#endif
-
-    gTargetMachine = target;
+    gTargetMachine = createTargetMachine(mTargetTriple, mArch, mCPU, mAttrs, bitness,
+        mRelocModel, mCodeModel, codeGenOptLevel(), global.params.symdebug);
+    global.params.targetTriple = llvm::Triple(gTargetMachine->getTargetTriple());
 
 #if LDC_LLVM_VER >= 302
-    gDataLayout = target->getDataLayout();
+    gDataLayout = gTargetMachine->getDataLayout();
 #else
-    gDataLayout = target->getTargetData();
+    gDataLayout = gTargetMachine->getTargetData();
 #endif
 
     // Starting with LLVM 3.1 we could also use global.params.targetTriple.isArch64Bit();

driver/target.cpp

@@ -0,0 +1,198 @@
+//===-- target.cpp --------------------------------------------------------===//
+//
+//                         LDC – the LLVM D compiler
+//
+// This file is distributed under the BSD-style LDC license. See the LICENSE
+// file for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Note: The target CPU detection logic has been adapted from Clang
+// (lib/Driver/Tools.cpp).
+//
+//===----------------------------------------------------------------------===//
+
+#include "driver/target.h"
+#include "gen/llvmcompat.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "mars.h"
+
+
+static std::string getX86TargetCPU(std::string arch,
+    const llvm::Triple &triple)
+{
+    if (!arch.empty()) {
+        if (arch != "native")
+          return arch;
+
+        // FIXME: Reject attempts to use -march=native unless the target matches
+        // the host.
+        //
+        // FIXME: We should also incorporate the detected target features for use
+        // with -native.
+        std::string cpu = llvm::sys::getHostCPUName();
+        if (!cpu.empty() && cpu != "generic")
+          return cpu;
+    }
+
+    // Select the default CPU if none was given (or detection failed).
+
+    bool is64Bit = triple.getArch() == llvm::Triple::x86_64;
+
+    if (triple.isOSDarwin())
+        return is64Bit ? "core2" : "yonah";
+
+    // Everything else goes to x86-64 in 64-bit mode.
+    if (is64Bit)
+        return "x86-64";
+
+    if (triple.getOSName().startswith("haiku"))
+        return "i586";
+    if (triple.getOSName().startswith("openbsd"))
+        return "i486";
+    if (triple.getOSName().startswith("bitrig"))
+        return "i686";
+    if (triple.getOSName().startswith("freebsd"))
+        return "i486";
+    if (triple.getOSName().startswith("netbsd"))
+        return "i486";
+#if LDC_LLVM_VER >= 302
+    // All x86 devices running Android have core2 as their common
+    // denominator. This makes a better choice than pentium4.
+    if (triple.getEnvironment() == llvm::Triple::Android)
+        return "core2";
+#endif
+
+    // Fallback to p4.
+    return "pentium4";
+}
+
+
+llvm::TargetMachine* createTargetMachine(
+    std::string targetTriple,
+    std::string arch,
+    std::string cpu,
+    std::vector<std::string> attrs,
+    ExplicitBitness::Type bitness,
+    llvm::Reloc::Model relocModel,
+    llvm::CodeModel::Model codeModel,
+    llvm::CodeGenOpt::Level codeGenOptLevel,
+    bool genDebugInfo)
+{
+    // override triple if needed
+    std::string defaultTriple = llvm::sys::getDefaultTargetTriple();
+    if (sizeof(void*) == 4 && bitness == ExplicitBitness::M64)
+    {
+#if LDC_LLVM_VER >= 301
+        defaultTriple = llvm::Triple(defaultTriple).get64BitArchVariant().str();
+#else
+        defaultTriple = llvm::Triple__get64BitArchVariant(defaultTriple).str();
+#endif
+    }
+    else if (sizeof(void*) == 8 && bitness == ExplicitBitness::M32)
+    {
+#if LDC_LLVM_VER >= 301
+        defaultTriple = llvm::Triple(defaultTriple).get32BitArchVariant().str();
+#else
+        defaultTriple = llvm::Triple__get32BitArchVariant(defaultTriple).str();
+#endif
+    }
+
+    llvm::Triple triple;
+
+    // did the user override the target triple?
+    if (targetTriple.empty())
+    {
+        if (!arch.empty())
+        {
+            error("you must specify a target triple as well with -mtriple when using the -arch option");
+            fatal();
+        }
+        triple = llvm::Triple(defaultTriple);
+    }
+    else
+    {
+        triple = llvm::Triple(llvm::Triple::normalize(targetTriple));
+    }
+
+    // Allocate target machine.
+    const llvm::Target *theTarget = NULL;
+    // Check whether the user has explicitly specified an architecture to compile for.
+    if (arch.empty())
+    {
+        std::string Err;
+        theTarget = llvm::TargetRegistry::lookupTarget(triple.str(), Err);
+        if (theTarget == 0)
+        {
+            error("%s Please use the -march option.", Err.c_str());
+            fatal();
+        }
+    }
+    else
+    {
+        for (llvm::TargetRegistry::iterator it = llvm::TargetRegistry::begin(),
+             ie = llvm::TargetRegistry::end(); it != ie; ++it)
+        {
+            if (arch == it->getName())
+            {
+                theTarget = &*it;
+                break;
+            }
+        }
+
+        if (!theTarget)
+        {
+            error("invalid target '%s'", arch.c_str());
+            fatal();
+        }
+    }
+
+
+    // With an empty CPU string, LLVM will default to the host CPU, which is
+    // usually not what we want (expected behavior from other compilers is
+    // to default to "generic").
+    if (cpu.empty())
+    {
+        if (triple.getArch() == llvm::Triple::x86_64 ||
+            triple.getArch() == llvm::Triple::x86)
+        {
+            cpu = getX86TargetCPU(arch, triple);
+        }
+    }
+
+    // Package up features to be passed to target/subtarget
+    std::string FeaturesStr;
+    if (cpu.size() || attrs.size())
+    {
+        llvm::SubtargetFeatures Features;
+        for (unsigned i = 0; i != attrs.size(); ++i)
+            Features.AddFeature(attrs[i]);
+        FeaturesStr = Features.getString();
+    }
+
+#if LDC_LLVM_VER == 300
+    llvm::NoFramePointerElim = genDebugInfo;
+
+    return theTarget->createTargetMachine(triple.str(), cpu, FeaturesStr,
+        relocModel, codeModel);
+#else
+    llvm::TargetOptions targetOptions;
+    targetOptions.NoFramePointerElim = genDebugInfo;
+
+    return theTarget->createTargetMachine(
+        triple.str(),
+        cpu,
+        FeaturesStr,
+        targetOptions,
+        relocModel,
+        codeModel,
+        codeGenOptLevel
+    );
+#endif
+}

driver/target.h

@@ -0,0 +1,52 @@
+//===-- driver/target.h - LLVM target setup ---------------------*- C++ -*-===//
+//
+//                         LDC – the LLVM D compiler
+//
+// This file is distributed under the BSD-style LDC license. See the LICENSE
+// file for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Handles setting up an LLVM TargetMachine from the ugiven command-line
+// arguments.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LDC_DRIVER_TARGET_H
+#define LDC_DRIVER_TARGET_H
+
+#include "llvm/Support/CodeGen.h"
+#if LDC_LLVM_VER == 300
+#include "llvm/Target/TargetMachine.h" // For llvm::CodeGenOpt::Level.
+#endif
+#include <string>
+#include <vector>
+
+namespace ExplicitBitness {
+    enum Type {
+        None,
+        M32,
+        M64
+    };
+}
+
+namespace llvm { class TargetMachine; }
+
+/**
+ * Creates an LLVM TargetMachine suitable for the given (usually command-line)
+ * parameters and the host platform defaults.
+ *
+ * Does not depend on any global state.
+ */
+llvm::TargetMachine* createTargetMachine(
+    std::string targetTriple,
+    std::string arch,
+    std::string cpu,
+    std::vector<std::string> attrs,
+    ExplicitBitness::Type bitness,
+    llvm::Reloc::Model relocModel,
+    llvm::CodeModel::Model codeModel,
+    llvm::CodeGenOpt::Level codeGenOptLevel,
+    bool genDebugInfo);
+
+#endif // LDC_DRIVER_TARGET_H