ldc/driver/targetmachine.cpp
Martin 60d676e2a1 Drop support for LLVM < 3.5
This allows to clean up the code a little.
2015-10-30 22:24:05 +01:00

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//===-- targetmachine.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
// (Tools.cpp and ToolChain.cpp in lib/Driver, the latter seems to have the
// more up-to-date version).
//
//===----------------------------------------------------------------------===//
#include "driver/targetmachine.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "mars.h"
#include "gen/logger.h"
#if LDC_LLVM_VER >= 307
#include "driver/cl_options.h"
static const char* getABI(const llvm::Triple &triple)
{
llvm::StringRef ABIName(opts::mABI);
if (ABIName != "")
{
switch (triple.getArch())
{
case llvm::Triple::arm:
case llvm::Triple::armeb:
if (ABIName.startswith("aapcs")) return "aapcs";
if (ABIName.startswith("eabi")) return "apcs";
break;
case llvm::Triple::mips:
case llvm::Triple::mipsel:
case llvm::Triple::mips64:
case llvm::Triple::mips64el:
if (ABIName.startswith("o32")) return "o32";
if (ABIName.startswith("n32")) return "n32";
if (ABIName.startswith("n64")) return "n64";
if (ABIName.startswith("eabi")) return "eabi";
break;
case llvm::Triple::ppc64:
case llvm::Triple::ppc64le:
if (ABIName.startswith("elfv1")) return "elfv1";
if (ABIName.startswith("elfv2")) return "elfv2";
break;
default:
break;
}
warning(Loc(), "Unknown ABI %s - using default ABI instead", ABIName.str().c_str());
}
switch (triple.getArch())
{
case llvm::Triple::mips64:
case llvm::Triple::mips64el:
return "n32";
case llvm::Triple::ppc64:
return "elfv1";
case llvm::Triple::ppc64le:
return "elfv2";
default:
return "";
}
}
#endif
extern llvm::TargetMachine* gTargetMachine;
MipsABI::Type getMipsABI()
{
#if LDC_LLVM_VER >= 307
// eabi can only be set on the commandline
if (strncmp(opts::mABI.c_str(), "eabi", 4) == 0)
return MipsABI::EABI;
else
{
#if LDC_LLVM_VER >= 308
const llvm::DataLayout dl = gTargetMachine->createDataLayout();
#else
const llvm::DataLayout& dl = *gTargetMachine->getDataLayout();
#endif
if (dl.getPointerSizeInBits() == 64)
return MipsABI::N64;
else if (dl.getLargestLegalIntTypeSize() == 64)
return MipsABI::N32;
else
return MipsABI::O32;
}
#else
llvm::StringRef features = gTargetMachine->getTargetFeatureString();
if (features.find("+o32") != std::string::npos)
return MipsABI::O32;
if (features.find("+n32") != std::string::npos)
return MipsABI::N32;
if (features.find("+n64") != std::string::npos)
return MipsABI::N32;
if (features.find("+eabi") != std::string::npos)
return MipsABI::EABI;
return MipsABI::Unknown;
#endif
}
static std::string getX86TargetCPU(const llvm::Triple &triple)
{
// Select the default CPU if none was given (or detection failed).
// Intel Macs are relatively recent, take advantage of that.
if (triple.isOSDarwin())
return triple.isArch64Bit() ? "core2" : "yonah";
// Everything else goes to x86-64 in 64-bit mode.
if (triple.isArch64Bit())
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";
// 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";
// Fallback to p4.
return "pentium4";
}
static std::string getARMTargetCPU(const llvm::Triple &triple)
{
const char *result = llvm::StringSwitch<const char *>(triple.getArchName())
.Cases("armv2", "armv2a","arm2")
.Case("armv3", "arm6")
.Case("armv3m", "arm7m")
.Case("armv4", "strongarm")
.Case("armv4t", "arm7tdmi")
.Cases("armv5", "armv5t", "arm10tdmi")
.Cases("armv5e", "armv5te", "arm1026ejs")
.Case("armv5tej", "arm926ej-s")
.Cases("armv6", "armv6k", "arm1136jf-s")
.Case("armv6j", "arm1136j-s")
.Cases("armv6z", "armv6zk", "arm1176jzf-s")
.Case("armv6t2", "arm1156t2-s")
.Cases("armv6m", "armv6-m", "cortex-m0")
.Cases("armv7", "armv7a", "armv7-a", "cortex-a8")
.Cases("armv7l", "armv7-l", "cortex-a8")
.Cases("armv7f", "armv7-f", "cortex-a9-mp")
.Cases("armv7s", "armv7-s", "swift")
.Cases("armv7r", "armv7-r", "cortex-r4")
.Cases("armv7m", "armv7-m", "cortex-m3")
.Cases("armv7em", "armv7e-m", "cortex-m4")
.Cases("armv8", "armv8a", "armv8-a", "cortex-a53")
.Case("ep9312", "ep9312")
.Case("iwmmxt", "iwmmxt")
.Case("xscale", "xscale")
// If all else failed, return the most base CPU with thumb interworking
// supported by LLVM.
.Default(0);
if (result)
return result;
return (triple.getEnvironment() == llvm::Triple::GNUEABIHF) ?
"arm1176jzf-s" : "arm7tdmi";
}
/// Returns the LLVM name of the target CPU to use given the provided
/// -mcpu argument and target triple.
static std::string getTargetCPU(const std::string &cpu,
const llvm::Triple &triple)
{
if (!cpu.empty())
{
if (cpu != "native")
return cpu;
// FIXME: Reject attempts to use -mcpu=native unless the target matches
// the host.
std::string hostCPU = llvm::sys::getHostCPUName();
if (!hostCPU.empty() && hostCPU != "generic")
return hostCPU;
}
switch (triple.getArch())
{
default:
// We don't know about the specifics of this platform, just return the
// empty string and let LLVM decide.
return cpu;
case llvm::Triple::x86:
case llvm::Triple::x86_64:
return getX86TargetCPU(triple);
case llvm::Triple::arm:
return getARMTargetCPU(triple);
}
}
static const char *getLLVMArchSuffixForARM(llvm::StringRef CPU)
{
return llvm::StringSwitch<const char *>(CPU)
.Case("strongarm", "v4")
.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-a5", "cortex-a7", "cortex-a8", "v7")
.Cases("cortex-a9", "cortex-a12", "cortex-a15", "v7")
.Cases("cortex-r4", "cortex-r5", "v7r")
.Case("cortex-m0", "v6m")
.Case("cortex-m3", "v7m")
.Case("cortex-m4", "v7em")
.Case("cortex-a9-mp", "v7f")
.Case("swift", "v7s")
.Case("cortex-a53", "v8")
.Case("krait", "v7")
.Default("");
}
static FloatABI::Type getARMFloatABI(const llvm::Triple &triple,
const char* llvmArchSuffix)
{
switch (triple.getOS()) {
case llvm::Triple::Darwin:
case llvm::Triple::MacOSX:
case llvm::Triple::IOS: {
// Darwin defaults to "softfp" for v6 and v7.
if (llvm::StringRef(llvmArchSuffix).startswith("v6") ||
llvm::StringRef(llvmArchSuffix).startswith("v7"))
return FloatABI::SoftFP;
return FloatABI::Soft;
}
case llvm::Triple::FreeBSD:
// FreeBSD defaults to soft float
return FloatABI::Soft;
default:
switch(triple.getEnvironment()) {
case llvm::Triple::GNUEABIHF:
return FloatABI::Hard;
case llvm::Triple::GNUEABI:
return FloatABI::SoftFP;
case llvm::Triple::EABI:
// EABI is always AAPCS, and if it was not marked 'hard', it's softfp
return FloatABI::SoftFP;
case llvm::Triple::Android: {
if (llvm::StringRef(llvmArchSuffix).startswith("v7"))
return FloatABI::SoftFP;
return FloatABI::Soft;
}
default:
// Assume "soft".
// TODO: Warn the user we are guessing.
return FloatABI::Soft;
}
}
}
#if LDC_LLVM_VER < 307
/// Sanitizes the MIPS ABI in the feature string.
static void addMipsABI(const llvm::Triple &triple, std::vector<std::string> &attrs)
{
enum ABI { O32 = 1<<0, N32 = 1<<1, N64 = 1<<2, EABI = 1<<3 };
const bool is64Bit = triple.getArch() == llvm::Triple::mips64 ||
triple.getArch() == llvm::Triple::mips64el;
const uint32_t defaultABI = is64Bit ? N64 : O32;
uint32_t bits = defaultABI;
std::vector<std::string>::iterator I = attrs.begin();
while (I != attrs.end())
{
std::string str = *I;
bool enabled = str[0] == '+';
std::string flag = (str[0] == '+' || str[0] == '-') ? str.substr(1) : str;
uint32_t newBit = 0;
if (flag == "o32") newBit = O32;
if (flag == "n32") newBit = N32;
if (flag == "n64") newBit = N64;
if (flag == "eabi") newBit = EABI;
if (newBit)
{
I = attrs.erase(I);
if (enabled) bits |= newBit;
else bits &= ~newBit;
}
else
++I;
}
switch (bits)
{
case O32: attrs.push_back("+o32"); break;
case N32: attrs.push_back("+n32"); break;
case N64: attrs.push_back("+n64"); break;
case EABI: attrs.push_back("+eabi"); break;
default: error(Loc(), "Only one ABI argument is supported"); fatal();
}
if (bits != defaultABI)
attrs.push_back(is64Bit ? "-n64" : "-o32");
}
#endif
/// Looks up a target based on an arch name and a target triple.
///
/// If the arch name is non-empty, then the lookup is done by arch. Otherwise,
/// the target triple is used.
///
/// This has been adapted from the corresponding LLVM 3.2+ overload of
/// llvm::TargetRegistry::lookupTarget. Once support for LLVM 3.1 is dropped,
/// the registry method can be used instead.
const llvm::Target *lookupTarget(const std::string &arch, llvm::Triple &triple,
std::string &errorMsg)
{
// Allocate target machine. First, check whether the user has explicitly
// specified an architecture to compile for. If so we have to look it up by
// name, because it might be a backend that has no mapping to a target triple.
const llvm::Target *target = 0;
if (!arch.empty())
{
#if LDC_LLVM_VER >= 307
for (const llvm::Target &T : llvm::TargetRegistry::targets())
{
#else
for (llvm::TargetRegistry::iterator it = llvm::TargetRegistry::begin(),
ie = llvm::TargetRegistry::end(); it != ie; ++it)
{
const llvm::Target& T = *it;
#endif
if (arch == T.getName())
{
target = &T;
break;
}
}
if (!target)
{
errorMsg = "invalid target architecture '" + arch + "', see "
"-version for a list of supported targets.";
return 0;
}
// Adjust the triple to match (if known), otherwise stick with the
// given triple.
llvm::Triple::ArchType Type = llvm::Triple::getArchTypeForLLVMName(arch);
if (Type != llvm::Triple::UnknownArch)
triple.setArch(Type);
}
else
{
std::string tempError;
target = llvm::TargetRegistry::lookupTarget(triple.getTriple(), tempError);
if (!target)
{
errorMsg = "unable to get target for '" + triple.getTriple() +
"', see -version and -mtriple.";
}
}
return target;
}
llvm::TargetMachine* createTargetMachine(
std::string targetTriple,
std::string arch,
std::string cpu,
std::vector<std::string> attrs,
ExplicitBitness::Type bitness,
FloatABI::Type floatABI,
llvm::Reloc::Model relocModel,
llvm::CodeModel::Model codeModel,
llvm::CodeGenOpt::Level codeGenOptLevel,
bool noFramePointerElim,
bool noLinkerStripDead)
{
// Determine target triple. If the user didn't explicitly specify one, use
// the one set at LLVM configure time.
llvm::Triple triple;
if (targetTriple.empty())
{
triple = llvm::Triple(llvm::sys::getDefaultTargetTriple());
// Handle -m32/-m64.
if (sizeof(void*) == 4 && bitness == ExplicitBitness::M64)
{
triple = triple.get64BitArchVariant();
}
else if (sizeof(void*) == 8 && bitness == ExplicitBitness::M32)
{
triple = triple.get32BitArchVariant();
}
}
else
{
triple = llvm::Triple(llvm::Triple::normalize(targetTriple));
}
// Look up the LLVM backend to use. This also updates triple with the
// user-specified arch, if any.
std::string errMsg;
const llvm::Target *target = lookupTarget(arch, triple, errMsg);
if (target == 0)
{
error(Loc(), "%s", errMsg.c_str());
fatal();
}
// Package up features to be passed to target/subtarget.
llvm::SubtargetFeatures features;
features.getDefaultSubtargetFeatures(triple);
if (cpu == "native")
{
llvm::StringMap<bool> hostFeatures;
if (llvm::sys::getHostCPUFeatures(hostFeatures))
{
llvm::StringMapConstIterator<bool> i = hostFeatures.begin(),
end = hostFeatures.end();
for (; i != end; ++i)
features.AddFeature(std::string((i->second ? "+" : "-")).append(i->first()));
}
}
#if LDC_LLVM_VER < 307
if (triple.getArch() == llvm::Triple::mips ||
triple.getArch() == llvm::Triple::mipsel ||
triple.getArch() == llvm::Triple::mips64 ||
triple.getArch() == llvm::Triple::mips64el)
addMipsABI(triple, attrs);
#endif
for (unsigned i = 0; i < attrs.size(); ++i)
features.AddFeature(attrs[i]);
// 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").
cpu = getTargetCPU(cpu, triple);
// cmpxchg16b is not available on old 64bit CPUs. Enable code generation
// if the user did not make an explicit choice.
if (cpu == "x86-64")
{
const char* cx16_plus = "+cx16";
const char* cx16_minus = "-cx16";
bool cx16 = false;
for (unsigned i = 0; i < attrs.size(); ++i)
if (attrs[i] == cx16_plus || attrs[i] == cx16_minus) cx16 = true;
if (!cx16)
features.AddFeature(cx16_plus);
}
if (Logger::enabled())
{
Logger::println("Targeting '%s' (CPU '%s' with features '%s')",
triple.str().c_str(), cpu.c_str(), features.getString().c_str());
}
if (triple.isMacOSX() && relocModel == llvm::Reloc::Default)
{
// OS X defaults to PIC (and as of 10.7.5/LLVM 3.1-3.3, TLS use leads
// to crashes for non-PIC code). LLVM doesn't handle this.
relocModel = llvm::Reloc::PIC_;
}
if (floatABI == FloatABI::Default)
{
switch (triple.getArch())
{
default: // X86, ...
floatABI = FloatABI::Hard;
break;
case llvm::Triple::arm:
case llvm::Triple::thumb:
floatABI = getARMFloatABI(triple, getLLVMArchSuffixForARM(cpu));
break;
}
}
llvm::TargetOptions targetOptions;
#if LDC_LLVM_VER < 307
targetOptions.NoFramePointerElim = noFramePointerElim;
#endif
#if LDC_LLVM_VER >= 307
targetOptions.MCOptions.ABIName = getABI(triple);
#endif
switch (floatABI)
{
default: llvm_unreachable("Floating point ABI type unknown.");
case FloatABI::Soft:
#if LDC_LLVM_VER < 307
targetOptions.UseSoftFloat = true;
#endif
targetOptions.FloatABIType = llvm::FloatABI::Soft;
break;
case FloatABI::SoftFP:
#if LDC_LLVM_VER < 307
targetOptions.UseSoftFloat = false;
#endif
targetOptions.FloatABIType = llvm::FloatABI::Soft;
break;
case FloatABI::Hard:
#if LDC_LLVM_VER < 307
targetOptions.UseSoftFloat = false;
#endif
targetOptions.FloatABIType = llvm::FloatABI::Hard;
break;
}
// Right now, we only support linker-level dead code elimination on Linux
// using the GNU toolchain (based on ld's --gc-sections flag). The Apple ld
// on OS X supports a similar flag (-dead_strip) that doesn't require
// emitting the symbols into different sections. The MinGW ld doesn't seem
// to support --gc-sections at all, and FreeBSD needs more investigation.
if (!noLinkerStripDead &&
(triple.getOS() == llvm::Triple::Linux || triple.getOS() == llvm::Triple::Win32))
{
targetOptions.FunctionSections = true;
targetOptions.DataSections = true;
}
return target->createTargetMachine(
triple.str(),
cpu,
features.getString(),
targetOptions,
relocModel,
codeModel,
codeGenOptLevel
);
}