ldc/driver/targetmachine.cpp
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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 "dmd/errors.h"
#include "driver/args.h"
#include "driver/cl_options.h"
#include "gen/logger.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#if LDC_LLVM_VER < 1700
#include "llvm/ADT/Triple.h"
#include "llvm/MC/SubtargetFeature.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/TargetParser.h"
#if LDC_LLVM_VER >= 1400
#include "llvm/Support/AArch64TargetParser.h"
#include "llvm/Support/ARMTargetParser.h"
#endif
#else
#include "llvm/TargetParser/AArch64TargetParser.h"
#include "llvm/TargetParser/ARMTargetParser.h"
#include "llvm/TargetParser/Host.h"
#include "llvm/TargetParser/SubtargetFeature.h"
#include "llvm/TargetParser/TargetParser.h"
#include "llvm/TargetParser/Triple.h"
#endif
#include "llvm/IR/Module.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/Support/CommandLine.h"
#if LDC_LLVM_VER >= 1400
#include "llvm/MC/TargetRegistry.h"
#else
#include "llvm/Support/TargetRegistry.h"
#endif
#include "llvm/Support/TargetSelect.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "gen/optimizer.h"
#ifdef LDC_LLVM_SUPPORTS_MACHO_DWARF_LINE_AS_REGULAR_SECTION
// LDC-LLVM >= 6.0.1:
// On Mac, emit __debug_line section in __DWARF segment as regular (non-debug)
// section, like DMD, to enable file/line infos in backtraces. See
// https://github.com/dlang/dmd/commit/2bf7d0db29416eacbb01a91e6502140e354ee0ef
// https://github.com/ldc-developers/llvm-project/commit/110deda1bc1cf195983fea8c1107886057987955
static llvm::cl::opt<bool, true> preserveDwarfLineSection(
"preserve-dwarf-line-section",
llvm::cl::desc("Mac: preserve DWARF line section during linking for "
"file/line infos in backtraces. Defaults to true."),
llvm::cl::Hidden, llvm::cl::ZeroOrMore,
llvm::cl::location(ldc::emitMachODwarfLineAsRegularSection),
llvm::cl::init(false));
#endif
// Returns true if 'feature' is enabled and false otherwise. Handles the
// case where the feature is specified multiple times ('+m,-m'), and
// takes the last occurrence.
bool isFeatureEnabled(const llvm::SmallVectorImpl<llvm::StringRef> &features,
llvm::StringRef feature) {
for (auto it = features.rbegin(), end = features.rend(); it != end; ++it) {
if (it->substr(1) == feature) {
return (*it)[0] == '+';
}
}
return false;
};
const char *getABI(const llvm::Triple &triple, const llvm::SmallVectorImpl<llvm::StringRef> &features) {
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;
case llvm::Triple::riscv64:
if (ABIName.startswith("lp64f"))
return "lp64f";
if (ABIName.startswith("lp64d"))
return "lp64d";
if (ABIName.startswith("lp64"))
return "lp64";
break;
case llvm::Triple::riscv32:
if (ABIName.startswith("ilp32f"))
return "ilp32f";
if (ABIName.startswith("ilp32d"))
return "ilp32d";
if (ABIName.startswith("ilp32"))
return "ilp32";
break;
#if LDC_LLVM_VER >= 1600
case llvm::Triple::loongarch32:
if (ABIName.startswith("ilp32s"))
return "ilp32s";
if (ABIName.startswith("ilp32f"))
return "ilp32f";
if (ABIName.startswith("ilp32d"))
return "ilp32d";
break;
case llvm::Triple::loongarch64:
if (ABIName.startswith("lp64f"))
return "lp64f";
if (ABIName.startswith("lp64d"))
return "lp64d";
if (ABIName.startswith("lp64s"))
return "lp64s";
break;
#endif // LDC_LLVM_VER >= 1600
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";
case llvm::Triple::riscv64:
if (isFeatureEnabled(features, "d"))
return "lp64d";
if (isFeatureEnabled(features, "f"))
return "lp64f";
return "lp64";
case llvm::Triple::riscv32:
return "ilp32";
#if LDC_LLVM_VER >= 1600
case llvm::Triple::loongarch32:
if (isFeatureEnabled(features, "d"))
return "ilp32d";
if (isFeatureEnabled(features, "f"))
return "ilp32f";
return "ilp32s";
case llvm::Triple::loongarch64:
if (isFeatureEnabled(features, "d"))
return "lp64d";
if (isFeatureEnabled(features, "f"))
return "lp64f";
return "lp64d";
#endif // LDC_LLVM_VER >= 1600
default:
return "";
}
}
extern llvm::TargetMachine *gTargetMachine;
MipsABI::Type getMipsABI() {
// eabi can only be set on the commandline
if (strncmp(opts::mABI.c_str(), "eabi", 4) == 0)
return MipsABI::EABI;
const llvm::DataLayout dl = gTargetMachine->createDataLayout();
if (dl.getPointerSizeInBits() == 64)
return MipsABI::N64;
const auto largestInt = dl.getLargestLegalIntTypeSizeInBits();
return (largestInt == 64) ? MipsABI::N32 : MipsABI::O32;
}
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";
}
// All x86 devices running Android have core2 as their common
// denominator.
if (triple.getEnvironment() == llvm::Triple::Android) {
return "core2";
}
// 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("freebsd")) {
return "i486";
}
if (triple.getOSName().startswith("netbsd")) {
return "i486";
}
if (triple.getOSName().startswith("openbsd")) {
return "i486";
}
if (triple.getOSName().startswith("dragonfly")) {
return "i486";
}
// Fallback to p4.
return "pentium4";
}
static std::string getARMTargetCPU(const llvm::Triple &triple) {
auto defaultCPU = llvm::ARM::getDefaultCPU(triple.getArchName());
// 32-bit Android: default to cortex-a8
if (defaultCPU == "generic" &&
triple.getEnvironment() == llvm::Triple::Android) {
return "cortex-a8";
}
if (!defaultCPU.empty())
return std::string(defaultCPU);
// Return the most base CPU with thumb interworking supported by LLVM.
return (triple.getEnvironment() == llvm::Triple::GNUEABIHF) ? "arm1176jzf-s"
: "arm7tdmi";
}
static std::string getAArch64TargetCPU(const llvm::Triple &triple) {
#if LDC_LLVM_VER < 1600
auto defaultCPU = llvm::AArch64::getDefaultCPU(triple.getArchName());
if (!defaultCPU.empty())
return std::string(defaultCPU);
#endif
return "generic";
}
static std::string getRiscv32TargetCPU(const llvm::Triple &triple) {
return "generic-rv32";
}
static std::string getRiscv64TargetCPU(const llvm::Triple &triple) {
return "generic-rv64";
}
static std::string getLoongArch32TargetCPU(const llvm::Triple &triple) {
return "generic-la32";
}
static std::string getLoongArch64TargetCPU(const llvm::Triple &triple) {
return "generic-la64";
}
/// Returns the LLVM name of the default CPU for the provided target triple.
static std::string getTargetCPU(const llvm::Triple &triple) {
switch (triple.getArch()) {
default:
// We don't know about the specifics of this platform, just return the
// empty string and let LLVM decide.
return "";
case llvm::Triple::x86:
case llvm::Triple::x86_64:
return getX86TargetCPU(triple);
case llvm::Triple::arm:
case llvm::Triple::armeb:
case llvm::Triple::thumb:
return getARMTargetCPU(triple);
case llvm::Triple::aarch64:
case llvm::Triple::aarch64_be:
return getAArch64TargetCPU(triple);
case llvm::Triple::riscv32:
return getRiscv32TargetCPU(triple);
case llvm::Triple::riscv64:
return getRiscv64TargetCPU(triple);
#if LDC_LLVM_VER >= 1600
case llvm::Triple::loongarch32:
return getLoongArch32TargetCPU(triple);
case llvm::Triple::loongarch64:
return getLoongArch64TargetCPU(triple);
#endif // LDC_LLVM_VER >= 1600
}
}
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) {
if (triple.isOSDarwin()) {
// 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;
}
if (triple.isOSFreeBSD()) {
// FreeBSD defaults to soft float
return FloatABI::Soft;
}
if (triple.getVendorName().startswith("hardfloat"))
return FloatABI::Hard;
if (triple.getVendorName().startswith("softfloat"))
return FloatABI::SoftFP;
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;
}
}
/// 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 = nullptr;
if (!arch.empty()) {
for (const llvm::Target &T : llvm::TargetRegistry::targets()) {
if (arch == T.getName()) {
target = &T;
break;
}
}
if (!target) {
errorMsg = "invalid target architecture '" + arch +
"', see -version for a list of supported targets.";
return nullptr;
}
// Adjust the triple to match (if known), otherwise stick with the
// given triple.
const auto Type = llvm::Triple::getArchTypeForLLVMName(arch);
if (Type != llvm::Triple::UnknownArch) {
triple.setArch(Type);
if (Type == llvm::Triple::x86)
triple.setArchName("i686"); // instead of i386
}
} 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(const std::string targetTriple, const std::string arch,
std::string cpu, const std::string featuresString,
const ExplicitBitness::Type bitness,
FloatABI::Type &floatABI,
llvm::Optional<llvm::Reloc::Model> relocModel,
llvm::Optional<llvm::CodeModel::Model> codeModel,
const llvm::CodeGenOpt::Level codeGenOptLevel,
const 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::Triple::normalize(llvm::sys::getDefaultTargetTriple()));
if (triple.getOS() == llvm::Triple::Darwin) {
// We only support OSX, so darwin should really be macosx.
llvm::SmallString<16> osname;
osname += "macosx";
// We have to specify OS version in the triple to avoid linker warnings,
// see https://github.com/ldc-developers/ldc/issues/4501.
// If environment variable MACOSX_DEPLOYMENT_TARGET is not set, then use
// host OS version.
// https://developer.apple.com/library/archive/documentation/DeveloperTools/Conceptual/cross_development/Configuring/configuring.html
std::string envVersion = env::get("MACOSX_DEPLOYMENT_TARGET");
if (!envVersion.empty()) {
osname += envVersion;
} else {
#if LDC_LLVM_VER >= 1400
llvm::VersionTuple OSVersion;
triple.getMacOSXVersion(OSVersion);
osname += OSVersion.getAsString();
#else
// Hardcode the version, because `getMacOSXVersion` is not available.
osname += "10.7";
#endif
}
triple.setOSName(osname);
}
// Handle -m32/-m64.
if (!triple.isArch64Bit() && bitness == ExplicitBitness::M64) {
triple = triple.get64BitArchVariant();
} else if (!triple.isArch32Bit() && bitness == ExplicitBitness::M32) {
triple = triple.get32BitArchVariant();
if (triple.getArch() == llvm::Triple::ArchType::x86)
triple.setArchName("i686"); // instead of i386
}
} 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 == nullptr) {
error(Loc(), "%s", errMsg.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() || cpu == "generic") {
cpu = getTargetCPU(triple);
if (cpu.empty())
cpu = "generic";
}
// Package up features to be passed to target/subtarget.
llvm::SmallVector<llvm::StringRef, 8> features;
// NOTE: needs a persistent (non-temporary) string
auto splitAndAddFeatures = [&features](llvm::StringRef str) {
str.split(features, ",", -1, /* KeepEmpty */ false);
};
llvm::SubtargetFeatures defaultSubtargetFeatures;
defaultSubtargetFeatures.getDefaultSubtargetFeatures(triple);
const std::string defaultSubtargetFeaturesString =
defaultSubtargetFeatures.getString();
splitAndAddFeatures(defaultSubtargetFeaturesString);
splitAndAddFeatures(featuresString);
// checks if the features include ±<feature>
auto hasFeature = [&features](llvm::StringRef feature) {
return std::any_of(
features.begin(), features.end(),
[feature](llvm::StringRef f) { return f.substr(1) == feature; });
};
// cmpxchg16b is not available on old 64bit CPUs. Enable code generation
// if the user did not make an explicit choice.
if (cpu == "x86-64" && !hasFeature("cx16")) {
features.push_back("+cx16");
}
// For a hosted RISC-V 64-bit target default to rv64gc if nothing has
// been selected
if (triple.getArch() == llvm::Triple::riscv64 && features.empty()) {
const llvm::StringRef os = triple.getOSName();
const bool isFreeStanding = os.empty() || os == "unknown" || os == "none";
if (!isFreeStanding) {
features = {"+m", "+a", "+f", "+d", "+c"};
}
}
// For LoongArch 64-bit target default to la64 if nothing has been selected
// All current LoongArch targets have 64-bit floating point registers.
#if LDC_LLVM_VER >= 1600
if (triple.getArch() == llvm::Triple::loongarch64 && features.empty()) {
features = {"+d"};
}
#endif
// Handle cases where LLVM picks wrong default relocModel
#if LDC_LLVM_VER >= 1600
if (relocModel.has_value()) {}
#else
if (relocModel.hasValue()) {}
#endif
else {
if (triple.isOSDarwin()) {
// Darwin 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_;
} else if (triple.isOSLinux()) {
// Modern Linux distributions have their toolchain generate PIC code for
// additional security
// features (like ASLR). We default to PIC code to avoid linking issues on
// these OSes.
// On Android, PIC is default as well.
relocModel = llvm::Reloc::PIC_;
} else if (triple.isOSFreeBSD()) {
// We default to PIC code to avoid linking issues on FreeBSD, especially
// on aarch64.
relocModel = llvm::Reloc::PIC_;
} else {
// ARM for other than Darwin or Android defaults to static
switch (triple.getArch()) {
default:
break;
case llvm::Triple::arm:
case llvm::Triple::armeb:
case llvm::Triple::thumb:
case llvm::Triple::thumbeb:
relocModel = llvm::Reloc::Static;
break;
}
}
}
llvm::TargetOptions targetOptions =
opts::InitTargetOptionsFromCodeGenFlags(triple);
if (targetOptions.MCOptions.ABIName.empty())
targetOptions.MCOptions.ABIName = getABI(triple, features);
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;
}
}
switch (floatABI) {
default:
llvm_unreachable("Floating point ABI type unknown.");
case FloatABI::Soft:
features.push_back("+soft-float");
targetOptions.FloatABIType = llvm::FloatABI::Soft;
break;
case FloatABI::SoftFP:
targetOptions.FloatABIType = llvm::FloatABI::Soft;
break;
case FloatABI::Hard:
targetOptions.FloatABIType = llvm::FloatABI::Hard;
break;
}
// Linker-level dead code elimination for ELF/wasm binaries using GNU or LLD
// linkers (based on the --gc-sections flag) requires a separate section per
// symbol.
// The Apple ld64 on macOS supports a similar flag (-dead_strip) that doesn't
// require emitting the symbols into different sections.
// On Windows, the MSVC link.exe / lld-link.exe has `/REF`; LLD enforces
// separate sections with LTO, so do the same here.
if (!noLinkerStripDead && !triple.isOSBinFormatMachO()) {
targetOptions.FunctionSections = true;
targetOptions.DataSections = true;
}
// On Android, we depend on a custom TLS emulation scheme implemented in our
// LLVM fork. LLVM 7+ enables regular emutls by default; prevent that.
if (triple.getEnvironment() == llvm::Triple::Android) {
targetOptions.EmulatedTLS = false;
#if LDC_LLVM_VER < 1700
// Removed in this commit: https://github.com/llvm/llvm-project/commit/0d333bf0e3aa37e2e6ae211e3aa80631c3e01b85
targetOptions.ExplicitEmulatedTLS = true;
#endif
}
const std::string finalFeaturesString =
llvm::join(features.begin(), features.end(), ",");
if (Logger::enabled()) {
Logger::println("Targeting '%s' (CPU '%s' with features '%s')",
triple.str().c_str(), cpu.c_str(),
finalFeaturesString.c_str());
}
return target->createTargetMachine(triple.str(), cpu, finalFeaturesString,
targetOptions, relocModel, codeModel,
codeGenOptLevel);
}
ComputeBackend::Type getComputeTargetType(llvm::Module* m) {
llvm::Triple::ArchType a = llvm::Triple(m->getTargetTriple()).getArch();
if (a == llvm::Triple::spir || a == llvm::Triple::spir64)
return ComputeBackend::SPIRV;
else if (a == llvm::Triple::nvptx || a == llvm::Triple::nvptx64)
return ComputeBackend::NVPTX;
else
return ComputeBackend::None;
}