| //===-- X86Subtarget.cpp - X86 Subtarget Information ----------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the X86 specific subclass of TargetSubtargetInfo. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "X86Subtarget.h" |
| #include "X86InstrInfo.h" |
| #include "X86TargetMachine.h" |
| #include "llvm/IR/Attributes.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/GlobalValue.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/Host.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| |
| #if defined(_MSC_VER) |
| #include <intrin.h> |
| #endif |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "subtarget" |
| |
| #define GET_SUBTARGETINFO_TARGET_DESC |
| #define GET_SUBTARGETINFO_CTOR |
| #include "X86GenSubtargetInfo.inc" |
| |
| // Temporary option to control early if-conversion for x86 while adding machine |
| // models. |
| static cl::opt<bool> |
| X86EarlyIfConv("x86-early-ifcvt", cl::Hidden, |
| cl::desc("Enable early if-conversion on X86")); |
| |
| |
| /// Classify a blockaddress reference for the current subtarget according to how |
| /// we should reference it in a non-pcrel context. |
| unsigned char X86Subtarget::ClassifyBlockAddressReference() const { |
| if (isPICStyleGOT()) // 32-bit ELF targets. |
| return X86II::MO_GOTOFF; |
| |
| if (isPICStyleStubPIC()) // Darwin/32 in PIC mode. |
| return X86II::MO_PIC_BASE_OFFSET; |
| |
| // Direct static reference to label. |
| return X86II::MO_NO_FLAG; |
| } |
| |
| /// Classify a global variable reference for the current subtarget according to |
| /// how we should reference it in a non-pcrel context. |
| unsigned char X86Subtarget:: |
| ClassifyGlobalReference(const GlobalValue *GV, const TargetMachine &TM) const { |
| // DLLImport only exists on windows, it is implemented as a load from a |
| // DLLIMPORT stub. |
| if (GV->hasDLLImportStorageClass()) |
| return X86II::MO_DLLIMPORT; |
| |
| bool isDef = GV->isStrongDefinitionForLinker(); |
| |
| // X86-64 in PIC mode. |
| if (isPICStyleRIPRel()) { |
| // Large model never uses stubs. |
| if (TM.getCodeModel() == CodeModel::Large) |
| return X86II::MO_NO_FLAG; |
| |
| if (isTargetDarwin()) { |
| // If symbol visibility is hidden, the extra load is not needed if |
| // target is x86-64 or the symbol is definitely defined in the current |
| // translation unit. |
| if (GV->hasDefaultVisibility() && !isDef) |
| return X86II::MO_GOTPCREL; |
| } else if (!isTargetWin64()) { |
| assert(isTargetELF() && "Unknown rip-relative target"); |
| |
| // Extra load is needed for all externally visible. |
| if (!GV->hasLocalLinkage() && GV->hasDefaultVisibility()) |
| return X86II::MO_GOTPCREL; |
| } |
| |
| return X86II::MO_NO_FLAG; |
| } |
| |
| if (isPICStyleGOT()) { // 32-bit ELF targets. |
| // Extra load is needed for all externally visible. |
| if (GV->hasLocalLinkage() || GV->hasHiddenVisibility()) |
| return X86II::MO_GOTOFF; |
| return X86II::MO_GOT; |
| } |
| |
| if (isPICStyleStubPIC()) { // Darwin/32 in PIC mode. |
| // Determine whether we have a stub reference and/or whether the reference |
| // is relative to the PIC base or not. |
| |
| // If this is a strong reference to a definition, it is definitely not |
| // through a stub. |
| if (isDef) |
| return X86II::MO_PIC_BASE_OFFSET; |
| |
| // Unless we have a symbol with hidden visibility, we have to go through a |
| // normal $non_lazy_ptr stub because this symbol might be resolved late. |
| if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference. |
| return X86II::MO_DARWIN_NONLAZY_PIC_BASE; |
| |
| // If symbol visibility is hidden, we have a stub for common symbol |
| // references and external declarations. |
| if (GV->isDeclarationForLinker() || GV->hasCommonLinkage()) { |
| // Hidden $non_lazy_ptr reference. |
| return X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE; |
| } |
| |
| // Otherwise, no stub. |
| return X86II::MO_PIC_BASE_OFFSET; |
| } |
| |
| if (isPICStyleStubNoDynamic()) { // Darwin/32 in -mdynamic-no-pic mode. |
| // Determine whether we have a stub reference. |
| |
| // If this is a strong reference to a definition, it is definitely not |
| // through a stub. |
| if (isDef) |
| return X86II::MO_NO_FLAG; |
| |
| // Unless we have a symbol with hidden visibility, we have to go through a |
| // normal $non_lazy_ptr stub because this symbol might be resolved late. |
| if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference. |
| return X86II::MO_DARWIN_NONLAZY; |
| |
| // Otherwise, no stub. |
| return X86II::MO_NO_FLAG; |
| } |
| |
| // Direct static reference to global. |
| return X86II::MO_NO_FLAG; |
| } |
| |
| |
| /// This function returns the name of a function which has an interface like |
| /// the non-standard bzero function, if such a function exists on the |
| /// current subtarget and it is considered preferable over memset with zero |
| /// passed as the second argument. Otherwise it returns null. |
| const char *X86Subtarget::getBZeroEntry() const { |
| // Darwin 10 has a __bzero entry point for this purpose. |
| if (getTargetTriple().isMacOSX() && |
| !getTargetTriple().isMacOSXVersionLT(10, 6)) |
| return "__bzero"; |
| |
| return nullptr; |
| } |
| |
| bool X86Subtarget::hasSinCos() const { |
| return getTargetTriple().isMacOSX() && |
| !getTargetTriple().isMacOSXVersionLT(10, 9) && |
| is64Bit(); |
| } |
| |
| /// Return true if the subtarget allows calls to immediate address. |
| bool X86Subtarget::IsLegalToCallImmediateAddr(const TargetMachine &TM) const { |
| // FIXME: I386 PE/COFF supports PC relative calls using IMAGE_REL_I386_REL32 |
| // but WinCOFFObjectWriter::RecordRelocation cannot emit them. Once it does, |
| // the following check for Win32 should be removed. |
| if (In64BitMode || isTargetWin32()) |
| return false; |
| return isTargetELF() || TM.getRelocationModel() == Reloc::Static; |
| } |
| |
| void X86Subtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) { |
| std::string CPUName = CPU; |
| if (CPUName.empty()) |
| CPUName = "generic"; |
| |
| // Make sure 64-bit features are available in 64-bit mode. (But make sure |
| // SSE2 can be turned off explicitly.) |
| std::string FullFS = FS; |
| if (In64BitMode) { |
| if (!FullFS.empty()) |
| FullFS = "+64bit,+sse2," + FullFS; |
| else |
| FullFS = "+64bit,+sse2"; |
| } |
| |
| // LAHF/SAHF are always supported in non-64-bit mode. |
| if (!In64BitMode) { |
| if (!FullFS.empty()) |
| FullFS = "+sahf," + FullFS; |
| else |
| FullFS = "+sahf"; |
| } |
| |
| |
| // Parse features string and set the CPU. |
| ParseSubtargetFeatures(CPUName, FullFS); |
| |
| // All CPUs that implement SSE4.2 or SSE4A support unaligned accesses of |
| // 16-bytes and under that are reasonably fast. These features were |
| // introduced with Intel's Nehalem/Silvermont and AMD's Family10h |
| // micro-architectures respectively. |
| if (hasSSE42() || hasSSE4A()) |
| IsUAMem16Slow = false; |
| |
| InstrItins = getInstrItineraryForCPU(CPUName); |
| |
| // It's important to keep the MCSubtargetInfo feature bits in sync with |
| // target data structure which is shared with MC code emitter, etc. |
| if (In64BitMode) |
| ToggleFeature(X86::Mode64Bit); |
| else if (In32BitMode) |
| ToggleFeature(X86::Mode32Bit); |
| else if (In16BitMode) |
| ToggleFeature(X86::Mode16Bit); |
| else |
| llvm_unreachable("Not 16-bit, 32-bit or 64-bit mode!"); |
| |
| DEBUG(dbgs() << "Subtarget features: SSELevel " << X86SSELevel |
| << ", 3DNowLevel " << X863DNowLevel |
| << ", 64bit " << HasX86_64 << "\n"); |
| assert((!In64BitMode || HasX86_64) && |
| "64-bit code requested on a subtarget that doesn't support it!"); |
| |
| // Stack alignment is 16 bytes on Darwin, Linux and Solaris (both |
| // 32 and 64 bit) and for all 64-bit targets. |
| if (StackAlignOverride) |
| stackAlignment = StackAlignOverride; |
| else if (isTargetDarwin() || isTargetLinux() || isTargetSolaris() || |
| In64BitMode) |
| stackAlignment = 16; |
| } |
| |
| void X86Subtarget::initializeEnvironment() { |
| X86SSELevel = NoSSE; |
| X863DNowLevel = NoThreeDNow; |
| HasCMov = false; |
| HasX86_64 = false; |
| HasPOPCNT = false; |
| HasSSE4A = false; |
| HasAES = false; |
| HasFXSR = false; |
| HasXSAVE = false; |
| HasXSAVEOPT = false; |
| HasXSAVEC = false; |
| HasXSAVES = false; |
| HasPCLMUL = false; |
| HasFMA = false; |
| HasFMA4 = false; |
| HasXOP = false; |
| HasTBM = false; |
| HasMOVBE = false; |
| HasRDRAND = false; |
| HasF16C = false; |
| HasFSGSBase = false; |
| HasLZCNT = false; |
| HasBMI = false; |
| HasBMI2 = false; |
| HasRTM = false; |
| HasHLE = false; |
| HasERI = false; |
| HasCDI = false; |
| HasPFI = false; |
| HasDQI = false; |
| HasBWI = false; |
| HasVLX = false; |
| HasADX = false; |
| HasPKU = false; |
| HasSHA = false; |
| HasPRFCHW = false; |
| HasRDSEED = false; |
| HasLAHFSAHF = false; |
| HasMPX = false; |
| IsBTMemSlow = false; |
| IsSHLDSlow = false; |
| IsUAMem16Slow = false; |
| IsUAMem32Slow = false; |
| HasSSEUnalignedMem = false; |
| HasCmpxchg16b = false; |
| UseLeaForSP = false; |
| HasSlowDivide32 = false; |
| HasSlowDivide64 = false; |
| PadShortFunctions = false; |
| CallRegIndirect = false; |
| LEAUsesAG = false; |
| SlowLEA = false; |
| SlowIncDec = false; |
| stackAlignment = 4; |
| // FIXME: this is a known good value for Yonah. How about others? |
| MaxInlineSizeThreshold = 128; |
| UseSoftFloat = false; |
| } |
| |
| X86Subtarget &X86Subtarget::initializeSubtargetDependencies(StringRef CPU, |
| StringRef FS) { |
| initializeEnvironment(); |
| initSubtargetFeatures(CPU, FS); |
| return *this; |
| } |
| |
| X86Subtarget::X86Subtarget(const Triple &TT, const std::string &CPU, |
| const std::string &FS, const X86TargetMachine &TM, |
| unsigned StackAlignOverride) |
| : X86GenSubtargetInfo(TT, CPU, FS), X86ProcFamily(Others), |
| PICStyle(PICStyles::None), TargetTriple(TT), |
| StackAlignOverride(StackAlignOverride), |
| In64BitMode(TargetTriple.getArch() == Triple::x86_64), |
| In32BitMode(TargetTriple.getArch() == Triple::x86 && |
| TargetTriple.getEnvironment() != Triple::CODE16), |
| In16BitMode(TargetTriple.getArch() == Triple::x86 && |
| TargetTriple.getEnvironment() == Triple::CODE16), |
| TSInfo(), InstrInfo(initializeSubtargetDependencies(CPU, FS)), |
| TLInfo(TM, *this), FrameLowering(*this, getStackAlignment()) { |
| // Determine the PICStyle based on the target selected. |
| if (TM.getRelocationModel() == Reloc::Static) { |
| // Unless we're in PIC or DynamicNoPIC mode, set the PIC style to None. |
| setPICStyle(PICStyles::None); |
| } else if (is64Bit()) { |
| // PIC in 64 bit mode is always rip-rel. |
| setPICStyle(PICStyles::RIPRel); |
| } else if (isTargetCOFF()) { |
| setPICStyle(PICStyles::None); |
| } else if (isTargetDarwin()) { |
| if (TM.getRelocationModel() == Reloc::PIC_) |
| setPICStyle(PICStyles::StubPIC); |
| else { |
| assert(TM.getRelocationModel() == Reloc::DynamicNoPIC); |
| setPICStyle(PICStyles::StubDynamicNoPIC); |
| } |
| } else if (isTargetELF()) { |
| setPICStyle(PICStyles::GOT); |
| } |
| } |
| |
| bool X86Subtarget::enableEarlyIfConversion() const { |
| return hasCMov() && X86EarlyIfConv; |
| } |
| |