lib/Target/X86/X86Subtarget.h

   1 //=====---- X86Subtarget.h - Define Subtarget for the X86 -----*- C++ -*--====//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file declares the X86 specific subclass of TargetSubtarget.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef X86SUBTARGET_H
  15 #define X86SUBTARGET_H
  16
  17 #include "llvm/Target/TargetSubtarget.h"
  18 #include <string>
  19
  20 namespace llvm {
  21 class Module;
  22 class GlobalValue;
  23 class TargetMachine;
  24
  25 namespace PICStyles {
  26 enum Style {
  27   Stub, GOT, RIPRel, WinPIC, None
  28 };
  29 }
  30
  31 class X86Subtarget : public TargetSubtarget {
  32 public:
  33   enum AsmWriterFlavorTy {
  34     // Note: This numbering has to match the GCC assembler dialects for inline
  35     // asm alternatives to work right.
  36     ATT = 0, Intel = 1, Unset
  37   };
  38 protected:
  39   enum X86SSEEnum {
  40     NoMMXSSE, MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42
  41   };
  42
  43   enum X863DNowEnum {
  44     NoThreeDNow, ThreeDNow, ThreeDNowA
  45   };
  46
  47   /// AsmFlavor - Which x86 asm dialect to use.
  48   ///
  49   AsmWriterFlavorTy AsmFlavor;
  50
  51   /// PICStyle - Which PIC style to use
  52   ///
  53   PICStyles::Style PICStyle;
  54
  55   /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
  56   /// none supported.
  57   X86SSEEnum X86SSELevel;
  58
  59   /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
  60   ///
  61   X863DNowEnum X863DNowLevel;
  62
  63   /// HasX86_64 - True if the processor supports X86-64 instructions.
  64   ///
  65   bool HasX86_64;
  66
  67   /// IsBTMemSlow - True if BT (bit test) of memory instructions are slow.
  68   bool IsBTMemSlow;
  69
  70   /// DarwinVers - Nonzero if this is a darwin platform: the numeric
  71   /// version of the platform, e.g. 8 = 10.4 (Tiger), 9 = 10.5 (Leopard), etc.
  72   unsigned char DarwinVers; // Is any darwin-x86 platform.
  73
  74   /// isLinux - true if this is a "linux" platform.
  75   bool IsLinux;
  76
  77   /// stackAlignment - The minimum alignment known to hold of the stack frame on
  78   /// entry to the function and which must be maintained by every function.
  79   unsigned stackAlignment;
  80
  81   /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
  82   ///
  83   unsigned MaxInlineSizeThreshold;
  84
  85 private:
  86   /// Is64Bit - True if the processor supports 64-bit instructions and module
  87   /// pointer size is 64 bit.
  88   bool Is64Bit;
  89
  90 public:
  91   enum {
  92     isELF, isCygwin, isDarwin, isWindows, isMingw
  93   } TargetType;
  94
  95   /// This constructor initializes the data members to match that
  96   /// of the specified module.
  97   ///
  98   X86Subtarget(const Module &M, const std::string &FS, bool is64Bit);
  99
 100   /// getStackAlignment - Returns the minimum alignment known to hold of the
 101   /// stack frame on entry to the function and which must be maintained by every
 102   /// function for this subtarget.
 103   unsigned getStackAlignment() const { return stackAlignment; }
 104
 105   /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
 106   /// that still makes it profitable to inline the call.
 107   unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
 108
 109   /// ParseSubtargetFeatures - Parses features string setting specified
 110   /// subtarget options.  Definition of function is auto generated by tblgen.
 111   void ParseSubtargetFeatures(const std::string &FS, const std::string &CPU);
 112
 113   /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
 114   /// instruction.
 115   void AutoDetectSubtargetFeatures();
 116
 117   bool is64Bit() const { return Is64Bit; }
 118
 119   PICStyles::Style getPICStyle() const { return PICStyle; }
 120   void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
 121
 122   bool hasMMX() const { return X86SSELevel >= MMX; }
 123   bool hasSSE1() const { return X86SSELevel >= SSE1; }
 124   bool hasSSE2() const { return X86SSELevel >= SSE2; }
 125   bool hasSSE3() const { return X86SSELevel >= SSE3; }
 126   bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
 127   bool hasSSE41() const { return X86SSELevel >= SSE41; }
 128   bool hasSSE42() const { return X86SSELevel >= SSE42; }
 129   bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
 130   bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
 131
 132   bool isBTMemSlow() const { return IsBTMemSlow; }
 133
 134   unsigned getAsmFlavor() const {
 135     return AsmFlavor != Unset ? unsigned(AsmFlavor) : 0;
 136   }
 137
 138   bool isFlavorAtt() const { return AsmFlavor == ATT; }
 139   bool isFlavorIntel() const { return AsmFlavor == Intel; }
 140
 141   bool isTargetDarwin() const { return TargetType == isDarwin; }
 142   bool isTargetELF() const {
 143     return TargetType == isELF;
 144   }
 145   bool isTargetWindows() const { return TargetType == isWindows; }
 146   bool isTargetMingw() const { return TargetType == isMingw; }
 147   bool isTargetCygMing() const { return (TargetType == isMingw ||
 148                                          TargetType == isCygwin); }
 149   bool isTargetCygwin() const { return TargetType == isCygwin; }
 150   bool isTargetWin64() const {
 151     return (Is64Bit && (TargetType == isMingw || TargetType == isWindows));
 152   }
 153
 154   std::string getDataLayout() const {
 155     const char *p;
 156     if (is64Bit())
 157       p = "e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128";
 158     else {
 159       if (isTargetDarwin())
 160         p = "e-p:32:32-f64:32:64-i64:32:64-f80:128:128";
 161       else
 162         p = "e-p:32:32-f64:32:64-i64:32:64-f80:32:32";
 163     }
 164     return std::string(p);
 165   }
 166
 167   bool isPICStyleSet() const { return PICStyle != PICStyles::None; }
 168   bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
 169   bool isPICStyleStub() const { return PICStyle == PICStyles::Stub; }
 170   bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
 171   bool isPICStyleWinPIC() const { return PICStyle == PICStyles:: WinPIC; }
 172
 173   /// getDarwinVers - Return the darwin version number, 8 = tiger, 9 = leopard.
 174   unsigned getDarwinVers() const { return DarwinVers; }
 175
 176   /// isLinux - Return true if the target is "Linux".
 177   bool isLinux() const { return IsLinux; }
 178
 179   /// True if accessing the GV requires an extra load. For Windows, dllimported
 180   /// symbols are indirect, loading the value at address GV rather then the
 181   /// value of GV itself. This means that the GlobalAddress must be in the base
 182   /// or index register of the address, not the GV offset field.
 183   bool GVRequiresExtraLoad(const GlobalValue* GV, const TargetMachine& TM,
 184                            bool isDirectCall) const;
 185
 186   /// True if accessing the GV requires a register.  This is a superset of the
 187   /// cases where GVRequiresExtraLoad is true.  Some variations of PIC require
 188   /// a register, but not an extra load.
 189   bool GVRequiresRegister(const GlobalValue* GV, const TargetMachine& TM,
 190                            bool isDirectCall) const;
 191
 192   /// This function returns the name of a function which has an interface
 193   /// like the non-standard bzero function, if such a function exists on
 194   /// the current subtarget and it is considered prefereable over
 195   /// memset with zero passed as the second argument. Otherwise it
 196   /// returns null.
 197   const char *getBZeroEntry() const;
 198
 199   /// getSpecialAddressLatency - For targets where it is beneficial to
 200   /// backschedule instructions that compute addresses, return a value
 201   /// indicating the number of scheduling cycles of backscheduling that
 202   /// should be attempted.
 203   unsigned getSpecialAddressLatency() const;
 204 };
 205
 206 namespace X86 {
 207   /// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in
 208   /// the specified arguments.  If we can't run cpuid on the host, return true.
 209   bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
 210                        unsigned *rECX, unsigned *rEDX);
 211 }
 212
 213 } // End llvm namespace
 214
 215 #endif