X86Subtarget.h revision ed0dca6a5dfa26e63c5636eb092640159182df89 
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
20namespace llvm {
21class Module;
22class GlobalValue;
23class TargetMachine;
24
25/// PICStyles - The X86 backend supports a number of different styles of PIC.
26///
27namespace PICStyles {
28enum Style {
29  Stub,   // Used on i386-darwin
30  GOT,    // Used on many 32-bit unices.
31  RIPRel, // Used on X86-64 when not in -static mode.
32  None    // Set when in -static mode (not PIC or DynamicNoPIC mode).
33};
34}
35
36class X86Subtarget : public TargetSubtarget {
37public:
38  enum AsmWriterFlavorTy {
39    // Note: This numbering has to match the GCC assembler dialects for inline
40    // asm alternatives to work right.
41    ATT = 0, Intel = 1, Unset
42  };
43protected:
44  enum X86SSEEnum {
45    NoMMXSSE, MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42
46  };
47
48  enum X863DNowEnum {
49    NoThreeDNow, ThreeDNow, ThreeDNowA
50  };
51
52  /// AsmFlavor - Which x86 asm dialect to use.
53  ///
54  AsmWriterFlavorTy AsmFlavor;
55
56  /// PICStyle - Which PIC style to use
57  ///
58  PICStyles::Style PICStyle;
59
60  /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
61  /// none supported.
62  X86SSEEnum X86SSELevel;
63
64  /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
65  ///
66  X863DNowEnum X863DNowLevel;
67
68  /// HasX86_64 - True if the processor supports X86-64 instructions.
69  ///
70  bool HasX86_64;
71
72  /// HasSSE4A - True if the processor supports SSE4A instructions.
73  bool HasSSE4A;
74
75  /// HasAVX - Target has AVX instructions
76  bool HasAVX;
77
78  /// HasFMA3 - Target has 3-operand fused multiply-add
79  bool HasFMA3;
80
81  /// HasFMA4 - Target has 4-operand fused multiply-add
82  bool HasFMA4;
83
84  /// IsBTMemSlow - True if BT (bit test) of memory instructions are slow.
85  bool IsBTMemSlow;
86
87  /// DarwinVers - Nonzero if this is a darwin platform: the numeric
88  /// version of the platform, e.g. 8 = 10.4 (Tiger), 9 = 10.5 (Leopard), etc.
89  unsigned char DarwinVers; // Is any darwin-x86 platform.
90
91  /// isLinux - true if this is a "linux" platform.
92  bool IsLinux;
93
94  /// stackAlignment - The minimum alignment known to hold of the stack frame on
95  /// entry to the function and which must be maintained by every function.
96  unsigned stackAlignment;
97
98  /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
99  ///
100  unsigned MaxInlineSizeThreshold;
101
102private:
103  /// Is64Bit - True if the processor supports 64-bit instructions and module
104  /// pointer size is 64 bit.
105  bool Is64Bit;
106
107public:
108  enum {
109    isELF, isCygwin, isDarwin, isWindows, isMingw
110  } TargetType;
111
112  /// This constructor initializes the data members to match that
113  /// of the specified module.
114  ///
115  X86Subtarget(const Module &M, const std::string &FS, bool is64Bit);
116
117  /// getStackAlignment - Returns the minimum alignment known to hold of the
118  /// stack frame on entry to the function and which must be maintained by every
119  /// function for this subtarget.
120  unsigned getStackAlignment() const { return stackAlignment; }
121
122  /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
123  /// that still makes it profitable to inline the call.
124  unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
125
126  /// ParseSubtargetFeatures - Parses features string setting specified
127  /// subtarget options.  Definition of function is auto generated by tblgen.
128  std::string ParseSubtargetFeatures(const std::string &FS,
129                                     const std::string &CPU);
130
131  /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
132  /// instruction.
133  void AutoDetectSubtargetFeatures();
134
135  bool is64Bit() const { return Is64Bit; }
136
137  PICStyles::Style getPICStyle() const { return PICStyle; }
138  void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
139
140  bool hasMMX() const { return X86SSELevel >= MMX; }
141  bool hasSSE1() const { return X86SSELevel >= SSE1; }
142  bool hasSSE2() const { return X86SSELevel >= SSE2; }
143  bool hasSSE3() const { return X86SSELevel >= SSE3; }
144  bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
145  bool hasSSE41() const { return X86SSELevel >= SSE41; }
146  bool hasSSE42() const { return X86SSELevel >= SSE42; }
147  bool hasSSE4A() const { return HasSSE4A; }
148  bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
149  bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
150  bool hasAVX() const { return HasAVX; }
151  bool hasFMA3() const { return HasFMA3; }
152  bool hasFMA4() const { return HasFMA4; }
153
154  bool isBTMemSlow() const { return IsBTMemSlow; }
155
156  unsigned getAsmFlavor() const {
157    return AsmFlavor != Unset ? unsigned(AsmFlavor) : 0;
158  }
159
160  bool isFlavorAtt() const { return AsmFlavor == ATT; }
161  bool isFlavorIntel() const { return AsmFlavor == Intel; }
162
163  bool isTargetDarwin() const { return TargetType == isDarwin; }
164  bool isTargetELF() const {
165    return TargetType == isELF;
166  }
167  bool isTargetWindows() const { return TargetType == isWindows; }
168  bool isTargetMingw() const { return TargetType == isMingw; }
169  bool isTargetCygMing() const { return (TargetType == isMingw ||
170                                         TargetType == isCygwin); }
171  bool isTargetCygwin() const { return TargetType == isCygwin; }
172  bool isTargetWin64() const {
173    return (Is64Bit && (TargetType == isMingw || TargetType == isWindows));
174  }
175
176  std::string getDataLayout() const {
177    const char *p;
178    if (is64Bit())
179      p = "e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128";
180    else {
181      if (isTargetDarwin())
182        p = "e-p:32:32-f64:32:64-i64:32:64-f80:128:128";
183      else
184        p = "e-p:32:32-f64:32:64-i64:32:64-f80:32:32";
185    }
186    return std::string(p);
187  }
188
189  bool isPICStyleSet() const { return PICStyle != PICStyles::None; }
190  bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
191  bool isPICStyleStub() const { return PICStyle == PICStyles::Stub; }
192  bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
193
194  /// getDarwinVers - Return the darwin version number, 8 = tiger, 9 = leopard.
195  unsigned getDarwinVers() const { return DarwinVers; }
196
197  /// isLinux - Return true if the target is "Linux".
198  bool isLinux() const { return IsLinux; }
199
200  /// True if accessing the GV requires an extra load. For Windows, dllimported
201  /// symbols are indirect, loading the value at address GV rather then the
202  /// value of GV itself. This means that the GlobalAddress must be in the base
203  /// or index register of the address, not the GV offset field.
204  bool GVRequiresExtraLoad(const GlobalValue* GV, const TargetMachine &TM)const;
205
206  /// True if accessing the GV requires a register.  This is a superset of the
207  /// cases where GVRequiresExtraLoad is true.  Some variations of PIC require
208  /// a register, but not an extra load.
209  bool GVRequiresRegister(const GlobalValue *GV, const TargetMachine &TM) const;
210
211  /// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
212  /// to immediate address.
213  bool IsLegalToCallImmediateAddr(const TargetMachine &TM) const;
214
215  /// This function returns the name of a function which has an interface
216  /// like the non-standard bzero function, if such a function exists on
217  /// the current subtarget and it is considered prefereable over
218  /// memset with zero passed as the second argument. Otherwise it
219  /// returns null.
220  const char *getBZeroEntry() const;
221
222  /// getSpecialAddressLatency - For targets where it is beneficial to
223  /// backschedule instructions that compute addresses, return a value
224  /// indicating the number of scheduling cycles of backscheduling that
225  /// should be attempted.
226  unsigned getSpecialAddressLatency() const;
227};
228
229namespace X86 {
230  /// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in
231  /// the specified arguments.  If we can't run cpuid on the host, return true.
232  bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
233                       unsigned *rECX, unsigned *rEDX);
234}
235
236} // End llvm namespace
237
238#endif
239