X86Subtarget.h revision cdae7e8244e37f539a5f1c9b780de7817b40de52 
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/ADT/Triple.h"
18#include "llvm/Target/TargetSubtarget.h"
19#include "llvm/CallingConv.h"
20#include <string>
21
22namespace llvm {
23class GlobalValue;
24class TargetMachine;
25
26/// PICStyles - The X86 backend supports a number of different styles of PIC.
27///
28namespace PICStyles {
29enum Style {
30  StubPIC,          // Used on i386-darwin in -fPIC mode.
31  StubDynamicNoPIC, // Used on i386-darwin in -mdynamic-no-pic mode.
32  GOT,              // Used on many 32-bit unices in -fPIC mode.
33  RIPRel,           // Used on X86-64 when not in -static mode.
34  None              // Set when in -static mode (not PIC or DynamicNoPIC mode).
35};
36}
37
38class X86Subtarget : public TargetSubtarget {
39protected:
40  enum X86SSEEnum {
41    NoMMXSSE, MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42
42  };
43
44  enum X863DNowEnum {
45    NoThreeDNow, ThreeDNow, ThreeDNowA
46  };
47
48  /// PICStyle - Which PIC style to use
49  ///
50  PICStyles::Style PICStyle;
51
52  /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
53  /// none supported.
54  X86SSEEnum X86SSELevel;
55
56  /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
57  ///
58  X863DNowEnum X863DNowLevel;
59
60  /// HasCMov - True if this processor has conditional move instructions
61  /// (generally pentium pro+).
62  bool HasCMov;
63
64  /// HasX86_64 - True if the processor supports X86-64 instructions.
65  ///
66  bool HasX86_64;
67
68  /// HasSSE4A - True if the processor supports SSE4A instructions.
69  bool HasSSE4A;
70
71  /// HasAVX - Target has AVX instructions
72  bool HasAVX;
73
74  /// HasAES - Target has AES instructions
75  bool HasAES;
76
77  /// HasCLMUL - Target has carry-less multiplication
78  bool HasCLMUL;
79
80  /// HasFMA3 - Target has 3-operand fused multiply-add
81  bool HasFMA3;
82
83  /// HasFMA4 - Target has 4-operand fused multiply-add
84  bool HasFMA4;
85
86  /// IsBTMemSlow - True if BT (bit test) of memory instructions are slow.
87  bool IsBTMemSlow;
88
89  /// IsUAMemFast - True if unaligned memory access is fast.
90  bool IsUAMemFast;
91
92  /// HasVectorUAMem - True if SIMD operations can have unaligned memory
93  /// operands. This may require setting a feature bit in the processor.
94  bool HasVectorUAMem;
95
96  /// stackAlignment - The minimum alignment known to hold of the stack frame on
97  /// entry to the function and which must be maintained by every function.
98  unsigned stackAlignment;
99
100  /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
101  ///
102  unsigned MaxInlineSizeThreshold;
103
104  /// TargetTriple - What processor and OS we're targeting.
105  Triple TargetTriple;
106
107private:
108  /// Is64Bit - True if the processor supports 64-bit instructions and
109  /// pointer size is 64 bit.
110  bool Is64Bit;
111
112public:
113
114  /// This constructor initializes the data members to match that
115  /// of the specified triple.
116  ///
117  X86Subtarget(const std::string &TT, const std::string &FS, bool is64Bit);
118
119  /// getStackAlignment - Returns the minimum alignment known to hold of the
120  /// stack frame on entry to the function and which must be maintained by every
121  /// function for this subtarget.
122  unsigned getStackAlignment() const { return stackAlignment; }
123
124  /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
125  /// that still makes it profitable to inline the call.
126  unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
127
128  /// ParseSubtargetFeatures - Parses features string setting specified
129  /// subtarget options.  Definition of function is auto generated by tblgen.
130  std::string ParseSubtargetFeatures(const std::string &FS,
131                                     const std::string &CPU);
132
133  /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
134  /// instruction.
135  void AutoDetectSubtargetFeatures();
136
137  bool is64Bit() const { return Is64Bit; }
138
139  PICStyles::Style getPICStyle() const { return PICStyle; }
140  void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
141
142  bool hasCMov() const { return HasCMov; }
143  bool hasMMX() const { return X86SSELevel >= MMX; }
144  bool hasSSE1() const { return X86SSELevel >= SSE1; }
145  bool hasSSE2() const { return X86SSELevel >= SSE2; }
146  bool hasSSE3() const { return X86SSELevel >= SSE3; }
147  bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
148  bool hasSSE41() const { return X86SSELevel >= SSE41; }
149  bool hasSSE42() const { return X86SSELevel >= SSE42; }
150  bool hasSSE4A() const { return HasSSE4A; }
151  bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
152  bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
153  bool hasAVX() const { return HasAVX; }
154  bool hasAES() const { return HasAES; }
155  bool hasCLMUL() const { return HasCLMUL; }
156  bool hasFMA3() const { return HasFMA3; }
157  bool hasFMA4() const { return HasFMA4; }
158  bool isBTMemSlow() const { return IsBTMemSlow; }
159  bool isUnalignedMemAccessFast() const { return IsUAMemFast; }
160  bool hasVectorUAMem() const { return HasVectorUAMem; }
161
162  bool isTargetDarwin() const { return TargetTriple.getOS() == Triple::Darwin; }
163
164  // ELF is a reasonably sane default and the only other X86 targets we
165  // support are Darwin and Windows. Just use "not those".
166  bool isTargetELF() const {
167    return !isTargetDarwin() && !isTargetWindows() && !isTargetCygMing();
168  }
169  bool isTargetLinux() const { return TargetTriple.getOS() == Triple::Linux; }
170
171  bool isTargetWindows() const { return TargetTriple.getOS() == Triple::Win32; }
172  bool isTargetMingw() const {
173    return TargetTriple.getOS() == Triple::MinGW32 ||
174           TargetTriple.getOS() == Triple::MinGW64; }
175  bool isTargetCygwin() const { return TargetTriple.getOS() == Triple::Cygwin; }
176  bool isTargetCygMing() const {
177    return isTargetMingw() || isTargetCygwin();
178  }
179
180  /// isTargetCOFF - Return true if this is any COFF/Windows target variant.
181  bool isTargetCOFF() const {
182    return isTargetMingw() || isTargetCygwin() || isTargetWindows();
183  }
184
185  bool isTargetWin64() const {
186    return Is64Bit && (isTargetMingw() || isTargetWindows());
187  }
188
189  std::string getDataLayout() const {
190    const char *p;
191    if (is64Bit())
192      p = "e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128-n8:16:32:64";
193    else if (isTargetDarwin())
194      p = "e-p:32:32-f64:32:64-i64:32:64-f80:128:128-n8:16:32";
195    else if (isTargetMingw() || isTargetWindows())
196      p = "e-p:32:32-f64:64:64-i64:64:64-f80:32:32-n8:16:32";
197    else
198      p = "e-p:32:32-f64:32:64-i64:32:64-f80:32:32-n8:16:32";
199
200    return std::string(p);
201  }
202
203  bool isPICStyleSet() const { return PICStyle != PICStyles::None; }
204  bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
205  bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
206
207  bool isPICStyleStubPIC() const {
208    return PICStyle == PICStyles::StubPIC;
209  }
210
211  bool isPICStyleStubNoDynamic() const {
212    return PICStyle == PICStyles::StubDynamicNoPIC;
213  }
214  bool isPICStyleStubAny() const {
215    return PICStyle == PICStyles::StubDynamicNoPIC ||
216           PICStyle == PICStyles::StubPIC; }
217
218  /// getDarwinVers - Return the darwin version number, 8 = Tiger, 9 = Leopard,
219  /// 10 = Snow Leopard, etc.
220  unsigned getDarwinVers() const {
221    if (isTargetDarwin()) return TargetTriple.getDarwinMajorNumber();
222    return 0;
223  }
224
225  /// ClassifyGlobalReference - Classify a global variable reference for the
226  /// current subtarget according to how we should reference it in a non-pcrel
227  /// context.
228  unsigned char ClassifyGlobalReference(const GlobalValue *GV,
229                                        const TargetMachine &TM)const;
230
231  /// ClassifyBlockAddressReference - Classify a blockaddress reference for the
232  /// current subtarget according to how we should reference it in a non-pcrel
233  /// context.
234  unsigned char ClassifyBlockAddressReference() const;
235
236  /// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
237  /// to immediate address.
238  bool IsLegalToCallImmediateAddr(const TargetMachine &TM) const;
239
240  /// This function returns the name of a function which has an interface
241  /// like the non-standard bzero function, if such a function exists on
242  /// the current subtarget and it is considered prefereable over
243  /// memset with zero passed as the second argument. Otherwise it
244  /// returns null.
245  const char *getBZeroEntry() const;
246
247  /// getSpecialAddressLatency - For targets where it is beneficial to
248  /// backschedule instructions that compute addresses, return a value
249  /// indicating the number of scheduling cycles of backscheduling that
250  /// should be attempted.
251  unsigned getSpecialAddressLatency() const;
252
253  /// IsCalleePop - Test whether a function should pop its own arguments.
254  bool IsCalleePop(bool isVarArg, CallingConv::ID CallConv) const;
255};
256
257} // End llvm namespace
258
259#endif
260