X86Subtarget.h revision e2de606e0b1c061ed88fa144d1ab503c52200f33 
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 GlobalValue;
22class TargetMachine;
23
24/// PICStyles - The X86 backend supports a number of different styles of PIC.
25///
26namespace PICStyles {
27enum Style {
28  StubPIC,          // Used on i386-darwin in -fPIC mode.
29  StubDynamicNoPIC, // Used on i386-darwin in -mdynamic-no-pic mode.
30  GOT,              // Used on many 32-bit unices in -fPIC mode.
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 {
37protected:
38  enum X86SSEEnum {
39    NoMMXSSE, MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42
40  };
41
42  enum X863DNowEnum {
43    NoThreeDNow, ThreeDNow, ThreeDNowA
44  };
45
46  /// PICStyle - Which PIC style to use
47  ///
48  PICStyles::Style PICStyle;
49
50  /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
51  /// none supported.
52  X86SSEEnum X86SSELevel;
53
54  /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
55  ///
56  X863DNowEnum X863DNowLevel;
57
58  /// HasCMov - True if this processor has conditional move instructions
59  /// (generally pentium pro+).
60  bool HasCMov;
61
62  /// HasX86_64 - True if the processor supports X86-64 instructions.
63  ///
64  bool HasX86_64;
65
66  /// HasSSE4A - True if the processor supports SSE4A instructions.
67  bool HasSSE4A;
68
69  /// HasAVX - Target has AVX instructions
70  bool HasAVX;
71
72  /// HasFMA3 - Target has 3-operand fused multiply-add
73  bool HasFMA3;
74
75  /// HasFMA4 - Target has 4-operand fused multiply-add
76  bool HasFMA4;
77
78  /// IsBTMemSlow - True if BT (bit test) of memory instructions are slow.
79  bool IsBTMemSlow;
80
81  /// HasVectorUAMem - True if SIMD operations can have unaligned memory operands.
82  ///                  This may require setting a feature bit in the processor.
83  bool HasVectorUAMem;
84
85  /// DarwinVers - Nonzero if this is a darwin platform: the numeric
86  /// version of the platform, e.g. 8 = 10.4 (Tiger), 9 = 10.5 (Leopard), etc.
87  unsigned char DarwinVers; // Is any darwin-x86 platform.
88
89  /// stackAlignment - The minimum alignment known to hold of the stack frame on
90  /// entry to the function and which must be maintained by every function.
91  unsigned stackAlignment;
92
93  /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
94  ///
95  unsigned MaxInlineSizeThreshold;
96
97private:
98  /// Is64Bit - True if the processor supports 64-bit instructions and
99  /// pointer size is 64 bit.
100  bool Is64Bit;
101
102public:
103  enum {
104    isELF, isCygwin, isDarwin, isWindows, isMingw
105  } TargetType;
106
107  /// This constructor initializes the data members to match that
108  /// of the specified triple.
109  ///
110  X86Subtarget(const std::string &TT, const std::string &FS, bool is64Bit);
111
112  /// getStackAlignment - Returns the minimum alignment known to hold of the
113  /// stack frame on entry to the function and which must be maintained by every
114  /// function for this subtarget.
115  unsigned getStackAlignment() const { return stackAlignment; }
116
117  /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
118  /// that still makes it profitable to inline the call.
119  unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
120
121  /// ParseSubtargetFeatures - Parses features string setting specified
122  /// subtarget options.  Definition of function is auto generated by tblgen.
123  std::string ParseSubtargetFeatures(const std::string &FS,
124                                     const std::string &CPU);
125
126  /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
127  /// instruction.
128  void AutoDetectSubtargetFeatures();
129
130  bool is64Bit() const { return Is64Bit; }
131
132  PICStyles::Style getPICStyle() const { return PICStyle; }
133  void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
134
135  bool hasMMX() const { return X86SSELevel >= MMX; }
136  bool hasSSE1() const { return X86SSELevel >= SSE1; }
137  bool hasSSE2() const { return X86SSELevel >= SSE2; }
138  bool hasSSE3() const { return X86SSELevel >= SSE3; }
139  bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
140  bool hasSSE41() const { return X86SSELevel >= SSE41; }
141  bool hasSSE42() const { return X86SSELevel >= SSE42; }
142  bool hasSSE4A() const { return HasSSE4A; }
143  bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
144  bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
145  bool hasAVX() const { return HasAVX; }
146  bool hasFMA3() const { return HasFMA3; }
147  bool hasFMA4() const { return HasFMA4; }
148  bool isBTMemSlow() const { return IsBTMemSlow; }
149  bool hasVectorUAMem() const { return HasVectorUAMem; }
150
151  bool isTargetDarwin() const { return TargetType == isDarwin; }
152  bool isTargetELF() const { return TargetType == isELF; }
153
154  bool isTargetWindows() const { return TargetType == isWindows; }
155  bool isTargetMingw() const { return TargetType == isMingw; }
156  bool isTargetCygwin() const { return TargetType == isCygwin; }
157  bool isTargetCygMing() const {
158    return TargetType == isMingw || TargetType == isCygwin;
159  }
160
161  /// isTargetCOFF - Return true if this is any COFF/Windows target variant.
162  bool isTargetCOFF() const {
163    return TargetType == isMingw || TargetType == isCygwin ||
164           TargetType == isWindows;
165  }
166
167  bool isTargetWin64() const {
168    return Is64Bit && (TargetType == isMingw || TargetType == isWindows);
169  }
170
171  std::string getDataLayout() const {
172    const char *p;
173    if (is64Bit())
174      p = "e-p:64:64-s:64-f64:64:64-i64:64:64-f80:128:128-n8:16:32:64";
175    else if (isTargetDarwin())
176      p = "e-p:32:32-f64:32:64-i64:32:64-f80:128:128-n8:16:32";
177    else if (isTargetMing() || isTargetWindows())
178      p = "e-p:32:32-f64:64:64-i64:64:64-f80:128:128-n8:16:32";
179    else
180      p = "e-p:32:32-f64:32:64-i64:32:64-f80:32:32-n8:16:32";
181
182    return std::string(p);
183  }
184
185  bool isPICStyleSet() const { return PICStyle != PICStyles::None; }
186  bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
187  bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
188
189  bool isPICStyleStubPIC() const {
190    return PICStyle == PICStyles::StubPIC;
191  }
192
193  bool isPICStyleStubNoDynamic() const {
194    return PICStyle == PICStyles::StubDynamicNoPIC;
195  }
196  bool isPICStyleStubAny() const {
197    return PICStyle == PICStyles::StubDynamicNoPIC ||
198           PICStyle == PICStyles::StubPIC; }
199
200  /// getDarwinVers - Return the darwin version number, 8 = Tiger, 9 = Leopard,
201  /// 10 = Snow Leopard, etc.
202  unsigned getDarwinVers() const { return DarwinVers; }
203
204  /// ClassifyGlobalReference - Classify a global variable reference for the
205  /// current subtarget according to how we should reference it in a non-pcrel
206  /// context.
207  unsigned char ClassifyGlobalReference(const GlobalValue *GV,
208                                        const TargetMachine &TM)const;
209
210  /// ClassifyBlockAddressReference - Classify a blockaddress reference for the
211  /// current subtarget according to how we should reference it in a non-pcrel
212  /// context.
213  unsigned char ClassifyBlockAddressReference() const;
214
215  /// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
216  /// to immediate address.
217  bool IsLegalToCallImmediateAddr(const TargetMachine &TM) const;
218
219  /// This function returns the name of a function which has an interface
220  /// like the non-standard bzero function, if such a function exists on
221  /// the current subtarget and it is considered prefereable over
222  /// memset with zero passed as the second argument. Otherwise it
223  /// returns null.
224  const char *getBZeroEntry() const;
225
226  /// getSpecialAddressLatency - For targets where it is beneficial to
227  /// backschedule instructions that compute addresses, return a value
228  /// indicating the number of scheduling cycles of backscheduling that
229  /// should be attempted.
230  unsigned getSpecialAddressLatency() const;
231
232  /// enablePostRAScheduler - X86 target is enabling post-alloc scheduling
233  /// at 'More' optimization level.
234  bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
235                             TargetSubtarget::AntiDepBreakMode& Mode,
236                             RegClassVector& CriticalPathRCs) const;
237};
238
239} // End llvm namespace
240
241#endif
242