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 TargetSubtargetInfo.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef X86SUBTARGET_H
15 #define X86SUBTARGET_H
16 
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/Target/TargetSubtargetInfo.h"
19 #include "llvm/CallingConv.h"
20 #include <string>
21 
22 #define GET_SUBTARGETINFO_HEADER
23 #include "X86GenSubtargetInfo.inc"
24 
25 namespace llvm {
26 class GlobalValue;
27 class StringRef;
28 class TargetMachine;
29 
30 /// PICStyles - The X86 backend supports a number of different styles of PIC.
31 ///
32 namespace PICStyles {
33 enum Style {
34   StubPIC,          // Used on i386-darwin in -fPIC mode.
35   StubDynamicNoPIC, // Used on i386-darwin in -mdynamic-no-pic mode.
36   GOT,              // Used on many 32-bit unices in -fPIC mode.
37   RIPRel,           // Used on X86-64 when not in -static mode.
38   None              // Set when in -static mode (not PIC or DynamicNoPIC mode).
39 };
40 }
41 
42 class X86Subtarget : public X86GenSubtargetInfo {
43 protected:
44   enum X86SSEEnum {
45     NoMMXSSE, MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42
46   };
47 
48   enum X863DNowEnum {
49     NoThreeDNow, ThreeDNow, ThreeDNowA
50   };
51 
52   /// PICStyle - Which PIC style to use
53   ///
54   PICStyles::Style PICStyle;
55 
56   /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
57   /// none supported.
58   X86SSEEnum X86SSELevel;
59 
60   /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
61   ///
62   X863DNowEnum X863DNowLevel;
63 
64   /// HasCMov - True if this processor has conditional move instructions
65   /// (generally pentium pro+).
66   bool HasCMov;
67 
68   /// HasX86_64 - True if the processor supports X86-64 instructions.
69   ///
70   bool HasX86_64;
71 
72   /// HasPOPCNT - True if the processor supports POPCNT.
73   bool HasPOPCNT;
74 
75   /// HasSSE4A - True if the processor supports SSE4A instructions.
76   bool HasSSE4A;
77 
78   /// HasAVX - Target has AVX instructions
79   bool HasAVX;
80 
81   /// HasAES - Target has AES instructions
82   bool HasAES;
83 
84   /// HasCLMUL - Target has carry-less multiplication
85   bool HasCLMUL;
86 
87   /// HasFMA3 - Target has 3-operand fused multiply-add
88   bool HasFMA3;
89 
90   /// HasFMA4 - Target has 4-operand fused multiply-add
91   bool HasFMA4;
92 
93   /// HasMOVBE - True if the processor has the MOVBE instruction.
94   bool HasMOVBE;
95 
96   /// HasRDRAND - True if the processor has the RDRAND instruction.
97   bool HasRDRAND;
98 
99   /// HasF16C - Processor has 16-bit floating point conversion instructions.
100   bool HasF16C;
101 
102   /// HasLZCNT - Processor has LZCNT instruction.
103   bool HasLZCNT;
104 
105   /// HasBMI - Processor has BMI1 instructions.
106   bool HasBMI;
107 
108   /// IsBTMemSlow - True if BT (bit test) of memory instructions are slow.
109   bool IsBTMemSlow;
110 
111   /// IsUAMemFast - True if unaligned memory access is fast.
112   bool IsUAMemFast;
113 
114   /// HasVectorUAMem - True if SIMD operations can have unaligned memory
115   /// operands. This may require setting a feature bit in the processor.
116   bool HasVectorUAMem;
117 
118   /// HasCmpxchg16b - True if this processor has the CMPXCHG16B instruction;
119   /// this is true for most x86-64 chips, but not the first AMD chips.
120   bool HasCmpxchg16b;
121 
122   /// stackAlignment - The minimum alignment known to hold of the stack frame on
123   /// entry to the function and which must be maintained by every function.
124   unsigned stackAlignment;
125 
126   /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
127   ///
128   unsigned MaxInlineSizeThreshold;
129 
130   /// TargetTriple - What processor and OS we're targeting.
131   Triple TargetTriple;
132 
133 private:
134   /// In64BitMode - True if compiling for 64-bit, false for 32-bit.
135   bool In64BitMode;
136 
137   /// InNaClMode - True if compiling for Native Client target.
138   bool InNaClMode;
139 
140 public:
141 
142   /// This constructor initializes the data members to match that
143   /// of the specified triple.
144   ///
145   X86Subtarget(const std::string &TT, const std::string &CPU,
146                const std::string &FS,
147                unsigned StackAlignOverride, bool is64Bit);
148 
149   /// getStackAlignment - Returns the minimum alignment known to hold of the
150   /// stack frame on entry to the function and which must be maintained by every
151   /// function for this subtarget.
getStackAlignment()152   unsigned getStackAlignment() const { return stackAlignment; }
153 
154   /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
155   /// that still makes it profitable to inline the call.
getMaxInlineSizeThreshold()156   unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
157 
158   /// ParseSubtargetFeatures - Parses features string setting specified
159   /// subtarget options.  Definition of function is auto generated by tblgen.
160   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
161 
162   /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
163   /// instruction.
164   void AutoDetectSubtargetFeatures();
165 
is64Bit()166   bool is64Bit() const { return In64BitMode; }
167 
getPICStyle()168   PICStyles::Style getPICStyle() const { return PICStyle; }
setPICStyle(PICStyles::Style Style)169   void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
170 
hasCMov()171   bool hasCMov() const { return HasCMov; }
hasMMX()172   bool hasMMX() const { return X86SSELevel >= MMX; }
hasSSE1()173   bool hasSSE1() const { return X86SSELevel >= SSE1; }
hasSSE2()174   bool hasSSE2() const { return X86SSELevel >= SSE2; }
hasSSE3()175   bool hasSSE3() const { return X86SSELevel >= SSE3; }
hasSSSE3()176   bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
hasSSE41()177   bool hasSSE41() const { return X86SSELevel >= SSE41; }
hasSSE42()178   bool hasSSE42() const { return X86SSELevel >= SSE42; }
hasSSE4A()179   bool hasSSE4A() const { return HasSSE4A; }
has3DNow()180   bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
has3DNowA()181   bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
hasPOPCNT()182   bool hasPOPCNT() const { return HasPOPCNT; }
hasAVX()183   bool hasAVX() const { return HasAVX; }
hasXMM()184   bool hasXMM() const { return hasSSE1() || hasAVX(); }
hasXMMInt()185   bool hasXMMInt() const { return hasSSE2() || hasAVX(); }
hasAES()186   bool hasAES() const { return HasAES; }
hasCLMUL()187   bool hasCLMUL() const { return HasCLMUL; }
hasFMA3()188   bool hasFMA3() const { return HasFMA3; }
hasFMA4()189   bool hasFMA4() const { return HasFMA4; }
hasMOVBE()190   bool hasMOVBE() const { return HasMOVBE; }
hasRDRAND()191   bool hasRDRAND() const { return HasRDRAND; }
hasF16C()192   bool hasF16C() const { return HasF16C; }
hasLZCNT()193   bool hasLZCNT() const { return HasLZCNT; }
hasBMI()194   bool hasBMI() const { return HasBMI; }
isBTMemSlow()195   bool isBTMemSlow() const { return IsBTMemSlow; }
isUnalignedMemAccessFast()196   bool isUnalignedMemAccessFast() const { return IsUAMemFast; }
hasVectorUAMem()197   bool hasVectorUAMem() const { return HasVectorUAMem; }
hasCmpxchg16b()198   bool hasCmpxchg16b() const { return HasCmpxchg16b; }
199 
getTargetTriple()200   const Triple &getTargetTriple() const { return TargetTriple; }
201 
isTargetDarwin()202   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
isTargetFreeBSD()203   bool isTargetFreeBSD() const {
204     return TargetTriple.getOS() == Triple::FreeBSD;
205   }
isTargetSolaris()206   bool isTargetSolaris() const {
207     return TargetTriple.getOS() == Triple::Solaris;
208   }
209 
210   // ELF is a reasonably sane default and the only other X86 targets we
211   // support are Darwin and Windows. Just use "not those".
isTargetELF()212   bool isTargetELF() const {
213     return !isTargetDarwin() && !isTargetWindows() && !isTargetCygMing();
214   }
isTargetLinux()215   bool isTargetLinux() const { return TargetTriple.getOS() == Triple::Linux; }
isTargetNaCl()216   bool isTargetNaCl() const {
217     return TargetTriple.getOS() == Triple::NativeClient;
218   }
isTargetNaCl32()219   bool isTargetNaCl32() const { return isTargetNaCl() && !is64Bit(); }
isTargetNaCl64()220   bool isTargetNaCl64() const { return isTargetNaCl() && is64Bit(); }
221 
isTargetWindows()222   bool isTargetWindows() const { return TargetTriple.getOS() == Triple::Win32; }
isTargetMingw()223   bool isTargetMingw() const { return TargetTriple.getOS() == Triple::MinGW32; }
isTargetCygwin()224   bool isTargetCygwin() const { return TargetTriple.getOS() == Triple::Cygwin; }
isTargetCygMing()225   bool isTargetCygMing() const {
226     return isTargetMingw() || isTargetCygwin();
227   }
228 
229   /// isTargetCOFF - Return true if this is any COFF/Windows target variant.
isTargetCOFF()230   bool isTargetCOFF() const {
231     return isTargetMingw() || isTargetCygwin() || isTargetWindows();
232   }
233 
isTargetWin64()234   bool isTargetWin64() const {
235     // FIXME: x86_64-cygwin has not been released yet.
236     return In64BitMode && (isTargetCygMing() || isTargetWindows());
237   }
238 
isTargetEnvMacho()239   bool isTargetEnvMacho() const {
240     return isTargetDarwin() || (TargetTriple.getEnvironment() == Triple::MachO);
241   }
242 
isTargetWin32()243   bool isTargetWin32() const {
244     return !In64BitMode && (isTargetMingw() || isTargetWindows());
245   }
246 
isPICStyleSet()247   bool isPICStyleSet() const { return PICStyle != PICStyles::None; }
isPICStyleGOT()248   bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
isPICStyleRIPRel()249   bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
250 
isPICStyleStubPIC()251   bool isPICStyleStubPIC() const {
252     return PICStyle == PICStyles::StubPIC;
253   }
254 
isPICStyleStubNoDynamic()255   bool isPICStyleStubNoDynamic() const {
256     return PICStyle == PICStyles::StubDynamicNoPIC;
257   }
isPICStyleStubAny()258   bool isPICStyleStubAny() const {
259     return PICStyle == PICStyles::StubDynamicNoPIC ||
260            PICStyle == PICStyles::StubPIC; }
261 
262   /// ClassifyGlobalReference - Classify a global variable reference for the
263   /// current subtarget according to how we should reference it in a non-pcrel
264   /// context.
265   unsigned char ClassifyGlobalReference(const GlobalValue *GV,
266                                         const TargetMachine &TM)const;
267 
268   /// ClassifyBlockAddressReference - Classify a blockaddress reference for the
269   /// current subtarget according to how we should reference it in a non-pcrel
270   /// context.
271   unsigned char ClassifyBlockAddressReference() const;
272 
273   /// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
274   /// to immediate address.
275   bool IsLegalToCallImmediateAddr(const TargetMachine &TM) const;
276 
277   /// This function returns the name of a function which has an interface
278   /// like the non-standard bzero function, if such a function exists on
279   /// the current subtarget and it is considered prefereable over
280   /// memset with zero passed as the second argument. Otherwise it
281   /// returns null.
282   const char *getBZeroEntry() const;
283 
284   /// getSpecialAddressLatency - For targets where it is beneficial to
285   /// backschedule instructions that compute addresses, return a value
286   /// indicating the number of scheduling cycles of backscheduling that
287   /// should be attempted.
288   unsigned getSpecialAddressLatency() const;
289 };
290 
291 } // End llvm namespace
292 
293 #endif
294