1 //=====-- PPCSubtarget.h - Define Subtarget for the PPC -------*- 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 PowerPC specific subclass of TargetSubtarget.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef POWERPCSUBTARGET_H
15 #define POWERPCSUBTARGET_H
16 
17 #include "llvm/Target/TargetInstrItineraries.h"
18 #include "llvm/Target/TargetSubtarget.h"
19 
20 #include <string>
21 
22 // GCC #defines PPC on Linux but we use it as our namespace name
23 #undef PPC
24 
25 namespace llvm {
26 
27 namespace PPC {
28   // -m directive values.
29   enum {
30     DIR_NONE,
31     DIR_32,
32     DIR_601,
33     DIR_602,
34     DIR_603,
35     DIR_7400,
36     DIR_750,
37     DIR_970,
38     DIR_64
39   };
40 }
41 
42 class Module;
43 class GlobalValue;
44 class TargetMachine;
45 
46 class PPCSubtarget : public TargetSubtarget {
47 public:
48   enum AsmWriterFlavorTy {
49     OldMnemonic, NewMnemonic, Unset
50   };
51 protected:
52   const TargetMachine &TM;
53 
54   /// stackAlignment - The minimum alignment known to hold of the stack frame on
55   /// entry to the function and which must be maintained by every function.
56   unsigned StackAlignment;
57 
58   /// Selected instruction itineraries (one entry per itinerary class.)
59   InstrItineraryData InstrItins;
60 
61   /// Which cpu directive was used.
62   unsigned DarwinDirective;
63 
64   /// AsmFlavor - Which PPC asm dialect to use.
65   AsmWriterFlavorTy AsmFlavor;
66 
67   /// Used by the ISel to turn in optimizations for POWER4-derived architectures
68   bool IsGigaProcessor;
69   bool Has64BitSupport;
70   bool Use64BitRegs;
71   bool IsPPC64;
72   bool HasAltivec;
73   bool HasFSQRT;
74   bool HasSTFIWX;
75   bool HasLazyResolverStubs;
76 
77   /// DarwinVers - Nonzero if this is a darwin platform.  Otherwise, the numeric
78   /// version of the platform, e.g. 8 = 10.4 (Tiger), 9 = 10.5 (Leopard), etc.
79   unsigned char DarwinVers; // Is any darwin-ppc platform.
80 public:
81   /// This constructor initializes the data members to match that
82   /// of the specified module.
83   ///
84   PPCSubtarget(const TargetMachine &TM, const Module &M,
85                const std::string &FS, bool is64Bit);
86 
87   /// ParseSubtargetFeatures - Parses features string setting specified
88   /// subtarget options.  Definition of function is auto generated by tblgen.
89   std::string ParseSubtargetFeatures(const std::string &FS,
90                                      const std::string &CPU);
91 
92 
93   /// SetJITMode - This is called to inform the subtarget info that we are
94   /// producing code for the JIT.
95   void SetJITMode();
96 
97   /// getStackAlignment - Returns the minimum alignment known to hold of the
98   /// stack frame on entry to the function and which must be maintained by every
99   /// function for this subtarget.
100   unsigned getStackAlignment() const { return StackAlignment; }
101 
102   /// getDarwinDirective - Returns the -m directive specified for the cpu.
103   ///
104   unsigned getDarwinDirective() const { return DarwinDirective; }
105 
106   /// getInstrItins - Return the instruction itineraies based on subtarget
107   /// selection.
108   const InstrItineraryData &getInstrItineraryData() const { return InstrItins; }
109 
110   /// getTargetDataString - Return the pointer size and type alignment
111   /// properties of this subtarget.
112   const char *getTargetDataString() const {
113     // Note, the alignment values for f64 and i64 on ppc64 in Darwin
114     // documentation are wrong; these are correct (i.e. "what gcc does").
115     return isPPC64() ? "E-p:64:64-f64:64:64-i64:64:64-f128:64:128"
116                      : "E-p:32:32-f64:32:64-i64:32:64-f128:64:128";
117   }
118 
119   /// isPPC64 - Return true if we are generating code for 64-bit pointer mode.
120   ///
121   bool isPPC64() const { return IsPPC64; }
122 
123   /// has64BitSupport - Return true if the selected CPU supports 64-bit
124   /// instructions, regardless of whether we are in 32-bit or 64-bit mode.
125   bool has64BitSupport() const { return Has64BitSupport; }
126 
127   /// use64BitRegs - Return true if in 64-bit mode or if we should use 64-bit
128   /// registers in 32-bit mode when possible.  This can only true if
129   /// has64BitSupport() returns true.
130   bool use64BitRegs() const { return Use64BitRegs; }
131 
132   /// hasLazyResolverStub - Return true if accesses to the specified global have
133   /// to go through a dyld lazy resolution stub.  This means that an extra load
134   /// is required to get the address of the global.
135   bool hasLazyResolverStub(const GlobalValue *GV) const;
136 
137   // Specific obvious features.
138   bool hasFSQRT() const { return HasFSQRT; }
139   bool hasSTFIWX() const { return HasSTFIWX; }
140   bool hasAltivec() const { return HasAltivec; }
141   bool isGigaProcessor() const { return IsGigaProcessor; }
142 
143   /// isDarwin - True if this is any darwin platform.
144   bool isDarwin() const { return DarwinVers != 0; }
145   /// isDarwin - True if this is darwin9 (leopard, 10.5) or above.
146   bool isDarwin9() const { return DarwinVers >= 9; }
147 
148   /// getDarwinVers - Return the darwin version number, 8 = tiger, 9 = leopard.
149   unsigned getDarwinVers() const { return DarwinVers; }
150 
151   bool isMachoABI() const { return isDarwin() || IsPPC64; }
152   bool isELF32_ABI() const { return !isDarwin() && !IsPPC64; }
153 
154   unsigned getAsmFlavor() const {
155     return AsmFlavor != Unset ? unsigned(AsmFlavor) : 0;
156   }
157 };
158 } // End llvm namespace
159 
160 #endif
161