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 GlobalValue;
43 class TargetMachine;
44 
45 class PPCSubtarget : public TargetSubtarget {
46 public:
47   enum AsmWriterFlavorTy {
48     OldMnemonic, NewMnemonic, Unset
49   };
50 protected:
51   /// stackAlignment - The minimum alignment known to hold of the stack frame on
52   /// entry to the function and which must be maintained by every function.
53   unsigned StackAlignment;
54 
55   /// Selected instruction itineraries (one entry per itinerary class.)
56   InstrItineraryData InstrItins;
57 
58   /// Which cpu directive was used.
59   unsigned DarwinDirective;
60 
61   /// AsmFlavor - Which PPC asm dialect to use.
62   AsmWriterFlavorTy AsmFlavor;
63 
64   /// Used by the ISel to turn in optimizations for POWER4-derived architectures
65   bool IsGigaProcessor;
66   bool Has64BitSupport;
67   bool Use64BitRegs;
68   bool IsPPC64;
69   bool HasAltivec;
70   bool HasFSQRT;
71   bool HasSTFIWX;
72   bool HasLazyResolverStubs;
73 
74   /// DarwinVers - Nonzero if this is a darwin platform.  Otherwise, the numeric
75   /// version of the platform, e.g. 8 = 10.4 (Tiger), 9 = 10.5 (Leopard), etc.
76   unsigned char DarwinVers; // Is any darwin-ppc platform.
77 public:
78   /// This constructor initializes the data members to match that
79   /// of the specified triple.
80   ///
81   PPCSubtarget(const std::string &TT, const std::string &FS, bool is64Bit);
82 
83   /// ParseSubtargetFeatures - Parses features string setting specified
84   /// subtarget options.  Definition of function is auto generated by tblgen.
85   std::string ParseSubtargetFeatures(const std::string &FS,
86                                      const std::string &CPU);
87 
88 
89   /// SetJITMode - This is called to inform the subtarget info that we are
90   /// producing code for the JIT.
91   void SetJITMode();
92 
93   /// getStackAlignment - Returns the minimum alignment known to hold of the
94   /// stack frame on entry to the function and which must be maintained by every
95   /// function for this subtarget.
96   unsigned getStackAlignment() const { return StackAlignment; }
97 
98   /// getDarwinDirective - Returns the -m directive specified for the cpu.
99   ///
100   unsigned getDarwinDirective() const { return DarwinDirective; }
101 
102   /// getInstrItins - Return the instruction itineraies based on subtarget
103   /// selection.
104   const InstrItineraryData &getInstrItineraryData() const { return InstrItins; }
105 
106   /// getTargetDataString - Return the pointer size and type alignment
107   /// properties of this subtarget.
108   const char *getTargetDataString() const {
109     // Note, the alignment values for f64 and i64 on ppc64 in Darwin
110     // documentation are wrong; these are correct (i.e. "what gcc does").
111     return isPPC64() ? "E-p:64:64-f64:64:64-i64:64:64-f128:64:128"
112                      : "E-p:32:32-f64:32:64-i64:32:64-f128:64:128";
113   }
114 
115   /// isPPC64 - Return true if we are generating code for 64-bit pointer mode.
116   ///
117   bool isPPC64() const { return IsPPC64; }
118 
119   /// has64BitSupport - Return true if the selected CPU supports 64-bit
120   /// instructions, regardless of whether we are in 32-bit or 64-bit mode.
121   bool has64BitSupport() const { return Has64BitSupport; }
122 
123   /// use64BitRegs - Return true if in 64-bit mode or if we should use 64-bit
124   /// registers in 32-bit mode when possible.  This can only true if
125   /// has64BitSupport() returns true.
126   bool use64BitRegs() const { return Use64BitRegs; }
127 
128   /// hasLazyResolverStub - Return true if accesses to the specified global have
129   /// to go through a dyld lazy resolution stub.  This means that an extra load
130   /// is required to get the address of the global.
131   bool hasLazyResolverStub(const GlobalValue *GV,
132                            const TargetMachine &TM) const;
133 
134   // Specific obvious features.
135   bool hasFSQRT() const { return HasFSQRT; }
136   bool hasSTFIWX() const { return HasSTFIWX; }
137   bool hasAltivec() const { return HasAltivec; }
138   bool isGigaProcessor() const { return IsGigaProcessor; }
139 
140   /// isDarwin - True if this is any darwin platform.
141   bool isDarwin() const { return DarwinVers != 0; }
142   /// isDarwin - True if this is darwin9 (leopard, 10.5) or above.
143   bool isDarwin9() const { return DarwinVers >= 9; }
144 
145   /// getDarwinVers - Return the darwin version number, 8 = tiger, 9 = leopard.
146   unsigned getDarwinVers() const { return DarwinVers; }
147 
148   bool isDarwinABI() const { return isDarwin() || IsPPC64; }
149   bool isSVR4ABI() const { return !isDarwin() && !IsPPC64; }
150 
151   unsigned getAsmFlavor() const {
152     return AsmFlavor != Unset ? unsigned(AsmFlavor) : 0;
153   }
154 };
155 } // End llvm namespace
156 
157 #endif
158