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1 //==-- llvm/Target/TargetSubtargetInfo.h - Target Information ----*- 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 describes the subtarget options of a Target machine.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_TARGET_TARGETSUBTARGETINFO_H
15 #define LLVM_TARGET_TARGETSUBTARGETINFO_H
16 
17 #include "llvm/MC/MCSubtargetInfo.h"
18 #include "llvm/Support/CodeGen.h"
19 
20 namespace llvm {
21 
22 class SDep;
23 class SUnit;
24 class TargetRegisterClass;
25 template <typename T> class SmallVectorImpl;
26 
27 //===----------------------------------------------------------------------===//
28 ///
29 /// TargetSubtargetInfo - Generic base class for all target subtargets.  All
30 /// Target-specific options that control code generation and printing should
31 /// be exposed through a TargetSubtargetInfo-derived class.
32 ///
33 class TargetSubtargetInfo : public MCSubtargetInfo {
34   TargetSubtargetInfo(const TargetSubtargetInfo&);   // DO NOT IMPLEMENT
35   void operator=(const TargetSubtargetInfo&);  // DO NOT IMPLEMENT
36 protected: // Can only create subclasses...
37   TargetSubtargetInfo();
38 public:
39   // AntiDepBreakMode - Type of anti-dependence breaking that should
40   // be performed before post-RA scheduling.
41   typedef enum { ANTIDEP_NONE, ANTIDEP_CRITICAL, ANTIDEP_ALL } AntiDepBreakMode;
42   typedef SmallVectorImpl<const TargetRegisterClass*> RegClassVector;
43 
44   virtual ~TargetSubtargetInfo();
45 
46   /// getSpecialAddressLatency - For targets where it is beneficial to
47   /// backschedule instructions that compute addresses, return a value
48   /// indicating the number of scheduling cycles of backscheduling that
49   /// should be attempted.
getSpecialAddressLatency()50   virtual unsigned getSpecialAddressLatency() const { return 0; }
51 
52   // enablePostRAScheduler - If the target can benefit from post-regalloc
53   // scheduling and the specified optimization level meets the requirement
54   // return true to enable post-register-allocation scheduling. In
55   // CriticalPathRCs return any register classes that should only be broken
56   // if on the critical path.
57   virtual bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
58                                      AntiDepBreakMode& Mode,
59                                      RegClassVector& CriticalPathRCs) const;
60   // adjustSchedDependency - Perform target specific adjustments to
61   // the latency of a schedule dependency.
adjustSchedDependency(SUnit * def,SUnit * use,SDep & dep)62   virtual void adjustSchedDependency(SUnit *def, SUnit *use,
63                                      SDep& dep) const { }
64 };
65 
66 } // End llvm namespace
67 
68 #endif
69