1//===--------------------- llvm/Target/TargetRecip.h ------------*- 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 class is used to customize machine-specific reciprocal estimate code
11// generation in a target-independent way.
12// If a target does not support operations in this specification, then code
13// generation will default to using supported operations.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_TARGET_TARGETRECIP_H
18#define LLVM_TARGET_TARGETRECIP_H
19
20#include "llvm/ADT/StringRef.h"
21#include <cstdint>
22#include <map>
23#include <string>
24#include <vector>
25
26namespace llvm {
27
28struct TargetRecip {
29public:
30  TargetRecip();
31
32  /// Initialize all or part of the operations from command-line options or
33  /// a front end.
34  TargetRecip(const std::vector<std::string> &Args);
35
36  /// Set whether a particular reciprocal operation is enabled and how many
37  /// refinement steps are needed when using it. Use "all" to set enablement
38  /// and refinement steps for all operations.
39  void setDefaults(StringRef Key, bool Enable, unsigned RefSteps);
40
41  /// Return true if the reciprocal operation has been enabled by default or
42  /// from the command-line. Return false if the operation has been disabled
43  /// by default or from the command-line.
44  bool isEnabled(StringRef Key) const;
45
46  /// Return the number of iterations necessary to refine the
47  /// the result of a machine instruction for the given reciprocal operation.
48  unsigned getRefinementSteps(StringRef Key) const;
49
50  bool operator==(const TargetRecip &Other) const;
51
52private:
53  enum {
54    Uninitialized = -1
55  };
56
57  struct RecipParams {
58    int8_t Enabled;
59    int8_t RefinementSteps;
60
61    RecipParams() : Enabled(Uninitialized), RefinementSteps(Uninitialized) {}
62  };
63
64  std::map<StringRef, RecipParams> RecipMap;
65  typedef std::map<StringRef, RecipParams>::iterator RecipIter;
66  typedef std::map<StringRef, RecipParams>::const_iterator ConstRecipIter;
67
68  bool parseGlobalParams(const std::string &Arg);
69  void parseIndividualParams(const std::vector<std::string> &Args);
70};
71
72} // end namespace llvm
73
74#endif // LLVM_TARGET_TARGETRECIP_H
75