1 //===-- llvm/Target/SubtargetFeature.h - CPU characteristics ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines and manages user or tool specified CPU characteristics.
11 // The intent is to be able to package specific features that should or should
12 // not be used on a specific target processor. A tool, such as llc, could, as
13 // as example, gather chip info from the command line, a long with features
14 // that should be used on that chip.
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_TARGET_SUBTARGETFEATURE_H
19 #define LLVM_TARGET_SUBTARGETFEATURE_H
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/System/DataTypes.h"
30 //===----------------------------------------------------------------------===//
32 /// SubtargetFeatureKV - Used to provide key value pairs for feature and
35 struct SubtargetFeatureKV {
36 const char *Key; // K-V key string
37 const char *Desc; // Help descriptor
38 uint32_t Value; // K-V integer value
39 uint32_t Implies; // K-V bit mask
41 // Compare routine for std binary search
42 bool operator<(const SubtargetFeatureKV &S) const {
43 return strcmp(Key, S.Key) < 0;
47 //===----------------------------------------------------------------------===//
49 /// SubtargetInfoKV - Used to provide key value pairs for CPU and arbitrary
52 struct SubtargetInfoKV {
53 const char *Key; // K-V key string
54 void *Value; // K-V pointer value
56 // Compare routine for std binary search
57 bool operator<(const SubtargetInfoKV &S) const {
58 return strcmp(Key, S.Key) < 0;
62 //===----------------------------------------------------------------------===//
64 /// SubtargetFeatures - Manages the enabling and disabling of subtarget
65 /// specific features. Features are encoded as a string of the form
66 /// "cpu,+attr1,+attr2,-attr3,...,+attrN"
67 /// A comma separates each feature from the next (all lowercase.)
68 /// The first feature is always the CPU subtype (eg. pentiumm). If the CPU
69 /// value is "generic" then the CPU subtype should be generic for the target.
70 /// Each of the remaining features is prefixed with + or - indicating whether
71 /// that feature should be enabled or disabled contrary to the cpu
75 class SubtargetFeatures {
76 std::vector<std::string> Features; // Subtarget features as a vector
78 explicit SubtargetFeatures(const std::string &Initial = std::string());
80 /// Features string accessors.
81 std::string getString() const;
82 void setString(const std::string &Initial);
84 /// Set the CPU string. Replaces previous setting. Setting to "" clears CPU.
85 void setCPU(const std::string &String);
87 /// Setting CPU string only if no string is set.
88 void setCPUIfNone(const std::string &String);
90 /// Returns current CPU string.
91 const std::string & getCPU() const;
94 void AddFeature(const std::string &String, bool IsEnabled = true);
97 uint32_t getBits(const SubtargetFeatureKV *CPUTable,
99 const SubtargetFeatureKV *FeatureTable,
100 size_t FeatureTableSize);
103 void *getInfo(const SubtargetInfoKV *Table, size_t TableSize);
105 /// Print feature string.
106 void print(raw_ostream &OS) const;
108 // Dump feature info.
111 /// Retrieve a formatted string of the default features for the specified
113 void getDefaultSubtargetFeatures(const std::string &CPU,
114 const Triple& Triple);
117 } // End namespace llvm