1 //===-- llvm/MC/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_MC_SUBTARGETFEATURE_H
19 #define LLVM_MC_SUBTARGETFEATURE_H
21 #include "llvm/ADT/ArrayRef.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/Support/DataTypes.h"
29 //===----------------------------------------------------------------------===//
31 /// SubtargetFeatureKV - Used to provide key value pairs for feature and
34 struct SubtargetFeatureKV {
35 const char *Key; // K-V key string
36 const char *Desc; // Help descriptor
37 uint64_t Value; // K-V integer value
38 uint64_t Implies; // K-V bit mask
40 // Compare routine for std::lower_bound
41 bool operator<(StringRef S) const {
42 return StringRef(Key) < S;
46 //===----------------------------------------------------------------------===//
48 /// SubtargetInfoKV - Used to provide key value pairs for CPU and arbitrary
51 struct SubtargetInfoKV {
52 const char *Key; // K-V key string
53 const void *Value; // K-V pointer value
55 // Compare routine for std::lower_bound
56 bool operator<(StringRef S) const {
57 return StringRef(Key) < S;
61 //===----------------------------------------------------------------------===//
63 /// SubtargetFeatures - Manages the enabling and disabling of subtarget
64 /// specific features. Features are encoded as a string of the form
65 /// "+attr1,+attr2,-attr3,...,+attrN"
66 /// A comma separates each feature from the next (all lowercase.)
67 /// Each of the remaining features is prefixed with + or - indicating whether
68 /// that feature should be enabled or disabled contrary to the cpu
72 class SubtargetFeatures {
73 std::vector<std::string> Features; // Subtarget features as a vector
75 explicit SubtargetFeatures(const StringRef Initial = "");
77 /// Features string accessors.
78 std::string getString() const;
81 void AddFeature(const StringRef String);
83 /// ToggleFeature - Toggle a feature and returns the newly updated feature
85 uint64_t ToggleFeature(uint64_t Bits, const StringRef String,
86 ArrayRef<SubtargetFeatureKV> FeatureTable);
88 /// Get feature bits of a CPU.
89 uint64_t getFeatureBits(const StringRef CPU,
90 ArrayRef<SubtargetFeatureKV> CPUTable,
91 ArrayRef<SubtargetFeatureKV> FeatureTable);
93 /// Print feature string.
94 void print(raw_ostream &OS) const;
99 /// Adds the default features for the specified target triple.
100 void getDefaultSubtargetFeatures(const Triple& Triple);
103 } // End namespace llvm