1 //===- SubtargetFeature.cpp - CPU characteristics Implementation ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Jim Laskey and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the SubtargetFeature interface.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Target/SubtargetFeature.h"
15 #include "llvm/ADT/StringExtras.h"
22 //===----------------------------------------------------------------------===//
23 // Static Helper Functions
24 //===----------------------------------------------------------------------===//
26 /// hasFlag - Determine if a feature has a flag; '+' or '-'
28 static inline bool hasFlag(const std::string &Feature) {
29 assert(!Feature.empty() && "Empty string");
30 // Get first character
32 // Check if first character is '+' or '-' flag
33 return Ch == '+' || Ch =='-';
36 /// StripFlag - Return string stripped of flag.
38 static inline std::string StripFlag(const std::string &Feature) {
39 return hasFlag(Feature) ? Feature.substr(1) : Feature;
42 /// isEnabled - Return true if enable flag; '+'.
44 static inline bool isEnabled(const std::string &Feature) {
45 assert(!Feature.empty() && "Empty string");
46 // Get first character
48 // Check if first character is '+' for enabled
52 /// PrependFlag - Return a string with a prepended flag; '+' or '-'.
54 static inline std::string PrependFlag(const std::string &Feature,
56 assert(!Feature.empty() && "Empty string");
57 if (hasFlag(Feature)) return Feature;
58 return std::string(IsEnabled ? "+" : "-") + Feature;
61 /// Split - Splits a string of comma separated items in to a vector of strings.
63 static void Split(std::vector<std::string> &V, const std::string &S) {
64 // Start at beginning of string.
67 // Find the next comma
68 size_t Comma = S.find(',', Pos);
69 // If no comma found then the the rest of the string is used
70 if (Comma == std::string::npos) {
71 // Add string to vector
72 V.push_back(S.substr(Pos));
75 // Otherwise add substring to vector
76 V.push_back(S.substr(Pos, Comma - Pos));
77 // Advance to next item
82 /// Join a vector of strings to a string with a comma separating each element.
84 static std::string Join(const std::vector<std::string> &V) {
85 // Start with empty string.
87 // If the vector is not empty
89 // Start with the CPU feature
91 // For each successive feature
92 for (size_t i = 1; i < V.size(); i++) {
99 // Return the features string
104 void SubtargetFeatures::AddFeature(const std::string &String,
106 // Don't add empty features
107 if (!String.empty()) {
108 // Convert to lowercase, prepend flag and add to vector
109 Features.push_back(PrependFlag(LowercaseString(String), IsEnabled));
113 /// Find KV in array using binary search.
114 template<typename T> const T *Find(const std::string &S, const T *A, size_t L) {
115 // Determine the end of the array
117 // Binary search the array
118 const T *F = std::lower_bound(A, Hi, S);
119 // If not found then return NULL
120 if (F == Hi || std::string(F->Key) != S) return NULL;
121 // Return the found array item
125 /// getLongestEntryLength - Return the length of the longest entry in the table.
127 static size_t getLongestEntryLength(const SubtargetFeatureKV *Table,
130 for (size_t i = 0; i < Size; i++)
131 MaxLen = std::max(MaxLen, std::strlen(Table[i].Key));
135 /// Display help for feature choices.
137 static void Help(const SubtargetFeatureKV *CPUTable, size_t CPUTableSize,
138 const SubtargetFeatureKV *FeatTable, size_t FeatTableSize) {
139 // Determine the length of the longest CPU and Feature entries.
140 unsigned MaxCPULen = getLongestEntryLength(CPUTable, CPUTableSize);
141 unsigned MaxFeatLen = getLongestEntryLength(FeatTable, FeatTableSize);
143 // Print the CPU table.
144 std::cerr << "Available CPUs for this target:\n\n";
145 for (size_t i = 0; i != CPUTableSize; i++)
146 std::cerr << " " << CPUTable[i].Key
147 << std::string(MaxCPULen - std::strlen(CPUTable[i].Key), ' ')
148 << " - " << CPUTable[i].Desc << ".\n";
151 // Print the Feature table.
152 std::cerr << "Available features for this target:\n\n";
153 for (size_t i = 0; i != FeatTableSize; i++)
154 std::cerr << " " << FeatTable[i].Key
155 << std::string(MaxFeatLen - std::strlen(FeatTable[i].Key), ' ')
156 << " - " << FeatTable[i].Desc << ".\n";
159 std::cerr << "Use +feature to enable a feature, or -feature to disable it.\n"
160 << "For example, llc -mcpu=mycpu -mattr=+feature1,-feature2\n";
164 //===----------------------------------------------------------------------===//
165 // SubtargetFeatures Implementation
166 //===----------------------------------------------------------------------===//
168 SubtargetFeatures::SubtargetFeatures(const std::string &Initial) {
169 // Break up string into separate features
170 Split(Features, Initial);
174 std::string SubtargetFeatures::getString() const {
175 return Join(Features);
177 void SubtargetFeatures::setString(const std::string &Initial) {
178 // Throw out old features
180 // Break up string into separate features
181 Split(Features, LowercaseString(Initial));
185 /// setCPU - Set the CPU string. Replaces previous setting. Setting to ""
187 void SubtargetFeatures::setCPU(const std::string &String) {
188 Features[0] = LowercaseString(String);
192 /// setCPUIfNone - Setting CPU string only if no string is set.
194 void SubtargetFeatures::setCPUIfNone(const std::string &String) {
195 if (Features[0].empty()) setCPU(String);
199 /// getBits - Get feature bits.
201 uint32_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
203 const SubtargetFeatureKV *FeatureTable,
204 size_t FeatureTableSize) {
205 assert(CPUTable && "missing CPU table");
206 assert(FeatureTable && "missing features table");
208 for (size_t i = 1; i < CPUTableSize; i++) {
209 assert(strcmp(CPUTable[i - 1].Key, CPUTable[i].Key) < 0 &&
210 "CPU table is not sorted");
212 for (size_t i = 1; i < FeatureTableSize; i++) {
213 assert(strcmp(FeatureTable[i - 1].Key, FeatureTable[i].Key) < 0 &&
214 "CPU features table is not sorted");
217 uint32_t Bits = 0; // Resulting bits
219 // Check if help is needed
220 if (Features[0] == "help")
221 Help(CPUTable, CPUTableSize, FeatureTable, FeatureTableSize);
224 const SubtargetFeatureKV *CPUEntry =
225 Find(Features[0], CPUTable, CPUTableSize);
226 // If there is a match
228 // Set base feature bits
229 Bits = CPUEntry->Value;
231 std::cerr << "'" << Features[0]
232 << "' is not a recognized processor for this target"
233 << " (ignoring processor)"
236 // Iterate through each feature
237 for (size_t i = 1; i < Features.size(); i++) {
238 const std::string &Feature = Features[i];
241 if (Feature == "+help")
242 Help(CPUTable, CPUTableSize, FeatureTable, FeatureTableSize);
244 // Find feature in table.
245 const SubtargetFeatureKV *FeatureEntry =
246 Find(StripFlag(Feature), FeatureTable, FeatureTableSize);
247 // If there is a match
249 // Enable/disable feature in bits
250 if (isEnabled(Feature)) Bits |= FeatureEntry->Value;
251 else Bits &= ~FeatureEntry->Value;
253 std::cerr << "'" << Feature
254 << "' is not a recognized feature for this target"
255 << " (ignoring feature)"
263 void *SubtargetFeatures::getInfo(const SubtargetInfoKV *Table,
265 assert(Table && "missing table");
267 for (size_t i = 1; i < TableSize; i++) {
268 assert(strcmp(Table[i - 1].Key, Table[i].Key) < 0 && "Table is not sorted");
273 const SubtargetInfoKV *Entry = Find(Features[0], Table, TableSize);
278 std::cerr << "'" << Features[0]
279 << "' is not a recognized processor for this target"
280 << " (ignoring processor)"
286 /// print - Print feature string.
288 void SubtargetFeatures::print(std::ostream &OS) const {
289 for (size_t i = 0; i < Features.size(); i++) {
290 OS << Features[i] << " ";
295 /// dump - Dump feature info.
297 void SubtargetFeatures::dump() const {