Mercurial > projects > ldc

comparison gen/passes/SimplifyDRuntimeCalls.cpp @ 1286:23b23b74e326

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Remove calls to some runtime functions if their results are unused
author Frits van Bommel <fvbommel wxs.nl>
date Sat, 02 May 2009 11:58:50 +0200
parents bedf0bfb8fdb
children c32e27f9a61d
comparison
equal deleted inserted replaced
1285:91d9386d4a5a 1286:23b23b74e326
143 } 143 }
144 return 0; 144 return 0;
145 } 145 }
146 }; 146 };
147 147
148 /// DeleteUnusedOpt - remove libcall if the return value is unused.
149 struct VISIBILITY_HIDDEN DeleteUnusedOpt : public LibCallOptimization {
150 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
151 if (CI->use_empty())
152 return CI;
153 return 0;
154 }
155 };
156
148 // TODO: More optimizations! :) 157 // TODO: More optimizations! :)
149 158
150 } // end anonymous namespace. 159 } // end anonymous namespace.
151 160
152 //===----------------------------------------------------------------------===// 161 //===----------------------------------------------------------------------===//
161 170
162 // Array operations 171 // Array operations
163 ArraySetLengthOpt ArraySetLength; 172 ArraySetLengthOpt ArraySetLength;
164 ArrayCastLenOpt ArrayCastLen; 173 ArrayCastLenOpt ArrayCastLen;
165 174
175 // GC allocations
176 DeleteUnusedOpt DeleteUnused;
177
166 public: 178 public:
167 static char ID; // Pass identification 179 static char ID; // Pass identification
168 SimplifyDRuntimeCalls() : FunctionPass(&ID) {} 180 SimplifyDRuntimeCalls() : FunctionPass(&ID) {}
169 181
170 void InitOptimizations(); 182 void InitOptimizations();
186 } 198 }
187 199
188 /// Optimizations - Populate the Optimizations map with all the optimizations 200 /// Optimizations - Populate the Optimizations map with all the optimizations
189 /// we know. 201 /// we know.
190 void SimplifyDRuntimeCalls::InitOptimizations() { 202 void SimplifyDRuntimeCalls::InitOptimizations() {
203 // Some array-related optimizations
191 Optimizations["_d_arraysetlengthT"] = &ArraySetLength; 204 Optimizations["_d_arraysetlengthT"] = &ArraySetLength;
192 Optimizations["_d_arraysetlengthiT"] = &ArraySetLength; 205 Optimizations["_d_arraysetlengthiT"] = &ArraySetLength;
193 Optimizations["_d_array_cast_len"] = &ArrayCastLen; 206 Optimizations["_d_array_cast_len"] = &ArrayCastLen;
207
208 /* Delete calls to runtime functions which aren't needed if their result is
209 * unused. That comes down to functions that don't do anything but
210 * GC-allocate and initialize some memory.
211 * We don't need to do this for functions which are marked 'readnone' or
212 * 'readonly', since LLVM doesn't need our help figuring out when those can
213 * be deleted.
214 * (We can't mark allocating calls as readonly/readnone because they don't
215 * return the same pointer every time when called with the same arguments)
216 */
217 Optimizations["_d_allocmemoryT"] = &DeleteUnused;
218 Optimizations["_d_newarrayT"] = &DeleteUnused;
219 Optimizations["_d_newarrayiT"] = &DeleteUnused;
220 Optimizations["_d_newarrayvT"] = &DeleteUnused;
221 Optimizations["_d_newarraymT"] = &DeleteUnused;
222 Optimizations["_d_newarraymiT"] = &DeleteUnused;
223 Optimizations["_d_newarraymvT"] = &DeleteUnused;
224 Optimizations["_d_allocclass"] = &DeleteUnused;
194 } 225 }
195 226
196 227
197 /// runOnFunction - Top level algorithm. 228 /// runOnFunction - Top level algorithm.
198 /// 229 ///