Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 1 | //===- InlineCost.cpp - Cost analysis for inliner -------------------------===// |
| 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 file implements inline cost analysis. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "llvm/Analysis/InlineCost.h" |
| 15 | #include "llvm/Support/CallSite.h" |
| 16 | #include "llvm/CallingConv.h" |
| 17 | #include "llvm/IntrinsicInst.h" |
| 18 | #include "llvm/ADT/SmallPtrSet.h" |
| 19 | using namespace llvm; |
| 20 | |
| 21 | // CountCodeReductionForConstant - Figure out an approximation for how many |
| 22 | // instructions will be constant folded if the specified value is constant. |
| 23 | // |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 24 | unsigned InlineCostAnalyzer::FunctionInfo:: |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 25 | CountCodeReductionForConstant(Value *V) { |
| 26 | unsigned Reduction = 0; |
| 27 | for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ++UI) |
| 28 | if (isa<BranchInst>(*UI)) |
| 29 | Reduction += 40; // Eliminating a conditional branch is a big win |
| 30 | else if (SwitchInst *SI = dyn_cast<SwitchInst>(*UI)) |
| 31 | // Eliminating a switch is a big win, proportional to the number of edges |
| 32 | // deleted. |
| 33 | Reduction += (SI->getNumSuccessors()-1) * 40; |
Chris Lattner | ab21db7 | 2009-10-28 00:19:10 +0000 | [diff] [blame] | 34 | else if (isa<IndirectBrInst>(*UI)) |
Chris Lattner | 2688bcb | 2009-10-27 21:27:42 +0000 | [diff] [blame] | 35 | // Eliminating an indirect branch is a big win. |
| 36 | Reduction += 200; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 37 | else if (CallInst *CI = dyn_cast<CallInst>(*UI)) { |
| 38 | // Turning an indirect call into a direct call is a BIG win |
| 39 | Reduction += CI->getCalledValue() == V ? 500 : 0; |
| 40 | } else if (InvokeInst *II = dyn_cast<InvokeInst>(*UI)) { |
| 41 | // Turning an indirect call into a direct call is a BIG win |
| 42 | Reduction += II->getCalledValue() == V ? 500 : 0; |
| 43 | } else { |
| 44 | // Figure out if this instruction will be removed due to simple constant |
| 45 | // propagation. |
| 46 | Instruction &Inst = cast<Instruction>(**UI); |
| 47 | |
| 48 | // We can't constant propagate instructions which have effects or |
| 49 | // read memory. |
| 50 | // |
| 51 | // FIXME: It would be nice to capture the fact that a load from a |
| 52 | // pointer-to-constant-global is actually a *really* good thing to zap. |
| 53 | // Unfortunately, we don't know the pointer that may get propagated here, |
| 54 | // so we can't make this decision. |
| 55 | if (Inst.mayReadFromMemory() || Inst.mayHaveSideEffects() || |
Victor Hernandez | 7b929da | 2009-10-23 21:09:37 +0000 | [diff] [blame] | 56 | isa<AllocaInst>(Inst)) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 57 | continue; |
| 58 | |
| 59 | bool AllOperandsConstant = true; |
| 60 | for (unsigned i = 0, e = Inst.getNumOperands(); i != e; ++i) |
| 61 | if (!isa<Constant>(Inst.getOperand(i)) && Inst.getOperand(i) != V) { |
| 62 | AllOperandsConstant = false; |
| 63 | break; |
| 64 | } |
| 65 | |
| 66 | if (AllOperandsConstant) { |
| 67 | // We will get to remove this instruction... |
| 68 | Reduction += 7; |
| 69 | |
| 70 | // And any other instructions that use it which become constants |
| 71 | // themselves. |
| 72 | Reduction += CountCodeReductionForConstant(&Inst); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | return Reduction; |
| 77 | } |
| 78 | |
| 79 | // CountCodeReductionForAlloca - Figure out an approximation of how much smaller |
| 80 | // the function will be if it is inlined into a context where an argument |
| 81 | // becomes an alloca. |
| 82 | // |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 83 | unsigned InlineCostAnalyzer::FunctionInfo:: |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 84 | CountCodeReductionForAlloca(Value *V) { |
| 85 | if (!isa<PointerType>(V->getType())) return 0; // Not a pointer |
| 86 | unsigned Reduction = 0; |
| 87 | for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){ |
| 88 | Instruction *I = cast<Instruction>(*UI); |
| 89 | if (isa<LoadInst>(I) || isa<StoreInst>(I)) |
| 90 | Reduction += 10; |
| 91 | else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) { |
| 92 | // If the GEP has variable indices, we won't be able to do much with it. |
| 93 | if (!GEP->hasAllConstantIndices()) |
| 94 | Reduction += CountCodeReductionForAlloca(GEP)+15; |
| 95 | } else { |
| 96 | // If there is some other strange instruction, we're not going to be able |
| 97 | // to do much if we inline this. |
| 98 | return 0; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | return Reduction; |
| 103 | } |
| 104 | |
Eric Christopher | 745d8c9 | 2010-01-14 21:48:00 +0000 | [diff] [blame^] | 105 | // callIsSmall - If a call is likely to lower to a single target instruction, or |
Eric Christopher | 2d59ae6 | 2010-01-14 20:12:34 +0000 | [diff] [blame] | 106 | // is otherwise deemed small return true. |
| 107 | // TODO: Perhaps calls like memcpy, strcpy, etc? |
| 108 | static bool callIsSmall(const Function *F) { |
Eric Christopher | 745d8c9 | 2010-01-14 21:48:00 +0000 | [diff] [blame^] | 109 | if (!F) return false; |
| 110 | |
| 111 | if (F->hasLocalLinkage()) return false; |
| 112 | |
| 113 | if (F->hasName()) { |
Eric Christopher | 2d59ae6 | 2010-01-14 20:12:34 +0000 | [diff] [blame] | 114 | StringRef Name = F->getName(); |
| 115 | |
| 116 | // These will all likely lower to a single selection DAG node. |
| 117 | if (Name == "copysign" || Name == "copysignf" || |
| 118 | Name == "fabs" || Name == "fabsf" || Name == "fabsl" || |
| 119 | Name == "sin" || Name == "sinf" || Name == "sinl" || |
| 120 | Name == "cos" || Name == "cosf" || Name == "cosl" || |
| 121 | Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl" ) |
| 122 | return true; |
| 123 | |
| 124 | // These are all likely to be optimized into something smaller. |
| 125 | if (Name == "pow" || Name == "powf" || Name == "powl" || |
| 126 | Name == "exp2" || Name == "exp2l" || Name == "exp2f" || |
| 127 | Name == "floor" || Name == "floorf" || Name == "ceil" || |
| 128 | Name == "round" || Name == "ffs" || Name == "ffsl" || |
| 129 | Name == "abs" || Name == "labs" || Name == "llabs") |
| 130 | return true; |
| 131 | } |
| 132 | return false; |
| 133 | } |
| 134 | |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 135 | /// analyzeBasicBlock - Fill in the current structure with information gleaned |
| 136 | /// from the specified block. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 137 | void CodeMetrics::analyzeBasicBlock(const BasicBlock *BB) { |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 138 | ++NumBlocks; |
| 139 | |
| 140 | for (BasicBlock::const_iterator II = BB->begin(), E = BB->end(); |
| 141 | II != E; ++II) { |
| 142 | if (isa<PHINode>(II)) continue; // PHI nodes don't count. |
| 143 | |
| 144 | // Special handling for calls. |
| 145 | if (isa<CallInst>(II) || isa<InvokeInst>(II)) { |
| 146 | if (isa<DbgInfoIntrinsic>(II)) |
| 147 | continue; // Debug intrinsics don't count as size. |
| 148 | |
| 149 | CallSite CS = CallSite::get(const_cast<Instruction*>(&*II)); |
| 150 | |
| 151 | // If this function contains a call to setjmp or _setjmp, never inline |
| 152 | // it. This is a hack because we depend on the user marking their local |
| 153 | // variables as volatile if they are live across a setjmp call, and they |
| 154 | // probably won't do this in callers. |
| 155 | if (Function *F = CS.getCalledFunction()) |
| 156 | if (F->isDeclaration() && |
Dan Gohman | 497f619 | 2009-10-13 20:10:10 +0000 | [diff] [blame] | 157 | (F->getName() == "setjmp" || F->getName() == "_setjmp")) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 158 | NeverInline = true; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 159 | |
| 160 | // Calls often compile into many machine instructions. Bump up their |
| 161 | // cost to reflect this. |
Eric Christopher | 2d59ae6 | 2010-01-14 20:12:34 +0000 | [diff] [blame] | 162 | if (!isa<IntrinsicInst>(II) && !callIsSmall(CS.getCalledFunction())) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 163 | NumInsts += InlineConstants::CallPenalty; |
| 164 | } |
| 165 | |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 166 | if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) { |
| 167 | if (!AI->isStaticAlloca()) |
| 168 | this->usesDynamicAlloca = true; |
| 169 | } |
| 170 | |
| 171 | if (isa<ExtractElementInst>(II) || isa<VectorType>(II->getType())) |
| 172 | ++NumVectorInsts; |
| 173 | |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 174 | if (const CastInst *CI = dyn_cast<CastInst>(II)) { |
Evan Cheng | 1a67dd2 | 2010-01-14 21:04:31 +0000 | [diff] [blame] | 175 | // Noop casts, including ptr <-> int, don't count. |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 176 | if (CI->isLosslessCast() || isa<IntToPtrInst>(CI) || |
| 177 | isa<PtrToIntInst>(CI)) |
| 178 | continue; |
Evan Cheng | 1a67dd2 | 2010-01-14 21:04:31 +0000 | [diff] [blame] | 179 | // Result of a cmp instruction is often extended (to be used by other |
| 180 | // cmp instructions, logical or return instructions). These are usually |
| 181 | // nop on most sane targets. |
| 182 | if (isa<CmpInst>(CI->getOperand(0))) |
| 183 | continue; |
Chris Lattner | b93a23a | 2009-11-01 03:07:53 +0000 | [diff] [blame] | 184 | } else if (const GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(II)){ |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 185 | // If a GEP has all constant indices, it will probably be folded with |
| 186 | // a load/store. |
| 187 | if (GEPI->hasAllConstantIndices()) |
| 188 | continue; |
| 189 | } |
| 190 | |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 191 | ++NumInsts; |
| 192 | } |
Chris Lattner | b93a23a | 2009-11-01 03:07:53 +0000 | [diff] [blame] | 193 | |
| 194 | if (isa<ReturnInst>(BB->getTerminator())) |
| 195 | ++NumRets; |
| 196 | |
Chris Lattner | 6658870 | 2009-11-01 18:16:30 +0000 | [diff] [blame] | 197 | // We never want to inline functions that contain an indirectbr. This is |
Duncan Sands | b046964 | 2009-11-01 19:12:43 +0000 | [diff] [blame] | 198 | // incorrect because all the blockaddress's (in static global initializers |
| 199 | // for example) would be referring to the original function, and this indirect |
Chris Lattner | 6658870 | 2009-11-01 18:16:30 +0000 | [diff] [blame] | 200 | // jump would jump from the inlined copy of the function into the original |
| 201 | // function which is extremely undefined behavior. |
Chris Lattner | b93a23a | 2009-11-01 03:07:53 +0000 | [diff] [blame] | 202 | if (isa<IndirectBrInst>(BB->getTerminator())) |
| 203 | NeverInline = true; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 204 | } |
| 205 | |
| 206 | /// analyzeFunction - Fill in the current structure with information gleaned |
| 207 | /// from the specified function. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 208 | void CodeMetrics::analyzeFunction(Function *F) { |
| 209 | // Look at the size of the callee. |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 210 | for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) |
| 211 | analyzeBasicBlock(&*BB); |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 212 | } |
| 213 | |
| 214 | /// analyzeFunction - Fill in the current structure with information gleaned |
| 215 | /// from the specified function. |
| 216 | void InlineCostAnalyzer::FunctionInfo::analyzeFunction(Function *F) { |
| 217 | Metrics.analyzeFunction(F); |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 218 | |
| 219 | // A function with exactly one return has it removed during the inlining |
| 220 | // process (see InlineFunction), so don't count it. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 221 | // FIXME: This knowledge should really be encoded outside of FunctionInfo. |
| 222 | if (Metrics.NumRets==1) |
| 223 | --Metrics.NumInsts; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 224 | |
| 225 | // Check out all of the arguments to the function, figuring out how much |
| 226 | // code can be eliminated if one of the arguments is a constant. |
| 227 | for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I) |
| 228 | ArgumentWeights.push_back(ArgInfo(CountCodeReductionForConstant(I), |
| 229 | CountCodeReductionForAlloca(I))); |
| 230 | } |
| 231 | |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 232 | // getInlineCost - The heuristic used to determine if we should inline the |
| 233 | // function call or not. |
| 234 | // |
| 235 | InlineCost InlineCostAnalyzer::getInlineCost(CallSite CS, |
| 236 | SmallPtrSet<const Function *, 16> &NeverInline) { |
| 237 | Instruction *TheCall = CS.getInstruction(); |
| 238 | Function *Callee = CS.getCalledFunction(); |
| 239 | Function *Caller = TheCall->getParent()->getParent(); |
| 240 | |
| 241 | // Don't inline functions which can be redefined at link-time to mean |
| 242 | // something else. Don't inline functions marked noinline. |
| 243 | if (Callee->mayBeOverridden() || |
| 244 | Callee->hasFnAttr(Attribute::NoInline) || NeverInline.count(Callee)) |
| 245 | return llvm::InlineCost::getNever(); |
| 246 | |
| 247 | // InlineCost - This value measures how good of an inline candidate this call |
| 248 | // site is to inline. A lower inline cost make is more likely for the call to |
| 249 | // be inlined. This value may go negative. |
| 250 | // |
| 251 | int InlineCost = 0; |
| 252 | |
| 253 | // If there is only one call of the function, and it has internal linkage, |
| 254 | // make it almost guaranteed to be inlined. |
| 255 | // |
| 256 | if (Callee->hasLocalLinkage() && Callee->hasOneUse()) |
| 257 | InlineCost += InlineConstants::LastCallToStaticBonus; |
| 258 | |
| 259 | // If this function uses the coldcc calling convention, prefer not to inline |
| 260 | // it. |
| 261 | if (Callee->getCallingConv() == CallingConv::Cold) |
| 262 | InlineCost += InlineConstants::ColdccPenalty; |
| 263 | |
| 264 | // If the instruction after the call, or if the normal destination of the |
| 265 | // invoke is an unreachable instruction, the function is noreturn. As such, |
| 266 | // there is little point in inlining this. |
| 267 | if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) { |
| 268 | if (isa<UnreachableInst>(II->getNormalDest()->begin())) |
| 269 | InlineCost += InlineConstants::NoreturnPenalty; |
| 270 | } else if (isa<UnreachableInst>(++BasicBlock::iterator(TheCall))) |
| 271 | InlineCost += InlineConstants::NoreturnPenalty; |
| 272 | |
| 273 | // Get information about the callee... |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 274 | FunctionInfo &CalleeFI = CachedFunctionInfo[Callee]; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 275 | |
| 276 | // If we haven't calculated this information yet, do so now. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 277 | if (CalleeFI.Metrics.NumBlocks == 0) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 278 | CalleeFI.analyzeFunction(Callee); |
| 279 | |
| 280 | // If we should never inline this, return a huge cost. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 281 | if (CalleeFI.Metrics.NeverInline) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 282 | return InlineCost::getNever(); |
| 283 | |
| 284 | // FIXME: It would be nice to kill off CalleeFI.NeverInline. Then we |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 285 | // could move this up and avoid computing the FunctionInfo for |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 286 | // things we are going to just return always inline for. This |
| 287 | // requires handling setjmp somewhere else, however. |
| 288 | if (!Callee->isDeclaration() && Callee->hasFnAttr(Attribute::AlwaysInline)) |
| 289 | return InlineCost::getAlways(); |
| 290 | |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 291 | if (CalleeFI.Metrics.usesDynamicAlloca) { |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 292 | // Get infomation about the caller... |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 293 | FunctionInfo &CallerFI = CachedFunctionInfo[Caller]; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 294 | |
| 295 | // If we haven't calculated this information yet, do so now. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 296 | if (CallerFI.Metrics.NumBlocks == 0) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 297 | CallerFI.analyzeFunction(Caller); |
| 298 | |
| 299 | // Don't inline a callee with dynamic alloca into a caller without them. |
| 300 | // Functions containing dynamic alloca's are inefficient in various ways; |
| 301 | // don't create more inefficiency. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 302 | if (!CallerFI.Metrics.usesDynamicAlloca) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 303 | return InlineCost::getNever(); |
| 304 | } |
| 305 | |
| 306 | // Add to the inline quality for properties that make the call valuable to |
| 307 | // inline. This includes factors that indicate that the result of inlining |
| 308 | // the function will be optimizable. Currently this just looks at arguments |
| 309 | // passed into the function. |
| 310 | // |
| 311 | unsigned ArgNo = 0; |
| 312 | for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); |
| 313 | I != E; ++I, ++ArgNo) { |
| 314 | // Each argument passed in has a cost at both the caller and the callee |
| 315 | // sides. This favors functions that take many arguments over functions |
| 316 | // that take few arguments. |
| 317 | InlineCost -= 20; |
| 318 | |
| 319 | // If this is a function being passed in, it is very likely that we will be |
| 320 | // able to turn an indirect function call into a direct function call. |
| 321 | if (isa<Function>(I)) |
| 322 | InlineCost -= 100; |
| 323 | |
| 324 | // If an alloca is passed in, inlining this function is likely to allow |
| 325 | // significant future optimization possibilities (like scalar promotion, and |
| 326 | // scalarization), so encourage the inlining of the function. |
| 327 | // |
| 328 | else if (isa<AllocaInst>(I)) { |
| 329 | if (ArgNo < CalleeFI.ArgumentWeights.size()) |
| 330 | InlineCost -= CalleeFI.ArgumentWeights[ArgNo].AllocaWeight; |
| 331 | |
| 332 | // If this is a constant being passed into the function, use the argument |
| 333 | // weights calculated for the callee to determine how much will be folded |
| 334 | // away with this information. |
| 335 | } else if (isa<Constant>(I)) { |
| 336 | if (ArgNo < CalleeFI.ArgumentWeights.size()) |
| 337 | InlineCost -= CalleeFI.ArgumentWeights[ArgNo].ConstantWeight; |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | // Now that we have considered all of the factors that make the call site more |
| 342 | // likely to be inlined, look at factors that make us not want to inline it. |
| 343 | |
| 344 | // Don't inline into something too big, which would make it bigger. |
| 345 | // "size" here is the number of basic blocks, not instructions. |
| 346 | // |
| 347 | InlineCost += Caller->size()/15; |
| 348 | |
| 349 | // Look at the size of the callee. Each instruction counts as 5. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 350 | InlineCost += CalleeFI.Metrics.NumInsts*5; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 351 | |
| 352 | return llvm::InlineCost::get(InlineCost); |
| 353 | } |
| 354 | |
| 355 | // getInlineFudgeFactor - Return a > 1.0 factor if the inliner should use a |
| 356 | // higher threshold to determine if the function call should be inlined. |
| 357 | float InlineCostAnalyzer::getInlineFudgeFactor(CallSite CS) { |
| 358 | Function *Callee = CS.getCalledFunction(); |
| 359 | |
| 360 | // Get information about the callee... |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 361 | FunctionInfo &CalleeFI = CachedFunctionInfo[Callee]; |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 362 | |
| 363 | // If we haven't calculated this information yet, do so now. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 364 | if (CalleeFI.Metrics.NumBlocks == 0) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 365 | CalleeFI.analyzeFunction(Callee); |
| 366 | |
| 367 | float Factor = 1.0f; |
| 368 | // Single BB functions are often written to be inlined. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 369 | if (CalleeFI.Metrics.NumBlocks == 1) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 370 | Factor += 0.5f; |
| 371 | |
| 372 | // Be more aggressive if the function contains a good chunk (if it mades up |
| 373 | // at least 10% of the instructions) of vector instructions. |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 374 | if (CalleeFI.Metrics.NumVectorInsts > CalleeFI.Metrics.NumInsts/2) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 375 | Factor += 2.0f; |
Dan Gohman | e7f0ed5 | 2009-10-13 19:58:07 +0000 | [diff] [blame] | 376 | else if (CalleeFI.Metrics.NumVectorInsts > CalleeFI.Metrics.NumInsts/10) |
Dan Gohman | e4aeec0 | 2009-10-13 18:30:07 +0000 | [diff] [blame] | 377 | Factor += 1.5f; |
| 378 | return Factor; |
| 379 | } |