19b081d9691f4509af58919db5760235ca319c9daChandler Carruth//===- CodeMetrics.cpp - Code cost measurements ---------------------------===// 29b081d9691f4509af58919db5760235ca319c9daChandler Carruth// 39b081d9691f4509af58919db5760235ca319c9daChandler Carruth// The LLVM Compiler Infrastructure 49b081d9691f4509af58919db5760235ca319c9daChandler Carruth// 59b081d9691f4509af58919db5760235ca319c9daChandler Carruth// This file is distributed under the University of Illinois Open Source 69b081d9691f4509af58919db5760235ca319c9daChandler Carruth// License. See LICENSE.TXT for details. 79b081d9691f4509af58919db5760235ca319c9daChandler Carruth// 89b081d9691f4509af58919db5760235ca319c9daChandler Carruth//===----------------------------------------------------------------------===// 99b081d9691f4509af58919db5760235ca319c9daChandler Carruth// 109b081d9691f4509af58919db5760235ca319c9daChandler Carruth// This file implements code cost measurement utilities. 119b081d9691f4509af58919db5760235ca319c9daChandler Carruth// 129b081d9691f4509af58919db5760235ca319c9daChandler Carruth//===----------------------------------------------------------------------===// 139b081d9691f4509af58919db5760235ca319c9daChandler Carruth 149b081d9691f4509af58919db5760235ca319c9daChandler Carruth#include "llvm/Analysis/CodeMetrics.h" 15a5157e68d183e1bdf010e94a15dc0c44b65f889bChandler Carruth#include "llvm/Analysis/TargetTransformInfo.h" 160b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/DataLayout.h" 170b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/Function.h" 180b8c9a80f20772c3793201ab5b251d3520b9cea3Chandler Carruth#include "llvm/IR/IntrinsicInst.h" 19d04a8d4b33ff316ca4cf961e06c9e312eff8e64fChandler Carruth#include "llvm/Support/CallSite.h" 209b081d9691f4509af58919db5760235ca319c9daChandler Carruth 219b081d9691f4509af58919db5760235ca319c9daChandler Carruthusing namespace llvm; 229b081d9691f4509af58919db5760235ca319c9daChandler Carruth 239b081d9691f4509af58919db5760235ca319c9daChandler Carruth/// analyzeBasicBlock - Fill in the current structure with information gleaned 249b081d9691f4509af58919db5760235ca319c9daChandler Carruth/// from the specified block. 259b081d9691f4509af58919db5760235ca319c9daChandler Carruthvoid CodeMetrics::analyzeBasicBlock(const BasicBlock *BB, 26a5157e68d183e1bdf010e94a15dc0c44b65f889bChandler Carruth const TargetTransformInfo &TTI) { 279b081d9691f4509af58919db5760235ca319c9daChandler Carruth ++NumBlocks; 289b081d9691f4509af58919db5760235ca319c9daChandler Carruth unsigned NumInstsBeforeThisBB = NumInsts; 299b081d9691f4509af58919db5760235ca319c9daChandler Carruth for (BasicBlock::const_iterator II = BB->begin(), E = BB->end(); 309b081d9691f4509af58919db5760235ca319c9daChandler Carruth II != E; ++II) { 319b081d9691f4509af58919db5760235ca319c9daChandler Carruth // Special handling for calls. 329b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (isa<CallInst>(II) || isa<InvokeInst>(II)) { 339b081d9691f4509af58919db5760235ca319c9daChandler Carruth ImmutableCallSite CS(cast<Instruction>(II)); 349b081d9691f4509af58919db5760235ca319c9daChandler Carruth 359b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (const Function *F = CS.getCalledFunction()) { 369b081d9691f4509af58919db5760235ca319c9daChandler Carruth // If a function is both internal and has a single use, then it is 379b081d9691f4509af58919db5760235ca319c9daChandler Carruth // extremely likely to get inlined in the future (it was probably 389b081d9691f4509af58919db5760235ca319c9daChandler Carruth // exposed by an interleaved devirtualization pass). 399b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (!CS.isNoInline() && F->hasInternalLinkage() && F->hasOneUse()) 409b081d9691f4509af58919db5760235ca319c9daChandler Carruth ++NumInlineCandidates; 419b081d9691f4509af58919db5760235ca319c9daChandler Carruth 429b081d9691f4509af58919db5760235ca319c9daChandler Carruth // If this call is to function itself, then the function is recursive. 439b081d9691f4509af58919db5760235ca319c9daChandler Carruth // Inlining it into other functions is a bad idea, because this is 449b081d9691f4509af58919db5760235ca319c9daChandler Carruth // basically just a form of loop peeling, and our metrics aren't useful 459b081d9691f4509af58919db5760235ca319c9daChandler Carruth // for that case. 469b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (F == BB->getParent()) 479b081d9691f4509af58919db5760235ca319c9daChandler Carruth isRecursive = true; 489b081d9691f4509af58919db5760235ca319c9daChandler Carruth 4913086a658ae06046ded902229f9918b8bad505bdChandler Carruth if (TTI.isLoweredToCall(F)) 5013086a658ae06046ded902229f9918b8bad505bdChandler Carruth ++NumCalls; 5113086a658ae06046ded902229f9918b8bad505bdChandler Carruth } else { 529b081d9691f4509af58919db5760235ca319c9daChandler Carruth // We don't want inline asm to count as a call - that would prevent loop 539b081d9691f4509af58919db5760235ca319c9daChandler Carruth // unrolling. The argument setup cost is still real, though. 549b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (!isa<InlineAsm>(CS.getCalledValue())) 559b081d9691f4509af58919db5760235ca319c9daChandler Carruth ++NumCalls; 569b081d9691f4509af58919db5760235ca319c9daChandler Carruth } 579b081d9691f4509af58919db5760235ca319c9daChandler Carruth } 589b081d9691f4509af58919db5760235ca319c9daChandler Carruth 599b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) { 609b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (!AI->isStaticAlloca()) 619b081d9691f4509af58919db5760235ca319c9daChandler Carruth this->usesDynamicAlloca = true; 629b081d9691f4509af58919db5760235ca319c9daChandler Carruth } 639b081d9691f4509af58919db5760235ca319c9daChandler Carruth 649b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (isa<ExtractElementInst>(II) || II->getType()->isVectorTy()) 659b081d9691f4509af58919db5760235ca319c9daChandler Carruth ++NumVectorInsts; 669b081d9691f4509af58919db5760235ca319c9daChandler Carruth 6767ae13575900e8efd056672987249fd0adbf5e73James Molloy if (const CallInst *CI = dyn_cast<CallInst>(II)) 6867ae13575900e8efd056672987249fd0adbf5e73James Molloy if (CI->hasFnAttr(Attribute::NoDuplicate)) 6967ae13575900e8efd056672987249fd0adbf5e73James Molloy notDuplicatable = true; 7067ae13575900e8efd056672987249fd0adbf5e73James Molloy 7167ae13575900e8efd056672987249fd0adbf5e73James Molloy if (const InvokeInst *InvI = dyn_cast<InvokeInst>(II)) 7267ae13575900e8efd056672987249fd0adbf5e73James Molloy if (InvI->hasFnAttr(Attribute::NoDuplicate)) 7367ae13575900e8efd056672987249fd0adbf5e73James Molloy notDuplicatable = true; 7467ae13575900e8efd056672987249fd0adbf5e73James Molloy 7513086a658ae06046ded902229f9918b8bad505bdChandler Carruth NumInsts += TTI.getUserCost(&*II); 769b081d9691f4509af58919db5760235ca319c9daChandler Carruth } 779b081d9691f4509af58919db5760235ca319c9daChandler Carruth 789b081d9691f4509af58919db5760235ca319c9daChandler Carruth if (isa<ReturnInst>(BB->getTerminator())) 799b081d9691f4509af58919db5760235ca319c9daChandler Carruth ++NumRets; 809b081d9691f4509af58919db5760235ca319c9daChandler Carruth 819b081d9691f4509af58919db5760235ca319c9daChandler Carruth // We never want to inline functions that contain an indirectbr. This is 829b081d9691f4509af58919db5760235ca319c9daChandler Carruth // incorrect because all the blockaddress's (in static global initializers 839b081d9691f4509af58919db5760235ca319c9daChandler Carruth // for example) would be referring to the original function, and this indirect 849b081d9691f4509af58919db5760235ca319c9daChandler Carruth // jump would jump from the inlined copy of the function into the original 859b081d9691f4509af58919db5760235ca319c9daChandler Carruth // function which is extremely undefined behavior. 869b081d9691f4509af58919db5760235ca319c9daChandler Carruth // FIXME: This logic isn't really right; we can safely inline functions 879b081d9691f4509af58919db5760235ca319c9daChandler Carruth // with indirectbr's as long as no other function or global references the 889b081d9691f4509af58919db5760235ca319c9daChandler Carruth // blockaddress of a block within the current function. And as a QOI issue, 899b081d9691f4509af58919db5760235ca319c9daChandler Carruth // if someone is using a blockaddress without an indirectbr, and that 909b081d9691f4509af58919db5760235ca319c9daChandler Carruth // reference somehow ends up in another function or global, we probably 919b081d9691f4509af58919db5760235ca319c9daChandler Carruth // don't want to inline this function. 9267ae13575900e8efd056672987249fd0adbf5e73James Molloy notDuplicatable |= isa<IndirectBrInst>(BB->getTerminator()); 939b081d9691f4509af58919db5760235ca319c9daChandler Carruth 949b081d9691f4509af58919db5760235ca319c9daChandler Carruth // Remember NumInsts for this BB. 959b081d9691f4509af58919db5760235ca319c9daChandler Carruth NumBBInsts[BB] = NumInsts - NumInstsBeforeThisBB; 969b081d9691f4509af58919db5760235ca319c9daChandler Carruth} 97