1 //===- CodeMetrics.h - Code cost measurements -------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements various weight measurements for code, helping 10 // the Inliner and other passes decide whether to duplicate its contents. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_ANALYSIS_CODEMETRICS_H 15 #define LLVM_ANALYSIS_CODEMETRICS_H 16 17 #include "llvm/ADT/DenseMap.h" 18 #include "llvm/Support/InstructionCost.h" 19 20 namespace llvm { 21 class AssumptionCache; 22 class BasicBlock; 23 class Loop; 24 class Function; 25 template <class T> class SmallPtrSetImpl; 26 class TargetTransformInfo; 27 class Value; 28 29 /// Utility to calculate the size and a few similar metrics for a set 30 /// of basic blocks. 31 struct CodeMetrics { 32 /// True if this function contains a call to setjmp or other functions 33 /// with attribute "returns twice" without having the attribute itself. 34 bool exposesReturnsTwice = false; 35 36 /// True if this function calls itself. 37 bool isRecursive = false; 38 39 /// True if this function cannot be duplicated. 40 /// 41 /// True if this function contains one or more indirect branches, or it contains 42 /// one or more 'noduplicate' instructions. 43 bool notDuplicatable = false; 44 45 /// True if this function contains a call to a convergent function. 46 bool convergent = false; 47 48 /// True if this function calls alloca (in the C sense). 49 bool usesDynamicAlloca = false; 50 51 /// Code size cost of the analyzed blocks. 52 InstructionCost NumInsts = 0; 53 54 /// Number of analyzed blocks. 55 unsigned NumBlocks = false; 56 57 /// Keeps track of basic block code size estimates. 58 DenseMap<const BasicBlock *, InstructionCost> NumBBInsts; 59 60 /// Keep track of the number of calls to 'big' functions. 61 unsigned NumCalls = false; 62 63 /// The number of calls to internal functions with a single caller. 64 /// 65 /// These are likely targets for future inlining, likely exposed by 66 /// interleaved devirtualization. 67 unsigned NumInlineCandidates = 0; 68 69 /// How many instructions produce vector values. 70 /// 71 /// The inliner is more aggressive with inlining vector kernels. 72 unsigned NumVectorInsts = 0; 73 74 /// How many 'ret' instructions the blocks contain. 75 unsigned NumRets = 0; 76 77 /// Add information about a block to the current state. 78 void analyzeBasicBlock(const BasicBlock *BB, const TargetTransformInfo &TTI, 79 const SmallPtrSetImpl<const Value *> &EphValues, 80 bool PrepareForLTO = false); 81 82 /// Collect a loop's ephemeral values (those used only by an assume 83 /// or similar intrinsics in the loop). 84 static void collectEphemeralValues(const Loop *L, AssumptionCache *AC, 85 SmallPtrSetImpl<const Value *> &EphValues); 86 87 /// Collect a functions's ephemeral values (those used only by an 88 /// assume or similar intrinsics in the function). 89 static void collectEphemeralValues(const Function *L, AssumptionCache *AC, 90 SmallPtrSetImpl<const Value *> &EphValues); 91 }; 92 93 } 94 95 #endif 96