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 19 namespace llvm { 20 class AssumptionCache; 21 class BasicBlock; 22 class Loop; 23 class Function; 24 template <class T> class SmallPtrSetImpl; 25 class TargetTransformInfo; 26 class Value; 27 28 /// Utility to calculate the size and a few similar metrics for a set 29 /// of basic blocks. 30 struct CodeMetrics { 31 /// True if this function contains a call to setjmp or other functions 32 /// with attribute "returns twice" without having the attribute itself. 33 bool exposesReturnsTwice = false; 34 35 /// True if this function calls itself. 36 bool isRecursive = false; 37 38 /// True if this function cannot be duplicated. 39 /// 40 /// True if this function contains one or more indirect branches, or it contains 41 /// one or more 'noduplicate' instructions. 42 bool notDuplicatable = false; 43 44 /// True if this function contains a call to a convergent function. 45 bool convergent = false; 46 47 /// True if this function calls alloca (in the C sense). 48 bool usesDynamicAlloca = false; 49 50 /// Number of instructions in the analyzed blocks. 51 unsigned NumInsts = false; 52 53 /// Number of analyzed blocks. 54 unsigned NumBlocks = false; 55 56 /// Keeps track of basic block code size estimates. 57 DenseMap<const BasicBlock *, unsigned> NumBBInsts; 58 59 /// Keep track of the number of calls to 'big' functions. 60 unsigned NumCalls = false; 61 62 /// The number of calls to internal functions with a single caller. 63 /// 64 /// These are likely targets for future inlining, likely exposed by 65 /// interleaved devirtualization. 66 unsigned NumInlineCandidates = 0; 67 68 /// How many instructions produce vector values. 69 /// 70 /// The inliner is more aggressive with inlining vector kernels. 71 unsigned NumVectorInsts = 0; 72 73 /// How many 'ret' instructions the blocks contain. 74 unsigned NumRets = 0; 75 76 /// Add information about a block to the current state. 77 void analyzeBasicBlock(const BasicBlock *BB, const TargetTransformInfo &TTI, 78 const SmallPtrSetImpl<const Value *> &EphValues, 79 bool PrepareForLTO = false); 80 81 /// Collect a loop's ephemeral values (those used only by an assume 82 /// or similar intrinsics in the loop). 83 static void collectEphemeralValues(const Loop *L, AssumptionCache *AC, 84 SmallPtrSetImpl<const Value *> &EphValues); 85 86 /// Collect a functions's ephemeral values (those used only by an 87 /// assume or similar intrinsics in the function). 88 static void collectEphemeralValues(const Function *L, AssumptionCache *AC, 89 SmallPtrSetImpl<const Value *> &EphValues); 90 }; 91 92 } 93 94 #endif 95