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