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
20namespace llvm {
21class AssumptionCache;
22class BasicBlock;
23class Loop;
24class Function;
25template <class T> class SmallPtrSetImpl;
26class TargetTransformInfo;
27class Value;
28
29/// Utility to calculate the size and a few similar metrics for a set
30/// of basic blocks.
31struct 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

source code of llvm/include/llvm/Analysis/CodeMetrics.h