1//===-- MachineFunctionPass.cpp -------------------------------------------===//
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 contains the definitions of the MachineFunctionPass members.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/CodeGen/MachineFunctionPass.h"
14#include "llvm/Analysis/BasicAliasAnalysis.h"
15#include "llvm/Analysis/DominanceFrontier.h"
16#include "llvm/Analysis/GlobalsModRef.h"
17#include "llvm/Analysis/IVUsers.h"
18#include "llvm/Analysis/LoopInfo.h"
19#include "llvm/Analysis/MemoryDependenceAnalysis.h"
20#include "llvm/Analysis/OptimizationRemarkEmitter.h"
21#include "llvm/Analysis/ScalarEvolution.h"
22#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
23#include "llvm/CodeGen/MachineFunction.h"
24#include "llvm/CodeGen/MachineModuleInfo.h"
25#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
26#include "llvm/CodeGen/Passes.h"
27#include "llvm/IR/Dominators.h"
28#include "llvm/IR/Function.h"
29#include "llvm/IR/PrintPasses.h"
30
31using namespace llvm;
32using namespace ore;
33
34Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O,
35 const std::string &Banner) const {
36 return createMachineFunctionPrinterPass(OS&: O, Banner);
37}
38
39bool MachineFunctionPass::runOnFunction(Function &F) {
40 // Do not codegen any 'available_externally' functions at all, they have
41 // definitions outside the translation unit.
42 if (F.hasAvailableExternallyLinkage())
43 return false;
44
45 MachineModuleInfo &MMI = getAnalysis<MachineModuleInfoWrapperPass>().getMMI();
46 MachineFunction &MF = MMI.getOrCreateMachineFunction(F);
47
48 MachineFunctionProperties &MFProps = MF.getProperties();
49
50#ifndef NDEBUG
51 if (!MFProps.verifyRequiredProperties(V: RequiredProperties)) {
52 errs() << "MachineFunctionProperties required by " << getPassName()
53 << " pass are not met by function " << F.getName() << ".\n"
54 << "Required properties: ";
55 RequiredProperties.print(OS&: errs());
56 errs() << "\nCurrent properties: ";
57 MFProps.print(OS&: errs());
58 errs() << "\n";
59 llvm_unreachable("MachineFunctionProperties check failed");
60 }
61#endif
62 // Collect the MI count of the function before the pass.
63 unsigned CountBefore, CountAfter;
64
65 // Check if the user asked for size remarks.
66 bool ShouldEmitSizeRemarks =
67 F.getParent()->shouldEmitInstrCountChangedRemark();
68
69 // If we want size remarks, collect the number of MachineInstrs in our
70 // MachineFunction before the pass runs.
71 if (ShouldEmitSizeRemarks)
72 CountBefore = MF.getInstructionCount();
73
74 // For --print-changed, if the function name is a candidate, save the
75 // serialized MF to be compared later.
76 SmallString<0> BeforeStr, AfterStr;
77 StringRef PassID;
78 if (PrintChanged != ChangePrinter::None) {
79 if (const PassInfo *PI = Pass::lookupPassInfo(TI: getPassID()))
80 PassID = PI->getPassArgument();
81 }
82 const bool IsInterestingPass = isPassInPrintList(PassName: PassID);
83 const bool ShouldPrintChanged = PrintChanged != ChangePrinter::None &&
84 IsInterestingPass &&
85 isFunctionInPrintList(FunctionName: MF.getName());
86 if (ShouldPrintChanged) {
87 raw_svector_ostream OS(BeforeStr);
88 MF.print(OS);
89 }
90
91 MFProps.reset(MFP: ClearedProperties);
92
93 bool RV = runOnMachineFunction(MF);
94
95 if (ShouldEmitSizeRemarks) {
96 // We wanted size remarks. Check if there was a change to the number of
97 // MachineInstrs in the module. Emit a remark if there was a change.
98 CountAfter = MF.getInstructionCount();
99 if (CountBefore != CountAfter) {
100 MachineOptimizationRemarkEmitter MORE(MF, nullptr);
101 MORE.emit(RemarkBuilder: [&]() {
102 int64_t Delta = static_cast<int64_t>(CountAfter) -
103 static_cast<int64_t>(CountBefore);
104 MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange",
105 MF.getFunction().getSubprogram(),
106 &MF.front());
107 R << NV("Pass", getPassName())
108 << ": Function: " << NV("Function", F.getName()) << ": "
109 << "MI Instruction count changed from "
110 << NV("MIInstrsBefore", CountBefore) << " to "
111 << NV("MIInstrsAfter", CountAfter)
112 << "; Delta: " << NV("Delta", Delta);
113 return R;
114 });
115 }
116 }
117
118 MFProps.set(SetProperties);
119
120 // For --print-changed, print if the serialized MF has changed. Modes other
121 // than quiet/verbose are unimplemented and treated the same as 'quiet'.
122 if (ShouldPrintChanged || !IsInterestingPass) {
123 if (ShouldPrintChanged) {
124 raw_svector_ostream OS(AfterStr);
125 MF.print(OS);
126 }
127 if (IsInterestingPass && BeforeStr != AfterStr) {
128 errs() << ("*** IR Dump After " + getPassName() + " (" + PassID +
129 ") on " + MF.getName() + " ***\n");
130 switch (PrintChanged) {
131 case ChangePrinter::None:
132 llvm_unreachable("");
133 case ChangePrinter::Quiet:
134 case ChangePrinter::Verbose:
135 case ChangePrinter::DotCfgQuiet: // unimplemented
136 case ChangePrinter::DotCfgVerbose: // unimplemented
137 errs() << AfterStr;
138 break;
139 case ChangePrinter::DiffQuiet:
140 case ChangePrinter::DiffVerbose:
141 case ChangePrinter::ColourDiffQuiet:
142 case ChangePrinter::ColourDiffVerbose: {
143 bool Color = llvm::is_contained(
144 Set: {ChangePrinter::ColourDiffQuiet, ChangePrinter::ColourDiffVerbose},
145 Element: PrintChanged.getValue());
146 StringRef Removed = Color ? "\033[31m-%l\033[0m\n" : "-%l\n";
147 StringRef Added = Color ? "\033[32m+%l\033[0m\n" : "+%l\n";
148 StringRef NoChange = " %l\n";
149 errs() << doSystemDiff(Before: BeforeStr, After: AfterStr, OldLineFormat: Removed, NewLineFormat: Added, UnchangedLineFormat: NoChange);
150 break;
151 }
152 }
153 } else if (llvm::is_contained(Set: {ChangePrinter::Verbose,
154 ChangePrinter::DiffVerbose,
155 ChangePrinter::ColourDiffVerbose},
156 Element: PrintChanged.getValue())) {
157 const char *Reason =
158 IsInterestingPass ? " omitted because no change" : " filtered out";
159 errs() << "*** IR Dump After " << getPassName();
160 if (!PassID.empty())
161 errs() << " (" << PassID << ")";
162 errs() << " on " << MF.getName() + Reason + " ***\n";
163 }
164 }
165 return RV;
166}
167
168void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const {
169 AU.addRequired<MachineModuleInfoWrapperPass>();
170 AU.addPreserved<MachineModuleInfoWrapperPass>();
171
172 // MachineFunctionPass preserves all LLVM IR passes, but there's no
173 // high-level way to express this. Instead, just list a bunch of
174 // passes explicitly. This does not include setPreservesCFG,
175 // because CodeGen overloads that to mean preserving the MachineBasicBlock
176 // CFG in addition to the LLVM IR CFG.
177 AU.addPreserved<BasicAAWrapperPass>();
178 AU.addPreserved<DominanceFrontierWrapperPass>();
179 AU.addPreserved<DominatorTreeWrapperPass>();
180 AU.addPreserved<AAResultsWrapperPass>();
181 AU.addPreserved<GlobalsAAWrapperPass>();
182 AU.addPreserved<IVUsersWrapperPass>();
183 AU.addPreserved<LoopInfoWrapperPass>();
184 AU.addPreserved<MemoryDependenceWrapperPass>();
185 AU.addPreserved<ScalarEvolutionWrapperPass>();
186 AU.addPreserved<SCEVAAWrapperPass>();
187
188 FunctionPass::getAnalysisUsage(AU);
189}
190

source code of llvm/lib/CodeGen/MachineFunctionPass.cpp