xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/DroppedVariableStatsMIR.cpp (revision 770cf0a5f02dc8983a89c6568d741fbc25baa999)
1 ///===- DroppedVariableStatsMIR.cpp ---------------------------------------===//
2 ///
3 /// Part of the LLVM Project, under the Apache License v2.0 with LLVM
4 /// Exceptions. See https://llvm.org/LICENSE.txt for license information.
5 /// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 ///
7 ///===---------------------------------------------------------------------===//
8 /// \file
9 /// Dropped Variable Statistics for Debug Information. Reports any number
10 /// of DBG_VALUEs that get dropped due to an optimization pass.
11 ///
12 ///===---------------------------------------------------------------------===//
13 
14 #include "llvm/CodeGen/DroppedVariableStatsMIR.h"
15 #include "llvm/IR/DebugInfoMetadata.h"
16 
17 using namespace llvm;
18 
19 void DroppedVariableStatsMIR::runBeforePass(StringRef PassID,
20                                             MachineFunction *MF) {
21   if (PassID == "Debug Variable Analysis")
22     return;
23   setup();
24   return runOnMachineFunction(MF, true);
25 }
26 
27 void DroppedVariableStatsMIR::runAfterPass(StringRef PassID,
28                                            MachineFunction *MF) {
29   if (PassID == "Debug Variable Analysis")
30     return;
31   runOnMachineFunction(MF, false);
32   calculateDroppedVarStatsOnMachineFunction(MF, PassID, MF->getName().str());
33   cleanup();
34 }
35 
36 void DroppedVariableStatsMIR::runOnMachineFunction(const MachineFunction *MF,
37                                                    bool Before) {
38   auto &DebugVariables = DebugVariablesStack.back()[&MF->getFunction()];
39   auto FuncName = MF->getName();
40   MFunc = MF;
41   run(DebugVariables, FuncName, Before);
42 }
43 
44 void DroppedVariableStatsMIR::calculateDroppedVarStatsOnMachineFunction(
45     const MachineFunction *MF, StringRef PassID, StringRef FuncOrModName) {
46   MFunc = MF;
47   StringRef FuncName = MF->getName();
48   const Function *Func = &MF->getFunction();
49   DebugVariables &DbgVariables = DebugVariablesStack.back()[Func];
50   calculateDroppedStatsAndPrint(DbgVariables, FuncName, PassID, FuncOrModName,
51                                 "MachineFunction", Func);
52 }
53 
54 void DroppedVariableStatsMIR::visitEveryInstruction(
55     unsigned &DroppedCount, DenseMap<VarID, DILocation *> &InlinedAtsMap,
56     VarID Var) {
57   unsigned PrevDroppedCount = DroppedCount;
58   const DIScope *DbgValScope = std::get<0>(Var);
59   for (const auto &MBB : *MFunc) {
60     for (const auto &MI : MBB) {
61       if (!MI.isDebugInstr()) {
62         auto *DbgLoc = MI.getDebugLoc().get();
63         if (!DbgLoc)
64           continue;
65 
66         auto *Scope = DbgLoc->getScope();
67         if (updateDroppedCount(DbgLoc, Scope, DbgValScope, InlinedAtsMap, Var,
68                                DroppedCount))
69           break;
70       }
71     }
72     if (PrevDroppedCount != DroppedCount) {
73       PrevDroppedCount = DroppedCount;
74       break;
75     }
76   }
77 }
78 
79 void DroppedVariableStatsMIR::visitEveryDebugRecord(
80     DenseSet<VarID> &VarIDSet,
81     DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
82     StringRef FuncName, bool Before) {
83   for (const auto &MBB : *MFunc) {
84     for (const auto &MI : MBB) {
85       if (MI.isDebugValueLike()) {
86         auto *DbgVar = MI.getDebugVariable();
87         if (!DbgVar)
88           continue;
89         auto DbgLoc = MI.getDebugLoc();
90         populateVarIDSetAndInlinedMap(DbgVar, DbgLoc, VarIDSet, InlinedAtsMap,
91                                       FuncName, Before);
92       }
93     }
94   }
95 }
96