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Change DroppedVariableStats to be extensible.
Change DroppedVariableStats to have an extensible design so that we can use it to add dropped statistics to MIR passes and the instruction selector.
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6 files changed

+316
-217
lines changed

6 files changed

+316
-217
lines changed

llvm/include/llvm/CodeGen/DroppedVariableStats.h

Lines changed: 148 additions & 33 deletions
Original file line numberDiff line numberDiff line change
@@ -23,9 +23,16 @@
2323

2424
namespace llvm {
2525

26-
/// A class to collect and print dropped debug information variable statistics.
27-
/// After every LLVM IR pass is run, it will print how many #dbg_values were
28-
/// dropped due to that pass.
26+
/// A unique key that represents a debug variable.
27+
/// First const DIScope *: Represents the scope of the debug variable.
28+
/// Second const DIScope *: Represents the InlinedAt scope of the debug
29+
/// variable. const DILocalVariable *: It is a pointer to the debug variable
30+
/// itself.
31+
using VarID =
32+
std::tuple<const DIScope *, const DIScope *, const DILocalVariable *>;
33+
34+
/// A base class to collect and print dropped debug information variable
35+
/// statistics.
2936
class DroppedVariableStats {
3037
public:
3138
DroppedVariableStats(bool DroppedVarStatsEnabled)
@@ -35,22 +42,33 @@ class DroppedVariableStats {
3542
<< "Pass Level, Pass Name, Num of Dropped Variables, Func or "
3643
"Module Name\n";
3744
};
45+
46+
virtual ~DroppedVariableStats() = default;
47+
3848
// We intend this to be unique per-compilation, thus no copies.
3949
DroppedVariableStats(const DroppedVariableStats &) = delete;
4050
void operator=(const DroppedVariableStats &) = delete;
4151

42-
void registerCallbacks(PassInstrumentationCallbacks &PIC);
43-
void runBeforePass(StringRef PassID, Any IR);
44-
void runAfterPass(StringRef PassID, Any IR, const PreservedAnalyses &PA);
45-
void runAfterPassInvalidated(StringRef PassID, const PreservedAnalyses &PA);
4652
bool getPassDroppedVariables() { return PassDroppedVariables; }
4753

48-
private:
54+
protected:
55+
void setup() {
56+
DebugVariablesStack.push_back(
57+
{DenseMap<const Function *, DebugVariables>()});
58+
InlinedAts.push_back(
59+
{DenseMap<StringRef, DenseMap<VarID, DILocation *>>()});
60+
}
61+
62+
void cleanup() {
63+
assert(!DebugVariablesStack.empty() &&
64+
"DebugVariablesStack shouldn't be empty!");
65+
assert(!InlinedAts.empty() && "InlinedAts shouldn't be empty!");
66+
DebugVariablesStack.pop_back();
67+
InlinedAts.pop_back();
68+
}
69+
4970
bool PassDroppedVariables = false;
5071
bool DroppedVariableStatsEnabled = false;
51-
/// A unique key that represents a #dbg_value.
52-
using VarID =
53-
std::tuple<const DIScope *, const DIScope *, const DILocalVariable *>;
5472

5573
struct DebugVariables {
5674
/// DenseSet of VarIDs before an optimization pass has run.
@@ -70,36 +88,133 @@ class DroppedVariableStats {
7088
/// DenseMap of VarIDs and their inlinedAt locations before an optimization
7189
/// pass has run.
7290
SmallVector<DenseMap<StringRef, DenseMap<VarID, DILocation *>>> InlinedAts;
91+
/// Calculate the number of dropped variables in an llvm::Function or
92+
/// llvm::MachineFunction and print the relevant information to stdout.
93+
void calculateDroppedStatsAndPrint(DebugVariables &DbgVariables,
94+
StringRef FuncName, StringRef PassID,
95+
StringRef FuncOrModName,
96+
StringRef PassLevel, const Function *Func);
7397

74-
/// Iterate over all Functions in a Module and report any dropped debug
75-
/// information. Will call calculateDroppedVarStatsOnFunction on every
76-
/// Function.
77-
void calculateDroppedVarStatsOnModule(const Module *M, StringRef PassID,
78-
std::string FuncOrModName,
79-
std::string PassLevel);
80-
/// Iterate over all Instructions in a Function and report any dropped debug
81-
/// information.
82-
void calculateDroppedVarStatsOnFunction(const Function *F, StringRef PassID,
83-
std::string FuncOrModName,
84-
std::string PassLevel);
98+
/// Check if a \p Var has been dropped or is a false positive. Also update the
99+
/// \p DroppedCount if a debug variable is dropped.
100+
bool updateDroppedCount(DILocation *DbgLoc, const DIScope *Scope,
101+
const DIScope *DbgValScope,
102+
DenseMap<VarID, DILocation *> &InlinedAtsMap,
103+
VarID Var, unsigned &DroppedCount);
104+
/// Run code to populate relevant data structures over an llvm::Function or
105+
/// llvm::MachineFunction.
106+
void run(DebugVariables &DbgVariables, StringRef FuncName, bool Before);
107+
/// Populate the VarIDSet and InlinedAtMap with the relevant information
108+
/// needed for before and after pass analysis to determine dropped variable
109+
/// status.
110+
void populateVarIDSetAndInlinedMap(
111+
const DILocalVariable *DbgVar, DebugLoc DbgLoc, DenseSet<VarID> &VarIDSet,
112+
DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
113+
StringRef FuncName, bool Before);
114+
/// Visit every llvm::Instruction or llvm::MachineInstruction and check if the
115+
/// debug variable denoted by its ID \p Var may have been dropped by an
116+
/// optimization pass.
117+
virtual void
118+
visitEveryInstruction(unsigned &DroppedCount,
119+
DenseMap<VarID, DILocation *> &InlinedAtsMap,
120+
VarID Var) = 0;
121+
/// Visit every debug record in an llvm::Function or llvm::MachineFunction
122+
/// and call populateVarIDSetAndInlinedMap on it.
123+
virtual void visitEveryDebugRecord(
124+
DenseSet<VarID> &VarIDSet,
125+
DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
126+
StringRef FuncName, bool Before) = 0;
127+
128+
private:
129+
/// Remove a dropped debug variable's VarID from all Sets in the
130+
/// DroppedVariablesBefore stack.
131+
void removeVarFromAllSets(VarID Var, const Function *F) {
132+
// Do not remove Var from the last element, it will be popped from the
133+
// stack.
134+
for (auto &DebugVariablesMap : llvm::drop_end(DebugVariablesStack))
135+
DebugVariablesMap[F].DebugVariablesBefore.erase(Var);
136+
}
137+
/// Return true if \p Scope is the same as \p DbgValScope or a child scope of
138+
/// \p DbgValScope, return false otherwise.
139+
bool isScopeChildOfOrEqualTo(const DIScope *Scope,
140+
const DIScope *DbgValScope);
141+
/// Return true if \p InlinedAt is the same as \p DbgValInlinedAt or part of
142+
/// the InlinedAt chain, return false otherwise.
143+
bool isInlinedAtChildOfOrEqualTo(const DILocation *InlinedAt,
144+
const DILocation *DbgValInlinedAt);
145+
};
146+
147+
/// A class to collect and print dropped debug information due to LLVM IR
148+
/// optimization passes. After every LLVM IR pass is run, it will print how many
149+
/// #dbg_values were dropped due to that pass.
150+
class DroppedVariableStatsIR : public DroppedVariableStats {
151+
public:
152+
DroppedVariableStatsIR(bool DroppedVarStatsEnabled)
153+
: llvm::DroppedVariableStats(DroppedVarStatsEnabled) {}
154+
155+
virtual ~DroppedVariableStatsIR() = default;
156+
157+
void runBeforePass(Any IR) {
158+
setup();
159+
if (const auto *M = unwrapIR<Module>(IR))
160+
return this->runOnModule(M, true);
161+
if (const auto *F = unwrapIR<Function>(IR))
162+
return this->runOnFunction(F, true);
163+
}
164+
165+
void runAfterPass(StringRef P, Any IR) {
166+
if (const auto *M = unwrapIR<Module>(IR))
167+
runAfterPassModule(P, M);
168+
else if (const auto *F = unwrapIR<Function>(IR))
169+
runAfterPassFunction(P, F);
170+
cleanup();
171+
}
172+
173+
void registerCallbacks(PassInstrumentationCallbacks &PIC);
174+
175+
private:
176+
const Function *Func;
177+
178+
void runAfterPassFunction(StringRef PassID, const Function *F) {
179+
runOnFunction(F, false);
180+
calculateDroppedVarStatsOnFunction(F, PassID, F->getName().str(),
181+
"Function");
182+
}
183+
184+
void runAfterPassModule(StringRef PassID, const Module *M) {
185+
runOnModule(M, false);
186+
calculateDroppedVarStatsOnModule(M, PassID, M->getName().str(), "Module");
187+
}
85188
/// Populate DebugVariablesBefore, DebugVariablesAfter, InlinedAts before or
86189
/// after a pass has run to facilitate dropped variable calculation for an
87190
/// llvm::Function.
88191
void runOnFunction(const Function *F, bool Before);
192+
/// Iterate over all Instructions in a Function and report any dropped debug
193+
/// information.
194+
void calculateDroppedVarStatsOnFunction(const Function *F, StringRef PassID,
195+
StringRef FuncOrModName,
196+
StringRef PassLevel);
89197
/// Populate DebugVariablesBefore, DebugVariablesAfter, InlinedAts before or
90198
/// after a pass has run to facilitate dropped variable calculation for an
91199
/// llvm::Module. Calls runOnFunction on every Function in the Module.
92200
void runOnModule(const Module *M, bool Before);
93-
/// Remove a dropped #dbg_value VarID from all Sets in the
94-
/// DroppedVariablesBefore stack.
95-
void removeVarFromAllSets(VarID Var, const Function *F);
96-
/// Return true if \p Scope is the same as \p DbgValScope or a child scope of
97-
/// \p DbgValScope, return false otherwise.
98-
bool isScopeChildOfOrEqualTo(DIScope *Scope, const DIScope *DbgValScope);
99-
/// Return true if \p InlinedAt is the same as \p DbgValInlinedAt or part of
100-
/// the InlinedAt chain, return false otherwise.
101-
bool isInlinedAtChildOfOrEqualTo(const DILocation *InlinedAt,
102-
const DILocation *DbgValInlinedAt);
201+
/// Iterate over all Functions in a Module and report any dropped debug
202+
/// information. Will call calculateDroppedVarStatsOnFunction on every
203+
/// Function.
204+
void calculateDroppedVarStatsOnModule(const Module *M, StringRef PassID,
205+
StringRef FuncOrModName,
206+
StringRef PassLevel);
207+
/// Override base class method to run on an llvm::Function specifically.
208+
virtual void
209+
visitEveryInstruction(unsigned &DroppedCount,
210+
DenseMap<VarID, DILocation *> &InlinedAtsMap,
211+
VarID Var) override;
212+
/// Override base class method to run on #dbg_values specifically.
213+
virtual void visitEveryDebugRecord(
214+
DenseSet<VarID> &VarIDSet,
215+
DenseMap<StringRef, DenseMap<VarID, DILocation *>> &InlinedAtsMap,
216+
StringRef FuncName, bool Before) override;
217+
103218
template <typename IRUnitT> static const IRUnitT *unwrapIR(Any IR) {
104219
const IRUnitT **IRPtr = llvm::any_cast<const IRUnitT *>(&IR);
105220
return IRPtr ? *IRPtr : nullptr;
@@ -108,4 +223,4 @@ class DroppedVariableStats {
108223

109224
} // namespace llvm
110225

111-
#endif
226+
#endif

llvm/include/llvm/Passes/StandardInstrumentations.h

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -597,7 +597,7 @@ class StandardInstrumentations {
597597
PrintCrashIRInstrumentation PrintCrashIR;
598598
IRChangedTester ChangeTester;
599599
VerifyInstrumentation Verify;
600-
DroppedVariableStats DroppedStats;
600+
DroppedVariableStatsIR DroppedStatsIR;
601601

602602
bool VerifyEach;
603603

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