[Coverage] Introduce getBranchCounterPair(). NFC.
#112702
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This aggregates the generation of branch counter pair as `ExecCnt` and `SkipCnt`, to aggregate `CounterExpr::subtract`. At the moment: - This change preserves the behavior of `llvm::EnableSingleByteCoverage`. Almost of SingleByteCoverage will be cleaned up by coming commits. - `getBranchCounterPair()` is not called in `llvm::EnableSingleByteCoverage`. I will implement the new behavior of SingleByteCoverage in it. - `IsCounterEqual(Out, Par)` is introduced instead of `Counter::operator==`. Tweaks would be required for the comparison for additional counters. - Braces around `assert()` is intentional. I will add a statement there. https://discourse.llvm.org/t/rfc-integrating-singlebytecoverage-with-branch-coverage/82492
llvmbot
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clang
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@llvm/pr-subscribers-clang-codegen @llvm/pr-subscribers-clang Author: NAKAMURA Takumi (chapuni) ChangesThis aggregates the generation of branch counter pair as
https://discourse.llvm.org/t/rfc-integrating-singlebytecoverage-with-branch-coverage/82492 Full diff: https://github.com/llvm/llvm-project/pull/112702.diff 1 Files Affected:
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 07015834bc84f3..0bfad9cbcbe12b 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -941,6 +941,19 @@ struct CounterCoverageMappingBuilder
return Counter::getCounter(CounterMap[S]);
}
+ std::pair<Counter, Counter> getBranchCounterPair(const Stmt *S,
+ Counter ParentCnt) {
+ Counter ExecCnt = getRegionCounter(S);
+ return {ExecCnt, Builder.subtract(ParentCnt, ExecCnt)};
+ }
+
+ bool IsCounterEqual(Counter OutCount, Counter ParentCount) {
+ if (OutCount == ParentCount)
+ return true;
+
+ return false;
+ }
+
/// Push a region onto the stack.
///
/// Returns the index on the stack where the region was pushed. This can be
@@ -1592,6 +1605,13 @@ struct CounterCoverageMappingBuilder
llvm::EnableSingleByteCoverage
? getRegionCounter(S->getCond())
: addCounters(ParentCount, BackedgeCount, BC.ContinueCount);
+ auto [ExecCount, ExitCount] =
+ (llvm::EnableSingleByteCoverage
+ ? std::make_pair(getRegionCounter(S), Counter::getZero())
+ : getBranchCounterPair(S, CondCount));
+ if (!llvm::EnableSingleByteCoverage) {
+ assert(ExecCount.isZero() || ExecCount == BodyCount);
+ }
propagateCounts(CondCount, S->getCond());
adjustForOutOfOrderTraversal(getEnd(S));
@@ -1600,13 +1620,11 @@ struct CounterCoverageMappingBuilder
if (Gap)
fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), BodyCount);
- Counter OutCount =
- llvm::EnableSingleByteCoverage
- ? getRegionCounter(S)
- : addCounters(BC.BreakCount,
- subtractCounters(CondCount, BodyCount));
+ Counter OutCount = llvm::EnableSingleByteCoverage
+ ? getRegionCounter(S)
+ : addCounters(BC.BreakCount, ExitCount);
- if (OutCount != ParentCount) {
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
if (BodyHasTerminateStmt)
@@ -1615,8 +1633,7 @@ struct CounterCoverageMappingBuilder
// Create Branch Region around condition.
if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(S->getCond(), BodyCount,
- subtractCounters(CondCount, BodyCount));
+ createBranchRegion(S->getCond(), BodyCount, ExitCount);
}
void VisitDoStmt(const DoStmt *S) {
@@ -1645,22 +1662,26 @@ struct CounterCoverageMappingBuilder
Counter CondCount = llvm::EnableSingleByteCoverage
? getRegionCounter(S->getCond())
: addCounters(BackedgeCount, BC.ContinueCount);
+ auto [ExecCount, ExitCount] =
+ (llvm::EnableSingleByteCoverage
+ ? std::make_pair(getRegionCounter(S), Counter::getZero())
+ : getBranchCounterPair(S, CondCount));
+ if (!llvm::EnableSingleByteCoverage) {
+ assert(ExecCount.isZero() || ExecCount == BodyCount);
+ }
propagateCounts(CondCount, S->getCond());
- Counter OutCount =
- llvm::EnableSingleByteCoverage
- ? getRegionCounter(S)
- : addCounters(BC.BreakCount,
- subtractCounters(CondCount, BodyCount));
- if (OutCount != ParentCount) {
+ Counter OutCount = llvm::EnableSingleByteCoverage
+ ? getRegionCounter(S)
+ : addCounters(BC.BreakCount, ExitCount);
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
}
// Create Branch Region around condition.
if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(S->getCond(), BodyCount,
- subtractCounters(CondCount, BodyCount));
+ createBranchRegion(S->getCond(), BodyCount, ExitCount);
if (BodyHasTerminateStmt)
HasTerminateStmt = true;
@@ -1709,6 +1730,13 @@ struct CounterCoverageMappingBuilder
: addCounters(
addCounters(ParentCount, BackedgeCount, BodyBC.ContinueCount),
IncrementBC.ContinueCount);
+ auto [ExecCount, ExitCount] =
+ (llvm::EnableSingleByteCoverage
+ ? std::make_pair(getRegionCounter(S), Counter::getZero())
+ : getBranchCounterPair(S, CondCount));
+ if (!llvm::EnableSingleByteCoverage) {
+ assert(ExecCount.isZero() || ExecCount == BodyCount);
+ }
if (const Expr *Cond = S->getCond()) {
propagateCounts(CondCount, Cond);
@@ -1723,9 +1751,8 @@ struct CounterCoverageMappingBuilder
Counter OutCount =
llvm::EnableSingleByteCoverage
? getRegionCounter(S)
- : addCounters(BodyBC.BreakCount, IncrementBC.BreakCount,
- subtractCounters(CondCount, BodyCount));
- if (OutCount != ParentCount) {
+ : addCounters(BodyBC.BreakCount, IncrementBC.BreakCount, ExitCount);
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
if (BodyHasTerminateStmt)
@@ -1734,8 +1761,7 @@ struct CounterCoverageMappingBuilder
// Create Branch Region around condition.
if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(S->getCond(), BodyCount,
- subtractCounters(CondCount, BodyCount));
+ createBranchRegion(S->getCond(), BodyCount, ExitCount);
}
void VisitCXXForRangeStmt(const CXXForRangeStmt *S) {
@@ -1764,15 +1790,21 @@ struct CounterCoverageMappingBuilder
fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), BodyCount);
Counter OutCount;
+ Counter ExitCount;
Counter LoopCount;
if (llvm::EnableSingleByteCoverage)
OutCount = getRegionCounter(S);
else {
- LoopCount = addCounters(ParentCount, BackedgeCount, BC.ContinueCount);
- OutCount =
- addCounters(BC.BreakCount, subtractCounters(LoopCount, BodyCount));
+ LoopCount =
+ (ParentCount.isZero()
+ ? ParentCount
+ : addCounters(ParentCount, BackedgeCount, BC.ContinueCount));
+ auto [ExecCount, SkipCount] = getBranchCounterPair(S, LoopCount);
+ ExitCount = SkipCount;
+ assert(ExecCount.isZero() || ExecCount == BodyCount);
+ OutCount = addCounters(BC.BreakCount, ExitCount);
}
- if (OutCount != ParentCount) {
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
if (BodyHasTerminateStmt)
@@ -1781,8 +1813,7 @@ struct CounterCoverageMappingBuilder
// Create Branch Region around condition.
if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(S->getCond(), BodyCount,
- subtractCounters(LoopCount, BodyCount));
+ createBranchRegion(S->getCond(), BodyCount, ExitCount);
}
void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) {
@@ -1803,10 +1834,13 @@ struct CounterCoverageMappingBuilder
fillGapAreaWithCount(Gap->getBegin(), Gap->getEnd(), BodyCount);
Counter LoopCount =
- addCounters(ParentCount, BackedgeCount, BC.ContinueCount);
- Counter OutCount =
- addCounters(BC.BreakCount, subtractCounters(LoopCount, BodyCount));
- if (OutCount != ParentCount) {
+ (ParentCount.isZero()
+ ? ParentCount
+ : addCounters(ParentCount, BackedgeCount, BC.ContinueCount));
+ auto [ExecCount, ExitCount] = getBranchCounterPair(S, LoopCount);
+ assert(ExecCount.isZero() || ExecCount == BodyCount);
+ Counter OutCount = addCounters(BC.BreakCount, ExitCount);
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
}
@@ -2016,9 +2050,12 @@ struct CounterCoverageMappingBuilder
extendRegion(S->getCond());
Counter ParentCount = getRegion().getCounter();
- Counter ThenCount = llvm::EnableSingleByteCoverage
- ? getRegionCounter(S->getThen())
- : getRegionCounter(S);
+ auto [ThenCount, ElseCount] =
+ (llvm::EnableSingleByteCoverage
+ ? std::make_pair(getRegionCounter(S->getThen()),
+ (S->getElse() ? getRegionCounter(S->getElse())
+ : Counter::getZero()))
+ : getBranchCounterPair(S, ParentCount));
// Emitting a counter for the condition makes it easier to interpret the
// counter for the body when looking at the coverage.
@@ -2033,12 +2070,6 @@ struct CounterCoverageMappingBuilder
extendRegion(S->getThen());
Counter OutCount = propagateCounts(ThenCount, S->getThen());
- Counter ElseCount;
- if (!llvm::EnableSingleByteCoverage)
- ElseCount = subtractCounters(ParentCount, ThenCount);
- else if (S->getElse())
- ElseCount = getRegionCounter(S->getElse());
-
if (const Stmt *Else = S->getElse()) {
bool ThenHasTerminateStmt = HasTerminateStmt;
HasTerminateStmt = false;
@@ -2061,15 +2092,14 @@ struct CounterCoverageMappingBuilder
if (llvm::EnableSingleByteCoverage)
OutCount = getRegionCounter(S);
- if (OutCount != ParentCount) {
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
}
if (!S->isConsteval() && !llvm::EnableSingleByteCoverage)
// Create Branch Region around condition.
- createBranchRegion(S->getCond(), ThenCount,
- subtractCounters(ParentCount, ThenCount));
+ createBranchRegion(S->getCond(), ThenCount, ElseCount);
}
void VisitCXXTryStmt(const CXXTryStmt *S) {
@@ -2095,9 +2125,11 @@ struct CounterCoverageMappingBuilder
extendRegion(E);
Counter ParentCount = getRegion().getCounter();
- Counter TrueCount = llvm::EnableSingleByteCoverage
- ? getRegionCounter(E->getTrueExpr())
- : getRegionCounter(E);
+ auto [TrueCount, FalseCount] =
+ (llvm::EnableSingleByteCoverage
+ ? std::make_pair(getRegionCounter(E->getTrueExpr()),
+ getRegionCounter(E->getFalseExpr()))
+ : getBranchCounterPair(E, ParentCount));
Counter OutCount;
if (const auto *BCO = dyn_cast<BinaryConditionalOperator>(E)) {
@@ -2116,25 +2148,20 @@ struct CounterCoverageMappingBuilder
}
extendRegion(E->getFalseExpr());
- Counter FalseCount = llvm::EnableSingleByteCoverage
- ? getRegionCounter(E->getFalseExpr())
- : subtractCounters(ParentCount, TrueCount);
-
Counter FalseOutCount = propagateCounts(FalseCount, E->getFalseExpr());
if (llvm::EnableSingleByteCoverage)
OutCount = getRegionCounter(E);
else
OutCount = addCounters(OutCount, FalseOutCount);
- if (OutCount != ParentCount) {
+ if (!IsCounterEqual(OutCount, ParentCount)) {
pushRegion(OutCount);
GapRegionCounter = OutCount;
}
// Create Branch Region around condition.
if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(E->getCond(), TrueCount,
- subtractCounters(ParentCount, TrueCount));
+ createBranchRegion(E->getCond(), TrueCount, FalseCount);
}
void createOrCancelDecision(const BinaryOperator *E, unsigned Since) {
@@ -2233,27 +2260,27 @@ struct CounterCoverageMappingBuilder
extendRegion(E->getRHS());
propagateCounts(getRegionCounter(E), E->getRHS());
+ if (llvm::EnableSingleByteCoverage)
+ return;
+
// Track RHS True/False Decision.
const auto DecisionRHS = MCDCBuilder.back();
+ // Extract the Parent Region Counter.
+ Counter ParentCnt = getRegion().getCounter();
+
// Extract the RHS's Execution Counter.
- Counter RHSExecCnt = getRegionCounter(E);
+ auto [RHSExecCnt, LHSExitCnt] = getBranchCounterPair(E, ParentCnt);
// Extract the RHS's "True" Instance Counter.
- Counter RHSTrueCnt = getRegionCounter(E->getRHS());
-
- // Extract the Parent Region Counter.
- Counter ParentCnt = getRegion().getCounter();
+ auto [RHSTrueCnt, RHSExitCnt] =
+ getBranchCounterPair(E->getRHS(), RHSExecCnt);
// Create Branch Region around LHS condition.
- if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(E->getLHS(), RHSExecCnt,
- subtractCounters(ParentCnt, RHSExecCnt), DecisionLHS);
+ createBranchRegion(E->getLHS(), RHSExecCnt, LHSExitCnt, DecisionLHS);
// Create Branch Region around RHS condition.
- if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(E->getRHS(), RHSTrueCnt,
- subtractCounters(RHSExecCnt, RHSTrueCnt), DecisionRHS);
+ createBranchRegion(E->getRHS(), RHSTrueCnt, RHSExitCnt, DecisionRHS);
// Create MCDC Decision Region if at top-level (root).
if (IsRootNode)
@@ -2294,31 +2321,31 @@ struct CounterCoverageMappingBuilder
extendRegion(E->getRHS());
propagateCounts(getRegionCounter(E), E->getRHS());
+ if (llvm::EnableSingleByteCoverage)
+ return;
+
// Track RHS True/False Decision.
const auto DecisionRHS = MCDCBuilder.back();
+ // Extract the Parent Region Counter.
+ Counter ParentCnt = getRegion().getCounter();
+
// Extract the RHS's Execution Counter.
- Counter RHSExecCnt = getRegionCounter(E);
+ auto [RHSExecCnt, LHSExitCnt] = getBranchCounterPair(E, ParentCnt);
// Extract the RHS's "False" Instance Counter.
- Counter RHSFalseCnt = getRegionCounter(E->getRHS());
+ auto [RHSFalseCnt, RHSExitCnt] =
+ getBranchCounterPair(E->getRHS(), RHSExecCnt);
if (!shouldVisitRHS(E->getLHS())) {
GapRegionCounter = OutCount;
}
- // Extract the Parent Region Counter.
- Counter ParentCnt = getRegion().getCounter();
-
// Create Branch Region around LHS condition.
- if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(E->getLHS(), subtractCounters(ParentCnt, RHSExecCnt),
- RHSExecCnt, DecisionLHS);
+ createBranchRegion(E->getLHS(), LHSExitCnt, RHSExecCnt, DecisionLHS);
// Create Branch Region around RHS condition.
- if (!llvm::EnableSingleByteCoverage)
- createBranchRegion(E->getRHS(), subtractCounters(RHSExecCnt, RHSFalseCnt),
- RHSFalseCnt, DecisionRHS);
+ createBranchRegion(E->getRHS(), RHSExitCnt, RHSFalseCnt, DecisionRHS);
// Create MCDC Decision Region if at top-level (root).
if (IsRootNode)
|
ornata
reviewed
Oct 18, 2024
| @@ -941,6 +941,19 @@ struct CounterCoverageMappingBuilder | |||
| return Counter::getCounter(CounterMap[S]); | |||
| } | |||
|
|
|||
| std::pair<Counter, Counter> getBranchCounterPair(const Stmt *S, | |||
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it's not immediately obvious what the pair represents from this function name.
getExecutionCountAnd...?
or, make a lightweight POD struct to represent this
struct ExecCntAnd... {
Counter ExecCnt
Counter ...
};
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I like a silly std::pair :) Let me think more.
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I think changing the name is sufficient for making me less confused
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Done but I am still dubious namings would be appropriate. Not all users expect [Exec, Skip], but [Exec, Exit] or similar. Do you have a better idea to resolve namings (not by structural assignments but by name)?
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Conflicts: clang/lib/CodeGen/CoverageMappingGen.cpp
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| @@ -938,6 +938,37 @@ struct CounterCoverageMappingBuilder | |||
| return Counter::getCounter(CounterMap[S]); | |||
| } | |||
|
|
|||
| struct BranchCounterPair { | |||
| Counter Executed; | |||
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Comments on member variables?
E.g.
/// Counter tracking number of times the branch was encountered and taken.
Counter Executed;
/// Counter tracking the number of times the branch was encountered, but not taken.
Counter Skipped;
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I still wonder which pair of names would fit best. I adopted "Exec" from BinOp stuff and applied "Skipped" since "Exit" would be an exaggeration. "Checked/Skipped" would make less sense. OTOH, "Taken/NotTaken" looks redundant. Better idea?
I want them self-explained.
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| Counter Skipped; | ||
| }; | ||
|
|
||
| BranchCounterPair getBranchCounterPair(const Stmt *S, Counter ParentCnt) { |
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Can we add Doxygen comments for this?
I'd like to be able to know what, e.g. ParentCnt is only by looking at this function.
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| } | ||
|
|
||
| /// Returns {TrueCnt,FalseCnt} for "implicit default". | ||
| /// FalseCnt is considered as the False count on SwitchStmt. |
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getSwitchImplicitDefaultCounterPair has been migrated to #113112. I suppose this explained what it did.
Note, I didn't migrate this using BranchCounterPair since I thought this was semantically different from others.
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This aggregates the generation of branch counter pair as
ExecCntandSkipCnt, to aggregateCounterExpr::subtract. At the moment:This change preserves the behavior of
llvm::EnableSingleByteCoverage. Almost of SingleByteCoverage will be cleaned up by coming commits.IsCounterEqual(Out, Par)is introduced instead ofCounter::operator==. Tweaks would be required for the comparison for additional counters.https://discourse.llvm.org/t/rfc-integrating-singlebytecoverage-with-branch-coverage/82492