[clang] 779c05a - [MC/DC] Create dedicated MCDCCondBitmapAddr for each Decision (#125411)
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Wed Jan 14 16:08:10 PST 2026
Author: NAKAMURA Takumi
Date: 2026-01-15T09:08:06+09:00
New Revision: 779c05a62548b694750be985d86fa193b0983fa7
URL: https://github.com/llvm/llvm-project/commit/779c05a62548b694750be985d86fa193b0983fa7
DIFF: https://github.com/llvm/llvm-project/commit/779c05a62548b694750be985d86fa193b0983fa7.diff
LOG: [MC/DC] Create dedicated MCDCCondBitmapAddr for each Decision (#125411)
MCDCCondBitmapAddr is moved from `CodeGenFunction` into `MCDCState` and
created for each Decision.
In `maybeCreateMCDCCondBitmap`, Allocate bitmaps for all valid Decisions
and emit them order by ID, to prevent nondeterminism.
Added:
Modified:
clang/lib/CodeGen/CodeGenFunction.h
clang/lib/CodeGen/CodeGenPGO.cpp
clang/lib/CodeGen/CodeGenPGO.h
clang/lib/CodeGen/MCDCState.h
clang/test/Profile/c-mcdc-logicalop-ternary.c
Removed:
################################################################################
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index caf68f28d4661..1073de1d25ec7 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -1644,9 +1644,6 @@ class CodeGenFunction : public CodeGenTypeCache {
std::unique_ptr<CodeGenPGO> PGO;
- /// Bitmap used by MC/DC to track condition outcomes of a boolean expression.
- Address MCDCCondBitmapAddr = Address::invalid();
-
/// Calculate branch weights appropriate for PGO data
llvm::MDNode *createProfileWeights(uint64_t TrueCount,
uint64_t FalseCount) const;
diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
index 9cd53208f8abd..d4d1abd50af42 100644
--- a/clang/lib/CodeGen/CodeGenPGO.cpp
+++ b/clang/lib/CodeGen/CodeGenPGO.cpp
@@ -1265,9 +1265,29 @@ void CodeGenPGO::emitMCDCParameters(CGBuilderTy &Builder) {
CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_parameters), Args);
}
+/// Fill mcdc.addr order by ID.
+std::vector<Address *>
+CodeGenPGO::getMCDCCondBitmapAddrArray(CGBuilderTy &Builder) {
+ std::vector<Address *> Result;
+
+ if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState)
+ return Result;
+
+ SmallVector<std::pair<unsigned, Address *>> SortedPair;
+ for (auto &[_, V] : RegionMCDCState->DecisionByStmt)
+ if (V.isValid())
+ SortedPair.emplace_back(V.ID, &V.MCDCCondBitmapAddr);
+
+ llvm::sort(SortedPair);
+
+ for (auto &[_, MCDCCondBitmapAddr] : SortedPair)
+ Result.push_back(MCDCCondBitmapAddr);
+
+ return Result;
+}
+
void CodeGenPGO::emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder,
const Expr *S,
- Address MCDCCondBitmapAddr,
CodeGenFunction &CGF) {
if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState)
return;
@@ -1278,6 +1298,10 @@ void CodeGenPGO::emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder,
if (DecisionStateIter == RegionMCDCState->DecisionByStmt.end())
return;
+ auto &MCDCCondBitmapAddr = DecisionStateIter->second.MCDCCondBitmapAddr;
+ if (!MCDCCondBitmapAddr.isValid())
+ return;
+
// Don't create tvbitmap_update if the record is allocated but excluded.
// Or `bitmap |= (1 << 0)` would be wrongly executed to the next bitmap.
if (DecisionStateIter->second.Indices.size() == 0)
@@ -1300,14 +1324,16 @@ void CodeGenPGO::emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder,
CGM.getIntrinsic(llvm::Intrinsic::instrprof_mcdc_tvbitmap_update), Args);
}
-void CodeGenPGO::emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S,
- Address MCDCCondBitmapAddr) {
+void CodeGenPGO::emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S) {
if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState)
return;
- S = S->IgnoreParens();
+ auto I = RegionMCDCState->DecisionByStmt.find(S->IgnoreParens());
+ if (I == RegionMCDCState->DecisionByStmt.end())
+ return;
- if (!RegionMCDCState->DecisionByStmt.contains(S))
+ auto &MCDCCondBitmapAddr = I->second.MCDCCondBitmapAddr;
+ if (!MCDCCondBitmapAddr.isValid())
return;
// Emit intrinsic that resets a dedicated temporary value on the stack to 0.
@@ -1315,7 +1341,6 @@ void CodeGenPGO::emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S,
}
void CodeGenPGO::emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
- Address MCDCCondBitmapAddr,
llvm::Value *Val,
CodeGenFunction &CGF) {
if (!canEmitMCDCCoverage(Builder) || !RegionMCDCState)
@@ -1345,6 +1370,10 @@ void CodeGenPGO::emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
if (DecisionIter == RegionMCDCState->DecisionByStmt.end())
return;
+ auto &MCDCCondBitmapAddr = DecisionIter->second.MCDCCondBitmapAddr;
+ if (!MCDCCondBitmapAddr.isValid())
+ return;
+
const auto &TVIdxs = DecisionIter->second.Indices[Branch.ID];
auto *CurTV = Builder.CreateLoad(MCDCCondBitmapAddr,
@@ -1558,7 +1587,12 @@ void CodeGenFunction::markStmtMaybeUsed(const Stmt *S) {
void CodeGenFunction::maybeCreateMCDCCondBitmap() {
if (isMCDCCoverageEnabled()) {
PGO->emitMCDCParameters(Builder);
- MCDCCondBitmapAddr = CreateIRTemp(getContext().UnsignedIntTy, "mcdc.addr");
+
+ // Set up MCDCCondBitmapAddr for each Decision.
+ // Note: This doesn't initialize Addrs in invalidated Decisions.
+ for (auto *MCDCCondBitmapAddr : PGO->getMCDCCondBitmapAddrArray(Builder))
+ *MCDCCondBitmapAddr =
+ CreateIRTemp(getContext().UnsignedIntTy, "mcdc.addr");
}
}
bool CodeGenFunction::isMCDCDecisionExpr(const Expr *E) const {
@@ -1569,13 +1603,13 @@ bool CodeGenFunction::isMCDCBranchExpr(const Expr *E) const {
}
void CodeGenFunction::maybeResetMCDCCondBitmap(const Expr *E) {
if (isMCDCCoverageEnabled() && isBinaryLogicalOp(E)) {
- PGO->emitMCDCCondBitmapReset(Builder, E, MCDCCondBitmapAddr);
+ PGO->emitMCDCCondBitmapReset(Builder, E);
PGO->setCurrentStmt(E);
}
}
void CodeGenFunction::maybeUpdateMCDCTestVectorBitmap(const Expr *E) {
if (isMCDCCoverageEnabled() && isBinaryLogicalOp(E)) {
- PGO->emitMCDCTestVectorBitmapUpdate(Builder, E, MCDCCondBitmapAddr, *this);
+ PGO->emitMCDCTestVectorBitmapUpdate(Builder, E, *this);
PGO->setCurrentStmt(E);
}
}
@@ -1583,7 +1617,7 @@ void CodeGenFunction::maybeUpdateMCDCTestVectorBitmap(const Expr *E) {
void CodeGenFunction::maybeUpdateMCDCCondBitmap(const Expr *E,
llvm::Value *Val) {
if (isMCDCCoverageEnabled()) {
- PGO->emitMCDCCondBitmapUpdate(Builder, E, MCDCCondBitmapAddr, Val, *this);
+ PGO->emitMCDCCondBitmapUpdate(Builder, E, Val, *this);
PGO->setCurrentStmt(E);
}
}
diff --git a/clang/lib/CodeGen/CodeGenPGO.h b/clang/lib/CodeGen/CodeGenPGO.h
index 05cb9d497b91e..5e2d72e8427fb 100644
--- a/clang/lib/CodeGen/CodeGenPGO.h
+++ b/clang/lib/CodeGen/CodeGenPGO.h
@@ -129,14 +129,12 @@ class CodeGenPGO {
bool UseFalsePath, bool UseBoth,
llvm::Value *StepV);
void emitMCDCTestVectorBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
- Address MCDCCondBitmapAddr,
CodeGenFunction &CGF);
void emitMCDCParameters(CGBuilderTy &Builder);
- void emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S,
- Address MCDCCondBitmapAddr);
+ std::vector<Address *> getMCDCCondBitmapAddrArray(CGBuilderTy &Builder);
+ void emitMCDCCondBitmapReset(CGBuilderTy &Builder, const Expr *S);
void emitMCDCCondBitmapUpdate(CGBuilderTy &Builder, const Expr *S,
- Address MCDCCondBitmapAddr, llvm::Value *Val,
- CodeGenFunction &CGF);
+ llvm::Value *Val, CodeGenFunction &CGF);
void markStmtAsUsed(bool Skipped, const Stmt *S) {
// Do nothing.
diff --git a/clang/lib/CodeGen/MCDCState.h b/clang/lib/CodeGen/MCDCState.h
index 4b89ddd12d672..583157409b02f 100644
--- a/clang/lib/CodeGen/MCDCState.h
+++ b/clang/lib/CodeGen/MCDCState.h
@@ -13,6 +13,7 @@
#ifndef LLVM_CLANG_LIB_CODEGEN_MCDCSTATE_H
#define LLVM_CLANG_LIB_CODEGEN_MCDCSTATE_H
+#include "Address.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ProfileData/Coverage/MCDCTypes.h"
@@ -38,6 +39,7 @@ struct State {
unsigned BitmapIdx;
IndicesTy Indices;
unsigned ID = InvalidID;
+ Address MCDCCondBitmapAddr = Address::invalid();
bool isValid() const { return ID != InvalidID; }
diff --git a/clang/test/Profile/c-mcdc-logicalop-ternary.c b/clang/test/Profile/c-mcdc-logicalop-ternary.c
index 18ce0b4e5dc14..18682ffdbfec3 100644
--- a/clang/test/Profile/c-mcdc-logicalop-ternary.c
+++ b/clang/test/Profile/c-mcdc-logicalop-ternary.c
@@ -13,12 +13,14 @@ int test(int a, int b, int c, int d, int e, int f) {
// ALLOCATE MCDC TEMP AND ZERO IT.
// MCDC-LABEL: @test(
-// MCDC: %mcdc.addr = alloca i32, align 4
-// MCDC: store i32 0, ptr %mcdc.addr, align 4
+// MCDC: %[[ADDR0:mcdc.+]] = alloca i32, align 4
+// MCDC: %[[ADDR1:mcdc.+]] = alloca i32, align 4
+// MCDC: %[[ADDR2:mcdc.+]] = alloca i32, align 4
+// MCDC: store i32 0, ptr %[[ADDR0]], align 4
// TERNARY TRUE SHOULD UPDATE THE BITMAP WITH RESULT AT ELEMENT 0.
// MCDC-LABEL: cond.true:
-// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %mcdc.addr, align 4
+// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %[[ADDR0]], align 4
// MCDC: %[[TEMP:[0-9]+]] = add i32 %[[TEMP0]], 0
// MCDC: %[[LAB1:[0-9]+]] = lshr i32 %[[TEMP]], 3
// MCDC: %[[LAB4:[0-9]+]] = getelementptr inbounds i8, ptr @__profbm_test, i32 %[[LAB1]]
@@ -30,12 +32,12 @@ int test(int a, int b, int c, int d, int e, int f) {
// MCDC: store i8 %[[LAB9]], ptr %[[LAB4]], align 1
// CHECK FOR ZERO OF MCDC TEMP
-// MCDC: store i32 0, ptr %mcdc.addr, align 4
+// MCDC: store i32 0, ptr %[[ADDR1]], align 4
// TERNARY TRUE YIELDS TERNARY LHS LOGICAL-AND.
// TERNARY LHS LOGICAL-AND SHOULD UPDATE THE BITMAP WITH RESULT AT ELEMENT 1.
// MCDC-LABEL: land.end:
-// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %mcdc.addr, align 4
+// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %[[ADDR1]], align 4
// MCDC: %[[TEMP:[0-9]+]] = add i32 %[[TEMP0]], 3
// MCDC: %[[LAB1:[0-9]+]] = lshr i32 %[[TEMP]], 3
// MCDC: %[[LAB4:[0-9]+]] = getelementptr inbounds i8, ptr @__profbm_test, i32 %[[LAB1]]
@@ -48,7 +50,7 @@ int test(int a, int b, int c, int d, int e, int f) {
// TERNARY FALSE SHOULD UPDATE THE BITMAP WITH RESULT AT ELEMENT 0.
// MCDC-LABEL: cond.false:
-// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %mcdc.addr, align 4
+// MCDC-DAG: %[[TEMP0:mcdc.+]] = load i32, ptr %[[ADDR0]], align 4
// MCDC: %[[TEMP:[0-9]+]] = add i32 %[[TEMP0]], 0
// MCDC: %[[LAB1:[0-9]+]] = lshr i32 %[[TEMP]], 3
// MCDC: %[[LAB4:[0-9]+]] = getelementptr inbounds i8, ptr @__profbm_test, i32 %[[LAB1]]
@@ -60,12 +62,12 @@ int test(int a, int b, int c, int d, int e, int f) {
// MCDC: store i8 %[[LAB9]], ptr %[[LAB4]], align 1
// CHECK FOR ZERO OF MCDC TEMP
-// MCDC: store i32 0, ptr %mcdc.addr, align 4
+// MCDC: store i32 0, ptr %[[ADDR2]], align 4
// TERNARY FALSE YIELDS TERNARY RHS LOGICAL-OR.
// TERNARY RHS LOGICAL-OR SHOULD UPDATE THE BITMAP WITH RESULT AT ELEMENT 2.
// MCDC-LABEL: lor.end:
-// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %mcdc.addr, align 4
+// MCDC-DAG: %[[TEMP0:mcdc.temp[0-9]*]] = load i32, ptr %[[ADDR2]], align 4
// MCDC: %[[TEMP:[0-9]+]] = add i32 %[[TEMP0]], 6
// MCDC: %[[LAB1:[0-9]+]] = lshr i32 %[[TEMP]], 3
// MCDC: %[[LAB4:[0-9]+]] = getelementptr inbounds i8, ptr @__profbm_test, i32 %[[LAB1]]
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