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[OPENMP]Reduce number of captured global vars.
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Try to reduce the number of global vars captured in the OpenMP regions
by capturing them only the regions, which mark them as not-shared.
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@alexey-bataev
alexey-bataev committed Mar 13, 2020
1 parent 6bbc173 commit 172f146
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Showing 8 changed files with 62 additions and 12 deletions.
7 changes: 7 additions & 0 deletions clang/include/clang/Sema/Sema.h
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Expand Up @@ -9858,6 +9858,13 @@ class Sema final {
bool isOpenMPTargetCapturedDecl(const ValueDecl *D, unsigned Level,
unsigned CaptureLevel) const;

/// Check if the specified global variable must be captured by outer capture
/// regions.
/// \param Level Relative level of nested OpenMP construct for that
/// the check is performed.
bool isOpenMPGlobalCapturedDecl(ValueDecl *D, unsigned Level,
unsigned CaptureLevel) const;

ExprResult PerformOpenMPImplicitIntegerConversion(SourceLocation OpLoc,
Expr *Op);
/// Called on start of new data sharing attribute block.
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9 changes: 7 additions & 2 deletions clang/lib/CodeGen/CGStmtOpenMP.cpp
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Expand Up @@ -57,7 +57,8 @@ class OMPLexicalScope : public CodeGenFunction::LexicalScope {
static bool isCapturedVar(CodeGenFunction &CGF, const VarDecl *VD) {
return CGF.LambdaCaptureFields.lookup(VD) ||
(CGF.CapturedStmtInfo && CGF.CapturedStmtInfo->lookup(VD)) ||
(CGF.CurCodeDecl && isa<BlockDecl>(CGF.CurCodeDecl));
(CGF.CurCodeDecl && isa<BlockDecl>(CGF.CurCodeDecl) &&
cast<BlockDecl>(CGF.CurCodeDecl)->capturesVariable(VD));
}

public:
Expand Down Expand Up @@ -5551,7 +5552,11 @@ void CodeGenFunction::EmitOMPTaskLoopBasedDirective(const OMPLoopDirective &S) {
assert(isOpenMPTaskLoopDirective(S.getDirectiveKind()));
// Emit outlined function for task construct.
const CapturedStmt *CS = S.getCapturedStmt(OMPD_taskloop);
Address CapturedStruct = GenerateCapturedStmtArgument(*CS);
Address CapturedStruct = Address::invalid();
{
OMPLexicalScope Scope(*this, S, OMPD_taskloop, /*EmitPreInitStmt=*/false);
CapturedStruct = GenerateCapturedStmtArgument(*CS);
}
QualType SharedsTy = getContext().getRecordType(CS->getCapturedRecordDecl());
const Expr *IfCond = nullptr;
for (const auto *C : S.getClausesOfKind<OMPIfClause>()) {
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8 changes: 7 additions & 1 deletion clang/lib/Sema/SemaExpr.cpp
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Expand Up @@ -16523,13 +16523,19 @@ bool Sema::tryCaptureVariable(
!IsOpenMPPrivateDecl &&
isOpenMPTargetCapturedDecl(Var, RSI->OpenMPLevel,
RSI->OpenMPCaptureLevel);
// Do not capture global if it is not privatized in outer regions.
bool IsGlobalCap =
IsGlobal && isOpenMPGlobalCapturedDecl(Var, RSI->OpenMPLevel,
RSI->OpenMPCaptureLevel);

// When we detect target captures we are looking from inside the
// target region, therefore we need to propagate the capture from the
// enclosing region. Therefore, the capture is not initially nested.
if (IsTargetCap)
adjustOpenMPTargetScopeIndex(FunctionScopesIndex, RSI->OpenMPLevel);

if (IsTargetCap || IsOpenMPPrivateDecl) {
if (IsTargetCap || IsOpenMPPrivateDecl ||
(IsGlobal && !IsGlobalCap)) {
Nested = !IsTargetCap;
DeclRefType = DeclRefType.getUnqualifiedType();
CaptureType = Context.getLValueReferenceType(DeclRefType);
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42 changes: 37 additions & 5 deletions clang/lib/Sema/SemaOpenMP.cpp
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Expand Up @@ -498,6 +498,8 @@ class DSAStackTy {
const DSAVarData getTopDSA(ValueDecl *D, bool FromParent);
/// Returns data-sharing attributes for the specified declaration.
const DSAVarData getImplicitDSA(ValueDecl *D, bool FromParent) const;
/// Returns data-sharing attributes for the specified declaration.
const DSAVarData getImplicitDSA(ValueDecl *D, unsigned Level) const;
/// Checks if the specified variables has data-sharing attributes which
/// match specified \a CPred predicate in any directive which matches \a DPred
/// predicate.
Expand Down Expand Up @@ -1552,6 +1554,15 @@ const DSAStackTy::DSAVarData DSAStackTy::getImplicitDSA(ValueDecl *D,
return getDSA(StartI, D);
}

const DSAStackTy::DSAVarData DSAStackTy::getImplicitDSA(ValueDecl *D,
unsigned Level) const {
if (getStackSize() <= Level)
return DSAVarData();
D = getCanonicalDecl(D);
const_iterator StartI = std::next(begin(), getStackSize() - 1 - Level);
return getDSA(StartI, D);
}

const DSAStackTy::DSAVarData
DSAStackTy::hasDSA(ValueDecl *D,
const llvm::function_ref<bool(OpenMPClauseKind)> CPred,
Expand Down Expand Up @@ -2108,9 +2119,7 @@ VarDecl *Sema::isOpenMPCapturedDecl(ValueDecl *D, bool CheckScopeInfo,

void Sema::adjustOpenMPTargetScopeIndex(unsigned &FunctionScopesIndex,
unsigned Level) const {
SmallVector<OpenMPDirectiveKind, 4> Regions;
getOpenMPCaptureRegions(Regions, DSAStack->getDirective(Level));
FunctionScopesIndex -= Regions.size();
FunctionScopesIndex -= getOpenMPCaptureLevels(DSAStack->getDirective(Level));
}

void Sema::startOpenMPLoop() {
Expand Down Expand Up @@ -2213,6 +2222,29 @@ bool Sema::isOpenMPTargetCapturedDecl(const ValueDecl *D, unsigned Level,
Regions[CaptureLevel] != OMPD_task;
}

bool Sema::isOpenMPGlobalCapturedDecl(ValueDecl *D, unsigned Level,
unsigned CaptureLevel) const {
assert(LangOpts.OpenMP && "OpenMP is not allowed");
// Return true if the current level is no longer enclosed in a target region.

if (const auto *VD = dyn_cast<VarDecl>(D)) {
if (!VD->hasLocalStorage()) {
DSAStackTy::DSAVarData TopDVar =
DSAStack->getTopDSA(D, /*FromParent=*/false);
unsigned NumLevels =
getOpenMPCaptureLevels(DSAStack->getDirective(Level));
if (Level == 0)
return (NumLevels == CaptureLevel + 1) && TopDVar.CKind != OMPC_shared;
DSAStackTy::DSAVarData DVar = DSAStack->getImplicitDSA(D, Level - 1);
return DVar.CKind != OMPC_shared ||
isOpenMPGlobalCapturedDecl(
D, Level - 1,
getOpenMPCaptureLevels(DSAStack->getDirective(Level - 1)) - 1);
}
}
return true;
}

void Sema::DestroyDataSharingAttributesStack() { delete DSAStack; }

void Sema::finalizeOpenMPDelayedAnalysis() {
Expand Down Expand Up @@ -3575,7 +3607,7 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
};
// Start a captured region for 'parallel'.
ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
ParamsParallel, /*OpenMPCaptureLevel=*/1);
ParamsParallel, /*OpenMPCaptureLevel=*/0);
QualType Args[] = {VoidPtrTy};
FunctionProtoType::ExtProtoInfo EPI;
EPI.Variadic = true;
Expand All @@ -3596,7 +3628,7 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
std::make_pair(StringRef(), QualType()) // __context with shared vars
};
ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
Params, /*OpenMPCaptureLevel=*/2);
Params, /*OpenMPCaptureLevel=*/1);
// Mark this captured region as inlined, because we don't use outlined
// function directly.
getCurCapturedRegion()->TheCapturedDecl->addAttr(
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2 changes: 1 addition & 1 deletion clang/test/OpenMP/parallel_master_taskloop_firstprivate_codegen.cpp
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Expand Up @@ -206,7 +206,7 @@ int main() {
// CHECK: [[VAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 4
// CHECK: store [[S_DOUBLE_TY]]* %{{.+}}, [[S_DOUBLE_TY]]** [[VAR_REF]],
// CHECK: [[SIVAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 5
// CHECK: [[SIVAR_VAL:%.+]] = load i32, i32* %{{.+}},
// CHECK: [[SIVAR_VAL:%.+]] = load i32, i32* @{{.+}},
// CHECK: store i{{[0-9]+}} [[SIVAR_VAL]], i{{[0-9]+}}* [[SIVAR_REF]],

// Allocate task.
Expand Down
2 changes: 1 addition & 1 deletion clang/test/OpenMP/parallel_master_taskloop_lastprivate_codegen.cpp
View file
Expand Up @@ -187,7 +187,7 @@ int main() {
// CHECK: [[VAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 3
// CHECK: store [[S_DOUBLE_TY]]* [[VAR_ADDR:%.+]], [[S_DOUBLE_TY]]** [[VAR_REF]],
// CHECK: [[SIVAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 4
// CHECK: store i{{[0-9]+}}* [[SIVAR:%.+]], i{{[0-9]+}}** [[SIVAR_REF]],
// CHECK: store i{{[0-9]+}}* [[SIVAR:@.+]], i{{[0-9]+}}** [[SIVAR_REF]],

// Allocate task.
// Returns struct kmp_task_t {
Expand Down
2 changes: 1 addition & 1 deletion clang/test/OpenMP/parallel_master_taskloop_simd_firstprivate_codegen.cpp
View file
Expand Up @@ -206,7 +206,7 @@ int main() {
// CHECK: [[VAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 4
// CHECK: store [[S_DOUBLE_TY]]* %{{.+}}, [[S_DOUBLE_TY]]** [[VAR_REF]],
// CHECK: [[SIVAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 5
// CHECK: [[SIVAR_VAL:%.+]] = load i32, i32* %{{.+}},
// CHECK: [[SIVAR_VAL:%.+]] = load i32, i32* @{{.+}},
// CHECK: store i{{[0-9]+}} [[SIVAR_VAL]], i{{[0-9]+}}* [[SIVAR_REF]],

// Allocate task.
Expand Down
2 changes: 1 addition & 1 deletion clang/test/OpenMP/parallel_master_taskloop_simd_lastprivate_codegen.cpp
View file
Expand Up @@ -187,7 +187,7 @@ int main() {
// CHECK: [[VAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 3
// CHECK: store [[S_DOUBLE_TY]]* [[VAR_ADDR:%.+]], [[S_DOUBLE_TY]]** [[VAR_REF]],
// CHECK: [[SIVAR_REF:%.+]] = getelementptr inbounds [[CAP_MAIN_TY]], [[CAP_MAIN_TY]]* %{{.+}}, i{{[0-9]+}} 0, i{{[0-9]+}} 4
// CHECK: store i{{[0-9]+}}* [[SIVAR:%.+]], i{{[0-9]+}}** [[SIVAR_REF]],
// CHECK: store i{{[0-9]+}}* [[SIVAR:@.+]], i{{[0-9]+}}** [[SIVAR_REF]],

// Allocate task.
// Returns struct kmp_task_t {
Expand Down

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