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Merged
delaram-talaashrafi merged 5 commits into from
Aug 25, 2026
Merged

[flang][OpenACC] Reject valued gang/worker/vector outside kernels #218695

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dda8d08
[flang][OpenACC] Reject valued gang/worker/vector outside kernels
Aug 25, 2026
94ecab5
Relocate
Aug 25, 2026
d3889d6
Merge branch 'main' of https://github.com/llvm/llvm-project into vect…
Aug 25, 2026
7a66289
Fix str
Aug 25, 2026
43171e1
Merge branch 'main' into vectorLenSemantic
delaram-talaashrafi Aug 25, 2026
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120 changes: 119 additions & 1 deletion flang/lib/Semantics/check-acc-structure.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -157,7 +157,9 @@ void AccStructureChecker::Enter(const parser::AccClause &x) {
SetContextClause(x);
}

void AccStructureChecker::Leave(const parser::AccClauseList &) {}
void AccStructureChecker::Leave(const parser::AccClauseList &) {
CheckLoopLevelClauseKernelsConflicts();
}

void AccStructureChecker::Enter(const parser::OpenACCBlockConstruct &x) {
const auto &beginBlockDir{std::get<parser::AccBeginBlockDirective>(x.t)};
Expand Down Expand Up @@ -293,6 +295,105 @@ std::optional<std::int64_t> AccStructureChecker::getGangDimensionSize(
return std::nullopt;
}

void AccStructureChecker::CheckLoopLevelClauseValue(
llvm::StringRef clauseName) {
if (GetContext().directive == llvm::acc::ACCD_kernels_loop ||
IsInsideKernelsConstruct())
return;

if (GetContext().directive == llvm::acc::ACCD_routine ||
HasOpenACCRoutineDirective(
&context_.FindScope(GetContext().clauseSource))) {
context_.Say(GetContext().clauseSource,
"'%s(value)' not allowed in subprogram compiled with ROUTINE directive"_err_en_US,
clauseName.str());
return;
}

llvm::acc::Directive dir{GetContext().directive};
if (dir == llvm::acc::ACCD_loop) {
if (std::optional<llvm::acc::Directive> parent{
getParentComputeConstruct()}) {
if (*parent == llvm::acc::ACCD_parallel)
dir = llvm::acc::ACCD_parallel_loop;
else if (*parent == llvm::acc::ACCD_serial)
dir = llvm::acc::ACCD_serial_loop;
}
}
context_.Say(GetContext().clauseSource,
"'%s(value)' not allowed in %s directive"_err_en_US, clauseName.str(),
parser::ToUpperCaseLetters(getDirectiveName(dir).str()));
}

static bool AccClauseHasVectorValue(const parser::AccClause &clause) {
const auto *vectorClause{std::get_if<parser::AccClause::Vector>(&clause.u)};
return vectorClause && vectorClause->v.has_value();
}

static bool AccClauseHasWorkerValue(const parser::AccClause &clause) {
const auto *workerClause{std::get_if<parser::AccClause::Worker>(&clause.u)};
return workerClause && workerClause->v.has_value();
}

static bool AccClauseHasGangNum(const parser::AccClause &clause) {
const auto *gangClause{std::get_if<parser::AccClause::Gang>(&clause.u)};
if (!gangClause || !gangClause->v)
return false;
for (const parser::AccGangArg &gangArg : gangClause->v->v)
if (std::get_if<parser::AccGangArg::Num>(&gangArg.u))
return true;
return false;
}

void AccStructureChecker::CheckLoopLevelClauseKernelsConflicts() {
if (dirContext_.empty())
return;
if (GetContext().directive != llvm::acc::ACCD_kernels_loop &&
!IsInsideKernelsConstruct())
return;

auto hasKernelsSizeClause{[&](llvm::acc::Clause sizeClause) {
for (DirectiveContext &ctx : dirContext_) {
if ((ctx.directive == llvm::acc::ACCD_kernels ||
ctx.directive == llvm::acc::ACCD_kernels_loop) &&
FindClause(ctx, sizeClause))
return true;
}
return false;
}};

llvm::acc::Directive kernelsDir{
GetContext().directive == llvm::acc::ACCD_kernels_loop
? llvm::acc::ACCD_kernels_loop
: llvm::acc::ACCD_kernels};
std::string dirName{
parser::ToUpperCaseLetters(getDirectiveName(kernelsDir).str())};

auto emitConflicts{[&](llvm::acc::Clause loopClause,
llvm::acc::Clause sizeClause,
bool (*isValued)(const parser::AccClause &)) {
if (!hasKernelsSizeClause(sizeClause))
return;
for (const auto &entry : FindClauses(loopClause)) {
const parser::AccClause *clause{entry.second};
if (clause && isValued(*clause)) {
context_.Say(clause->source,
"'%s(value)' not allowed in %s region that has a %s clause"_err_en_US,
parser::ToUpperCaseLetters(getClauseName(loopClause).str()),
dirName,
parser::ToUpperCaseLetters(getClauseName(sizeClause).str()));
}
}
}};

emitConflicts(llvm::acc::Clause::ACCC_vector,
llvm::acc::Clause::ACCC_vector_length, AccClauseHasVectorValue);
emitConflicts(llvm::acc::Clause::ACCC_worker,
llvm::acc::Clause::ACCC_num_workers, AccClauseHasWorkerValue);
emitConflicts(llvm::acc::Clause::ACCC_gang, llvm::acc::Clause::ACCC_num_gangs,
AccClauseHasGangNum);
}

void AccStructureChecker::CheckNotInSameOrSubLevelLoopConstruct() {
for (std::size_t i = dirContext_.size() - 1; i > 0; --i) {
auto &parent{dirContext_[i - 1]};
Expand Down Expand Up @@ -1030,6 +1131,10 @@ void AccStructureChecker::Enter(const parser::AccClause::Vector &g) {
if (GetContext().directive != llvm::acc::Directive::ACCD_routine) {
CheckAllowedOncePerGroup(crtClause, llvm::acc::Clause::ACCC_device_type);
}
if (g.v) {
CheckLoopLevelClauseValue(
parser::ToUpperCaseLetters(getClauseName(crtClause).str()));
}
}

void AccStructureChecker::Enter(const parser::AccClause::Worker &g) {
Expand All @@ -1042,6 +1147,10 @@ void AccStructureChecker::Enter(const parser::AccClause::Worker &g) {
if (GetContext().directive != llvm::acc::Directive::ACCD_routine) {
CheckAllowedOncePerGroup(crtClause, llvm::acc::Clause::ACCC_device_type);
}
if (g.v) {
CheckLoopLevelClauseValue(
parser::ToUpperCaseLetters(getClauseName(crtClause).str()));
}
}

void AccStructureChecker::Enter(const parser::AccClause::Tile &g) {
Expand Down Expand Up @@ -1090,6 +1199,15 @@ void AccStructureChecker::Enter(const parser::AccClause::Gang &g) {
context_.Say(GetContext().clauseSource,
"The num argument is not allowed when dim is specified"_err_en_US);
}

// Only the num argument is restricted to kernels. The static and dim
// arguments are allowed on any loop. On ROUTINE, num is already diagnosed
// above as only dim being allowed.
if (hasNum &&
GetContext().directive != llvm::acc::Directive::ACCD_routine) {
CheckLoopLevelClauseValue(
parser::ToUpperCaseLetters(getClauseName(crtClause).str()));
}
}
}

Expand Down
2 changes: 2 additions & 0 deletions flang/lib/Semantics/check-acc-structure.h
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Original file line number Diff line number Diff line change
Expand Up @@ -117,6 +117,8 @@ class AccStructureChecker
std::optional<std::int64_t> getGangDimensionSize(
DirectiveContext &dirContext);
void CheckNotInSameOrSubLevelLoopConstruct();
void CheckLoopLevelClauseValue(llvm::StringRef clauseName);
void CheckLoopLevelClauseKernelsConflicts();
void CheckRoutineCallInLoop(const Symbol &);
void CheckMultipleOccurrenceInDeclare(
const parser::AccObjectList &, llvm::acc::Clause);
Expand Down
28 changes: 22 additions & 6 deletions flang/test/Lower/OpenACC/acc-loop.f90
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Original file line number Diff line number Diff line change
Expand Up @@ -72,6 +72,9 @@ program acc_loop
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent

! A GANG clause with a num argument requires the loop to be associated with a
! kernels construct, which also makes the loop default to auto.
!$acc kernels
!$acc loop gang(num: 8)
DO i = 1, n
a(i) = b(i)
Expand All @@ -81,7 +84,7 @@ program acc_loop
! CHECK: %[[PRIVATE_I:.*]] = acc.private varPtr(%{{.*}} : !fir.ref<i32>) recipe(@privatization_ref_i32) implicit(true) name("i") -> !fir.ref<i32>
! CHECK: acc.loop gang({num=[[GANGNUM1]] : i32}) private(%[[PRIVATE_I]] : !fir.ref<i32>) control(%arg0 : i32) = (%{{.*}} : i32) to (%{{.*}} : i32) step (%{{.*}} : i32) {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) auto_

!$acc loop gang(num: gangNum)
DO i = 1, n
Expand All @@ -92,17 +95,18 @@ program acc_loop
! CHECK: %[[PRIVATE_I:.*]] = acc.private varPtr(%{{.*}} : !fir.ref<i32>) recipe(@privatization_ref_i32) implicit(true) name("i") -> !fir.ref<i32>
! CHECK: acc.loop gang({num=[[GANGNUM2]] : i32}) private(%[[PRIVATE_I]] : !fir.ref<i32>) control(%arg0 : i32) = (%{{.*}} : i32) to (%{{.*}} : i32) step (%{{.*}} : i32) {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) auto_

!$acc loop gang(num: gangNum, static: gangStatic)
DO i = 1, n
a(i) = b(i)
END DO
!$acc end kernels

! CHECK: %[[PRIVATE_I:.*]] = acc.private varPtr(%{{.*}} : !fir.ref<i32>) recipe(@privatization_ref_i32) implicit(true) name("i") -> !fir.ref<i32>
! CHECK: acc.loop gang({num=%{{.*}} : i32, static=%{{.*}} : i32}) private(%[[PRIVATE_I]] : !fir.ref<i32>) control(%arg0 : i32) = (%{{.*}} : i32) to (%{{.*}} : i32) step (%{{.*}} : i32) {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) auto_

!$acc loop vector
DO i = 1, n
Expand All @@ -114,6 +118,9 @@ program acc_loop
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent

! A VECTOR clause with a value requires the loop to be associated with a
! kernels construct, which also makes the loop default to auto.
!$acc kernels
!$acc loop vector(128)
DO i = 1, n
a(i) = b(i)
Expand All @@ -123,18 +130,19 @@ program acc_loop
! CHECK: %[[PRIVATE_I:.*]] = acc.private varPtr(%{{.*}} : !fir.ref<i32>) recipe(@privatization_ref_i32) implicit(true) name("i") -> !fir.ref<i32>
! CHECK: acc.loop vector([[CONSTANT128]] : i32) private(%[[PRIVATE_I]] : !fir.ref<i32>) control(%arg0 : i32) = (%{{.*}} : i32) to (%{{.*}} : i32) step (%{{.*}} : i32) {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) auto_

!$acc loop vector(vectorLength)
DO i = 1, n
a(i) = b(i)
END DO
!$acc end kernels

! CHECK: [[VECTORLENGTH:%.*]] = fir.load %{{.*}} : !fir.ref<i32>
! CHECK: %[[PRIVATE_I:.*]] = acc.private varPtr(%{{.*}} : !fir.ref<i32>) recipe(@privatization_ref_i32) implicit(true) name("i") -> !fir.ref<i32>
! CHECK: acc.loop vector([[VECTORLENGTH]] : i32) private(%[[PRIVATE_I]] : !fir.ref<i32>) control(%arg0 : i32) = (%{{.*}} : i32) to (%{{.*}} : i32) step (%{{.*}} : i32) {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) auto_

!$acc loop worker
DO i = 1, n
Expand All @@ -146,16 +154,20 @@ program acc_loop
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent

! A WORKER clause with a value requires the loop to be associated with a
! kernels construct, which also makes the loop default to auto.
!$acc kernels
!$acc loop worker(128)
DO i = 1, n
a(i) = b(i)
END DO
!$acc end kernels

! CHECK: [[WORKER128:%.*]] = arith.constant 128 : i32
! CHECK: %[[PRIVATE_I:.*]] = acc.private varPtr(%{{.*}} : !fir.ref<i32>) recipe(@privatization_ref_i32) implicit(true) name("i") -> !fir.ref<i32>
! CHECK: acc.loop worker([[WORKER128]] : i32) private(%[[PRIVATE_I]] : !fir.ref<i32>) control(%arg0 : i32) = (%{{.*}} : i32) to (%{{.*}} : i32) step (%{{.*}} : i32) {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) auto_

!$acc loop private(c)
DO i = 1, n
Expand Down Expand Up @@ -364,9 +376,13 @@ program acc_loop
100 continue
! CHECK: acc.loop

! A GANG clause with a num argument requires the loop to be associated with a
! kernels construct.
!$acc kernels
!$acc loop gang device_type(nvidia) gang(8)
DO i = 1, n
END DO
!$acc end kernels

! CHECK: acc.loop gang([#acc.device_type<none>], {num=%c8{{.*}} : i32} [#acc.device_type<nvidia>])

Expand Down
82 changes: 6 additions & 76 deletions flang/test/Lower/OpenACC/acc-parallel-loop.f90
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Original file line number Diff line number Diff line change
Expand Up @@ -509,43 +509,8 @@ subroutine acc_parallel_loop
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}

!$acc parallel loop gang(num: 8)
DO i = 1, n
a(i) = b(i)
END DO

! CHECK: acc.parallel {{.*}} {
! CHECK: [[GANGNUM1:%.*]] = arith.constant 8 : i32
! CHECK: acc.loop {{.*}} gang({num=[[GANGNUM1]] : i32})
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}

!$acc parallel loop gang(num: gangNum)
DO i = 1, n
a(i) = b(i)
END DO

! CHECK: acc.parallel {{.*}} {
! CHECK: [[GANGNUM2:%.*]] = fir.load %{{.*}} : !fir.ref<i32>
! CHECK: acc.loop {{.*}} gang({num=[[GANGNUM2]] : i32})
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}

!$acc parallel loop gang(num: gangNum, static: gangStatic)
DO i = 1, n
a(i) = b(i)
END DO

! CHECK: acc.parallel {{.*}} {
! CHECK: acc.loop {{.*}} gang({num=%{{.*}} : i32, static=%{{.*}} : i32})
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}
! A GANG clause with a num argument is only allowed on a loop associated with
! a kernels construct, so it is covered by acc-kernels-loop.f90 instead.

!$acc parallel loop vector
DO i = 1, n
Expand All @@ -559,32 +524,8 @@ subroutine acc_parallel_loop
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}

!$acc parallel loop vector(128)
DO i = 1, n
a(i) = b(i)
END DO

! CHECK: acc.parallel {{.*}} {
! CHECK: [[CONSTANT128:%.*]] = arith.constant 128 : i32
! CHECK: acc.loop {{.*}} vector([[CONSTANT128]] : i32) {{.*}} {
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}

!$acc parallel loop vector(vectorLength)
DO i = 1, n
a(i) = b(i)
END DO

! CHECK: acc.parallel {{.*}} {
! CHECK: [[VECTORLENGTH:%.*]] = fir.load %{{.*}} : !fir.ref<i32>
! CHECK: acc.loop {{.*}} vector([[VECTORLENGTH]] : i32) {{.*}} {
! CHECK-NOT: fir.do_loop
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}
! A VECTOR clause with a value is only allowed on a loop associated with a
! kernels construct, so it is covered by acc-kernels-loop.f90 instead.

!$acc parallel loop worker
DO i = 1, n
Expand All @@ -599,19 +540,8 @@ subroutine acc_parallel_loop
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}

!$acc parallel loop worker(128)
DO i = 1, n
a(i) = b(i)
END DO

! CHECK: acc.parallel {{.*}}{
! CHECK: [[WORKER128:%.*]] = arith.constant 128 : i32
! CHECK: acc.loop {{.*}} worker([[WORKER128]] : i32) {{.*}} {
! CHECK-NOT: fir.do_loop
! CHECK: acc.yield
! CHECK-NEXT: } inclusiveUpperbound(array<i1: true>) independent
! CHECK: acc.yield
! CHECK-NEXT: }{{.*}}
! A WORKER clause with a value is only allowed on a loop associated with a
! kernels construct, so it is covered by acc-kernels-loop.f90 instead.

!$acc parallel loop collapse(2)
DO i = 1, n
Expand Down
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