[flang-commits] [flang] 29f167a - [Flang][OpenMP] Fixes for unstructured OpenMP code
Kiran Chandramohan via flang-commits
flang-commits at lists.llvm.org
Tue May 24 14:42:21 PDT 2022
Author: Kiran Chandramohan
Date: 2022-05-24T21:33:59Z
New Revision: 29f167abcf7d871d17dd3f38f361916de1a12470
URL: https://github.com/llvm/llvm-project/commit/29f167abcf7d871d17dd3f38f361916de1a12470
DIFF: https://github.com/llvm/llvm-project/commit/29f167abcf7d871d17dd3f38f361916de1a12470.diff
LOG: [Flang][OpenMP] Fixes for unstructured OpenMP code
Since the FIR operations are mostly structured, it is only the functions
that could contain multiple blocks inside an operation. This changes
with OpenMP since OpenMP regions can contain multiple blocks. For
unstructured code, the blocks are created in advance and belong to the
top-level function. This caused code in OpenMP region to be placed under
the function level.
In this fix, if the OpenMP region is unstructured then new blocks are
created inside it.
Note1: This is part of upstreaming from the fir-dev branch of
https://github.com/flang-compiler/f18-llvm-project. The code in this patch is a
subset of the changes in https://github.com/flang-compiler/f18-llvm-project/pull/1178.
Reviewed By: vdonaldson
Differential Revision: https://reviews.llvm.org/D126293
Co-authored-by: Val Donaldson <vdonaldson at nvidia.com>
Co-authored-by: Eric Schweitz <eschweitz at nvidia.com>
Co-authored-by: Valentin Clement <clementval at gmail.com>
Added:
flang/test/Lower/OpenMP/omp-unstructured.f90
Modified:
flang/lib/Lower/OpenMP.cpp
Removed:
################################################################################
diff --git a/flang/lib/Lower/OpenMP.cpp b/flang/lib/Lower/OpenMP.cpp
index e59d80c343638..b42fb95d50ffe 100644
--- a/flang/lib/Lower/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP.cpp
@@ -138,11 +138,35 @@ static mlir::Type getLoopVarType(Fortran::lower::AbstractConverter &converter,
return converter.getFirOpBuilder().getIntegerType(loopVarTypeSize);
}
+/// Create empty blocks for the current region.
+/// These blocks replace blocks parented to an enclosing region.
+void createEmptyRegionBlocks(
+ fir::FirOpBuilder &firOpBuilder,
+ std::list<Fortran::lower::pft::Evaluation> &evaluationList) {
+ auto *region = &firOpBuilder.getRegion();
+ for (auto &eval : evaluationList) {
+ if (eval.block) {
+ if (eval.block->empty()) {
+ eval.block->erase();
+ eval.block = firOpBuilder.createBlock(region);
+ } else {
+ [[maybe_unused]] auto &terminatorOp = eval.block->back();
+ assert((mlir::isa<mlir::omp::TerminatorOp>(terminatorOp) ||
+ mlir::isa<mlir::omp::YieldOp>(terminatorOp)) &&
+ "expected terminator op");
+ }
+ }
+ if (eval.hasNestedEvaluations())
+ createEmptyRegionBlocks(firOpBuilder, eval.getNestedEvaluations());
+ }
+}
+
/// Create the body (block) for an OpenMP Operation.
///
/// \param [in] op - the operation the body belongs to.
/// \param [inout] converter - converter to use for the clauses.
/// \param [in] loc - location in source code.
+/// \param [in] eval - current PFT node/evaluation.
/// \oaran [in] clauses - list of clauses to process.
/// \param [in] args - block arguments (induction variable[s]) for the
//// region.
@@ -151,14 +175,14 @@ static mlir::Type getLoopVarType(Fortran::lower::AbstractConverter &converter,
template <typename Op>
static void
createBodyOfOp(Op &op, Fortran::lower::AbstractConverter &converter,
- mlir::Location &loc,
+ mlir::Location &loc, Fortran::lower::pft::Evaluation &eval,
const Fortran::parser::OmpClauseList *clauses = nullptr,
const SmallVector<const Fortran::semantics::Symbol *> &args = {},
bool outerCombined = false) {
- fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
- // If arguments for the region are provided then create the block with those
- // arguments. Also update the symbol's address with the mlir argument values.
- // e.g. For loops the arguments are the induction variable. And all further
+ auto &firOpBuilder = converter.getFirOpBuilder();
+ // If an argument for the region is provided then create the block with that
+ // argument. Also update the symbol's address with the mlir argument value.
+ // e.g. For loops the argument is the induction variable. And all further
// uses of the induction variable should use this mlir value.
if (args.size()) {
std::size_t loopVarTypeSize = 0;
@@ -184,7 +208,10 @@ createBodyOfOp(Op &op, Fortran::lower::AbstractConverter &converter,
auto &block = op.getRegion().back();
firOpBuilder.setInsertionPointToStart(&block);
- // Insert the terminator.
+ if (eval.lowerAsUnstructured())
+ createEmptyRegionBlocks(firOpBuilder, eval.getNestedEvaluations());
+
+ // Ensure the block is well-formed by inserting terminators.
if constexpr (std::is_same_v<Op, omp::WsLoopOp>) {
mlir::ValueRange results;
firOpBuilder.create<mlir::omp::YieldOp>(loc, results);
@@ -369,7 +396,7 @@ createCombinedParallelOp(Fortran::lower::AbstractConverter &converter,
allocateOperands, allocatorOperands, /*reduction_vars=*/ValueRange(),
/*reductions=*/nullptr, procBindKindAttr);
- createBodyOfOp<omp::ParallelOp>(parallelOp, converter, currentLocation,
+ createBodyOfOp<omp::ParallelOp>(parallelOp, converter, currentLocation, eval,
&opClauseList, /*iv=*/{},
/*isCombined=*/true);
}
@@ -461,26 +488,27 @@ genOMP(Fortran::lower::AbstractConverter &converter,
allocateOperands, allocatorOperands, /*reduction_vars=*/ValueRange(),
/*reductions=*/nullptr, procBindKindAttr);
createBodyOfOp<omp::ParallelOp>(parallelOp, converter, currentLocation,
- &opClauseList);
+ eval, &opClauseList);
} else if (blockDirective.v == llvm::omp::OMPD_master) {
auto masterOp =
firOpBuilder.create<mlir::omp::MasterOp>(currentLocation, argTy);
- createBodyOfOp<omp::MasterOp>(masterOp, converter, currentLocation);
+ createBodyOfOp<omp::MasterOp>(masterOp, converter, currentLocation, eval);
} else if (blockDirective.v == llvm::omp::OMPD_single) {
auto singleOp = firOpBuilder.create<mlir::omp::SingleOp>(
currentLocation, allocateOperands, allocatorOperands, nowaitAttr);
- createBodyOfOp<omp::SingleOp>(singleOp, converter, currentLocation);
+ createBodyOfOp<omp::SingleOp>(singleOp, converter, currentLocation, eval);
} else if (blockDirective.v == llvm::omp::OMPD_ordered) {
auto orderedOp = firOpBuilder.create<mlir::omp::OrderedRegionOp>(
currentLocation, /*simd=*/nullptr);
- createBodyOfOp<omp::OrderedRegionOp>(orderedOp, converter, currentLocation);
+ createBodyOfOp<omp::OrderedRegionOp>(orderedOp, converter, currentLocation,
+ eval);
} else if (blockDirective.v == llvm::omp::OMPD_task) {
auto taskOp = firOpBuilder.create<mlir::omp::TaskOp>(
currentLocation, ifClauseOperand, finalClauseOperand, untiedAttr,
mergeableAttr, /*in_reduction_vars=*/ValueRange(),
/*in_reductions=*/nullptr, priorityClauseOperand, allocateOperands,
allocatorOperands);
- createBodyOfOp(taskOp, converter, currentLocation, &opClauseList);
+ createBodyOfOp(taskOp, converter, currentLocation, eval, &opClauseList);
} else {
TODO(converter.getCurrentLocation(), "Unhandled block directive");
}
@@ -644,7 +672,7 @@ static void genOMP(Fortran::lower::AbstractConverter &converter,
wsLoopOp.nowaitAttr(firOpBuilder.getUnitAttr());
}
- createBodyOfOp<omp::WsLoopOp>(wsLoopOp, converter, currentLocation,
+ createBodyOfOp<omp::WsLoopOp>(wsLoopOp, converter, currentLocation, eval,
&wsLoopOpClauseList, iv);
}
@@ -688,7 +716,7 @@ genOMP(Fortran::lower::AbstractConverter &converter,
firOpBuilder.getContext(), global.sym_name()));
}
}();
- createBodyOfOp<omp::CriticalOp>(criticalOp, converter, currentLocation);
+ createBodyOfOp<omp::CriticalOp>(criticalOp, converter, currentLocation, eval);
}
static void
@@ -700,7 +728,7 @@ genOMP(Fortran::lower::AbstractConverter &converter,
auto currentLocation = converter.getCurrentLocation();
mlir::omp::SectionOp sectionOp =
firOpBuilder.create<mlir::omp::SectionOp>(currentLocation);
- createBodyOfOp<omp::SectionOp>(sectionOp, converter, currentLocation);
+ createBodyOfOp<omp::SectionOp>(sectionOp, converter, currentLocation, eval);
}
// TODO: Add support for reduction
@@ -757,14 +785,15 @@ genOMP(Fortran::lower::AbstractConverter &converter,
currentLocation, /*reduction_vars*/ ValueRange(),
/*reductions=*/nullptr, allocateOperands, allocatorOperands,
/*nowait=*/nullptr);
- createBodyOfOp(sectionsOp, converter, currentLocation);
+ createBodyOfOp(sectionsOp, converter, currentLocation, eval);
// Sections Construct
} else if (dir == llvm::omp::Directive::OMPD_sections) {
auto sectionsOp = firOpBuilder.create<mlir::omp::SectionsOp>(
currentLocation, reductionVars, /*reductions = */ nullptr,
allocateOperands, allocatorOperands, noWaitClauseOperand);
- createBodyOfOp<omp::SectionsOp>(sectionsOp, converter, currentLocation);
+ createBodyOfOp<omp::SectionsOp>(sectionsOp, converter, currentLocation,
+ eval);
}
}
diff --git a/flang/test/Lower/OpenMP/omp-unstructured.f90 b/flang/test/Lower/OpenMP/omp-unstructured.f90
new file mode 100644
index 0000000000000..68f944b91abea
--- /dev/null
+++ b/flang/test/Lower/OpenMP/omp-unstructured.f90
@@ -0,0 +1,113 @@
+! Test unstructured code adjacent to and inside OpenMP constructs.
+
+! RUN: bbc %s -fopenmp -o "-" | FileCheck %s
+
+! CHECK-LABEL: func @_QPss1{{.*}} {
+! CHECK: br ^bb1
+! CHECK: ^bb1: // 2 preds: ^bb0, ^bb3
+! CHECK: cond_br %{{[0-9]*}}, ^bb2, ^bb4
+! CHECK: ^bb2: // pred: ^bb1
+! CHECK: cond_br %{{[0-9]*}}, ^bb4, ^bb3
+! CHECK: ^bb3: // pred: ^bb2
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: br ^bb1
+! CHECK: ^bb4: // 2 preds: ^bb1, ^bb2
+! CHECK: omp.master {
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: omp.terminator
+! CHECK: }
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: }
+subroutine ss1(n) ! unstructured code followed by a structured OpenMP construct
+ do i = 1, 3
+ if (i .eq. n) exit
+ print*, 'ss1-A', i
+ enddo
+ !$omp master
+ print*, 'ss1-B', i
+ !$omp end master
+ print*
+end
+
+! CHECK-LABEL: func @_QPss2{{.*}} {
+! CHECK: omp.master {
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: br ^bb1
+! CHECK: ^bb1: // 2 preds: ^bb0, ^bb3
+! CHECK: cond_br %{{[0-9]*}}, ^bb2, ^bb4
+! CHECK: ^bb2: // pred: ^bb1
+! CHECK: cond_br %{{[0-9]*}}, ^bb4, ^bb3
+! CHECK: ^bb3: // pred: ^bb2
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: br ^bb1
+! CHECK: ^bb4: // 2 preds: ^bb1, ^bb2
+! CHECK: omp.terminator
+! CHECK: }
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: }
+subroutine ss2(n) ! unstructured OpenMP construct; loop exit inside construct
+ !$omp master
+ print*, 'ss2-A', n
+ do i = 1, 3
+ if (i .eq. n) exit
+ print*, 'ss2-B', i
+ enddo
+ !$omp end master
+ print*, 'ss2-C', i
+ print*
+end
+
+! CHECK-LABEL: func @_QPss3{{.*}} {
+! CHECK: omp.parallel {
+! CHECK: br ^bb1
+! CHECK: ^bb1: // 2 preds: ^bb0, ^bb2
+! CHECK: cond_br %{{[0-9]*}}, ^bb2, ^bb3
+! CHECK: ^bb2: // pred: ^bb1
+! CHECK: omp.wsloop {{.*}} {
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: omp.yield
+! CHECK: }
+! CHECK: omp.wsloop {{.*}} {
+! CHECK: br ^bb1
+! CHECK: ^bb1: // 2 preds: ^bb0, ^bb3
+! CHECK: cond_br %{{[0-9]*}}, ^bb2, ^bb4
+! CHECK: ^bb2: // pred: ^bb1
+! CHECK: cond_br %{{[0-9]*}}, ^bb4, ^bb3
+! CHECK: ^bb3: // pred: ^bb2
+! CHECK: @_FortranAioBeginExternalListOutput
+! CHECK: br ^bb1
+! CHECK: ^bb4: // 2 preds: ^bb1, ^bb2
+! CHECK: omp.yield
+! CHECK: }
+! CHECK: br ^bb1
+! CHECK: ^bb3: // pred: ^bb1
+! CHECK: omp.terminator
+! CHECK: }
+! CHECK: }
+subroutine ss3(n) ! nested unstructured OpenMP constructs
+ !$omp parallel
+ do i = 1, 3
+ !$omp do
+ do k = 1, 3
+ print*, 'ss3-A', k
+ enddo
+ !$omp end do
+ !$omp do
+ do j = 1, 3
+ do k = 1, 3
+ if (k .eq. n) exit
+ print*, 'ss3-B', k
+ enddo
+ enddo
+ !$omp end do
+ enddo
+ !$omp end parallel
+end
+
+! CHECK-LABEL: func @_QQmain
+program p
+ call ss1(2)
+ call ss2(2)
+ call ss3(2)
+end
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