[MLIR][OpenMP] Add a new AutomapToTargetData conversion pass in FIR (#153048)

Add a new AutomapToTargetData pass. This gathers the declare target
enter variables which have the AUTOMAP modifier. And adds
omp.declare_target_enter/exit mapping directives for fir.alloca and
fir.free oeprations on the AUTOMAP enabled variables.

Automap Ref: OpenMP 6.0 section 7.9.7.
This commit is contained in:
Akash Banerjee 2025-08-12 15:18:15 +01:00 committed by GitHub
parent c69355e7d1
commit 4e6d510eb3
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8 changed files with 278 additions and 39 deletions

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@ -112,4 +112,15 @@ def GenericLoopConversionPass
];
}
def AutomapToTargetDataPass
: Pass<"omp-automap-to-target-data", "::mlir::ModuleOp"> {
let summary = "Insert OpenMP target data operations for AUTOMAP variables";
let description = [{
Inserts `omp.target_enter_data` and `omp.target_exit_data` operations to
map variables marked with the `AUTOMAP` modifier when their allocation
or deallocation is detected in the FIR.
}];
let dependentDialects = ["mlir::omp::OpenMPDialect"];
}
#endif //FORTRAN_OPTIMIZER_OPENMP_PASSES

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@ -9,8 +9,13 @@
#ifndef FORTRAN_SUPPORT_OPENMP_UTILS_H_
#define FORTRAN_SUPPORT_OPENMP_UTILS_H_
#include "flang/Optimizer/Builder/DirectivesCommon.h"
#include "flang/Optimizer/Builder/FIRBuilder.h"
#include "flang/Optimizer/Builder/HLFIRTools.h"
#include "flang/Optimizer/Dialect/FIRType.h"
#include "flang/Semantics/symbol.h"
#include "mlir/Dialect/OpenMP/OpenMPDialect.h"
#include "mlir/IR/Builders.h"
#include "mlir/IR/Value.h"
@ -72,6 +77,35 @@ struct EntryBlockArgs {
/// \param [in] region - Empty region in which to create the entry block.
mlir::Block *genEntryBlock(
mlir::OpBuilder &builder, const EntryBlockArgs &args, mlir::Region &region);
// Returns true if the variable has a dynamic size and therefore requires
// bounds operations to describe its extents.
inline bool needsBoundsOps(mlir::Value var) {
assert(mlir::isa<mlir::omp::PointerLikeType>(var.getType()) &&
"only pointer like types expected");
mlir::Type t = fir::unwrapRefType(var.getType());
if (mlir::Type inner = fir::dyn_cast_ptrOrBoxEleTy(t))
return fir::hasDynamicSize(inner);
return fir::hasDynamicSize(t);
}
// Generate MapBoundsOp operations for the variable if required.
inline void genBoundsOps(fir::FirOpBuilder &builder, mlir::Value var,
llvm::SmallVectorImpl<mlir::Value> &boundsOps) {
mlir::Location loc = var.getLoc();
fir::factory::AddrAndBoundsInfo info =
fir::factory::getDataOperandBaseAddr(builder, var,
/*isOptional=*/false, loc);
fir::ExtendedValue exv =
hlfir::translateToExtendedValue(loc, builder, hlfir::Entity{info.addr},
/*contiguousHint=*/true)
.first;
llvm::SmallVector<mlir::Value> tmp =
fir::factory::genImplicitBoundsOps<mlir::omp::MapBoundsOp,
mlir::omp::MapBoundsType>(
builder, info, exv, /*dataExvIsAssumedSize=*/false, loc);
llvm::append_range(boundsOps, tmp);
}
} // namespace Fortran::common::openmp
#endif // FORTRAN_SUPPORT_OPENMP_UTILS_H_

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@ -0,0 +1,130 @@
//===- AutomapToTargetData.cpp -------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "flang/Optimizer/Builder/FIRBuilder.h"
#include "flang/Optimizer/Builder/HLFIRTools.h"
#include "flang/Optimizer/Dialect/FIROps.h"
#include "flang/Optimizer/Dialect/FIRType.h"
#include "flang/Optimizer/Dialect/Support/KindMapping.h"
#include "flang/Optimizer/HLFIR/HLFIROps.h"
#include "flang/Support/OpenMP-utils.h"
#include "mlir/Dialect/OpenMP/OpenMPDialect.h"
#include "mlir/Dialect/OpenMP/OpenMPInterfaces.h"
#include "mlir/IR/BuiltinAttributes.h"
#include "mlir/IR/Operation.h"
#include "mlir/Pass/Pass.h"
#include "llvm/Frontend/OpenMP/OMPConstants.h"
namespace flangomp {
#define GEN_PASS_DEF_AUTOMAPTOTARGETDATAPASS
#include "flang/Optimizer/OpenMP/Passes.h.inc"
} // namespace flangomp
using namespace mlir;
using namespace Fortran::common::openmp;
namespace {
class AutomapToTargetDataPass
: public flangomp::impl::AutomapToTargetDataPassBase<
AutomapToTargetDataPass> {
void findRelatedAllocmemFreemem(fir::AddrOfOp addressOfOp,
llvm::DenseSet<fir::StoreOp> &allocmems,
llvm::DenseSet<fir::LoadOp> &freemems) {
assert(addressOfOp->hasOneUse() && "op must have single use");
auto declaredRef =
cast<hlfir::DeclareOp>(*addressOfOp->getUsers().begin())->getResult(0);
for (Operation *refUser : declaredRef.getUsers()) {
if (auto storeOp = dyn_cast<fir::StoreOp>(refUser))
if (auto emboxOp = storeOp.getValue().getDefiningOp<fir::EmboxOp>())
if (auto allocmemOp =
emboxOp.getOperand(0).getDefiningOp<fir::AllocMemOp>())
allocmems.insert(storeOp);
if (auto loadOp = dyn_cast<fir::LoadOp>(refUser))
for (Operation *loadUser : loadOp.getResult().getUsers())
if (auto boxAddrOp = dyn_cast<fir::BoxAddrOp>(loadUser))
for (Operation *boxAddrUser : boxAddrOp.getResult().getUsers())
if (auto freememOp = dyn_cast<fir::FreeMemOp>(boxAddrUser))
freemems.insert(loadOp);
}
}
void runOnOperation() override {
ModuleOp module = getOperation()->getParentOfType<ModuleOp>();
if (!module)
module = dyn_cast<ModuleOp>(getOperation());
if (!module)
return;
// Build FIR builder for helper utilities.
fir::KindMapping kindMap = fir::getKindMapping(module);
fir::FirOpBuilder builder{module, std::move(kindMap)};
// Collect global variables with AUTOMAP flag.
llvm::DenseSet<fir::GlobalOp> automapGlobals;
module.walk([&](fir::GlobalOp globalOp) {
if (auto iface =
dyn_cast<omp::DeclareTargetInterface>(globalOp.getOperation()))
if (iface.isDeclareTarget() && iface.getDeclareTargetAutomap() &&
iface.getDeclareTargetDeviceType() !=
omp::DeclareTargetDeviceType::host)
automapGlobals.insert(globalOp);
});
auto addMapInfo = [&](auto globalOp, auto memOp) {
builder.setInsertionPointAfter(memOp);
SmallVector<Value> bounds;
if (needsBoundsOps(memOp.getMemref()))
genBoundsOps(builder, memOp.getMemref(), bounds);
omp::TargetEnterExitUpdateDataOperands clauses;
mlir::omp::MapInfoOp mapInfo = mlir::omp::MapInfoOp::create(
builder, memOp.getLoc(), memOp.getMemref().getType(),
memOp.getMemref(),
TypeAttr::get(fir::unwrapRefType(memOp.getMemref().getType())),
builder.getIntegerAttr(
builder.getIntegerType(64, false),
static_cast<unsigned>(
isa<fir::StoreOp>(memOp)
? llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TO
: llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_DELETE)),
builder.getAttr<omp::VariableCaptureKindAttr>(
omp::VariableCaptureKind::ByCopy),
/*var_ptr_ptr=*/mlir::Value{},
/*members=*/SmallVector<Value>{},
/*members_index=*/ArrayAttr{}, bounds,
/*mapperId=*/mlir::FlatSymbolRefAttr(), globalOp.getSymNameAttr(),
builder.getBoolAttr(false));
clauses.mapVars.push_back(mapInfo);
isa<fir::StoreOp>(memOp)
? builder.create<omp::TargetEnterDataOp>(memOp.getLoc(), clauses)
: builder.create<omp::TargetExitDataOp>(memOp.getLoc(), clauses);
};
for (fir::GlobalOp globalOp : automapGlobals) {
if (auto uses = globalOp.getSymbolUses(module.getOperation())) {
llvm::DenseSet<fir::StoreOp> allocmemStores;
llvm::DenseSet<fir::LoadOp> freememLoads;
for (auto &x : *uses)
if (auto addrOp = dyn_cast<fir::AddrOfOp>(x.getUser()))
findRelatedAllocmemFreemem(addrOp, allocmemStores, freememLoads);
for (auto storeOp : allocmemStores)
addMapInfo(globalOp, storeOp);
for (auto loadOp : freememLoads)
addMapInfo(globalOp, loadOp);
}
}
}
};
} // namespace

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@ -1,6 +1,7 @@
get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
add_flang_library(FlangOpenMPTransforms
AutomapToTargetData.cpp
DoConcurrentConversion.cpp
FunctionFiltering.cpp
GenericLoopConversion.cpp

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@ -29,6 +29,7 @@
#include "flang/Optimizer/Dialect/Support/KindMapping.h"
#include "flang/Optimizer/HLFIR/HLFIROps.h"
#include "flang/Optimizer/OpenMP/Passes.h"
#include "flang/Support/OpenMP-utils.h"
#include "mlir/Dialect/Func/IR/FuncOps.h"
#include "mlir/Dialect/OpenMP/OpenMPDialect.h"
@ -47,6 +48,7 @@ namespace flangomp {
} // namespace flangomp
using namespace mlir;
using namespace Fortran::common::openmp;
namespace {
class MapsForPrivatizedSymbolsPass
@ -193,38 +195,5 @@ class MapsForPrivatizedSymbolsPass
}
}
}
// As the name suggests, this function examines var to determine if
// it has dynamic size. If true, this pass'll have to extract these
// bounds from descriptor of var and add the bounds to the resultant
// MapInfoOp.
bool needsBoundsOps(mlir::Value var) {
assert(mlir::isa<omp::PointerLikeType>(var.getType()) &&
"needsBoundsOps can deal only with pointer types");
mlir::Type t = fir::unwrapRefType(var.getType());
// t could be a box, so look inside the box
auto innerType = fir::dyn_cast_ptrOrBoxEleTy(t);
if (innerType)
return fir::hasDynamicSize(innerType);
return fir::hasDynamicSize(t);
}
void genBoundsOps(fir::FirOpBuilder &builder, mlir::Value var,
llvm::SmallVector<mlir::Value> &boundsOps) {
mlir::Location loc = var.getLoc();
fir::factory::AddrAndBoundsInfo info =
fir::factory::getDataOperandBaseAddr(builder, var,
/*isOptional=*/false, loc);
fir::ExtendedValue extendedValue =
hlfir::translateToExtendedValue(loc, builder, hlfir::Entity{info.addr},
/*continguousHint=*/true)
.first;
llvm::SmallVector<mlir::Value> boundsOpsVec =
fir::factory::genImplicitBoundsOps<mlir::omp::MapBoundsOp,
mlir::omp::MapBoundsType>(
builder, info, extendedValue,
/*dataExvIsAssumedSize=*/false, loc);
for (auto bounds : boundsOpsVec)
boundsOps.push_back(bounds);
}
};
} // namespace

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@ -316,13 +316,13 @@ void createOpenMPFIRPassPipeline(mlir::PassManager &pm,
pm.addPass(flangomp::createDoConcurrentConversionPass(
opts.doConcurrentMappingKind == DoConcurrentMappingKind::DCMK_Device));
// The MapsForPrivatizedSymbols pass needs to run before
// MapInfoFinalizationPass because the former creates new
// MapInfoOp instances, typically for descriptors.
// MapInfoFinalizationPass adds MapInfoOp instances for the descriptors
// underlying data which is necessary to access the data on the offload
// target device.
// The MapsForPrivatizedSymbols and AutomapToTargetDataPass pass need to run
// before MapInfoFinalizationPass because they create new MapInfoOp
// instances, typically for descriptors. MapInfoFinalizationPass adds
// MapInfoOp instances for the descriptors underlying data which is necessary
// to access the data on the offload target device.
pm.addPass(flangomp::createMapsForPrivatizedSymbolsPass());
pm.addPass(flangomp::createAutomapToTargetDataPass());
pm.addPass(flangomp::createMapInfoFinalizationPass());
pm.addPass(flangomp::createMarkDeclareTargetPass());
pm.addPass(flangomp::createGenericLoopConversionPass());

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@ -0,0 +1,58 @@
// RUN: fir-opt --omp-automap-to-target-data %s | FileCheck %s
// Test OMP AutomapToTargetData pass.
module {
fir.global
@_QMtestEarr{omp.declare_target = #omp.declaretarget<device_type = (any),
capture_clause = (enter), automap = true>} target
: !fir.box<!fir.heap<!fir.array<?xi32>>>
func.func @automap() {
%c0 = arith.constant 0 : index
%c10 = arith.constant 10 : i32
%addr = fir.address_of(@_QMtestEarr) : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
%decl:2 = hlfir.declare %addr {fortran_attrs = #fir.var_attrs<allocatable, target>, uniq_name = "_QMtestEarr"} : (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>) -> (!fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>, !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>)
%idx = fir.convert %c10 : (i32) -> index
%cond = arith.cmpi sgt, %idx, %c0 : index
%n = arith.select %cond, %idx, %c0 : index
%mem = fir.allocmem !fir.array<?xi32>, %n {fir.must_be_heap = true}
%shape = fir.shape %n : (index) -> !fir.shape<1>
%box = fir.embox %mem(%shape) : (!fir.heap<!fir.array<?xi32>>, !fir.shape<1>) -> !fir.box<!fir.heap<!fir.array<?xi32>>>
fir.store %box to %decl#0 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
%ld = fir.load %decl#0 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
%base = fir.box_addr %ld : (!fir.box<!fir.heap<!fir.array<?xi32>>>) -> !fir.heap<!fir.array<?xi32>>
fir.freemem %base : !fir.heap<!fir.array<?xi32>>
%undef = fir.zero_bits !fir.heap<!fir.array<?xi32>>
%sh0 = fir.shape %c0 : (index) -> !fir.shape<1>
%empty = fir.embox %undef(%sh0) : (!fir.heap<!fir.array<?xi32>>, !fir.shape<1>) -> !fir.box<!fir.heap<!fir.array<?xi32>>>
fir.store %empty to %decl#0 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
return
}
}
// CHECK: fir.global @[[AUTOMAP:.*]] {{{.*}} automap = true
// CHECK-LABEL: func.func @automap()
// CHECK: %[[AUTOMAP_ADDR:.*]] = fir.address_of(@[[AUTOMAP]])
// CHECK: %[[AUTOMAP_DECL:.*]]:2 = hlfir.declare %[[AUTOMAP_ADDR]]
// CHECK: %[[ALLOC_MEM:.*]] = fir.allocmem
// CHECK-NEXT: fir.shape
// CHECK-NEXT: %[[ARR_BOXED:.*]] = fir.embox %[[ALLOC_MEM]]
// CHECK-NEXT: fir.store %[[ARR_BOXED]]
// CHECK-NEXT: %[[ARR_BOXED_LOADED:.*]] = fir.load %[[AUTOMAP_DECL]]#0
// CHECK-NEXT: %[[ARR_HEAP_PTR:.*]] = fir.box_addr %[[ARR_BOXED_LOADED]]
// CHECK-NEXT: %[[DIM0:.*]] = arith.constant 0 : index
// CHECK-NEXT: %[[BOX_DIMS:.*]]:3 = fir.box_dims %[[ARR_BOXED_LOADED]], %[[DIM0]]
// CHECK-NEXT: %[[ONE:.*]] = arith.constant 1 : index
// CHECK-NEXT: %[[ZERO:.*]] = arith.constant 0 : index
// CHECK-NEXT: %[[BOX_DIMS2:.*]]:3 = fir.box_dims %[[ARR_BOXED_LOADED]], %[[ZERO]]
// CHECK-NEXT: %[[LOWER_BOUND:.*]] = arith.constant 0 : index
// CHECK-NEXT: %[[UPPER_BOUND:.*]] = arith.subi %[[BOX_DIMS2]]#1, %[[ONE]] : index
// CHECK-NEXT: omp.map.bounds lower_bound(%[[LOWER_BOUND]] : index) upper_bound(%[[UPPER_BOUND]] : index) extent(%[[BOX_DIMS2]]#1 : index) stride(%[[BOX_DIMS2]]#2 : index) start_idx(%[[BOX_DIMS]]#0 : index) {stride_in_bytes = true}
// CHECK-NEXT: arith.muli %[[BOX_DIMS2]]#2, %[[BOX_DIMS2]]#1 : index
// CHECK-NEXT: %[[MAP_INFO:.*]] = omp.map.info var_ptr(%[[AUTOMAP_DECL]]#0 {{.*}} map_clauses(to) capture(ByCopy)
// CHECK-NEXT: omp.target_enter_data map_entries(%[[MAP_INFO]]
// CHECK: %[[LOAD:.*]] = fir.load %[[AUTOMAP_DECL]]#0
// CHECK: %[[EXIT_MAP:.*]] = omp.map.info var_ptr(%[[AUTOMAP_DECL]]#0 {{.*}} map_clauses(delete) capture(ByCopy)
// CHECK-NEXT: omp.target_exit_data map_entries(%[[EXIT_MAP]]
// CHECK-NEXT: %[[BOXADDR:.*]] = fir.box_addr %[[LOAD]]
// CHECK-NEXT: fir.freemem %[[BOXADDR]]

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@ -0,0 +1,36 @@
!Offloading test for AUTOMAP modifier in declare target enter
! REQUIRES: flang, amdgpu
program automap_program
use iso_c_binding, only: c_loc
use omp_lib, only: omp_get_default_device, omp_target_is_present
integer, parameter :: N = 10
integer :: i
integer, allocatable, target :: automap_array(:)
!$omp declare target enter(automap:automap_array)
! false since the storage is not present even though the descriptor is present
write (*, *) omp_target_is_present(c_loc(automap_array), omp_get_default_device())
! CHECK: 0
allocate (automap_array(N))
! true since the storage should be allocated and reference count incremented by the allocate
write (*, *) omp_target_is_present(c_loc(automap_array), omp_get_default_device())
! CHECK: 1
! since storage is present this should not be a runtime error
!$omp target teams loop
do i = 1, N
automap_array(i) = i
end do
!$omp target update from(automap_array)
write (*, *) automap_array
! CHECK: 1 2 3 4 5 6 7 8 9 10
deallocate (automap_array)
! automap_array should have it's storage unmapped on device here
write (*, *) omp_target_is_present(c_loc(automap_array), omp_get_default_device())
! CHECK: 0
end program