[MLIR][OpenMP] Add OpenMPToLLVMIRTranslation support for is_device_ptr #169367
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TIFitis
November 24, 2025 17:11
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Pull request overview
This PR adds support for the OpenMP is_device_ptr clause in the MLIR to LLVM IR translation for target regions. The is_device_ptr clause allows device pointers (allocated via OpenMP runtime APIs) to be used directly in target regions without implicit mapping.
Key Changes:
- Implemented
is_device_ptrhandling incollectMapDataFromMapOperandsby detecting thestorageflag and setting appropriate LLVM map flags - Removed the unimplemented clause check for
is_device_ptrinomp.targetoperations - Added comprehensive Fortran tests validating the end-to-end functionality
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp |
Implemented is_device_ptr translation by detecting variables with the storage flag and setting OMP_MAP_TARGET_PARAM and OMP_MAP_LITERAL flags, along with the Pointer device info type |
mlir/test/Target/LLVMIR/openmp-todo.mlir |
Removed TODO test for is_device_ptr since it's now implemented |
offload/test/offloading/fortran/target-is-device-ptr.f90 |
Added comprehensive Fortran test validating device pointer allocation and usage with is_device_ptr clause |
flang/test/Integration/OpenMP/map-types-and-sizes.f90 |
Added test case verifying correct map type value (288) for is_device_ptr variables |
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@llvm/pr-subscribers-flang-fir-hlfir @llvm/pr-subscribers-offload Author: Akash Banerjee (TIFitis) ChangesThis PR adds support for the OpenMP Full diff: https://github.com/llvm/llvm-project/pull/169367.diff 4 Files Affected:
diff --git a/flang/test/Integration/OpenMP/map-types-and-sizes.f90 b/flang/test/Integration/OpenMP/map-types-and-sizes.f90
index 44a049f5ac510..85434460bbea6 100644
--- a/flang/test/Integration/OpenMP/map-types-and-sizes.f90
+++ b/flang/test/Integration/OpenMP/map-types-and-sizes.f90
@@ -33,6 +33,15 @@ subroutine mapType_array
!$omp end target
end subroutine mapType_array
+!CHECK: @.offload_sizes{{.*}} = private unnamed_addr constant [1 x i64] [i64 8]
+!CHECK: @.offload_maptypes{{.*}} = private unnamed_addr constant [1 x i64] [i64 288]
+subroutine mapType_is_device_ptr
+ use iso_c_binding, only : c_ptr
+ type(c_ptr) :: p
+ !$omp target is_device_ptr(p)
+ !$omp end target
+end subroutine mapType_is_device_ptr
+
!CHECK: @.offload_sizes{{.*}} = private unnamed_addr constant [4 x i64] [i64 0, i64 24, i64 8, i64 0]
!CHECK: @.offload_maptypes{{.*}} = private unnamed_addr constant [4 x i64] [i64 32, i64 281474976711169, i64 281474976711171, i64 281474976711187]
subroutine mapType_ptr
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index f28454075f1d3..00c4c351caa4e 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -332,10 +332,7 @@ static LogicalResult checkImplementationStatus(Operation &op) {
op.getInReductionSyms())
result = todo("in_reduction");
};
- auto checkIsDevicePtr = [&todo](auto op, LogicalResult &result) {
- if (!op.getIsDevicePtrVars().empty())
- result = todo("is_device_ptr");
- };
+ auto checkIsDevicePtr = [](auto, LogicalResult &) {};
auto checkLinear = [&todo](auto op, LogicalResult &result) {
if (!op.getLinearVars().empty() || !op.getLinearStepVars().empty())
result = todo("linear");
@@ -3996,6 +3993,8 @@ static void collectMapDataFromMapOperands(
llvm::Value *origValue = moduleTranslation.lookupValue(offloadPtr);
auto mapType = convertClauseMapFlags(mapOp.getMapType());
auto mapTypeAlways = llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_ALWAYS;
+ bool isDevicePtr = (mapOp.getMapType() & omp::ClauseMapFlags::storage) ==
+ omp::ClauseMapFlags::storage;
mapData.OriginalValue.push_back(origValue);
mapData.BasePointers.push_back(origValue);
@@ -4006,7 +4005,12 @@ static void collectMapDataFromMapOperands(
mapData.Sizes.push_back(
builder.getInt64(dl.getTypeSize(mapOp.getVarType())));
mapData.MapClause.push_back(mapOp.getOperation());
- if (llvm::to_underlying(mapType & mapTypeAlways)) {
+ if (isDevicePtr) {
+ mapType |= llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TARGET_PARAM;
+ mapType |= llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_LITERAL;
+ mapData.Types.push_back(mapType);
+ mapData.Mappers.push_back(nullptr);
+ } else if (llvm::to_underlying(mapType & mapTypeAlways)) {
// Descriptors are mapped with the ALWAYS flag, since they can get
// rematerialized, so the address of the decriptor for a given object
// may change from one place to another.
@@ -4029,7 +4033,8 @@ static void collectMapDataFromMapOperands(
mapData.Names.push_back(LLVM::createMappingInformation(
mapOp.getLoc(), *moduleTranslation.getOpenMPBuilder()));
mapData.DevicePointers.push_back(
- llvm::OpenMPIRBuilder::DeviceInfoTy::Address);
+ isDevicePtr ? llvm::OpenMPIRBuilder::DeviceInfoTy::Pointer
+ : llvm::OpenMPIRBuilder::DeviceInfoTy::Address);
mapData.IsAMapping.push_back(false);
mapData.IsAMember.push_back(checkIsAMember(hasDevAddrOperands, mapOp));
}
diff --git a/mlir/test/Target/LLVMIR/openmp-todo.mlir b/mlir/test/Target/LLVMIR/openmp-todo.mlir
index af6d254cfd3c3..0704008aa7135 100644
--- a/mlir/test/Target/LLVMIR/openmp-todo.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-todo.mlir
@@ -238,17 +238,6 @@ llvm.func @target_in_reduction(%x : !llvm.ptr) {
// -----
-llvm.func @target_is_device_ptr(%x : !llvm.ptr) {
- // expected-error@below {{not yet implemented: Unhandled clause is_device_ptr in omp.target operation}}
- // expected-error@below {{LLVM Translation failed for operation: omp.target}}
- omp.target is_device_ptr(%x : !llvm.ptr) {
- omp.terminator
- }
- llvm.return
-}
-
-// -----
-
llvm.func @target_enter_data_depend(%x: !llvm.ptr) {
// expected-error@below {{not yet implemented: Unhandled clause depend in omp.target_enter_data operation}}
// expected-error@below {{LLVM Translation failed for operation: omp.target_enter_data}}
diff --git a/offload/test/offloading/fortran/target-is-device-ptr.f90 b/offload/test/offloading/fortran/target-is-device-ptr.f90
new file mode 100644
index 0000000000000..6010d59113498
--- /dev/null
+++ b/offload/test/offloading/fortran/target-is-device-ptr.f90
@@ -0,0 +1,79 @@
+! Validate that a device pointer allocated via OpenMP runtime APIs can be
+! consumed by a TARGET region using the is_device_ptr clause.
+! REQUIRES: flang, amdgcn-amd-amdhsa
+! UNSUPPORTED: nvptx64-nvidia-cuda
+! UNSUPPORTED: nvptx64-nvidia-cuda-LTO
+! UNSUPPORTED: aarch64-unknown-linux-gnu
+! UNSUPPORTED: aarch64-unknown-linux-gnu-LTO
+! UNSUPPORTED: x86_64-unknown-linux-gnu
+! UNSUPPORTED: x86_64-unknown-linux-gnu-LTO
+
+! RUN: %libomptarget-compile-fortran-run-and-check-generic
+
+program is_device_ptr_target
+ use omp_lib
+ use iso_c_binding
+ implicit none
+
+ integer, parameter :: n = 4
+ integer, target :: host(n)
+ type(c_ptr) :: device_ptr
+ integer(c_int) :: rc
+ integer :: i
+
+ do i = 1, n
+ host(i) = i
+ end do
+
+ device_ptr = omp_target_alloc(int(n, c_size_t) * int(c_sizeof(host(1)), c_size_t), &
+ omp_get_default_device())
+ if (.not. c_associated(device_ptr)) then
+ print *, "device alloc failed"
+ stop 1
+ end if
+
+ rc = omp_target_memcpy(device_ptr, c_loc(host), &
+ int(n, c_size_t) * int(c_sizeof(host(1)), c_size_t), &
+ 0_c_size_t, 0_c_size_t, &
+ omp_get_default_device(), omp_get_initial_device())
+ if (rc .ne. 0) then
+ print *, "host->device memcpy failed"
+ call omp_target_free(device_ptr, omp_get_default_device())
+ stop 1
+ end if
+
+ call fill_on_device(device_ptr)
+
+ rc = omp_target_memcpy(c_loc(host), device_ptr, &
+ int(n, c_size_t) * int(c_sizeof(host(1)), c_size_t), &
+ 0_c_size_t, 0_c_size_t, &
+ omp_get_initial_device(), omp_get_default_device())
+ call omp_target_free(device_ptr, omp_get_default_device())
+
+ if (rc .ne. 0) then
+ print *, "device->host memcpy failed"
+ stop 1
+ end if
+
+ if (all(host == [2, 4, 6, 8])) then
+ print *, "PASS"
+ else
+ print *, "FAIL", host
+ end if
+
+contains
+ subroutine fill_on_device(ptr)
+ type(c_ptr) :: ptr
+ integer, pointer :: p(:)
+ call c_f_pointer(ptr, p, [n])
+
+ !$omp target is_device_ptr(ptr)
+ p(1) = 2
+ p(2) = 4
+ p(3) = 6
+ p(4) = 8
+ !$omp end target
+ end subroutine fill_on_device
+end program is_device_ptr_target
+
+!CHECK: PASS
|
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@llvm/pr-subscribers-mlir-openmp Author: Akash Banerjee (TIFitis) ChangesThis PR adds support for the OpenMP Full diff: https://github.com/llvm/llvm-project/pull/169367.diff 4 Files Affected:
diff --git a/flang/test/Integration/OpenMP/map-types-and-sizes.f90 b/flang/test/Integration/OpenMP/map-types-and-sizes.f90
index 44a049f5ac510..85434460bbea6 100644
--- a/flang/test/Integration/OpenMP/map-types-and-sizes.f90
+++ b/flang/test/Integration/OpenMP/map-types-and-sizes.f90
@@ -33,6 +33,15 @@ subroutine mapType_array
!$omp end target
end subroutine mapType_array
+!CHECK: @.offload_sizes{{.*}} = private unnamed_addr constant [1 x i64] [i64 8]
+!CHECK: @.offload_maptypes{{.*}} = private unnamed_addr constant [1 x i64] [i64 288]
+subroutine mapType_is_device_ptr
+ use iso_c_binding, only : c_ptr
+ type(c_ptr) :: p
+ !$omp target is_device_ptr(p)
+ !$omp end target
+end subroutine mapType_is_device_ptr
+
!CHECK: @.offload_sizes{{.*}} = private unnamed_addr constant [4 x i64] [i64 0, i64 24, i64 8, i64 0]
!CHECK: @.offload_maptypes{{.*}} = private unnamed_addr constant [4 x i64] [i64 32, i64 281474976711169, i64 281474976711171, i64 281474976711187]
subroutine mapType_ptr
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index f28454075f1d3..00c4c351caa4e 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -332,10 +332,7 @@ static LogicalResult checkImplementationStatus(Operation &op) {
op.getInReductionSyms())
result = todo("in_reduction");
};
- auto checkIsDevicePtr = [&todo](auto op, LogicalResult &result) {
- if (!op.getIsDevicePtrVars().empty())
- result = todo("is_device_ptr");
- };
+ auto checkIsDevicePtr = [](auto, LogicalResult &) {};
auto checkLinear = [&todo](auto op, LogicalResult &result) {
if (!op.getLinearVars().empty() || !op.getLinearStepVars().empty())
result = todo("linear");
@@ -3996,6 +3993,8 @@ static void collectMapDataFromMapOperands(
llvm::Value *origValue = moduleTranslation.lookupValue(offloadPtr);
auto mapType = convertClauseMapFlags(mapOp.getMapType());
auto mapTypeAlways = llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_ALWAYS;
+ bool isDevicePtr = (mapOp.getMapType() & omp::ClauseMapFlags::storage) ==
+ omp::ClauseMapFlags::storage;
mapData.OriginalValue.push_back(origValue);
mapData.BasePointers.push_back(origValue);
@@ -4006,7 +4005,12 @@ static void collectMapDataFromMapOperands(
mapData.Sizes.push_back(
builder.getInt64(dl.getTypeSize(mapOp.getVarType())));
mapData.MapClause.push_back(mapOp.getOperation());
- if (llvm::to_underlying(mapType & mapTypeAlways)) {
+ if (isDevicePtr) {
+ mapType |= llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_TARGET_PARAM;
+ mapType |= llvm::omp::OpenMPOffloadMappingFlags::OMP_MAP_LITERAL;
+ mapData.Types.push_back(mapType);
+ mapData.Mappers.push_back(nullptr);
+ } else if (llvm::to_underlying(mapType & mapTypeAlways)) {
// Descriptors are mapped with the ALWAYS flag, since they can get
// rematerialized, so the address of the decriptor for a given object
// may change from one place to another.
@@ -4029,7 +4033,8 @@ static void collectMapDataFromMapOperands(
mapData.Names.push_back(LLVM::createMappingInformation(
mapOp.getLoc(), *moduleTranslation.getOpenMPBuilder()));
mapData.DevicePointers.push_back(
- llvm::OpenMPIRBuilder::DeviceInfoTy::Address);
+ isDevicePtr ? llvm::OpenMPIRBuilder::DeviceInfoTy::Pointer
+ : llvm::OpenMPIRBuilder::DeviceInfoTy::Address);
mapData.IsAMapping.push_back(false);
mapData.IsAMember.push_back(checkIsAMember(hasDevAddrOperands, mapOp));
}
diff --git a/mlir/test/Target/LLVMIR/openmp-todo.mlir b/mlir/test/Target/LLVMIR/openmp-todo.mlir
index af6d254cfd3c3..0704008aa7135 100644
--- a/mlir/test/Target/LLVMIR/openmp-todo.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-todo.mlir
@@ -238,17 +238,6 @@ llvm.func @target_in_reduction(%x : !llvm.ptr) {
// -----
-llvm.func @target_is_device_ptr(%x : !llvm.ptr) {
- // expected-error@below {{not yet implemented: Unhandled clause is_device_ptr in omp.target operation}}
- // expected-error@below {{LLVM Translation failed for operation: omp.target}}
- omp.target is_device_ptr(%x : !llvm.ptr) {
- omp.terminator
- }
- llvm.return
-}
-
-// -----
-
llvm.func @target_enter_data_depend(%x: !llvm.ptr) {
// expected-error@below {{not yet implemented: Unhandled clause depend in omp.target_enter_data operation}}
// expected-error@below {{LLVM Translation failed for operation: omp.target_enter_data}}
diff --git a/offload/test/offloading/fortran/target-is-device-ptr.f90 b/offload/test/offloading/fortran/target-is-device-ptr.f90
new file mode 100644
index 0000000000000..6010d59113498
--- /dev/null
+++ b/offload/test/offloading/fortran/target-is-device-ptr.f90
@@ -0,0 +1,79 @@
+! Validate that a device pointer allocated via OpenMP runtime APIs can be
+! consumed by a TARGET region using the is_device_ptr clause.
+! REQUIRES: flang, amdgcn-amd-amdhsa
+! UNSUPPORTED: nvptx64-nvidia-cuda
+! UNSUPPORTED: nvptx64-nvidia-cuda-LTO
+! UNSUPPORTED: aarch64-unknown-linux-gnu
+! UNSUPPORTED: aarch64-unknown-linux-gnu-LTO
+! UNSUPPORTED: x86_64-unknown-linux-gnu
+! UNSUPPORTED: x86_64-unknown-linux-gnu-LTO
+
+! RUN: %libomptarget-compile-fortran-run-and-check-generic
+
+program is_device_ptr_target
+ use omp_lib
+ use iso_c_binding
+ implicit none
+
+ integer, parameter :: n = 4
+ integer, target :: host(n)
+ type(c_ptr) :: device_ptr
+ integer(c_int) :: rc
+ integer :: i
+
+ do i = 1, n
+ host(i) = i
+ end do
+
+ device_ptr = omp_target_alloc(int(n, c_size_t) * int(c_sizeof(host(1)), c_size_t), &
+ omp_get_default_device())
+ if (.not. c_associated(device_ptr)) then
+ print *, "device alloc failed"
+ stop 1
+ end if
+
+ rc = omp_target_memcpy(device_ptr, c_loc(host), &
+ int(n, c_size_t) * int(c_sizeof(host(1)), c_size_t), &
+ 0_c_size_t, 0_c_size_t, &
+ omp_get_default_device(), omp_get_initial_device())
+ if (rc .ne. 0) then
+ print *, "host->device memcpy failed"
+ call omp_target_free(device_ptr, omp_get_default_device())
+ stop 1
+ end if
+
+ call fill_on_device(device_ptr)
+
+ rc = omp_target_memcpy(c_loc(host), device_ptr, &
+ int(n, c_size_t) * int(c_sizeof(host(1)), c_size_t), &
+ 0_c_size_t, 0_c_size_t, &
+ omp_get_initial_device(), omp_get_default_device())
+ call omp_target_free(device_ptr, omp_get_default_device())
+
+ if (rc .ne. 0) then
+ print *, "device->host memcpy failed"
+ stop 1
+ end if
+
+ if (all(host == [2, 4, 6, 8])) then
+ print *, "PASS"
+ else
+ print *, "FAIL", host
+ end if
+
+contains
+ subroutine fill_on_device(ptr)
+ type(c_ptr) :: ptr
+ integer, pointer :: p(:)
+ call c_f_pointer(ptr, p, [n])
+
+ !$omp target is_device_ptr(ptr)
+ p(1) = 2
+ p(2) = 4
+ p(3) = 6
+ p(4) = 8
+ !$omp end target
+ end subroutine fill_on_device
+end program is_device_ptr_target
+
+!CHECK: PASS
|
ergawy
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Nov 25, 2025
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Thanks Akash. Just a few stop-by comments, I hope that's ok with you.
mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
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mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
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Thanks a lot for the comments, they are much appreciated. I've resolved them in the latest revision. |
abhinavgaba
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Nov 25, 2025
| call c_f_pointer(ptr, p, [n]) | ||
|
|
||
| !$omp target is_device_ptr(ptr) | ||
| p(1) = 2 |
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c_f_pointer should be called inside the target region, if the goal is to test whether the argument for ptr was set correctly. The uninitialized p can then be made private on the target construct.
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I've tweaked the test overall. Can you please comment if you're happy with the change? Thanks.
abhinavgaba
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Nov 26, 2025
| dptr = omp_get_mapped_ptr(c_loc(a), dev) | ||
|
|
||
| !$omp target is_device_ptr(dptr) map(tofrom: flag) | ||
| flag = flag + 1 |
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dptr is still not used inside the target construct. Is your goal to validate that dptr is correctly passed into the target, or just that this doesn't cause a segfault/offload-failure?
If it's the former, then one way to do it is by calling c_f_pointer inside the target region, and reading/writing the pointee via the fortran pointer. Another way is to transfer dptr into an INTEGER(C_INTPTR_T) both inside and outside the target region, print it, and CHECK that the two addresses printed are identical.
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I tried adding the call to c_f_pointer inside the target region in the previous test. But it causes a runtime failure, and I'm not sure if the failure is directly related to the is_device_ptr implementation or some other mapping bug.
If you're happy with the current simpler test for this PR, then I can work on debugging a fix for that failure when I return from vacation in the new year. Otherwise, I'll put this PR on hold until I can come up with a working version of that test with a call to c_f_pointer inside the target region.
Let me know which you prefer, thanks.
ergawy
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Thanks Akash. Just a few comments about mapping flags. Also, can you please add an MLIR to LLVM test?
mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
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This PR adds support for the OpenMP is_device_ptr clause in the MLIR to LLVM IR translation for target regions. The is_device_ptr clause allows device pointers (allocated via OpenMP runtime APIs) to be used directly in target regions without implicit mapping.
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Thanks for the review, I've added an MLIR test although it checks the same thing as the flang/test/Integration/OpenMP/map-types-and-sizes.f90 test. |
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This PR adds support for the OpenMP
is_device_ptrclause in the MLIR to LLVM IR translation for target regions. Theis_device_ptrclause allows device pointers (allocated via OpenMP runtime APIs) to be used directly in target regions without implicit mapping.