[flang-commits] [flang] 4a3bf27 - [OpenMP] Introduce omp.target_allocmem and omp.target_freemem omp dialect ops. (#145464)

via flang-commits flang-commits at lists.llvm.org
Mon Aug 18 05:45:15 PDT 2025


Author: Chaitanya
Date: 2025-08-18T18:15:11+05:30
New Revision: 4a3bf27c69473e65a9176858ff57c8b55dfb184c

URL: https://github.com/llvm/llvm-project/commit/4a3bf27c69473e65a9176858ff57c8b55dfb184c
DIFF: https://github.com/llvm/llvm-project/commit/4a3bf27c69473e65a9176858ff57c8b55dfb184c.diff

LOG: [OpenMP] Introduce omp.target_allocmem and omp.target_freemem omp dialect ops. (#145464)

This PR introduces two new ops in omp dialect, omp.target_allocmem and
omp.target_freemem.
omp.target_allocmem: Allocates heap memory on device. Will be lowered to
omp_target_alloc call in llvm.
omp.target_freemem: Deallocates heap memory on device. Will be lowered
to omp+target_free call in llvm.


Example:
  %1 = omp.target_allocmem %device : i32, i64
  omp.target_freemem %device, %1 : i32, i64

The work in this PR is C-P/inspired from @ivanradanov commit from
coexecute implementation:
[Add fir omp target alloc and free
ops](https://github.com/ivanradanov/llvm-project/commit/be860ac8baf24b8405e6f396c75d7f0d26375de5)
[Lower omp_target_{alloc,free} to
llvm](https://github.com/ivanradanov/llvm-project/commit/6e2d584dc93ff99bb89adc28c7afbc2b21c46d39)

Added: 
    flang/test/Fir/omp_target_allocmem_freemem.fir
    mlir/test/Target/LLVMIR/ompenmp-target-allocmem-freemem.mlir

Modified: 
    flang/include/flang/Optimizer/Support/Utils.h
    flang/lib/Optimizer/CodeGen/CodeGen.cpp
    flang/lib/Optimizer/CodeGen/CodeGenOpenMP.cpp
    flang/lib/Optimizer/Dialect/FIROps.cpp
    flang/lib/Optimizer/Support/Utils.cpp
    mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
    mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
    mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

Removed: 
    


################################################################################
diff  --git a/flang/include/flang/Optimizer/Support/Utils.h b/flang/include/flang/Optimizer/Support/Utils.h
index 83c936b7dcada..0b31cfea0430a 100644
--- a/flang/include/flang/Optimizer/Support/Utils.h
+++ b/flang/include/flang/Optimizer/Support/Utils.h
@@ -27,6 +27,8 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringRef.h"
 
+#include "flang/Optimizer/CodeGen/TypeConverter.h"
+
 namespace fir {
 /// Return the integer value of a arith::ConstantOp.
 inline std::int64_t toInt(mlir::arith::ConstantOp cop) {
@@ -198,6 +200,37 @@ std::optional<llvm::ArrayRef<int64_t>> getComponentLowerBoundsIfNonDefault(
     fir::RecordType recordType, llvm::StringRef component,
     mlir::ModuleOp module, const mlir::SymbolTable *symbolTable = nullptr);
 
+/// Generate a LLVM constant value of type `ity`, using the provided offset.
+mlir::LLVM::ConstantOp
+genConstantIndex(mlir::Location loc, mlir::Type ity,
+                 mlir::ConversionPatternRewriter &rewriter,
+                 std::int64_t offset);
+
+/// Helper function for generating the LLVM IR that computes the distance
+/// in bytes between adjacent elements pointed to by a pointer
+/// of type \p ptrTy. The result is returned as a value of \p idxTy integer
+/// type.
+mlir::Value computeElementDistance(mlir::Location loc,
+                                   mlir::Type llvmObjectType, mlir::Type idxTy,
+                                   mlir::ConversionPatternRewriter &rewriter,
+                                   const mlir::DataLayout &dataLayout);
+
+// Compute the alloc scale size (constant factors encoded in the array type).
+// We do this for arrays without a constant interior or arrays of character with
+// dynamic length arrays, since those are the only ones that get decayed to a
+// pointer to the element type.
+mlir::Value genAllocationScaleSize(mlir::Location loc, mlir::Type dataTy,
+                                   mlir::Type ity,
+                                   mlir::ConversionPatternRewriter &rewriter);
+
+/// Perform an extension or truncation as needed on an integer value. Lowering
+/// to the specific target may involve some sign-extending or truncation of
+/// values, particularly to fit them from abstract box types to the
+/// appropriate reified structures.
+mlir::Value integerCast(const fir::LLVMTypeConverter &converter,
+                        mlir::Location loc,
+                        mlir::ConversionPatternRewriter &rewriter,
+                        mlir::Type ty, mlir::Value val, bool fold = false);
 } // namespace fir
 
 #endif // FORTRAN_OPTIMIZER_SUPPORT_UTILS_H

diff  --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index ba5fef97c83ed..76f3cbd421cb9 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -87,14 +87,6 @@ static inline mlir::Type getI8Type(mlir::MLIRContext *context) {
   return mlir::IntegerType::get(context, 8);
 }
 
-static mlir::LLVM::ConstantOp
-genConstantIndex(mlir::Location loc, mlir::Type ity,
-                 mlir::ConversionPatternRewriter &rewriter,
-                 std::int64_t offset) {
-  auto cattr = rewriter.getI64IntegerAttr(offset);
-  return mlir::LLVM::ConstantOp::create(rewriter, loc, ity, cattr);
-}
-
 static mlir::Block *createBlock(mlir::ConversionPatternRewriter &rewriter,
                                 mlir::Block *insertBefore) {
   assert(insertBefore && "expected valid insertion block");
@@ -208,39 +200,6 @@ getDependentTypeMemSizeFn(fir::RecordType recTy, fir::AllocaOp op,
   TODO(op.getLoc(), "did not find allocation function");
 }
 
-// Compute the alloc scale size (constant factors encoded in the array type).
-// We do this for arrays without a constant interior or arrays of character with
-// dynamic length arrays, since those are the only ones that get decayed to a
-// pointer to the element type.
-template <typename OP>
-static mlir::Value
-genAllocationScaleSize(OP op, mlir::Type ity,
-                       mlir::ConversionPatternRewriter &rewriter) {
-  mlir::Location loc = op.getLoc();
-  mlir::Type dataTy = op.getInType();
-  auto seqTy = mlir::dyn_cast<fir::SequenceType>(dataTy);
-  fir::SequenceType::Extent constSize = 1;
-  if (seqTy) {
-    int constRows = seqTy.getConstantRows();
-    const fir::SequenceType::ShapeRef &shape = seqTy.getShape();
-    if (constRows != static_cast<int>(shape.size())) {
-      for (auto extent : shape) {
-        if (constRows-- > 0)
-          continue;
-        if (extent != fir::SequenceType::getUnknownExtent())
-          constSize *= extent;
-      }
-    }
-  }
-
-  if (constSize != 1) {
-    mlir::Value constVal{
-        genConstantIndex(loc, ity, rewriter, constSize).getResult()};
-    return constVal;
-  }
-  return nullptr;
-}
-
 namespace {
 struct DeclareOpConversion : public fir::FIROpConversion<fir::cg::XDeclareOp> {
 public:
@@ -275,7 +234,7 @@ struct AllocaOpConversion : public fir::FIROpConversion<fir::AllocaOp> {
     auto loc = alloc.getLoc();
     mlir::Type ity = lowerTy().indexType();
     unsigned i = 0;
-    mlir::Value size = genConstantIndex(loc, ity, rewriter, 1).getResult();
+    mlir::Value size = fir::genConstantIndex(loc, ity, rewriter, 1).getResult();
     mlir::Type firObjType = fir::unwrapRefType(alloc.getType());
     mlir::Type llvmObjectType = convertObjectType(firObjType);
     if (alloc.hasLenParams()) {
@@ -307,7 +266,8 @@ struct AllocaOpConversion : public fir::FIROpConversion<fir::AllocaOp> {
                << scalarType << " with type parameters";
       }
     }
-    if (auto scaleSize = genAllocationScaleSize(alloc, ity, rewriter))
+    if (auto scaleSize = fir::genAllocationScaleSize(
+            alloc.getLoc(), alloc.getInType(), ity, rewriter))
       size =
           rewriter.createOrFold<mlir::LLVM::MulOp>(loc, ity, size, scaleSize);
     if (alloc.hasShapeOperands()) {
@@ -484,7 +444,7 @@ struct BoxIsArrayOpConversion : public fir::FIROpConversion<fir::BoxIsArrayOp> {
     auto loc = boxisarray.getLoc();
     TypePair boxTyPair = getBoxTypePair(boxisarray.getVal().getType());
     mlir::Value rank = getRankFromBox(loc, boxTyPair, a, rewriter);
-    mlir::Value c0 = genConstantIndex(loc, rank.getType(), rewriter, 0);
+    mlir::Value c0 = fir::genConstantIndex(loc, rank.getType(), rewriter, 0);
     rewriter.replaceOpWithNewOp<mlir::LLVM::ICmpOp>(
         boxisarray, mlir::LLVM::ICmpPredicate::ne, rank, c0);
     return mlir::success();
@@ -820,7 +780,7 @@ struct ConvertOpConversion : public fir::FIROpConversion<fir::ConvertOp> {
       // Do folding for constant inputs.
       if (auto constVal = fir::getIntIfConstant(op0)) {
         mlir::Value normVal =
-            genConstantIndex(loc, toTy, rewriter, *constVal ? 1 : 0);
+            fir::genConstantIndex(loc, toTy, rewriter, *constVal ? 1 : 0);
         rewriter.replaceOp(convert, normVal);
         return mlir::success();
       }
@@ -833,7 +793,7 @@ struct ConvertOpConversion : public fir::FIROpConversion<fir::ConvertOp> {
       }
 
       // Compare the input with zero.
-      mlir::Value zero = genConstantIndex(loc, fromTy, rewriter, 0);
+      mlir::Value zero = fir::genConstantIndex(loc, fromTy, rewriter, 0);
       auto isTrue = mlir::LLVM::ICmpOp::create(
           rewriter, loc, mlir::LLVM::ICmpPredicate::ne, op0, zero);
 
@@ -1082,21 +1042,6 @@ static mlir::SymbolRefAttr getMalloc(fir::AllocMemOp op,
   return getMallocInModule(mod, op, rewriter, indexType);
 }
 
-/// Helper function for generating the LLVM IR that computes the distance
-/// in bytes between adjacent elements pointed to by a pointer
-/// of type \p ptrTy. The result is returned as a value of \p idxTy integer
-/// type.
-static mlir::Value
-computeElementDistance(mlir::Location loc, mlir::Type llvmObjectType,
-                       mlir::Type idxTy,
-                       mlir::ConversionPatternRewriter &rewriter,
-                       const mlir::DataLayout &dataLayout) {
-  llvm::TypeSize size = dataLayout.getTypeSize(llvmObjectType);
-  unsigned short alignment = dataLayout.getTypeABIAlignment(llvmObjectType);
-  std::int64_t distance = llvm::alignTo(size, alignment);
-  return genConstantIndex(loc, idxTy, rewriter, distance);
-}
-
 /// Return value of the stride in bytes between adjacent elements
 /// of LLVM type \p llTy. The result is returned as a value of
 /// \p idxTy integer type.
@@ -1105,7 +1050,7 @@ genTypeStrideInBytes(mlir::Location loc, mlir::Type idxTy,
                      mlir::ConversionPatternRewriter &rewriter, mlir::Type llTy,
                      const mlir::DataLayout &dataLayout) {
   // Create a pointer type and use computeElementDistance().
-  return computeElementDistance(loc, llTy, idxTy, rewriter, dataLayout);
+  return fir::computeElementDistance(loc, llTy, idxTy, rewriter, dataLayout);
 }
 
 namespace {
@@ -1124,8 +1069,9 @@ struct AllocMemOpConversion : public fir::FIROpConversion<fir::AllocMemOp> {
     if (fir::isRecordWithTypeParameters(fir::unwrapSequenceType(dataTy)))
       TODO(loc, "fir.allocmem codegen of derived type with length parameters");
     mlir::Value size = genTypeSizeInBytes(loc, ity, rewriter, llvmObjectTy);
-    if (auto scaleSize = genAllocationScaleSize(heap, ity, rewriter))
-      size = mlir::LLVM::MulOp::create(rewriter, loc, ity, size, scaleSize);
+    if (auto scaleSize =
+            fir::genAllocationScaleSize(loc, heap.getInType(), ity, rewriter))
+      size = rewriter.create<mlir::LLVM::MulOp>(loc, ity, size, scaleSize);
     for (mlir::Value opnd : adaptor.getOperands())
       size = mlir::LLVM::MulOp::create(rewriter, loc, ity, size,
                                        integerCast(loc, rewriter, ity, opnd));
@@ -1133,8 +1079,8 @@ struct AllocMemOpConversion : public fir::FIROpConversion<fir::AllocMemOp> {
     // As the return value of malloc(0) is implementation defined, allocate one
     // byte to ensure the allocation status being true. This behavior aligns to
     // what the runtime has.
-    mlir::Value zero = genConstantIndex(loc, ity, rewriter, 0);
-    mlir::Value one = genConstantIndex(loc, ity, rewriter, 1);
+    mlir::Value zero = fir::genConstantIndex(loc, ity, rewriter, 0);
+    mlir::Value one = fir::genConstantIndex(loc, ity, rewriter, 1);
     mlir::Value cmp = mlir::LLVM::ICmpOp::create(
         rewriter, loc, mlir::LLVM::ICmpPredicate::sgt, size, zero);
     size = mlir::LLVM::SelectOp::create(rewriter, loc, cmp, size, one);
@@ -1157,7 +1103,8 @@ struct AllocMemOpConversion : public fir::FIROpConversion<fir::AllocMemOp> {
   mlir::Value genTypeSizeInBytes(mlir::Location loc, mlir::Type idxTy,
                                  mlir::ConversionPatternRewriter &rewriter,
                                  mlir::Type llTy) const {
-    return computeElementDistance(loc, llTy, idxTy, rewriter, getDataLayout());
+    return fir::computeElementDistance(loc, llTy, idxTy, rewriter,
+                                       getDataLayout());
   }
 };
 } // namespace
@@ -1344,7 +1291,7 @@ genCUFAllocDescriptor(mlir::Location loc,
   mlir::Type structTy = typeConverter.convertBoxTypeAsStruct(boxTy);
   std::size_t boxSize = dl->getTypeSizeInBits(structTy) / 8;
   mlir::Value sizeInBytes =
-      genConstantIndex(loc, llvmIntPtrType, rewriter, boxSize);
+      fir::genConstantIndex(loc, llvmIntPtrType, rewriter, boxSize);
   llvm::SmallVector args = {sizeInBytes, sourceFile, sourceLine};
   return mlir::LLVM::CallOp::create(rewriter, loc, fctTy,
                                     RTNAME_STRING(CUFAllocDescriptor), args)
@@ -1599,7 +1546,7 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
       // representation of derived types with pointer/allocatable components.
       // This has been seen in hashing algorithms using TRANSFER.
       mlir::Value zero =
-          genConstantIndex(loc, rewriter.getI64Type(), rewriter, 0);
+          fir::genConstantIndex(loc, rewriter.getI64Type(), rewriter, 0);
       descriptor = insertField(rewriter, loc, descriptor,
                                {getLenParamFieldId(boxTy), 0}, zero);
     }
@@ -1944,8 +1891,8 @@ struct XEmboxOpConversion : public EmboxCommonConversion<fir::cg::XEmboxOp> {
     bool hasSlice = !xbox.getSlice().empty();
     unsigned sliceOffset = xbox.getSliceOperandIndex();
     mlir::Location loc = xbox.getLoc();
-    mlir::Value zero = genConstantIndex(loc, i64Ty, rewriter, 0);
-    mlir::Value one = genConstantIndex(loc, i64Ty, rewriter, 1);
+    mlir::Value zero = fir::genConstantIndex(loc, i64Ty, rewriter, 0);
+    mlir::Value one = fir::genConstantIndex(loc, i64Ty, rewriter, 1);
     mlir::Value prevPtrOff = one;
     mlir::Type eleTy = boxTy.getEleTy();
     const unsigned rank = xbox.getRank();
@@ -1994,7 +1941,7 @@ struct XEmboxOpConversion : public EmboxCommonConversion<fir::cg::XEmboxOp> {
         prevDimByteStride =
             getCharacterByteSize(loc, rewriter, charTy, adaptor.getLenParams());
       } else {
-        prevDimByteStride = genConstantIndex(
+        prevDimByteStride = fir::genConstantIndex(
             loc, i64Ty, rewriter,
             charTy.getLen() * lowerTy().characterBitsize(charTy) / 8);
       }
@@ -2152,7 +2099,7 @@ struct XReboxOpConversion : public EmboxCommonConversion<fir::cg::XReboxOp> {
     if (auto charTy = mlir::dyn_cast<fir::CharacterType>(inputEleTy)) {
       if (charTy.hasConstantLen()) {
         mlir::Value len =
-            genConstantIndex(loc, idxTy, rewriter, charTy.getLen());
+            fir::genConstantIndex(loc, idxTy, rewriter, charTy.getLen());
         lenParams.emplace_back(len);
       } else {
         mlir::Value len = getElementSizeFromBox(loc, idxTy, inputBoxTyPair,
@@ -2161,7 +2108,7 @@ struct XReboxOpConversion : public EmboxCommonConversion<fir::cg::XReboxOp> {
           assert(!isInGlobalOp(rewriter) &&
                  "character target in global op must have constant length");
           mlir::Value width =
-              genConstantIndex(loc, idxTy, rewriter, charTy.getFKind());
+              fir::genConstantIndex(loc, idxTy, rewriter, charTy.getFKind());
           len = mlir::LLVM::SDivOp::create(rewriter, loc, idxTy, len, width);
         }
         lenParams.emplace_back(len);
@@ -2215,8 +2162,9 @@ struct XReboxOpConversion : public EmboxCommonConversion<fir::cg::XReboxOp> {
                 mlir::ConversionPatternRewriter &rewriter) const {
     mlir::Location loc = rebox.getLoc();
     mlir::Value zero =
-        genConstantIndex(loc, lowerTy().indexType(), rewriter, 0);
-    mlir::Value one = genConstantIndex(loc, lowerTy().indexType(), rewriter, 1);
+        fir::genConstantIndex(loc, lowerTy().indexType(), rewriter, 0);
+    mlir::Value one =
+        fir::genConstantIndex(loc, lowerTy().indexType(), rewriter, 1);
     for (auto iter : llvm::enumerate(llvm::zip(extents, strides))) {
       mlir::Value extent = std::get<0>(iter.value());
       unsigned dim = iter.index();
@@ -2249,7 +2197,7 @@ struct XReboxOpConversion : public EmboxCommonConversion<fir::cg::XReboxOp> {
     mlir::Location loc = rebox.getLoc();
     mlir::Type byteTy = ::getI8Type(rebox.getContext());
     mlir::Type idxTy = lowerTy().indexType();
-    mlir::Value zero = genConstantIndex(loc, idxTy, rewriter, 0);
+    mlir::Value zero = fir::genConstantIndex(loc, idxTy, rewriter, 0);
     // Apply subcomponent and substring shift on base address.
     if (!rebox.getSubcomponent().empty() || !rebox.getSubstr().empty()) {
       // Cast to inputEleTy* so that a GEP can be used.
@@ -2277,7 +2225,7 @@ struct XReboxOpConversion : public EmboxCommonConversion<fir::cg::XReboxOp> {
     // and strides.
     llvm::SmallVector<mlir::Value> slicedExtents;
     llvm::SmallVector<mlir::Value> slicedStrides;
-    mlir::Value one = genConstantIndex(loc, idxTy, rewriter, 1);
+    mlir::Value one = fir::genConstantIndex(loc, idxTy, rewriter, 1);
     const bool sliceHasOrigins = !rebox.getShift().empty();
     unsigned sliceOps = rebox.getSliceOperandIndex();
     unsigned shiftOps = rebox.getShiftOperandIndex();
@@ -2350,7 +2298,7 @@ struct XReboxOpConversion : public EmboxCommonConversion<fir::cg::XReboxOp> {
     // which may be OK if all new extents are ones, the stride does not
     // matter, use one.
     mlir::Value stride = inputStrides.empty()
-                             ? genConstantIndex(loc, idxTy, rewriter, 1)
+                             ? fir::genConstantIndex(loc, idxTy, rewriter, 1)
                              : inputStrides[0];
     for (unsigned i = 0; i < rebox.getShape().size(); ++i) {
       mlir::Value rawExtent = operands[rebox.getShapeOperandIndex() + i];
@@ -2585,9 +2533,9 @@ struct XArrayCoorOpConversion
     unsigned shiftOffset = coor.getShiftOperandIndex();
     unsigned sliceOffset = coor.getSliceOperandIndex();
     auto sliceOps = coor.getSlice().begin();
-    mlir::Value one = genConstantIndex(loc, idxTy, rewriter, 1);
+    mlir::Value one = fir::genConstantIndex(loc, idxTy, rewriter, 1);
     mlir::Value prevExt = one;
-    mlir::Value offset = genConstantIndex(loc, idxTy, rewriter, 0);
+    mlir::Value offset = fir::genConstantIndex(loc, idxTy, rewriter, 0);
     const bool isShifted = !coor.getShift().empty();
     const bool isSliced = !coor.getSlice().empty();
     const bool baseIsBoxed =
@@ -2918,7 +2866,7 @@ struct CoordinateOpConversion
         // of lower bound aspects. This both accounts for dynamically sized
         // types and non contiguous arrays.
         auto idxTy = lowerTy().indexType();
-        mlir::Value off = genConstantIndex(loc, idxTy, rewriter, 0);
+        mlir::Value off = fir::genConstantIndex(loc, idxTy, rewriter, 0);
         unsigned arrayDim = arrTy.getDimension();
         for (unsigned dim = 0; dim < arrayDim && it != end; ++dim, ++it) {
           mlir::Value stride =
@@ -3846,7 +3794,7 @@ struct IsPresentOpConversion : public fir::FIROpConversion<fir::IsPresentOp> {
       ptr = mlir::LLVM::ExtractValueOp::create(rewriter, loc, ptr, 0);
     }
     mlir::LLVM::ConstantOp c0 =
-        genConstantIndex(isPresent.getLoc(), idxTy, rewriter, 0);
+        fir::genConstantIndex(isPresent.getLoc(), idxTy, rewriter, 0);
     auto addr = mlir::LLVM::PtrToIntOp::create(rewriter, loc, idxTy, ptr);
     rewriter.replaceOpWithNewOp<mlir::LLVM::ICmpOp>(
         isPresent, mlir::LLVM::ICmpPredicate::ne, addr, c0);

diff  --git a/flang/lib/Optimizer/CodeGen/CodeGenOpenMP.cpp b/flang/lib/Optimizer/CodeGen/CodeGenOpenMP.cpp
index 37f1c9f97e1ce..97912bda79b08 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGenOpenMP.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGenOpenMP.cpp
@@ -21,6 +21,7 @@
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Support/FatalError.h"
 #include "flang/Optimizer/Support/InternalNames.h"
+#include "flang/Optimizer/Support/Utils.h"
 #include "mlir/Conversion/LLVMCommon/ConversionTarget.h"
 #include "mlir/Conversion/LLVMCommon/Pattern.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
@@ -125,10 +126,58 @@ struct PrivateClauseOpConversion
     return mlir::success();
   }
 };
+
+// Convert FIR type to LLVM without turning fir.box<T> into memory
+// reference.
+static mlir::Type convertObjectType(const fir::LLVMTypeConverter &converter,
+                                    mlir::Type firType) {
+  if (auto boxTy = mlir::dyn_cast<fir::BaseBoxType>(firType))
+    return converter.convertBoxTypeAsStruct(boxTy);
+  return converter.convertType(firType);
+}
+
+// FIR Op specific conversion for TargetAllocMemOp
+struct TargetAllocMemOpConversion
+    : public OpenMPFIROpConversion<mlir::omp::TargetAllocMemOp> {
+  using OpenMPFIROpConversion::OpenMPFIROpConversion;
+
+  llvm::LogicalResult
+  matchAndRewrite(mlir::omp::TargetAllocMemOp allocmemOp, OpAdaptor adaptor,
+                  mlir::ConversionPatternRewriter &rewriter) const override {
+    mlir::Type heapTy = allocmemOp.getAllocatedType();
+    mlir::Location loc = allocmemOp.getLoc();
+    auto ity = lowerTy().indexType();
+    mlir::Type dataTy = fir::unwrapRefType(heapTy);
+    mlir::Type llvmObjectTy = convertObjectType(lowerTy(), dataTy);
+    if (fir::isRecordWithTypeParameters(fir::unwrapSequenceType(dataTy)))
+      TODO(loc, "omp.target_allocmem codegen of derived type with length "
+                "parameters");
+    mlir::Value size = fir::computeElementDistance(
+        loc, llvmObjectTy, ity, rewriter, lowerTy().getDataLayout());
+    if (auto scaleSize = fir::genAllocationScaleSize(
+            loc, allocmemOp.getInType(), ity, rewriter))
+      size = rewriter.create<mlir::LLVM::MulOp>(loc, ity, size, scaleSize);
+    for (mlir::Value opnd : adaptor.getOperands().drop_front())
+      size = rewriter.create<mlir::LLVM::MulOp>(
+          loc, ity, size, integerCast(lowerTy(), loc, rewriter, ity, opnd));
+    auto mallocTyWidth = lowerTy().getIndexTypeBitwidth();
+    auto mallocTy =
+        mlir::IntegerType::get(rewriter.getContext(), mallocTyWidth);
+    if (mallocTyWidth != ity.getIntOrFloatBitWidth())
+      size = integerCast(lowerTy(), loc, rewriter, mallocTy, size);
+    rewriter.modifyOpInPlace(allocmemOp, [&]() {
+      allocmemOp.setInType(rewriter.getI8Type());
+      allocmemOp.getTypeparamsMutable().clear();
+      allocmemOp.getTypeparamsMutable().append(size);
+    });
+    return mlir::success();
+  }
+};
 } // namespace
 
 void fir::populateOpenMPFIRToLLVMConversionPatterns(
     const LLVMTypeConverter &converter, mlir::RewritePatternSet &patterns) {
   patterns.add<MapInfoOpConversion>(converter);
   patterns.add<PrivateClauseOpConversion>(converter);
+  patterns.add<TargetAllocMemOpConversion>(converter);
 }

diff  --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
index 01975f357a8da..87f9899aa7879 100644
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -107,7 +107,6 @@ static bool verifyTypeParamCount(mlir::Type inType, unsigned numParams) {
 }
 
 /// Parser shared by Alloca and Allocmem
-///
 /// operation ::= %res = (`fir.alloca` | `fir.allocmem`) $in_type
 ///                      ( `(` $typeparams `)` )? ( `,` $shape )?
 ///                      attr-dict-without-keyword

diff  --git a/flang/lib/Optimizer/Support/Utils.cpp b/flang/lib/Optimizer/Support/Utils.cpp
index 5d663e28336c0..c71642ce4e806 100644
--- a/flang/lib/Optimizer/Support/Utils.cpp
+++ b/flang/lib/Optimizer/Support/Utils.cpp
@@ -50,3 +50,74 @@ std::optional<llvm::ArrayRef<int64_t>> fir::getComponentLowerBoundsIfNonDefault(
       return componentInfo.getLowerBounds();
   return std::nullopt;
 }
+
+mlir::LLVM::ConstantOp
+fir::genConstantIndex(mlir::Location loc, mlir::Type ity,
+                      mlir::ConversionPatternRewriter &rewriter,
+                      std::int64_t offset) {
+  auto cattr = rewriter.getI64IntegerAttr(offset);
+  return rewriter.create<mlir::LLVM::ConstantOp>(loc, ity, cattr);
+}
+
+mlir::Value
+fir::computeElementDistance(mlir::Location loc, mlir::Type llvmObjectType,
+                            mlir::Type idxTy,
+                            mlir::ConversionPatternRewriter &rewriter,
+                            const mlir::DataLayout &dataLayout) {
+  llvm::TypeSize size = dataLayout.getTypeSize(llvmObjectType);
+  unsigned short alignment = dataLayout.getTypeABIAlignment(llvmObjectType);
+  std::int64_t distance = llvm::alignTo(size, alignment);
+  return fir::genConstantIndex(loc, idxTy, rewriter, distance);
+}
+
+mlir::Value
+fir::genAllocationScaleSize(mlir::Location loc, mlir::Type dataTy,
+                            mlir::Type ity,
+                            mlir::ConversionPatternRewriter &rewriter) {
+  auto seqTy = mlir::dyn_cast<fir::SequenceType>(dataTy);
+  fir::SequenceType::Extent constSize = 1;
+  if (seqTy) {
+    int constRows = seqTy.getConstantRows();
+    const fir::SequenceType::ShapeRef &shape = seqTy.getShape();
+    if (constRows != static_cast<int>(shape.size())) {
+      for (auto extent : shape) {
+        if (constRows-- > 0)
+          continue;
+        if (extent != fir::SequenceType::getUnknownExtent())
+          constSize *= extent;
+      }
+    }
+  }
+
+  if (constSize != 1) {
+    mlir::Value constVal{
+        fir::genConstantIndex(loc, ity, rewriter, constSize).getResult()};
+    return constVal;
+  }
+  return nullptr;
+}
+
+mlir::Value fir::integerCast(const fir::LLVMTypeConverter &converter,
+                             mlir::Location loc,
+                             mlir::ConversionPatternRewriter &rewriter,
+                             mlir::Type ty, mlir::Value val, bool fold) {
+  auto valTy = val.getType();
+  // If the value was not yet lowered, lower its type so that it can
+  // be used in getPrimitiveTypeSizeInBits.
+  if (!mlir::isa<mlir::IntegerType>(valTy))
+    valTy = converter.convertType(valTy);
+  auto toSize = mlir::LLVM::getPrimitiveTypeSizeInBits(ty);
+  auto fromSize = mlir::LLVM::getPrimitiveTypeSizeInBits(valTy);
+  if (fold) {
+    if (toSize < fromSize)
+      return rewriter.createOrFold<mlir::LLVM::TruncOp>(loc, ty, val);
+    if (toSize > fromSize)
+      return rewriter.createOrFold<mlir::LLVM::SExtOp>(loc, ty, val);
+  } else {
+    if (toSize < fromSize)
+      return rewriter.create<mlir::LLVM::TruncOp>(loc, ty, val);
+    if (toSize > fromSize)
+      return rewriter.create<mlir::LLVM::SExtOp>(loc, ty, val);
+  }
+  return val;
+}

diff  --git a/flang/test/Fir/omp_target_allocmem_freemem.fir b/flang/test/Fir/omp_target_allocmem_freemem.fir
new file mode 100644
index 0000000000000..03eb94acb1ac7
--- /dev/null
+++ b/flang/test/Fir/omp_target_allocmem_freemem.fir
@@ -0,0 +1,294 @@
+// RUN: %flang_fc1 -emit-llvm  %s -o - | FileCheck %s
+
+// UNSUPPORTED: system-windows
+// Disabled on 32-bit targets due to the additional `trunc` opcodes required
+// UNSUPPORTED: target-x86
+// UNSUPPORTED: target=sparc-{{.*}}
+// UNSUPPORTED: target=sparcel-{{.*}}
+
+// CHECK-LABEL: define void @omp_target_allocmem_scalar_nonchar() {
+// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @omp_target_alloc(i64 4, i32 0)
+// CHECK-NEXT:    [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = inttoptr i64 [[TMP2]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP3]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_scalar_nonchar() -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, i32
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_scalars_nonchar() {
+// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @omp_target_alloc(i64 400, i32 0)
+// CHECK-NEXT:    [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = inttoptr i64 [[TMP2]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP3]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_scalars_nonchar() -> () {
+  %device = arith.constant 0 : i32
+  %0 = arith.constant 100 : index
+  %1 = omp.target_allocmem %device : i32, i32, %0
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_scalar_char() {
+// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @omp_target_alloc(i64 10, i32 0)
+// CHECK-NEXT:    [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = inttoptr i64 [[TMP2]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP3]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_scalar_char() -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.char<1,10>
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_scalar_char_kind() {
+// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @omp_target_alloc(i64 20, i32 0)
+// CHECK-NEXT:    [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = inttoptr i64 [[TMP2]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP3]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_scalar_char_kind() -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.char<2,10>
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_scalar_dynchar(
+// CHECK-SAME: i32 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = sext i32 [[TMP0]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 1, [[TMP2]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 1, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = call ptr @omp_target_alloc(i64 [[TMP4]], i32 0)
+// CHECK-NEXT:    [[TMP6:%.*]] = ptrtoint ptr [[TMP5]] to i64
+// CHECK-NEXT:    [[TMP7:%.*]] = inttoptr i64 [[TMP6]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP7]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_scalar_dynchar(%l : i32) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.char<1,?>(%l : i32)
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+
+// CHECK-LABEL: define void @omp_target_allocmem_scalar_dynchar_kind(
+// CHECK-SAME: i32 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = sext i32 [[TMP0]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 2, [[TMP2]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 1, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = call ptr @omp_target_alloc(i64 [[TMP4]], i32 0)
+// CHECK-NEXT:    [[TMP6:%.*]] = ptrtoint ptr [[TMP5]] to i64
+// CHECK-NEXT:    [[TMP7:%.*]] = inttoptr i64 [[TMP6]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP7]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_scalar_dynchar_kind(%l : i32) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.char<2,?>(%l : i32)
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+
+// CHECK-LABEL: define void @omp_target_allocmem_array_of_nonchar() {
+// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @omp_target_alloc(i64 36, i32 0)
+// CHECK-NEXT:    [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = inttoptr i64 [[TMP2]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP3]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_array_of_nonchar() -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x3xi32>
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_array_of_char() {
+// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @omp_target_alloc(i64 90, i32 0)
+// CHECK-NEXT:    [[TMP2:%.*]] = ptrtoint ptr [[TMP1]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = inttoptr i64 [[TMP2]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP3]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_array_of_char() -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x3x!fir.char<1,10>>
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_array_of_dynchar(
+// CHECK-SAME: i32 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = sext i32 [[TMP0]] to i64
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 9, [[TMP2]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 1, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = call ptr @omp_target_alloc(i64 [[TMP4]], i32 0)
+// CHECK-NEXT:    [[TMP6:%.*]] = ptrtoint ptr [[TMP5]] to i64
+// CHECK-NEXT:    [[TMP7:%.*]] = inttoptr i64 [[TMP6]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP7]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_array_of_dynchar(%l: i32) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x3x!fir.char<1,?>>(%l : i32)
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+
+// CHECK-LABEL: define void @omp_target_allocmem_dynarray_of_nonchar(
+// CHECK-SAME: i64 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = mul i64 12, [[TMP0]]
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 1, [[TMP2]]
+// CHECK-NEXT:    [[TMP4:%.*]] = call ptr @omp_target_alloc(i64 [[TMP3]], i32 0)
+// CHECK-NEXT:    [[TMP5:%.*]] = ptrtoint ptr [[TMP4]] to i64
+// CHECK-NEXT:    [[TMP6:%.*]] = inttoptr i64 [[TMP5]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP6]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_dynarray_of_nonchar(%e: index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x?xi32>, %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_dynarray_of_nonchar2(
+// CHECK-SAME: i64 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = mul i64 4, [[TMP0]]
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 [[TMP2]], [[TMP0]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 1, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = call ptr @omp_target_alloc(i64 [[TMP4]], i32 0)
+// CHECK-NEXT:    [[TMP6:%.*]] = ptrtoint ptr [[TMP5]] to i64
+// CHECK-NEXT:    [[TMP7:%.*]] = inttoptr i64 [[TMP6]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP7]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_dynarray_of_nonchar2(%e: index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<?x?xi32>, %e, %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_dynarray_of_char(
+// CHECK-SAME: i64 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = mul i64 60, [[TMP0]]
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 1, [[TMP2]]
+// CHECK-NEXT:    [[TMP4:%.*]] = call ptr @omp_target_alloc(i64 [[TMP3]], i32 0)
+// CHECK-NEXT:    [[TMP5:%.*]] = ptrtoint ptr [[TMP4]] to i64
+// CHECK-NEXT:    [[TMP6:%.*]] = inttoptr i64 [[TMP5]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP6]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_dynarray_of_char(%e : index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x?x!fir.char<2,10>>, %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+
+// CHECK-LABEL: define void @omp_target_allocmem_dynarray_of_char2(
+// CHECK-SAME: i64 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = mul i64 20, [[TMP0]]
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 [[TMP2]], [[TMP0]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 1, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = call ptr @omp_target_alloc(i64 [[TMP4]], i32 0)
+// CHECK-NEXT:    [[TMP6:%.*]] = ptrtoint ptr [[TMP5]] to i64
+// CHECK-NEXT:    [[TMP7:%.*]] = inttoptr i64 [[TMP6]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP7]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_dynarray_of_char2(%e : index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<?x?x!fir.char<2,10>>, %e, %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_dynarray_of_dynchar(
+// CHECK-SAME: i32 [[TMP0:%.*]], i64 [[TMP1:%.*]]) {
+// CHECK-NEXT:    [[TMP3:%.*]] = sext i32 [[TMP0]] to i64
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 6, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = mul i64 [[TMP4]], [[TMP1]]
+// CHECK-NEXT:    [[TMP6:%.*]] = mul i64 1, [[TMP5]]
+// CHECK-NEXT:    [[TMP7:%.*]] = call ptr @omp_target_alloc(i64 [[TMP6]], i32 0)
+// CHECK-NEXT:    [[TMP8:%.*]] = ptrtoint ptr [[TMP7]] to i64
+// CHECK-NEXT:    [[TMP9:%.*]] = inttoptr i64 [[TMP8]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP9]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_dynarray_of_dynchar(%l: i32, %e : index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x?x!fir.char<2,?>>(%l : i32), %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_dynarray_of_dynchar2(
+// CHECK-SAME: i32 [[TMP0:%.*]], i64 [[TMP1:%.*]]) {
+// CHECK-NEXT:    [[TMP3:%.*]] = sext i32 [[TMP0]] to i64
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 2, [[TMP3]]
+// CHECK-NEXT:    [[TMP5:%.*]] = mul i64 [[TMP4]], [[TMP1]]
+// CHECK-NEXT:    [[TMP6:%.*]] = mul i64 [[TMP5]], [[TMP1]]
+// CHECK-NEXT:    [[TMP7:%.*]] = mul i64 1, [[TMP6]]
+// CHECK-NEXT:    [[TMP8:%.*]] = call ptr @omp_target_alloc(i64 [[TMP7]], i32 0)
+// CHECK-NEXT:    [[TMP9:%.*]] = ptrtoint ptr [[TMP8]] to i64
+// CHECK-NEXT:    [[TMP10:%.*]] = inttoptr i64 [[TMP9]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP10]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_dynarray_of_dynchar2(%l: i32, %e : index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<?x?x!fir.char<2,?>>(%l : i32), %e, %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_array_with_holes_nonchar(
+// CHECK-SAME: i64 [[TMP0:%.*]], i64 [[TMP1:%.*]]) {
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 240, [[TMP0]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 [[TMP3]], [[TMP1]]
+// CHECK-NEXT:    [[TMP5:%.*]] = mul i64 1, [[TMP4]]
+// CHECK-NEXT:    [[TMP6:%.*]] = call ptr @omp_target_alloc(i64 [[TMP5]], i32 0)
+// CHECK-NEXT:    [[TMP7:%.*]] = ptrtoint ptr [[TMP6]] to i64
+// CHECK-NEXT:    [[TMP8:%.*]] = inttoptr i64 [[TMP7]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP8]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_array_with_holes_nonchar(%0 : index, %1 : index) -> () {
+  %device = arith.constant 0 : i32
+  %2 = omp.target_allocmem %device : i32, !fir.array<4x?x3x?x5xi32>, %0, %1
+  omp.target_freemem %device, %2 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_array_with_holes_char(
+// CHECK-SAME: i64 [[TMP0:%.*]]) {
+// CHECK-NEXT:    [[TMP2:%.*]] = mul i64 240, [[TMP0]]
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 1, [[TMP2]]
+// CHECK-NEXT:    [[TMP4:%.*]] = call ptr @omp_target_alloc(i64 [[TMP3]], i32 0)
+// CHECK-NEXT:    [[TMP5:%.*]] = ptrtoint ptr [[TMP4]] to i64
+// CHECK-NEXT:    [[TMP6:%.*]] = inttoptr i64 [[TMP5]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP6]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_array_with_holes_char(%e: index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x?x4x!fir.char<2,10>>, %e
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}
+
+// CHECK-LABEL: define void @omp_target_allocmem_array_with_holes_dynchar(
+// CHECK-SAME: i64 [[TMP0:%.*]], i64 [[TMP1:%.*]]) {
+// CHECK-NEXT:    [[TMP3:%.*]] = mul i64 24, [[TMP0]]
+// CHECK-NEXT:    [[TMP4:%.*]] = mul i64 [[TMP3]], [[TMP1]]
+// CHECK-NEXT:    [[TMP5:%.*]] = mul i64 1, [[TMP4]]
+// CHECK-NEXT:    [[TMP6:%.*]] = call ptr @omp_target_alloc(i64 [[TMP5]], i32 0)
+// CHECK-NEXT:    [[TMP7:%.*]] = ptrtoint ptr [[TMP6]] to i64
+// CHECK-NEXT:    [[TMP8:%.*]] = inttoptr i64 [[TMP7]] to ptr
+// CHECK-NEXT:    call void @omp_target_free(ptr [[TMP8]], i32 0)
+// CHECK-NEXT:    ret void
+func.func @omp_target_allocmem_array_with_holes_dynchar(%arg0: index, %arg1: index) -> () {
+  %device = arith.constant 0 : i32
+  %1 = omp.target_allocmem %device : i32, !fir.array<3x?x4x!fir.char<2,?>>(%arg0 : index), %arg1
+  omp.target_freemem %device, %1 : i32, i64
+  return
+}

diff  --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index be114ea4fb631..c956d69781b3d 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -2115,4 +2115,98 @@ def AllocateDirOp : OpenMP_Op<"allocate_dir", clauses = [
   let hasVerifier = 1;
 }
 
+//===----------------------------------------------------------------------===//
+// TargetAllocMemOp
+//===----------------------------------------------------------------------===//
+
+def TargetAllocMemOp : OpenMP_Op<"target_allocmem",
+    [MemoryEffects<[MemAlloc<DefaultResource>]>, AttrSizedOperandSegments]> {
+  let summary = "allocate storage on an openmp device for an object of a given type";
+
+  let description = [{
+    Allocates memory on the specified OpenMP device for an object of the given type.
+    Returns an integer value representing the device pointer to the allocated memory.
+    The memory is uninitialized after allocation. Operations must be paired with 
+    `omp.target_freemem` to avoid memory leaks.
+
+    * `$device`: The integer ID of the OpenMP device where the memory will be allocated.
+    * `$in_type`: The type of the object for which memory is being allocated. 
+      For arrays, this can be a static or dynamic array type.
+    * `$uniq_name`: An optional unique name for the allocated memory.
+    * `$bindc_name`: An optional name used for C interoperability.
+    * `$typeparams`: Runtime type parameters for polymorphic or parameterized types. 
+      These are typically integer values that define aspects of a type not fixed at compile time.
+    * `$shape`: Runtime shape operands for dynamic arrays. 
+      Each operand is an integer value representing the extent of a specific dimension. 
+
+  ```mlir
+    // Allocate a static 3x3 integer vector on device 0
+    %device_0 = arith.constant 0 : i32
+    %ptr_static = omp.target_allocmem %device_0 : i32, vector<3x3xi32>
+    // ... use %ptr_static ...
+    omp.target_freemem %device_0, %ptr_static : i32, i64
+
+    // Allocate a dynamic 2D Fortran array (fir.array) on device 1
+    %device_1 = arith.constant 1 : i32
+    %rows = arith.constant 10 : index
+    %cols = arith.constant 20 : index
+    %ptr_dynamic = omp.target_allocmem %device_1 : i32, !fir.array<?x?xf32>, %rows, %cols : index, index
+    // ... use %ptr_dynamic ...
+    omp.target_freemem %device_1, %ptr_dynamic : i32, i64
+  ```
+  }];
+
+  let arguments = (ins
+    Arg<AnyInteger>:$device,
+    TypeAttr:$in_type,
+    OptionalAttr<StrAttr>:$uniq_name,
+    OptionalAttr<StrAttr>:$bindc_name,
+    Variadic<IntLikeType>:$typeparams,
+    Variadic<IntLikeType>:$shape
+  );
+  let results = (outs I64);
+
+  let hasCustomAssemblyFormat = 1;
+  let hasVerifier = 1;
+
+  let extraClassDeclaration = [{
+    mlir::Type getAllocatedType();
+  }];
+}
+
+//===----------------------------------------------------------------------===//
+// TargetFreeMemOp
+//===----------------------------------------------------------------------===//
+
+def TargetFreeMemOp : OpenMP_Op<"target_freemem",
+  [MemoryEffects<[MemFree]>]> {
+  let summary = "free memory on an openmp device";
+
+  let description = [{
+    Deallocates memory on the specified OpenMP device that was previously
+    allocated by an `omp.target_allocmem` operation. After this operation, the
+    deallocated memory is in an undefined state and should not be accessed.
+    It is crucial to ensure that all accesses to the memory region are completed
+    before `omp.target_freemem` is called to avoid undefined behavior.
+
+    * `$device`: The integer ID of the OpenMP device from which the memory will be freed.
+    * `$heapref`: The integer value representing the device pointer to the memory
+      to be deallocated, which was previously returned by `omp.target_allocmem`.
+
+    ```mlir
+      // Example of allocating and freeing memory on an OpenMP device
+      %device_id = arith.constant 0 : i32
+      %allocated_ptr = omp.target_allocmem %device_id : i32, vector<3x3xi32>
+      // ... operations using %allocated_ptr on the device ...
+      omp.target_freemem %device_id, %allocated_ptr : i32, i64
+    ```
+  }];
+
+  let arguments = (ins
+  Arg<AnyInteger, "", [MemFree]>:$device,
+  Arg<I64, "", [MemFree]>:$heapref
+  );
+  let assemblyFormat = "$device `,` $heapref attr-dict `:` type($device) `,` qualified(type($heapref))";
+}
+
 #endif // OPENMP_OPS

diff  --git a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
index c1c1767ef90b0..fa94219016c1e 100644
--- a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
+++ b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
@@ -3874,6 +3874,107 @@ LogicalResult AllocateDirOp::verify() {
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// TargetAllocMemOp
+//===----------------------------------------------------------------------===//
+
+mlir::Type omp::TargetAllocMemOp::getAllocatedType() {
+  return getInTypeAttr().getValue();
+}
+
+/// operation ::= %res = (`omp.target_alloc_mem`) $device : devicetype,
+///                      $in_type ( `(` $typeparams `)` )? ( `,` $shape )?
+///                      attr-dict-without-keyword
+static mlir::ParseResult parseTargetAllocMemOp(mlir::OpAsmParser &parser,
+                                               mlir::OperationState &result) {
+  auto &builder = parser.getBuilder();
+  bool hasOperands = false;
+  std::int32_t typeparamsSize = 0;
+
+  // Parse device number as a new operand
+  mlir::OpAsmParser::UnresolvedOperand deviceOperand;
+  mlir::Type deviceType;
+  if (parser.parseOperand(deviceOperand) || parser.parseColonType(deviceType))
+    return mlir::failure();
+  if (parser.resolveOperand(deviceOperand, deviceType, result.operands))
+    return mlir::failure();
+  if (parser.parseComma())
+    return mlir::failure();
+
+  mlir::Type intype;
+  if (parser.parseType(intype))
+    return mlir::failure();
+  result.addAttribute("in_type", mlir::TypeAttr::get(intype));
+  llvm::SmallVector<mlir::OpAsmParser::UnresolvedOperand> operands;
+  llvm::SmallVector<mlir::Type> typeVec;
+  if (!parser.parseOptionalLParen()) {
+    // parse the LEN params of the derived type. (<params> : <types>)
+    if (parser.parseOperandList(operands, mlir::OpAsmParser::Delimiter::None) ||
+        parser.parseColonTypeList(typeVec) || parser.parseRParen())
+      return mlir::failure();
+    typeparamsSize = operands.size();
+    hasOperands = true;
+  }
+  std::int32_t shapeSize = 0;
+  if (!parser.parseOptionalComma()) {
+    // parse size to scale by, vector of n dimensions of type index
+    if (parser.parseOperandList(operands, mlir::OpAsmParser::Delimiter::None))
+      return mlir::failure();
+    shapeSize = operands.size() - typeparamsSize;
+    auto idxTy = builder.getIndexType();
+    for (std::int32_t i = typeparamsSize, end = operands.size(); i != end; ++i)
+      typeVec.push_back(idxTy);
+    hasOperands = true;
+  }
+  if (hasOperands &&
+      parser.resolveOperands(operands, typeVec, parser.getNameLoc(),
+                             result.operands))
+    return mlir::failure();
+
+  mlir::Type restype = builder.getIntegerType(64);
+  if (!restype) {
+    parser.emitError(parser.getNameLoc(), "invalid allocate type: ") << intype;
+    return mlir::failure();
+  }
+  llvm::SmallVector<std::int32_t> segmentSizes{1, typeparamsSize, shapeSize};
+  result.addAttribute("operandSegmentSizes",
+                      builder.getDenseI32ArrayAttr(segmentSizes));
+  if (parser.parseOptionalAttrDict(result.attributes) ||
+      parser.addTypeToList(restype, result.types))
+    return mlir::failure();
+  return mlir::success();
+}
+
+mlir::ParseResult omp::TargetAllocMemOp::parse(mlir::OpAsmParser &parser,
+                                               mlir::OperationState &result) {
+  return parseTargetAllocMemOp(parser, result);
+}
+
+void omp::TargetAllocMemOp::print(mlir::OpAsmPrinter &p) {
+  p << " ";
+  p.printOperand(getDevice());
+  p << " : ";
+  p << getDevice().getType();
+  p << ", ";
+  p << getInType();
+  if (!getTypeparams().empty()) {
+    p << '(' << getTypeparams() << " : " << getTypeparams().getTypes() << ')';
+  }
+  for (auto sh : getShape()) {
+    p << ", ";
+    p.printOperand(sh);
+  }
+  p.printOptionalAttrDict((*this)->getAttrs(),
+                          {"in_type", "operandSegmentSizes"});
+}
+
+llvm::LogicalResult omp::TargetAllocMemOp::verify() {
+  mlir::Type outType = getType();
+  if (!mlir::dyn_cast<IntegerType>(outType))
+    return emitOpError("must be a integer type");
+  return mlir::success();
+}
+
 #define GET_ATTRDEF_CLASSES
 #include "mlir/Dialect/OpenMP/OpenMPOpsAttributes.cpp.inc"
 

diff  --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index eb96cb211fdd5..6694de8383534 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -5867,6 +5867,10 @@ static bool isTargetDeviceOp(Operation *op) {
   if (mlir::isa<omp::ThreadprivateOp>(op))
     return true;
 
+  if (mlir::isa<omp::TargetAllocMemOp>(op) ||
+      mlir::isa<omp::TargetFreeMemOp>(op))
+    return true;
+
   if (auto parentFn = op->getParentOfType<LLVM::LLVMFuncOp>())
     if (auto declareTargetIface =
             llvm::dyn_cast<mlir::omp::DeclareTargetInterface>(
@@ -5879,6 +5883,85 @@ static bool isTargetDeviceOp(Operation *op) {
   return false;
 }
 
+static llvm::Function *getOmpTargetAlloc(llvm::IRBuilderBase &builder,
+                                         llvm::Module *llvmModule) {
+  llvm::Type *i64Ty = builder.getInt64Ty();
+  llvm::Type *i32Ty = builder.getInt32Ty();
+  llvm::Type *returnType = builder.getPtrTy(0);
+  llvm::FunctionType *fnType =
+      llvm::FunctionType::get(returnType, {i64Ty, i32Ty}, false);
+  llvm::Function *func = cast<llvm::Function>(
+      llvmModule->getOrInsertFunction("omp_target_alloc", fnType).getCallee());
+  return func;
+}
+
+static LogicalResult
+convertTargetAllocMemOp(Operation &opInst, llvm::IRBuilderBase &builder,
+                        LLVM::ModuleTranslation &moduleTranslation) {
+  auto allocMemOp = cast<omp::TargetAllocMemOp>(opInst);
+  if (!allocMemOp)
+    return failure();
+
+  // Get "omp_target_alloc" function
+  llvm::Module *llvmModule = moduleTranslation.getLLVMModule();
+  llvm::Function *ompTargetAllocFunc = getOmpTargetAlloc(builder, llvmModule);
+  // Get the corresponding device value in llvm
+  mlir::Value deviceNum = allocMemOp.getDevice();
+  llvm::Value *llvmDeviceNum = moduleTranslation.lookupValue(deviceNum);
+  // Get the allocation size.
+  llvm::DataLayout dataLayout = llvmModule->getDataLayout();
+  mlir::Type heapTy = allocMemOp.getAllocatedType();
+  llvm::Type *llvmHeapTy = moduleTranslation.convertType(heapTy);
+  llvm::TypeSize typeSize = dataLayout.getTypeStoreSize(llvmHeapTy);
+  llvm::Value *allocSize = builder.getInt64(typeSize.getFixedValue());
+  for (auto typeParam : allocMemOp.getTypeparams())
+    allocSize =
+        builder.CreateMul(allocSize, moduleTranslation.lookupValue(typeParam));
+  // Create call to "omp_target_alloc" with the args as translated llvm values.
+  llvm::CallInst *call =
+      builder.CreateCall(ompTargetAllocFunc, {allocSize, llvmDeviceNum});
+  llvm::Value *resultI64 = builder.CreatePtrToInt(call, builder.getInt64Ty());
+
+  // Map the result
+  moduleTranslation.mapValue(allocMemOp.getResult(), resultI64);
+  return success();
+}
+
+static llvm::Function *getOmpTargetFree(llvm::IRBuilderBase &builder,
+                                        llvm::Module *llvmModule) {
+  llvm::Type *ptrTy = builder.getPtrTy(0);
+  llvm::Type *i32Ty = builder.getInt32Ty();
+  llvm::Type *voidTy = builder.getVoidTy();
+  llvm::FunctionType *fnType =
+      llvm::FunctionType::get(voidTy, {ptrTy, i32Ty}, false);
+  llvm::Function *func = dyn_cast<llvm::Function>(
+      llvmModule->getOrInsertFunction("omp_target_free", fnType).getCallee());
+  return func;
+}
+
+static LogicalResult
+convertTargetFreeMemOp(Operation &opInst, llvm::IRBuilderBase &builder,
+                       LLVM::ModuleTranslation &moduleTranslation) {
+  auto freeMemOp = cast<omp::TargetFreeMemOp>(opInst);
+  if (!freeMemOp)
+    return failure();
+
+  // Get "omp_target_free" function
+  llvm::Module *llvmModule = moduleTranslation.getLLVMModule();
+  llvm::Function *ompTragetFreeFunc = getOmpTargetFree(builder, llvmModule);
+  // Get the corresponding device value in llvm
+  mlir::Value deviceNum = freeMemOp.getDevice();
+  llvm::Value *llvmDeviceNum = moduleTranslation.lookupValue(deviceNum);
+  // Get the corresponding heapref value in llvm
+  mlir::Value heapref = freeMemOp.getHeapref();
+  llvm::Value *llvmHeapref = moduleTranslation.lookupValue(heapref);
+  // Convert heapref int to ptr and call "omp_target_free"
+  llvm::Value *intToPtr =
+      builder.CreateIntToPtr(llvmHeapref, builder.getPtrTy(0));
+  builder.CreateCall(ompTragetFreeFunc, {intToPtr, llvmDeviceNum});
+  return success();
+}
+
 /// Given an OpenMP MLIR operation, create the corresponding LLVM IR (including
 /// OpenMP runtime calls).
 static LogicalResult
@@ -6053,6 +6136,12 @@ convertHostOrTargetOperation(Operation *op, llvm::IRBuilderBase &builder,
             // the omp.canonical_loop.
             return applyUnrollHeuristic(op, builder, moduleTranslation);
           })
+          .Case([&](omp::TargetAllocMemOp) {
+            return convertTargetAllocMemOp(*op, builder, moduleTranslation);
+          })
+          .Case([&](omp::TargetFreeMemOp) {
+            return convertTargetFreeMemOp(*op, builder, moduleTranslation);
+          })
           .Default([&](Operation *inst) {
             return inst->emitError()
                    << "not yet implemented: " << inst->getName();

diff  --git a/mlir/test/Target/LLVMIR/ompenmp-target-allocmem-freemem.mlir b/mlir/test/Target/LLVMIR/ompenmp-target-allocmem-freemem.mlir
new file mode 100644
index 0000000000000..1bc97609ccff4
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/ompenmp-target-allocmem-freemem.mlir
@@ -0,0 +1,42 @@
+// RUN: mlir-opt %s -convert-openmp-to-llvm | mlir-translate -mlir-to-llvmir | FileCheck %s
+
+// This file contains MLIR test cases for omp.target_allocmem and omp.target_freemem
+
+// CHECK-LABEL: test_alloc_free_i64
+// CHECK: %[[ALLOC:.*]] = call ptr @omp_target_alloc(i64 8, i32 0)
+// CHECK: %[[PTRTOINT:.*]] = ptrtoint ptr %[[ALLOC]] to i64
+// CHECK: %[[INTTOPTR:.*]] = inttoptr i64 %[[PTRTOINT]] to ptr
+// CHECK: call void @omp_target_free(ptr %[[INTTOPTR]], i32 0)
+// CHECK: ret void
+llvm.func @test_alloc_free_i64() -> () {
+  %device = llvm.mlir.constant(0 : i32) : i32
+  %1 = omp.target_allocmem %device : i32, i64
+  omp.target_freemem %device, %1 : i32, i64
+  llvm.return
+}
+
+// CHECK-LABEL: test_alloc_free_vector_1d_f32
+// CHECK: %[[ALLOC:.*]] = call ptr @omp_target_alloc(i64 64, i32 0)
+// CHECK: %[[PTRTOINT:.*]] = ptrtoint ptr %[[ALLOC]] to i64
+// CHECK: %[[INTTOPTR:.*]] = inttoptr i64 %[[PTRTOINT]] to ptr
+// CHECK: call void @omp_target_free(ptr %[[INTTOPTR]], i32 0)
+// CHECK: ret void
+llvm.func @test_alloc_free_vector_1d_f32() -> () {
+  %device = llvm.mlir.constant(0 : i32) : i32
+  %1 = omp.target_allocmem %device : i32, vector<16xf32>
+  omp.target_freemem %device, %1 : i32, i64
+  llvm.return
+}
+
+// CHECK-LABEL: test_alloc_free_vector_2d_f32
+// CHECK: %[[ALLOC:.*]] = call ptr @omp_target_alloc(i64 1024, i32 0)
+// CHECK: %[[PTRTOINT:.*]] = ptrtoint ptr %[[ALLOC]] to i64
+// CHECK: %[[INTTOPTR:.*]] = inttoptr i64 %[[PTRTOINT]] to ptr
+// CHECK: call void @omp_target_free(ptr %[[INTTOPTR]], i32 0)
+// CHECK: ret void
+llvm.func @test_alloc_free_vector_2d_f32() -> () {
+  %device = llvm.mlir.constant(0 : i32) : i32
+  %1 = omp.target_allocmem %device : i32, vector<16x16xf32>
+  omp.target_freemem %device, %1 : i32, i64
+  llvm.return
+}


        


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