[flang-commits] [flang] [mlir] [MLIR][OpenMP] Support basic materialization for `omp.private` ops (PR #81715)

Kareem Ergawy via flang-commits flang-commits at lists.llvm.org
Thu Feb 15 22:49:17 PST 2024


https://github.com/ergawy updated https://github.com/llvm/llvm-project/pull/81715

>From a8a577013ace78e38d0443e532213840cbcab0ff Mon Sep 17 00:00:00 2001
From: ergawy <kareem.ergawy at amd.com>
Date: Sun, 11 Feb 2024 09:37:59 -0600
Subject: [PATCH 1/3] [MLIR][OpenMP] Add `private` clause to `omp.parallel`

Extends the `omp.parallel` op by adding a `private` clause to model
[first]private variables. This uses the `omp.private` op to map
privatized variables to their corresponding privatizers.

Example `omp.private` op with `private` variable:
```
omp.parallel private(@x.privatizer %arg0 -> %arg1 : !llvm.ptr) {
    // ... use %arg1 ...
    omp.terminator
}
```

Whether the variable is private or firstprivate is determined by the
attributes of the corresponding `omp.private` op.
---
 flang/lib/Lower/OpenMP.cpp                    |   3 +-
 mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td |   8 +-
 .../Conversion/SCFToOpenMP/SCFToOpenMP.cpp    |   4 +-
 mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp  | 160 ++++++++++++++----
 mlir/test/Dialect/OpenMP/invalid.mlir         |  56 ++++++
 mlir/test/Dialect/OpenMP/ops-2.mlir           |  74 ++++++++
 mlir/test/Dialect/OpenMP/ops.mlir             |  10 +-
 mlir/test/Dialect/OpenMP/roundtrip.mlir       |  21 ---
 8 files changed, 269 insertions(+), 67 deletions(-)
 create mode 100644 mlir/test/Dialect/OpenMP/ops-2.mlir
 delete mode 100644 mlir/test/Dialect/OpenMP/roundtrip.mlir

diff --git a/flang/lib/Lower/OpenMP.cpp b/flang/lib/Lower/OpenMP.cpp
index 7519da844eebba..9397af8b8bd05e 100644
--- a/flang/lib/Lower/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP.cpp
@@ -2640,7 +2640,8 @@ genParallelOp(Fortran::lower::AbstractConverter &converter,
           ? nullptr
           : mlir::ArrayAttr::get(converter.getFirOpBuilder().getContext(),
                                  reductionDeclSymbols),
-      procBindKindAttr);
+      procBindKindAttr, /*private_vars=*/llvm::SmallVector<mlir::Value>{},
+      /*privatizers=*/nullptr);
 }
 
 static mlir::omp::SectionOp
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index 024f43f7e7e3b6..f907e21e9b4de2 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -276,7 +276,9 @@ def ParallelOp : OpenMP_Op<"parallel", [
              Variadic<AnyType>:$allocators_vars,
              Variadic<OpenMP_PointerLikeType>:$reduction_vars,
              OptionalAttr<SymbolRefArrayAttr>:$reductions,
-             OptionalAttr<ProcBindKindAttr>:$proc_bind_val);
+             OptionalAttr<ProcBindKindAttr>:$proc_bind_val,
+             Variadic<AnyType>:$private_vars,
+             OptionalAttr<SymbolRefArrayAttr>:$privatizers);
 
   let regions = (region AnyRegion:$region);
 
@@ -297,7 +299,9 @@ def ParallelOp : OpenMP_Op<"parallel", [
                 $allocators_vars, type($allocators_vars)
               ) `)`
           | `proc_bind` `(` custom<ClauseAttr>($proc_bind_val) `)`
-    ) custom<ParallelRegion>($region, $reduction_vars, type($reduction_vars), $reductions) attr-dict
+    ) custom<ParallelRegion>($region, $reduction_vars, type($reduction_vars),
+                             $reductions, $private_vars, type($private_vars),
+                             $privatizers) attr-dict
   }];
   let hasVerifier = 1;
 }
diff --git a/mlir/lib/Conversion/SCFToOpenMP/SCFToOpenMP.cpp b/mlir/lib/Conversion/SCFToOpenMP/SCFToOpenMP.cpp
index ea5f31ee8c6aa7..464a647564aced 100644
--- a/mlir/lib/Conversion/SCFToOpenMP/SCFToOpenMP.cpp
+++ b/mlir/lib/Conversion/SCFToOpenMP/SCFToOpenMP.cpp
@@ -450,7 +450,9 @@ struct ParallelOpLowering : public OpRewritePattern<scf::ParallelOp> {
         /* allocators_vars = */ llvm::SmallVector<Value>{},
         /* reduction_vars = */ llvm::SmallVector<Value>{},
         /* reductions = */ ArrayAttr{},
-        /* proc_bind_val = */ omp::ClauseProcBindKindAttr{});
+        /* proc_bind_val = */ omp::ClauseProcBindKindAttr{},
+        /* private_vars = */ ValueRange(),
+        /* privatizers = */ nullptr);
     {
 
       OpBuilder::InsertionGuard guard(rewriter);
diff --git a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
index 82e32da91aaeeb..c2b471ab96183f 100644
--- a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
+++ b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
@@ -430,68 +430,102 @@ static void printScheduleClause(OpAsmPrinter &p, Operation *op,
 // Parser, printer and verifier for ReductionVarList
 //===----------------------------------------------------------------------===//
 
-ParseResult
-parseReductionClause(OpAsmParser &parser, Region &region,
-                     SmallVectorImpl<OpAsmParser::UnresolvedOperand> &operands,
-                     SmallVectorImpl<Type> &types, ArrayAttr &reductionSymbols,
-                     SmallVectorImpl<OpAsmParser::Argument> &privates) {
-  if (failed(parser.parseOptionalKeyword("reduction")))
-    return failure();
-
+ParseResult parseClauseWithRegionArgs(
+    OpAsmParser &parser, Region &region,
+    SmallVectorImpl<OpAsmParser::UnresolvedOperand> &operands,
+    SmallVectorImpl<Type> &types, ArrayAttr &symbols,
+    SmallVectorImpl<OpAsmParser::Argument> &regionPrivateArgs) {
   SmallVector<SymbolRefAttr> reductionVec;
+  unsigned regionArgOffset = regionPrivateArgs.size();
 
   if (failed(
           parser.parseCommaSeparatedList(OpAsmParser::Delimiter::Paren, [&]() {
             if (parser.parseAttribute(reductionVec.emplace_back()) ||
                 parser.parseOperand(operands.emplace_back()) ||
                 parser.parseArrow() ||
-                parser.parseArgument(privates.emplace_back()) ||
+                parser.parseArgument(regionPrivateArgs.emplace_back()) ||
                 parser.parseColonType(types.emplace_back()))
               return failure();
             return success();
           })))
     return failure();
 
-  for (auto [prv, type] : llvm::zip_equal(privates, types)) {
+  auto *argsBegin = regionPrivateArgs.begin();
+  MutableArrayRef argsSubrange(argsBegin + regionArgOffset,
+                               argsBegin + regionArgOffset + types.size());
+  for (auto [prv, type] : llvm::zip_equal(argsSubrange, types)) {
     prv.type = type;
   }
   SmallVector<Attribute> reductions(reductionVec.begin(), reductionVec.end());
-  reductionSymbols = ArrayAttr::get(parser.getContext(), reductions);
+  symbols = ArrayAttr::get(parser.getContext(), reductions);
   return success();
 }
 
-static void printReductionClause(OpAsmPrinter &p, Operation *op,
-                                 ValueRange reductionArgs, ValueRange operands,
-                                 TypeRange types, ArrayAttr reductionSymbols) {
-  p << "reduction(";
+static void printClauseWithRegionArgs(OpAsmPrinter &p, Operation *op,
+                                      ValueRange argsSubrange,
+                                      StringRef clauseName, ValueRange operands,
+                                      TypeRange types, ArrayAttr symbols) {
+  p << clauseName << "(";
   llvm::interleaveComma(
-      llvm::zip_equal(reductionSymbols, operands, reductionArgs, types), p,
-      [&p](auto t) {
+      llvm::zip_equal(symbols, operands, argsSubrange, types), p, [&p](auto t) {
         auto [sym, op, arg, type] = t;
         p << sym << " " << op << " -> " << arg << " : " << type;
       });
   p << ") ";
 }
 
-static ParseResult
-parseParallelRegion(OpAsmParser &parser, Region &region,
-                    SmallVectorImpl<OpAsmParser::UnresolvedOperand> &operands,
-                    SmallVectorImpl<Type> &types, ArrayAttr &reductionSymbols) {
+static ParseResult parseParallelRegion(
+    OpAsmParser &parser, Region &region,
+    SmallVectorImpl<OpAsmParser::UnresolvedOperand> &reductionVarOperands,
+    SmallVectorImpl<Type> &reductionVarTypes, ArrayAttr &reductionSymbols,
+    llvm::SmallVectorImpl<OpAsmParser::UnresolvedOperand> &privateVarOperands,
+    llvm::SmallVectorImpl<Type> &privateVarsTypes,
+    ArrayAttr &privatizerSymbols) {
+  llvm::SmallVector<OpAsmParser::Argument> regionPrivateArgs;
 
-  llvm::SmallVector<OpAsmParser::Argument> privates;
-  if (succeeded(parseReductionClause(parser, region, operands, types,
-                                     reductionSymbols, privates)))
-    return parser.parseRegion(region, privates);
+  if (succeeded(parser.parseOptionalKeyword("reduction"))) {
+    if (failed(parseClauseWithRegionArgs(parser, region, reductionVarOperands,
+                                         reductionVarTypes, reductionSymbols,
+                                         regionPrivateArgs)))
+      return failure();
+  }
 
-  return parser.parseRegion(region);
+  if (succeeded(parser.parseOptionalKeyword("private"))) {
+    if (failed(parseClauseWithRegionArgs(parser, region, privateVarOperands,
+                                         privateVarsTypes, privatizerSymbols,
+                                         regionPrivateArgs)))
+      return failure();
+  }
+
+  return parser.parseRegion(region, regionPrivateArgs);
 }
 
 static void printParallelRegion(OpAsmPrinter &p, Operation *op, Region &region,
-                                ValueRange operands, TypeRange types,
-                                ArrayAttr reductionSymbols) {
-  if (reductionSymbols)
-    printReductionClause(p, op, region.front().getArguments(), operands, types,
-                         reductionSymbols);
+                                ValueRange reductionVarOperands,
+                                TypeRange reductionVarTypes,
+                                ArrayAttr reductionSymbols,
+                                ValueRange privateVarOperands,
+                                TypeRange privateVarTypes,
+                                ArrayAttr privatizerSymbols) {
+  if (reductionSymbols) {
+    auto *argsBegin = region.front().getArguments().begin();
+    MutableArrayRef argsSubrange(argsBegin,
+                                 argsBegin + reductionVarTypes.size());
+    printClauseWithRegionArgs(p, op, argsSubrange, "reduction",
+                              reductionVarOperands, reductionVarTypes,
+                              reductionSymbols);
+  }
+
+  if (privatizerSymbols) {
+    auto *argsBegin = region.front().getArguments().begin();
+    MutableArrayRef argsSubrange(argsBegin + reductionVarOperands.size(),
+                                 argsBegin + reductionVarOperands.size() +
+                                     privateVarTypes.size());
+    printClauseWithRegionArgs(p, op, argsSubrange, "private",
+                              privateVarOperands, privateVarTypes,
+                              privatizerSymbols);
+  }
+
   p.printRegion(region, /*printEntryBlockArgs=*/false);
 }
 
@@ -1174,14 +1208,64 @@ void ParallelOp::build(OpBuilder &builder, OperationState &state,
       builder, state, /*if_expr_var=*/nullptr, /*num_threads_var=*/nullptr,
       /*allocate_vars=*/ValueRange(), /*allocators_vars=*/ValueRange(),
       /*reduction_vars=*/ValueRange(), /*reductions=*/nullptr,
-      /*proc_bind_val=*/nullptr);
+      /*proc_bind_val=*/nullptr, /*private_vars=*/ValueRange(),
+      /*privatizers=*/nullptr);
   state.addAttributes(attributes);
 }
 
+template <typename OpType>
+static LogicalResult verifyPrivateVarList(OpType &op) {
+  auto privateVars = op.getPrivateVars();
+  auto privatizers = op.getPrivatizersAttr();
+
+  if (privateVars.empty() && (privatizers == nullptr || privatizers.empty()))
+    return success();
+
+  auto numPrivateVars = privateVars.size();
+  auto numPrivatizers = (privatizers == nullptr) ? 0 : privatizers.size();
+
+  if (numPrivateVars != numPrivatizers)
+    return op.emitError() << "inconsistent number of private variables and "
+                             "privatizer op symbols, private vars: "
+                          << numPrivateVars
+                          << " vs. privatizer op symbols: " << numPrivatizers;
+
+  for (auto privateVarInfo : llvm::zip_equal(privateVars, privatizers)) {
+    Type varType = std::get<0>(privateVarInfo).getType();
+    SymbolRefAttr privatizerSym =
+        std::get<1>(privateVarInfo).template cast<SymbolRefAttr>();
+    PrivateClauseOp privatizerOp =
+        SymbolTable::lookupNearestSymbolFrom<PrivateClauseOp>(op,
+                                                              privatizerSym);
+
+    if (privatizerOp == nullptr)
+      return op.emitError() << "failed to lookup privatizer op with symbol: '"
+                            << privatizerSym << "'";
+
+    Type privatizerType = privatizerOp.getType();
+
+    if (varType != privatizerType)
+      return op.emitError()
+             << "type mismatch between a "
+             << (privatizerOp.getDataSharingType() ==
+                         DataSharingClauseType::Private
+                     ? "private"
+                     : "firstprivate")
+             << " variable and its privatizer op, var type: " << varType
+             << " vs. privatizer op type: " << privatizerType;
+  }
+
+  return success();
+}
+
 LogicalResult ParallelOp::verify() {
   if (getAllocateVars().size() != getAllocatorsVars().size())
     return emitError(
         "expected equal sizes for allocate and allocator variables");
+
+  if (failed(verifyPrivateVarList(*this)))
+    return failure();
+
   return verifyReductionVarList(*this, getReductions(), getReductionVars());
 }
 
@@ -1279,9 +1363,10 @@ parseWsLoop(OpAsmParser &parser, Region &region,
 
   // Parse an optional reduction clause
   llvm::SmallVector<OpAsmParser::Argument> privates;
-  bool hasReduction = succeeded(
-      parseReductionClause(parser, region, reductionOperands, reductionTypes,
-                           reductionSymbols, privates));
+  bool hasReduction = succeeded(parser.parseOptionalKeyword("reduction")) &&
+                      succeeded(parseClauseWithRegionArgs(
+                          parser, region, reductionOperands, reductionTypes,
+                          reductionSymbols, privates));
 
   if (parser.parseKeyword("for"))
     return failure();
@@ -1328,8 +1413,9 @@ void printWsLoop(OpAsmPrinter &p, Operation *op, Region &region,
   if (reductionSymbols) {
     auto reductionArgs =
         region.front().getArguments().drop_front(loopVarTypes.size());
-    printReductionClause(p, op, reductionArgs, reductionOperands,
-                         reductionTypes, reductionSymbols);
+    printClauseWithRegionArgs(p, op, reductionArgs, "reduction",
+                              reductionOperands, reductionTypes,
+                              reductionSymbols);
   }
 
   p << " for ";
diff --git a/mlir/test/Dialect/OpenMP/invalid.mlir b/mlir/test/Dialect/OpenMP/invalid.mlir
index 7965d6dc284203..d9261b89e24e3a 100644
--- a/mlir/test/Dialect/OpenMP/invalid.mlir
+++ b/mlir/test/Dialect/OpenMP/invalid.mlir
@@ -1865,3 +1865,59 @@ omp.private {type = firstprivate} @x.privatizer : f32 alloc {
 ^bb0(%arg0: f32):
   omp.yield(%arg0 : f32)
 }
+
+// -----
+
+func.func @private_type_mismatch(%arg0: index) {
+// expected-error @below {{type mismatch between a private variable and its privatizer op, var type: 'index' vs. privatizer op type: '!llvm.ptr'}}
+  omp.parallel private(@var1.privatizer %arg0 -> %arg2 : index) {
+    omp.terminator
+  }
+
+  return
+}
+
+omp.private {type = private} @var1.privatizer : !llvm.ptr alloc {
+^bb0(%arg0: !llvm.ptr):
+  omp.yield(%arg0 : !llvm.ptr)
+}
+
+// -----
+
+func.func @firstprivate_type_mismatch(%arg0: index) {
+  // expected-error @below {{type mismatch between a firstprivate variable and its privatizer op, var type: 'index' vs. privatizer op type: '!llvm.ptr'}}
+  omp.parallel private(@var1.privatizer %arg0 -> %arg2 : index) {
+    omp.terminator
+  }
+
+  return
+}
+
+omp.private {type = firstprivate} @var1.privatizer : !llvm.ptr alloc {
+^bb0(%arg0: !llvm.ptr):
+  omp.yield(%arg0 : !llvm.ptr)
+} copy {
+^bb0(%arg0: !llvm.ptr, %arg1: !llvm.ptr):
+  omp.yield(%arg0 : !llvm.ptr)
+}
+
+// -----
+
+func.func @undefined_privatizer(%arg0: index) {
+  // expected-error @below {{failed to lookup privatizer op with symbol: '@var1.privatizer'}}
+  omp.parallel private(@var1.privatizer %arg0 -> %arg2 : index) {
+    omp.terminator
+  }
+
+  return
+}
+
+// -----
+func.func @undefined_privatizer(%arg0: !llvm.ptr) {
+  // expected-error @below {{inconsistent number of private variables and privatizer op symbols, private vars: 1 vs. privatizer op symbols: 2}}
+  "omp.parallel"(%arg0) <{operandSegmentSizes = array<i32: 0, 0, 0, 0, 0, 1>, privatizers = [@x.privatizer, @y.privatizer]}> ({
+    ^bb0(%arg2: !llvm.ptr):
+      omp.terminator
+    }) : (!llvm.ptr) -> ()
+  return
+}
diff --git a/mlir/test/Dialect/OpenMP/ops-2.mlir b/mlir/test/Dialect/OpenMP/ops-2.mlir
new file mode 100644
index 00000000000000..9340e0b5fdf971
--- /dev/null
+++ b/mlir/test/Dialect/OpenMP/ops-2.mlir
@@ -0,0 +1,74 @@
+// RUN: mlir-opt -verify-diagnostics %s | mlir-opt | FileCheck %s
+
+// CHECK-LABEL: parallel_op_privatizers
+func.func @parallel_op_privatizers(%arg0: !llvm.ptr, %arg1: !llvm.ptr) {
+  // CHECK: omp.parallel private(@x.privatizer %arg0 -> %arg2 : !llvm.ptr, @y.privatizer %arg1 -> %arg3 : !llvm.ptr)
+  omp.parallel private(@x.privatizer %arg0 -> %arg2 : !llvm.ptr, @y.privatizer %arg1 -> %arg3 : !llvm.ptr) {
+    %0 = llvm.load %arg2 : !llvm.ptr -> i32
+    %1 = llvm.load %arg3 : !llvm.ptr -> i32
+    omp.terminator
+  }
+  return
+}
+
+// CHECK: omp.private {type = private} @x.privatizer : !llvm.ptr alloc {
+omp.private {type = private} @x.privatizer : !llvm.ptr alloc {
+// CHECK: ^bb0(%arg0: {{.*}}):
+^bb0(%arg0: !llvm.ptr):
+  omp.yield(%arg0 : !llvm.ptr)
+}
+
+// CHECK: omp.private {type = firstprivate} @y.privatizer : !llvm.ptr alloc {
+omp.private {type = firstprivate} @y.privatizer : !llvm.ptr alloc {
+// CHECK: ^bb0(%arg0: {{.*}}):
+^bb0(%arg0: !llvm.ptr):
+  omp.yield(%arg0 : !llvm.ptr)
+// CHECK: } copy {
+} copy {
+// CHECK: ^bb0(%arg0: {{.*}}, %arg1: {{.*}}):
+^bb0(%arg0: !llvm.ptr, %arg1: !llvm.ptr):
+  omp.yield(%arg0 : !llvm.ptr)
+}
+
+// CHECK-LABEL: parallel_op_reduction_and_private
+func.func @parallel_op_reduction_and_private(%priv_var: !llvm.ptr, %priv_var2: !llvm.ptr, %reduc_var: !llvm.ptr, %reduc_var2: !llvm.ptr) {
+  // CHECK: omp.parallel
+  // CHECK-SAME: reduction(
+  // CHECK-SAME: @add_f32 %[[reduc_var:[0-9a-z]+]] -> %[[reduc_arg:[0-9a-z]+]] : !llvm.ptr,
+  // CHECK-SAME: @add_f32 %[[reduc_var2:[0-9a-z]+]] -> %[[reduc_arg2:[0-9a-z]+]] : !llvm.ptr)
+  //
+  // CHECK-SAME: private(
+  // CHECK-SAME: @x.privatizer %[[priv_var:[0-9a-z]+]] -> %[[priv_arg:[0-9a-z]+]] : !llvm.ptr,
+  // CHECK-SAME: @y.privatizer %[[priv_var2:[0-9a-z]+]] -> %[[priv_arg2:[0-9a-z]+]] : !llvm.ptr)
+  omp.parallel reduction(@add_f32 %reduc_var -> %reduc_arg : !llvm.ptr, @add_f32 %reduc_var2 -> %reduc_arg2 : !llvm.ptr)
+               private(@x.privatizer %priv_var -> %priv_arg : !llvm.ptr, @y.privatizer %priv_var2 -> %priv_arg2 : !llvm.ptr) {
+    // CHECK: llvm.load %[[priv_arg]]
+    %0 = llvm.load %priv_arg : !llvm.ptr -> f32
+    // CHECK: llvm.load %[[priv_arg2]]
+    %1 = llvm.load %priv_arg2 : !llvm.ptr -> f32
+    // CHECK: llvm.load %[[reduc_arg]]
+    %2 = llvm.load %reduc_arg : !llvm.ptr -> f32
+    // CHECK: llvm.load %[[reduc_arg2]]
+    %3 = llvm.load %reduc_arg2 : !llvm.ptr -> f32
+    omp.terminator
+  }
+  return
+}
+
+omp.reduction.declare @add_f32 : f32
+init {
+^bb0(%arg: f32):
+  %0 = arith.constant 0.0 : f32
+  omp.yield (%0 : f32)
+}
+combiner {
+^bb1(%arg0: f32, %arg1: f32):
+  %1 = arith.addf %arg0, %arg1 : f32
+  omp.yield (%1 : f32)
+}
+atomic {
+^bb2(%arg2: !llvm.ptr, %arg3: !llvm.ptr):
+  %2 = llvm.load %arg3 : !llvm.ptr -> f32
+  llvm.atomicrmw fadd %arg2, %2 monotonic : !llvm.ptr, f32
+  omp.yield
+}
diff --git a/mlir/test/Dialect/OpenMP/ops.mlir b/mlir/test/Dialect/OpenMP/ops.mlir
index d92a554caf77ca..c92ef895306ed3 100644
--- a/mlir/test/Dialect/OpenMP/ops.mlir
+++ b/mlir/test/Dialect/OpenMP/ops.mlir
@@ -59,7 +59,7 @@ func.func @omp_parallel(%data_var : memref<i32>, %if_cond : i1, %num_threads : i
   // CHECK: omp.parallel num_threads(%{{.*}} : i32) allocate(%{{.*}} : memref<i32> -> %{{.*}} : memref<i32>)
     "omp.parallel"(%num_threads, %data_var, %data_var) ({
       omp.terminator
-    }) {operandSegmentSizes = array<i32: 0,1,1,1,0>} : (i32, memref<i32>, memref<i32>) -> ()
+    }) {operandSegmentSizes = array<i32: 0,1,1,1,0,0>} : (i32, memref<i32>, memref<i32>) -> ()
 
   // CHECK: omp.barrier
     omp.barrier
@@ -68,22 +68,22 @@ func.func @omp_parallel(%data_var : memref<i32>, %if_cond : i1, %num_threads : i
   // CHECK: omp.parallel if(%{{.*}}) allocate(%{{.*}} : memref<i32> -> %{{.*}} : memref<i32>)
     "omp.parallel"(%if_cond, %data_var, %data_var) ({
       omp.terminator
-    }) {operandSegmentSizes = array<i32: 1,0,1,1,0>} : (i1, memref<i32>, memref<i32>) -> ()
+    }) {operandSegmentSizes = array<i32: 1,0,1,1,0,0>} : (i1, memref<i32>, memref<i32>) -> ()
 
   // test without allocate
   // CHECK: omp.parallel if(%{{.*}}) num_threads(%{{.*}} : i32)
     "omp.parallel"(%if_cond, %num_threads) ({
       omp.terminator
-    }) {operandSegmentSizes = array<i32: 1,1,0,0,0>} : (i1, i32) -> ()
+    }) {operandSegmentSizes = array<i32: 1,1,0,0,0,0>} : (i1, i32) -> ()
 
     omp.terminator
-  }) {operandSegmentSizes = array<i32: 1,1,1,1,0>, proc_bind_val = #omp<procbindkind spread>} : (i1, i32, memref<i32>, memref<i32>) -> ()
+  }) {operandSegmentSizes = array<i32: 1,1,1,1,0,0>, proc_bind_val = #omp<procbindkind spread>} : (i1, i32, memref<i32>, memref<i32>) -> ()
 
   // test with multiple parameters for single variadic argument
   // CHECK: omp.parallel allocate(%{{.*}} : memref<i32> -> %{{.*}} : memref<i32>)
   "omp.parallel" (%data_var, %data_var) ({
     omp.terminator
-  }) {operandSegmentSizes = array<i32: 0,0,1,1,0>} : (memref<i32>, memref<i32>) -> ()
+  }) {operandSegmentSizes = array<i32: 0,0,1,1,0,0>} : (memref<i32>, memref<i32>) -> ()
 
   return
 }
diff --git a/mlir/test/Dialect/OpenMP/roundtrip.mlir b/mlir/test/Dialect/OpenMP/roundtrip.mlir
deleted file mode 100644
index 2553442638ee84..00000000000000
--- a/mlir/test/Dialect/OpenMP/roundtrip.mlir
+++ /dev/null
@@ -1,21 +0,0 @@
-// RUN: mlir-opt -verify-diagnostics %s | mlir-opt | FileCheck %s
-
-// CHECK: omp.private {type = private} @x.privatizer : !llvm.ptr alloc {
-omp.private {type = private} @x.privatizer : !llvm.ptr alloc {
-// CHECK: ^bb0(%arg0: {{.*}}):
-^bb0(%arg0: !llvm.ptr):
-  omp.yield(%arg0 : !llvm.ptr)
-}
-
-// CHECK: omp.private {type = firstprivate} @y.privatizer : !llvm.ptr alloc {
-omp.private {type = firstprivate} @y.privatizer : !llvm.ptr alloc {
-// CHECK: ^bb0(%arg0: {{.*}}):
-^bb0(%arg0: !llvm.ptr):
-  omp.yield(%arg0 : !llvm.ptr)
-// CHECK: } copy {
-} copy {
-// CHECK: ^bb0(%arg0: {{.*}}, %arg1: {{.*}}):
-^bb0(%arg0: !llvm.ptr, %arg1: !llvm.ptr):
-  omp.yield(%arg0 : !llvm.ptr)
-}
-

>From 8350e2b58a69907c2586b0e933b32ecf9a7c717d Mon Sep 17 00:00:00 2001
From: ergawy <kareem.ergawy at amd.com>
Date: Tue, 13 Feb 2024 04:46:50 -0600
Subject: [PATCH 2/3] [MLIR][OpenMP] Support basic materialization for
 `omp.private` ops

Adds basic support for materializing delayed privatization. So far, the
restrictions on the implementation are:
- Only `private` clauses are supported (`firstprivate` support will be
  added in a later PR).
- Only single-block `omp.private -> alloc` regions are supported
  (multi-block ones will be supported in a later PR).
---
 .../OpenMP/OpenMPToLLVMIRTranslation.cpp      | 121 +++++++++++++++++-
 mlir/test/Target/LLVMIR/openmp-private.mlir   |  91 +++++++++++++
 2 files changed, 205 insertions(+), 7 deletions(-)
 create mode 100644 mlir/test/Target/LLVMIR/openmp-private.mlir

diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 78a2ad76a1e3b8..5d6e07b08a87e2 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1000,6 +1000,24 @@ convertOmpWsLoop(Operation &opInst, llvm::IRBuilderBase &builder,
   return success();
 }
 
+/// Replace the region arguments of the parallel op (which correspond to private
+/// variables) with the actual private varibles they correspond to. This
+/// prepares the parallel op so that it matches what is expected by the
+/// OMPIRBuilder.
+static void prepareOmpParallelForPrivatization(omp::ParallelOp opInst) {
+  Region &region = opInst.getRegion();
+  auto privateVars = opInst.getPrivateVars();
+
+  auto privateVarsIt = privateVars.begin();
+  // Reduction precede private arguments, so skip them first.
+  unsigned privateArgBeginIdx = opInst.getNumReductionVars();
+  unsigned privateArgEndIdx = privateArgBeginIdx + privateVars.size();
+  for (size_t argIdx = privateArgBeginIdx; argIdx < privateArgEndIdx;
+       ++argIdx, ++privateVarsIt)
+    replaceAllUsesInRegionWith(region.getArgument(argIdx), *privateVarsIt,
+                               region);
+}
+
 /// Converts the OpenMP parallel operation to LLVM IR.
 static LogicalResult
 convertOmpParallel(omp::ParallelOp opInst, llvm::IRBuilderBase &builder,
@@ -1043,6 +1061,8 @@ convertOmpParallel(omp::ParallelOp opInst, llvm::IRBuilderBase &builder,
       builder.CreateStore(phis[0], privateReductionVariables[i]);
     }
 
+    prepareOmpParallelForPrivatization(opInst);
+
     // Save the alloca insertion point on ModuleTranslation stack for use in
     // nested regions.
     LLVM::ModuleTranslation::SaveStack<OpenMPAllocaStackFrame> frame(
@@ -1085,13 +1105,99 @@ convertOmpParallel(omp::ParallelOp opInst, llvm::IRBuilderBase &builder,
   };
 
   // TODO: Perform appropriate actions according to the data-sharing
-  // attribute (shared, private, firstprivate, ...) of variables.
+  // attribute (shared, firstprivate, ...) of variables.
   // Currently defaults to shared.
   auto privCB = [&](InsertPointTy allocaIP, InsertPointTy codeGenIP,
                     llvm::Value &, llvm::Value &vPtr,
                     llvm::Value *&replacementValue) -> InsertPointTy {
     replacementValue = &vPtr;
 
+    // If this is a private value, this lambda will return the corresponding
+    // mlir value and its `PrivateClauseOp`. Otherwise, empty values are
+    // returned.
+    auto [privVar, privatizerClone] =
+        [&]() -> std::pair<mlir::Value, omp::PrivateClauseOp> {
+      if (!opInst.getPrivateVars().empty()) {
+        auto privVars = opInst.getPrivateVars();
+        auto privatizers = opInst.getPrivatizers();
+
+        for (auto [privVar, privatizerAttr] :
+             llvm::zip_equal(privVars, *privatizers)) {
+          // Find the MLIR private variable corresponding to the LLVM value
+          // being privatized.
+          llvm::Value *llvmPrivVar = moduleTranslation.lookupValue(privVar);
+          if (llvmPrivVar != &vPtr)
+            continue;
+
+          SymbolRefAttr privSym = llvm::cast<SymbolRefAttr>(privatizerAttr);
+          omp::PrivateClauseOp privatizer =
+              SymbolTable::lookupNearestSymbolFrom<omp::PrivateClauseOp>(
+                  opInst, privSym);
+
+          // Clone the privatizer in case it used by more than one parallel
+          // region. The privatizer is processed in-place (see below) before it
+          // gets inlined in the parallel region and therefore processing the
+          // original op is dangerous.
+          return {privVar, privatizer.clone()};
+        }
+      }
+
+      return {mlir::Value(), omp::PrivateClauseOp()};
+    }();
+
+    if (privVar) {
+      if (privatizerClone.getDataSharingType() ==
+          omp::DataSharingClauseType::FirstPrivate) {
+        privatizerClone.emitOpError(
+            "TODO: delayed privatization is not "
+            "supported for `firstprivate` clauses yet.");
+        bodyGenStatus = failure();
+        return codeGenIP;
+      }
+
+      Region &allocRegion = privatizerClone.getAllocRegion();
+
+      if (!allocRegion.hasOneBlock()) {
+        privatizerClone.emitOpError(
+            "TODO: multi-block alloc regions are not supported yet. Seems "
+            "like there is a difference in `inlineConvertOmpRegions`'s "
+            "pre-conditions for single- and multi-block regions.");
+        bodyGenStatus = failure();
+        return codeGenIP;
+      }
+
+      // Replace the privatizer block argument with mlir value being privatized.
+      // This way, the body of the privatizer will be changed from using the
+      // region/block argument to the value being privatized.
+      auto allocRegionArg = allocRegion.getArgument(0);
+      replaceAllUsesInRegionWith(allocRegionArg, privVar, allocRegion);
+
+      auto oldIP = builder.saveIP();
+      builder.restoreIP(allocaIP);
+
+      // Temporarily unlink the terminator from its parent since
+      // `inlineConvertOmpRegions` expects the insertion block to **not**
+      // contain a terminator.
+      llvm::Instruction &allocaTerminator = builder.GetInsertBlock()->back();
+      assert(allocaTerminator.isTerminator());
+      allocaTerminator.removeFromParent();
+
+      SmallVector<llvm::Value *, 1> yieldedValues;
+      if (failed(inlineConvertOmpRegions(allocRegion, "omp.privatizer", builder,
+                                         moduleTranslation, &yieldedValues))) {
+        opInst.emitError("failed to inline `alloc` region of an `omp.private` "
+                         "op in the parallel region");
+        bodyGenStatus = failure();
+      } else {
+        assert(yieldedValues.size() == 1);
+        replacementValue = yieldedValues.front();
+      }
+
+      allocaTerminator.insertAfter(&builder.GetInsertBlock()->back());
+      privatizerClone.erase();
+      builder.restoreIP(oldIP);
+    }
+
     return codeGenIP;
   };
 
@@ -3009,12 +3115,13 @@ LogicalResult OpenMPDialectLLVMIRTranslationInterface::convertOperation(
       .Case([&](omp::TargetOp) {
         return convertOmpTarget(*op, builder, moduleTranslation);
       })
-      .Case<omp::MapInfoOp, omp::DataBoundsOp>([&](auto op) {
-        // No-op, should be handled by relevant owning operations e.g.
-        // TargetOp, EnterDataOp, ExitDataOp, DataOp etc. and then
-        // discarded
-        return success();
-      })
+      .Case<omp::MapInfoOp, omp::DataBoundsOp, omp::PrivateClauseOp>(
+          [&](auto op) {
+            // No-op, should be handled by relevant owning operations e.g.
+            // TargetOp, EnterDataOp, ExitDataOp, DataOp etc. and then
+            // discarded
+            return success();
+          })
       .Default([&](Operation *inst) {
         return inst->emitError("unsupported OpenMP operation: ")
                << inst->getName();
diff --git a/mlir/test/Target/LLVMIR/openmp-private.mlir b/mlir/test/Target/LLVMIR/openmp-private.mlir
new file mode 100644
index 00000000000000..1ac87852d5300f
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/openmp-private.mlir
@@ -0,0 +1,91 @@
+// Test code-gen for `omp.parallel` ops with delayed privatizers (i.e. using
+// `omp.private` ops).
+
+// RUN: mlir-translate -mlir-to-llvmir -split-input-file %s | FileCheck %s
+
+llvm.func @parallel_op_1_private(%arg0: !llvm.ptr) {
+  omp.parallel private(@x.privatizer %arg0 -> %arg2 : !llvm.ptr) {
+    %0 = llvm.load %arg2 : !llvm.ptr -> f32
+    omp.terminator
+  }
+  llvm.return
+}
+
+// CHECK-LABEL: @parallel_op_1_private
+// CHECK-SAME: (ptr %[[ORIG:.*]]) {
+// CHECK: %[[OMP_PAR_ARG:.*]] = alloca { ptr }, align 8
+// CHECK: %[[ORIG_GEP:.*]] = getelementptr { ptr }, ptr %[[OMP_PAR_ARG]], i32 0, i32 0
+// CHECK: store ptr %[[ORIG]], ptr %[[ORIG_GEP]], align 8
+// CHECK: call void (ptr, i32, ptr, ...) @__kmpc_fork_call(ptr @1, i32 1, ptr @parallel_op_1_private..omp_par, ptr %[[OMP_PAR_ARG]])
+// CHECK: }
+
+// CHECK-LABEL: void @parallel_op_1_private..omp_par
+// CHECK-SAME: (ptr noalias %{{.*}}, ptr noalias %{{.*}}, ptr %[[ARG:.*]])
+// CHECK: %[[ORIG_PTR_PTR:.*]] = getelementptr { ptr }, ptr %[[ARG]], i32 0, i32 0
+// CHECK: %[[ORIG_PTR:.*]] = load ptr, ptr %[[ORIG_PTR_PTR]], align 8
+
+// Check that the privatizer alloc region was inlined properly.
+// CHECK: %[[PRIV_ALLOC:.*]] = alloca float, align 4
+// CHECK: %[[ORIG_VAL:.*]] = load float, ptr %[[ORIG_PTR]], align 4
+// CHECK: store float %[[ORIG_VAL]], ptr %[[PRIV_ALLOC]], align 4
+// CHECK-NEXT: br
+
+// Check that the privatized value is used (rather than the original one).
+// CHECK: load float, ptr %[[PRIV_ALLOC]], align 4
+// CHECK: }
+
+llvm.func @parallel_op_2_privates(%arg0: !llvm.ptr, %arg1: !llvm.ptr) {
+  omp.parallel private(@x.privatizer %arg0 -> %arg2 : !llvm.ptr, @y.privatizer %arg1 -> %arg3 : !llvm.ptr) {
+    %0 = llvm.load %arg2 : !llvm.ptr -> f32
+    %1 = llvm.load %arg3 : !llvm.ptr -> i32
+    omp.terminator
+  }
+  llvm.return
+}
+
+// CHECK-LABEL: @parallel_op_2_privates
+// CHECK-SAME: (ptr %[[ORIG1:.*]], ptr %[[ORIG2:.*]]) {
+// CHECK: %[[OMP_PAR_ARG:.*]] = alloca { ptr, ptr }, align 8
+// CHECK: %[[ORIG1_GEP:.*]] = getelementptr { ptr, ptr }, ptr %[[OMP_PAR_ARG]], i32 0, i32 0
+// CHECK: store ptr %[[ORIG1]], ptr %[[ORIG1_GEP]], align 8
+// CHECK: call void (ptr, i32, ptr, ...) @__kmpc_fork_call(ptr @1, i32 1, ptr @parallel_op_2_privates..omp_par, ptr %[[OMP_PAR_ARG]])
+// CHECK: }
+
+// CHECK-LABEL: void @parallel_op_2_privates..omp_par
+// CHECK-SAME: (ptr noalias %{{.*}}, ptr noalias %{{.*}}, ptr %[[ARG:.*]])
+// CHECK: %[[ORIG1_PTR_PTR:.*]] = getelementptr { ptr, ptr }, ptr %[[ARG]], i32 0, i32 0
+// CHECK: %[[ORIG1_PTR:.*]] = load ptr, ptr %[[ORIG1_PTR_PTR]], align 8
+// CHECK: %[[ORIG2_PTR_PTR:.*]] = getelementptr { ptr, ptr }, ptr %[[ARG]], i32 0, i32 1
+// CHECK: %[[ORIG2_PTR:.*]] = load ptr, ptr %[[ORIG2_PTR_PTR]], align 8
+
+// Check that the privatizer alloc region was inlined properly.
+// CHECK: %[[PRIV1_ALLOC:.*]] = alloca float, align 4
+// CHECK: %[[ORIG1_VAL:.*]] = load float, ptr %[[ORIG1_PTR]], align 4
+// CHECK: store float %[[ORIG1_VAL]], ptr %[[PRIV1_ALLOC]], align 4
+// CHECK: %[[PRIV2_ALLOC:.*]] = alloca i32, align 4
+// CHECK: %[[ORIG2_VAL:.*]] = load i32, ptr %[[ORIG2_PTR]], align 4
+// CHECK: store i32 %[[ORIG2_VAL]], ptr %[[PRIV2_ALLOC]], align 4
+// CHECK-NEXT: br
+
+// Check that the privatized value is used (rather than the original one).
+// CHECK: load float, ptr %[[PRIV1_ALLOC]], align 4
+// CHECK: load i32, ptr %[[PRIV2_ALLOC]], align 4
+// CHECK: }
+
+omp.private {type = private} @x.privatizer : !llvm.ptr alloc {
+^bb0(%arg0: !llvm.ptr):
+  %c1 = llvm.mlir.constant(1 : i32) : i32
+  %0 = llvm.alloca %c1 x f32 : (i32) -> !llvm.ptr
+  %1 = llvm.load %arg0 : !llvm.ptr -> f32
+  llvm.store %1, %0 : f32, !llvm.ptr
+  omp.yield(%0 : !llvm.ptr)
+}
+
+omp.private {type = private} @y.privatizer : !llvm.ptr alloc {
+^bb0(%arg0: !llvm.ptr):
+  %c1 = llvm.mlir.constant(1 : i32) : i32
+  %0 = llvm.alloca %c1 x i32 : (i32) -> !llvm.ptr
+  %1 = llvm.load %arg0 : !llvm.ptr -> i32
+  llvm.store %1, %0 : i32, !llvm.ptr
+  omp.yield(%0 : !llvm.ptr)
+}

>From f0cd5b07c489b1f508734b905f0df95d310ccb94 Mon Sep 17 00:00:00 2001
From: Kareem Ergawy <kareem.ergawy at amd.com>
Date: Fri, 16 Feb 2024 07:49:09 +0100
Subject: [PATCH 3/3] Update comment

---
 .../Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 5d6e07b08a87e2..dd4eeb061f6e82 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -622,7 +622,7 @@ convertOmpSections(Operation &opInst, llvm::IRBuilderBase &builder,
 
   // TODO: Perform appropriate actions according to the data-sharing
   // attribute (shared, private, firstprivate, ...) of variables.
-  // Currently defaults to shared.
+  // Currently shared and private are supported.
   auto privCB = [&](InsertPointTy, InsertPointTy codeGenIP, llvm::Value &,
                     llvm::Value &vPtr,
                     llvm::Value *&replacementValue) -> InsertPointTy {



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