[flang-commits] [flang] [mlir] [mlir][OpenMP] Pack task private variables into a heap-allocated context struct (PR #125307)
Tom Eccles via flang-commits
flang-commits at lists.llvm.org
Thu Feb 27 01:22:38 PST 2025
https://github.com/tblah updated https://github.com/llvm/llvm-project/pull/125307
>From ba908aaab9b7cd42a1ee37acd883d0b4ec231936 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Fri, 24 Jan 2025 17:32:41 +0000
Subject: [PATCH 01/12] [mlir][OpenMP] Pack task private variables into a
heap-allocated context struct
See RFC:
https://discourse.llvm.org/t/rfc-openmp-supporting-delayed-task-execution-with-firstprivate-variables/83084
The aim here is to ensure that tasks which are not executed for a while
after they are created do not try to reference any data which are now
out of scope. This is done by packing the data referred to by the task
into a heap allocated structure (freed at the end of the task).
I decided to create the task context structure in
OpenMPToLLVMIRTranslation instead of adapting how it is done
CodeExtractor (via OpenMPIRBuilder] because CodeExtractor is (at least
in theory) generic code which could have other unrelated uses.
---
.../OpenMP/OpenMPToLLVMIRTranslation.cpp | 209 ++++++++++++++----
mlir/test/Target/LLVMIR/openmp-llvm.mlir | 10 +-
.../LLVMIR/openmp-task-privatization.mlir | 80 +++++++
3 files changed, 258 insertions(+), 41 deletions(-)
create mode 100644 mlir/test/Target/LLVMIR/openmp-task-privatization.mlir
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 4b5a319f7cc8a..a676d2d981a8b 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -13,6 +13,7 @@
#include "mlir/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.h"
#include "mlir/Analysis/TopologicalSortUtils.h"
#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
+#include "mlir/Dialect/LLVMIR/LLVMTypes.h"
#include "mlir/Dialect/OpenMP/OpenMPDialect.h"
#include "mlir/Dialect/OpenMP/OpenMPInterfaces.h"
#include "mlir/IR/IRMapping.h"
@@ -24,10 +25,12 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TypeSwitch.h"
#include "llvm/Frontend/OpenMP/OMPConstants.h"
#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/ReplaceConstant.h"
#include "llvm/Support/FileSystem.h"
@@ -1349,15 +1352,16 @@ findAssociatedValue(Value privateVar, llvm::IRBuilderBase &builder,
/// Initialize a single (first)private variable. You probably want to use
/// allocateAndInitPrivateVars instead of this.
-static llvm::Error initPrivateVar(
+/// This returns the private variable which has been initialized. This
+/// variable should be mapped before constructing the body of the Op.
+static llvm::Expected<llvm::Value *> initPrivateVar(
llvm::IRBuilderBase &builder, LLVM::ModuleTranslation &moduleTranslation,
omp::PrivateClauseOp &privDecl, Value mlirPrivVar, BlockArgument &blockArg,
- llvm::Value **llvmPrivateVarIt, llvm::BasicBlock *privInitBlock,
+ llvm::Value *llvmPrivateVar, llvm::BasicBlock *privInitBlock,
llvm::DenseMap<Value, Value> *mappedPrivateVars = nullptr) {
Region &initRegion = privDecl.getInitRegion();
if (initRegion.empty()) {
- moduleTranslation.mapValue(blockArg, *llvmPrivateVarIt);
- return llvm::Error::success();
+ return llvmPrivateVar;
}
// map initialization region block arguments
@@ -1365,7 +1369,7 @@ static llvm::Error initPrivateVar(
mlirPrivVar, builder, moduleTranslation, mappedPrivateVars);
assert(nonPrivateVar);
moduleTranslation.mapValue(privDecl.getInitMoldArg(), nonPrivateVar);
- moduleTranslation.mapValue(privDecl.getInitPrivateArg(), *llvmPrivateVarIt);
+ moduleTranslation.mapValue(privDecl.getInitPrivateArg(), llvmPrivateVar);
// in-place convert the private initialization region
SmallVector<llvm::Value *, 1> phis;
@@ -1376,17 +1380,15 @@ static llvm::Error initPrivateVar(
assert(phis.size() == 1 && "expected one allocation to be yielded");
- // prefer the value yielded from the init region to the allocated private
- // variable in case the region is operating on arguments by-value (e.g.
- // Fortran character boxes).
- moduleTranslation.mapValue(blockArg, phis[0]);
- *llvmPrivateVarIt = phis[0];
-
// clear init region block argument mapping in case it needs to be
// re-created with a different source for another use of the same
// reduction decl
moduleTranslation.forgetMapping(initRegion);
- return llvm::Error::success();
+
+ // Prefer the value yielded from the init region to the allocated private
+ // variable in case the region is operating on arguments by-value (e.g.
+ // Fortran character boxes).
+ return phis[0];
}
static llvm::Error
@@ -1403,16 +1405,19 @@ initPrivateVars(llvm::IRBuilderBase &builder,
llvm::BasicBlock *privInitBlock = splitBB(builder, true, "omp.private.init");
setInsertPointForPossiblyEmptyBlock(builder, privInitBlock);
- for (auto [idx, zip] : llvm::enumerate(
- llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs))) {
- auto [privDecl, mlirPrivVar, blockArg] = zip;
- llvm::Error err = initPrivateVar(
+ for (auto [idx, zip] : llvm::enumerate(llvm::zip_equal(
+ privateDecls, mlirPrivateVars, privateBlockArgs, llvmPrivateVars))) {
+ auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVar] = zip;
+ llvm::Expected<llvm::Value *> privVarOrErr = initPrivateVar(
builder, moduleTranslation, privDecl, mlirPrivVar, blockArg,
- llvmPrivateVars.begin() + idx, privInitBlock, mappedPrivateVars);
+ llvmPrivateVar, privInitBlock, mappedPrivateVars);
- if (err)
+ if (auto err = privVarOrErr.takeError())
return err;
+ llvmPrivateVar = privVarOrErr.get();
+ moduleTranslation.mapValue(blockArg, llvmPrivateVar);
+
setInsertPointForPossiblyEmptyBlock(builder);
}
@@ -1762,6 +1767,97 @@ buildDependData(std::optional<ArrayAttr> dependKinds, OperandRange dependVars,
}
}
+namespace {
+/// TaskContextStructManager takes care of creating and freeing a structure
+/// containing information needed by the task body to execute.
+class TaskContextStructManager {
+public:
+ TaskContextStructManager(llvm::IRBuilderBase &builder,
+ LLVM::ModuleTranslation &moduleTranslation)
+ : builder{builder}, moduleTranslation{moduleTranslation} {}
+
+ /// Creates a heap allocated struct containing space for each private
+ /// variable. Returns nullptr if there are is no struct needed. Invariant:
+ /// privateVarTypes, privateDecls, and the elements of the structure should
+ /// all have the same order.
+ void
+ generateTaskContextStruct(MutableArrayRef<omp::PrivateClauseOp> privateDecls);
+
+ /// Create GEPs to access each member of the structure representing a private
+ /// variable, adding them to llvmPrivateVars.
+ void createGEPsToPrivateVars(SmallVectorImpl<llvm::Value *> &llvmPrivateVars);
+
+ /// De-allocate the task context structure.
+ void freeStructPtr();
+
+ llvm::Value *getStructPtr() { return structPtr; }
+
+private:
+ llvm::IRBuilderBase &builder;
+ LLVM::ModuleTranslation &moduleTranslation;
+
+ /// The type of each member of the structure, in order.
+ SmallVector<llvm::Type *> privateVarTypes;
+
+ /// A pointer to the structure containing context for this task.
+ llvm::Value *structPtr = nullptr;
+ /// The type of the structure
+ llvm::Type *structTy = nullptr;
+};
+} // namespace
+
+void TaskContextStructManager::generateTaskContextStruct(
+ MutableArrayRef<omp::PrivateClauseOp> privateDecls) {
+ if (privateDecls.empty())
+ return;
+ privateVarTypes.reserve(privateDecls.size());
+
+ for (omp::PrivateClauseOp &privOp : privateDecls) {
+ Type mlirType = privOp.getType();
+ privateVarTypes.push_back(moduleTranslation.convertType(mlirType));
+ }
+
+ structTy = llvm::StructType::get(moduleTranslation.getLLVMContext(),
+ privateVarTypes);
+
+ llvm::DataLayout dataLayout =
+ builder.GetInsertBlock()->getModule()->getDataLayout();
+ llvm::Type *intPtrTy = builder.getIntPtrTy(dataLayout);
+ llvm::Constant *allocSize = llvm::ConstantExpr::getSizeOf(structTy);
+
+ // Heap allocate the structure
+ structPtr = builder.CreateMalloc(intPtrTy, structTy, allocSize,
+ /*ArraySize=*/nullptr, /*MallocF=*/nullptr,
+ "omp.task.context_ptr");
+}
+
+void TaskContextStructManager::createGEPsToPrivateVars(
+ SmallVectorImpl<llvm::Value *> &llvmPrivateVars) {
+ if (!structPtr) {
+ assert(privateVarTypes.empty());
+ return;
+ }
+
+ // Create GEPs for each struct member and initialize llvmPrivateVars to point
+ llvmPrivateVars.reserve(privateVarTypes.size());
+ llvm::Value *zero = builder.getInt32(0);
+ for (auto [i, eleTy] : llvm::enumerate(privateVarTypes)) {
+ llvm::Value *iVal = builder.getInt32(i);
+ llvm::Value *gep = builder.CreateGEP(structTy, structPtr, {zero, iVal});
+ llvmPrivateVars.push_back(gep);
+ }
+}
+
+void TaskContextStructManager::freeStructPtr() {
+ if (!structPtr)
+ return;
+
+ llvm::IRBuilderBase::InsertPointGuard guard{builder};
+ // Ensure we don't put the call to free() after the terminator
+ builder.SetInsertPoint(builder.GetInsertBlock()->getTerminator());
+ builder.CreateFree(structPtr);
+}
+
/// Converts an OpenMP task construct into LLVM IR using OpenMPIRBuilder.
static LogicalResult
convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
@@ -1776,6 +1872,7 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
SmallVector<mlir::Value> mlirPrivateVars;
SmallVector<llvm::Value *> llvmPrivateVars;
SmallVector<omp::PrivateClauseOp> privateDecls;
+ TaskContextStructManager taskStructMgr{builder, moduleTranslation};
mlirPrivateVars.reserve(privateBlockArgs.size());
llvmPrivateVars.reserve(privateBlockArgs.size());
collectPrivatizationDecls(taskOp, privateDecls);
@@ -1826,30 +1923,51 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
moduleTranslation, allocaIP);
// Allocate and initialize private variables
- // TODO: package private variables up in a structure
- for (auto [privDecl, mlirPrivVar, blockArg] :
- llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs)) {
- llvm::Type *llvmAllocType =
- moduleTranslation.convertType(privDecl.getType());
-
- // Allocations:
- builder.SetInsertPoint(allocaIP.getBlock()->getTerminator());
- llvm::Value *llvmPrivateVar = builder.CreateAlloca(
- llvmAllocType, /*ArraySize=*/nullptr, "omp.private.alloc");
-
- builder.SetInsertPoint(initBlock->getTerminator());
- auto err = initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
- blockArg, &llvmPrivateVar, initBlock);
- if (err)
+ builder.SetInsertPoint(initBlock->getTerminator());
+
+ // Create task variable structure
+ llvm::SmallVector<llvm::Value *> privateVarAllocations;
+ taskStructMgr.generateTaskContextStruct(privateDecls);
+ // GEPs so that we can initialize the variables. Don't use these GEPs inside
+ // of the body otherwise it will be the GEP not the struct which is fowarded
+ // to the outlined function. GEPs forwarded in this way are passed in a
+ // stack-allocated (by OpenMPIRBuilder) structure which is not safe for tasks
+ // which may not be executed until after the current stack frame goes out of
+ // scope.
+ taskStructMgr.createGEPsToPrivateVars(privateVarAllocations);
+
+ for (auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVarAlloc] :
+ llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs,
+ privateVarAllocations)) {
+ llvm::Expected<llvm::Value *> privateVarOrErr =
+ initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
+ blockArg, llvmPrivateVarAlloc, initBlock);
+ if (auto err = privateVarOrErr.takeError())
return handleError(std::move(err), *taskOp.getOperation());
- llvmPrivateVars.push_back(llvmPrivateVar);
+ llvm::IRBuilderBase::InsertPointGuard guard(builder);
+ builder.SetInsertPoint(builder.GetInsertBlock()->getTerminator());
+
+ // TODO: this is a bit of a hack for Fortran character boxes
+ if ((privateVarOrErr.get() != llvmPrivateVarAlloc) &&
+ !mlir::isa<LLVM::LLVMPointerType>(blockArg.getType())) {
+ builder.CreateStore(privateVarOrErr.get(), llvmPrivateVarAlloc);
+ // Load it so we have the value pointed to by the GEP
+ llvmPrivateVarAlloc = builder.CreateLoad(privateVarOrErr.get()->getType(),
+ llvmPrivateVarAlloc);
+ }
+ assert(llvmPrivateVarAlloc->getType() ==
+ moduleTranslation.convertType(blockArg.getType()));
+
+ // Mapping blockArg -> llvmPrivateVarAlloc is done inside the body callback
+ // so that OpenMPIRBuilder doesn't try to pass each GEP address through a
+ // stack allocated structure.
}
// firstprivate copy region
- builder.SetInsertPoint(copyBlock->getTerminator());
+ setInsertPointForPossiblyEmptyBlock(builder, copyBlock);
if (failed(copyFirstPrivateVars(builder, moduleTranslation, mlirPrivateVars,
- llvmPrivateVars, privateDecls)))
+ privateVarAllocations, privateDecls)))
return llvm::failure();
// Set up for call to createTask()
@@ -1858,7 +1976,21 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
auto bodyCB = [&](InsertPointTy allocaIP,
InsertPointTy codegenIP) -> llvm::Error {
builder.restoreIP(codegenIP);
- // translate the body of the task:
+ // Find and map the addresses of each variable within the task context
+ // structure
+ taskStructMgr.createGEPsToPrivateVars(llvmPrivateVars);
+ for (auto [blockArg, llvmPrivateVar] :
+ llvm::zip_equal(privateBlockArgs, llvmPrivateVars)) {
+ // Fix broken pass-by-value case for Fortran character boxes
+ if (!mlir::isa<LLVM::LLVMPointerType>(blockArg.getType())) {
+ llvmPrivateVar = builder.CreateLoad(
+ moduleTranslation.convertType(blockArg.getType()), llvmPrivateVar);
+ }
+ assert(llvmPrivateVar->getType() ==
+ moduleTranslation.convertType(blockArg.getType()));
+ moduleTranslation.mapValue(blockArg, llvmPrivateVar);
+ }
+
auto continuationBlockOrError = convertOmpOpRegions(
taskOp.getRegion(), "omp.task.region", builder, moduleTranslation);
if (failed(handleError(continuationBlockOrError, *taskOp)))
@@ -1870,6 +2002,9 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
llvmPrivateVars, privateDecls)))
return llvm::make_error<PreviouslyReportedError>();
+ // Free heap allocated task context structure at the end of the task.
+ taskStructMgr.freeStructPtr();
+
return llvm::Error::success();
};
diff --git a/mlir/test/Target/LLVMIR/openmp-llvm.mlir b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
index 2f3df35f541d0..b8a5d36a2f024 100644
--- a/mlir/test/Target/LLVMIR/openmp-llvm.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
@@ -2825,14 +2825,15 @@ llvm.func @task(%arg0 : !llvm.ptr) {
// CHECK-LABEL: @task
// CHECK-SAME: (ptr %[[ARG:.*]])
// CHECK: %[[STRUCT_ARG:.*]] = alloca { ptr }, align 8
-// CHECK: %[[OMP_PRIVATE_ALLOC:.*]] = alloca i32, align 4
// ...
// CHECK: br label %omp.private.init
// CHECK: omp.private.init:
+// CHECK: %[[TASK_STRUCT:.*]] = tail call ptr @malloc(i64 ptrtoint (ptr getelementptr ({ i32 }, ptr null, i32 1) to i64))
+// CHECK: %[[GEP:.*]] = getelementptr { i32 }, ptr %[[TASK_STRUCT:.*]], i32 0, i32 0
// CHECK: br label %omp.private.copy1
// CHECK: omp.private.copy1:
// CHECK: %[[LOADED:.*]] = load i32, ptr %[[ARG]], align 4
-// CHECK: store i32 %[[LOADED]], ptr %[[OMP_PRIVATE_ALLOC]], align 4
+// CHECK: store i32 %[[LOADED]], ptr %[[GEP]], align 4
// ...
// CHECK: br label %omp.task.start
// CHECK: omp.task.start:
@@ -2846,12 +2847,13 @@ llvm.func @task(%arg0 : !llvm.ptr) {
// CHECK: %[[VAL_14:.*]] = load ptr, ptr %[[VAL_13]], align 8
// CHECK: br label %task.body
// CHECK: task.body: ; preds = %task.alloca
+// CHECK: %[[VAL_15:.*]] = getelementptr { i32 }, ptr %[[VAL_14]], i32 0, i32 0
// CHECK: br label %omp.task.region
// CHECK: omp.task.region: ; preds = %task.body
-// CHECK: call void @foo(ptr %[[VAL_14]])
+// CHECK: call void @foo(ptr %[[VAL_15]])
// CHECK: br label %omp.region.cont
// CHECK: omp.region.cont: ; preds = %omp.task.region
-// CHECK: call void @destroy(ptr %[[VAL_14]])
+// CHECK: call void @destroy(ptr %[[VAL_15]])
// CHECK: br label %task.exit.exitStub
// CHECK: task.exit.exitStub: ; preds = %omp.region.cont
// CHECK: ret void
diff --git a/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir b/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir
new file mode 100644
index 0000000000000..78cbda5de67d7
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir
@@ -0,0 +1,80 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+omp.private {type = private} @privatizer : i32
+
+omp.private {type = firstprivate} @firstprivatizer : i32 copy {
+^bb0(%arg0: !llvm.ptr, %arg1: !llvm.ptr):
+ %0 = llvm.load %arg0 : !llvm.ptr -> i32
+ llvm.store %0, %arg1 : i32, !llvm.ptr
+ omp.yield(%arg1 : !llvm.ptr)
+}
+
+llvm.func @task_privatization_test() {
+ %c0 = llvm.mlir.constant(0: i32) : i32
+ %c1 = llvm.mlir.constant(1: i32) : i32
+ %0 = llvm.alloca %c1 x i32 : (i32) -> !llvm.ptr
+ %1 = llvm.alloca %c1 x i32 : (i32) -> !llvm.ptr
+ llvm.store %c0, %0 : i32, !llvm.ptr
+ llvm.store %c1, %1 : i32, !llvm.ptr
+
+ omp.task private(@privatizer %0 -> %arg0, @firstprivatizer %1 -> %arg1 : !llvm.ptr, !llvm.ptr) {
+ %2 = llvm.load %arg1 : !llvm.ptr -> i32
+ llvm.store %2, %arg0 : i32, !llvm.ptr
+ omp.terminator
+ }
+ llvm.return
+}
+
+// CHECK: define void @task_privatization_test()
+// CHECK: %[[STRUCT_ARG:.*]] = alloca { ptr }, align 8
+// CHECK: %[[VAL_0:.*]] = alloca i32, align 4
+// CHECK: %[[VAL_1:.*]] = alloca i32, align 4
+// CHECK: store i32 0, ptr %[[VAL_0]], align 4
+// CHECK: store i32 1, ptr %[[VAL_1]], align 4
+// CHECK: br label %entry
+// CHECK: entry:
+// CHECK: br label %omp.private.init
+// CHECK: omp.private.init:
+// CHECK: %[[VAL_5:.*]] = tail call ptr @malloc(i64 ptrtoint (ptr getelementptr ([[STRUCT_KMP_PRIVATES_T:.*]], ptr null, i32 1) to i64))
+// CHECK: %[[VAL_7:.*]] = getelementptr { i32, i32 }, ptr %[[VAL_5]], i32 0, i32 0
+// CHECK: %[[VAL_8:.*]] = getelementptr { i32, i32 }, ptr %[[VAL_5]], i32 0, i32 1
+// CHECK: br label %omp.private.copy
+// CHECK: omp.private.copy:
+// CHECK: %[[VAL_10:.*]] = load i32, ptr %[[VAL_1]], align 4
+// CHECK: store i32 %[[VAL_10]], ptr %[[VAL_8]], align 4
+// CHECK: br label %omp.task.start
+// CHECK: omp.task.start:
+// CHECK: br label %codeRepl
+// CHECK: codeRepl:
+// CHECK: %[[GEP_OMP_TASK_CONTEXT_PTR:.*]] = getelementptr { ptr }, ptr %[[STRUCT_ARG]], i32 0, i32 0
+// CHECK: store ptr %[[VAL_5]], ptr %[[GEP_OMP_TASK_CONTEXT_PTR]], align 8
+// CHECK: %[[VAL_14:.*]] = call i32 @__kmpc_global_thread_num(ptr @1)
+// CHECK: %[[VAL_15:.*]] = call ptr @__kmpc_omp_task_alloc(ptr @1, i32 %[[VAL_14]], i32 1, i64 40, i64 8, ptr @task_privatization_test..omp_par)
+// CHECK: %[[ALLOCATED_TASK_STRUCT:.*]] = load ptr, ptr %[[VAL_15]], align 8
+// CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %[[ALLOCATED_TASK_STRUCT]], ptr align 1 %[[STRUCT_ARG]], i64 8, i1 false)
+// CHECK: %[[VAL_16:.*]] = call i32 @__kmpc_omp_task(ptr @1, i32 %[[VAL_14]], ptr %[[VAL_15]])
+// CHECK: br label %[[VAL_17:.*]]
+// CHECK: task.exit:
+// CHECK: ret void
+
+// CHECK-LABEL: define internal void @task_privatization_test..omp_par(
+// CHECK-SAME: i32 %[[GLOBAL_TID_VAL:.*]], ptr %[[OMP_TASK_CONTEXT_PTR_PTR_PTR_PTR:.*]])
+// CHECK: task.alloca:
+// CHECK: %[[OMP_TASK_CONEXT_PTR_PTR_PTR:.*]] = load ptr, ptr %[[OMP_TASK_CONTEXT_PTR_PTR_PTR_PTR]], align 8
+// CHECK: %[[OMP_TASK_CONTEXT_PTR_PTR:.*]] = getelementptr { ptr }, ptr %[[OMP_TASK_CONTEXT_PTR_PTR_PTR:.*]], i32 0, i32 0
+// CHECK: %[[OMP_TASK_CONTEXT_PTR:.*]] = load ptr, ptr %[[OMP_TASK_CONTEXT_PTR_PTR:.*]], align 8
+// CHECK: br label %[[VAL_18:.*]]
+// CHECK: task.body: ; preds = %[[VAL_19:.*]]
+// CHECK: %[[VAL_20:.*]] = getelementptr { i32, i32 }, ptr %[[OMP_TASK_CONTEXT_PTR]], i32 0, i32 0
+// CHECK: %[[VAL_22:.*]] = getelementptr { i32, i32 }, ptr %[[OMP_TASK_CONTEXT_PTR]], i32 0, i32 1
+// CHECK: br label %[[VAL_23:.*]]
+// CHECK: omp.task.region: ; preds = %[[VAL_18]]
+// CHECK: %[[VAL_24:.*]] = load i32, ptr %[[VAL_22]], align 4
+// CHECK: store i32 %[[VAL_24]], ptr %[[VAL_20]], align 4
+// CHECK: br label %[[VAL_25:.*]]
+// CHECK: omp.region.cont: ; preds = %[[VAL_23]]
+// CHECK: tail call void @free(ptr %[[OMP_TASK_CONTEXT_PTR]])
+// CHECK: br label %[[VAL_26:.*]]
+// CHECK: task.exit.exitStub: ; preds = %[[VAL_25]]
+// CHECK: ret void
+
>From 92b347c535ec1cc7c2dac250d02b26b34e452455 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Tue, 4 Feb 2025 11:16:13 +0000
Subject: [PATCH 02/12] Allocate simple private vars inside of the task
There's no need to put the variable in the context structure if it can
be initialized without reading from the mold variable.
This leads to much simpler code generation for nested tasks which only
privatize simple scalar variables and do not use firstprivate. This
works around the failure in 0226_0013 (Fujitsu test).
---
.../OpenMP/OpenMPToLLVMIRTranslation.cpp | 89 ++++++++++++++++---
mlir/test/Target/LLVMIR/openmp-llvm.mlir | 5 +-
.../LLVMIR/openmp-task-privatization.mlir | 13 ++-
3 files changed, 87 insertions(+), 20 deletions(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index a676d2d981a8b..8adaa68e3937d 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1767,24 +1767,42 @@ buildDependData(std::optional<ArrayAttr> dependKinds, OperandRange dependVars,
}
}
+static bool privatizerReadsSourceVariable(omp::PrivateClauseOp &priv) {
+ if (priv.getDataSharingType() == omp::DataSharingClauseType::FirstPrivate)
+ return true;
+
+ Region &initRegion = priv.getInitRegion();
+ if (initRegion.empty())
+ return false;
+
+ BlockArgument sourceVariable = priv.getInitMoldArg();
+ if (!sourceVariable)
+ return false;
+ return !sourceVariable.use_empty();
+}
+
namespace {
/// TaskContextStructManager takes care of creating and freeing a structure
/// containing information needed by the task body to execute.
class TaskContextStructManager {
public:
TaskContextStructManager(llvm::IRBuilderBase &builder,
- LLVM::ModuleTranslation &moduleTranslation)
- : builder{builder}, moduleTranslation{moduleTranslation} {}
+ LLVM::ModuleTranslation &moduleTranslation,
+ MutableArrayRef<omp::PrivateClauseOp> privateDecls)
+ : builder{builder}, moduleTranslation{moduleTranslation},
+ privateDecls{privateDecls} {}
/// Creates a heap allocated struct containing space for each private
/// variable. Returns nullptr if there are is no struct needed. Invariant:
/// privateVarTypes, privateDecls, and the elements of the structure should
- /// all have the same order.
- void
- generateTaskContextStruct(MutableArrayRef<omp::PrivateClauseOp> privateDecls);
+ /// all have the same order (although privateDecls which do not read from the
+ /// mold argument are skipped).
+ void generateTaskContextStruct();
/// Create GEPs to access each member of the structure representing a private
- /// variable, adding them to llvmPrivateVars.
+ /// variable, adding them to llvmPrivateVars. Null values are added where
+ /// private decls were skipped so that the ordering continues to match the
+ /// private decls.
void createGEPsToPrivateVars(SmallVectorImpl<llvm::Value *> &llvmPrivateVars);
/// De-allocate the task context structure.
@@ -1795,6 +1813,7 @@ class TaskContextStructManager {
private:
llvm::IRBuilderBase &builder;
LLVM::ModuleTranslation &moduleTranslation;
+ MutableArrayRef<omp::PrivateClauseOp> privateDecls;
/// The type of each member of the structure, in order.
SmallVector<llvm::Type *> privateVarTypes;
@@ -1806,13 +1825,16 @@ class TaskContextStructManager {
};
} // namespace
-void TaskContextStructManager::generateTaskContextStruct(
- MutableArrayRef<omp::PrivateClauseOp> privateDecls) {
+void TaskContextStructManager::generateTaskContextStruct() {
if (privateDecls.empty())
return;
privateVarTypes.reserve(privateDecls.size());
for (omp::PrivateClauseOp &privOp : privateDecls) {
+ // Skip private variables which can safely be allocated and initialised
+ // inside of the task
+ if (!privatizerReadsSourceVariable(privOp))
+ continue;
Type mlirType = privOp.getType();
privateVarTypes.push_back(moduleTranslation.convertType(mlirType));
}
@@ -1841,10 +1863,17 @@ void TaskContextStructManager::createGEPsToPrivateVars(
// Create GEPs for each struct member and initialize llvmPrivateVars to point
llvmPrivateVars.reserve(privateVarTypes.size());
llvm::Value *zero = builder.getInt32(0);
- for (auto [i, eleTy] : llvm::enumerate(privateVarTypes)) {
+ unsigned i = 0;
+ for (auto privDecl : privateDecls) {
+ if (!privatizerReadsSourceVariable(privDecl)) {
+ // Handle this inside of the task so we don't pass unnessecary vars in
+ llvmPrivateVars.push_back(nullptr);
+ continue;
+ }
llvm::Value *iVal = builder.getInt32(i);
llvm::Value *gep = builder.CreateGEP(structTy, structPtr, {zero, iVal});
llvmPrivateVars.push_back(gep);
+ i += 1;
}
}
@@ -1872,10 +1901,11 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
SmallVector<mlir::Value> mlirPrivateVars;
SmallVector<llvm::Value *> llvmPrivateVars;
SmallVector<omp::PrivateClauseOp> privateDecls;
- TaskContextStructManager taskStructMgr{builder, moduleTranslation};
mlirPrivateVars.reserve(privateBlockArgs.size());
llvmPrivateVars.reserve(privateBlockArgs.size());
collectPrivatizationDecls(taskOp, privateDecls);
+ TaskContextStructManager taskStructMgr{builder, moduleTranslation,
+ privateDecls};
for (mlir::Value privateVar : taskOp.getPrivateVars())
mlirPrivateVars.push_back(privateVar);
@@ -1927,7 +1957,7 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
// Create task variable structure
llvm::SmallVector<llvm::Value *> privateVarAllocations;
- taskStructMgr.generateTaskContextStruct(privateDecls);
+ taskStructMgr.generateTaskContextStruct();
// GEPs so that we can initialize the variables. Don't use these GEPs inside
// of the body otherwise it will be the GEP not the struct which is fowarded
// to the outlined function. GEPs forwarded in this way are passed in a
@@ -1939,6 +1969,10 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
for (auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVarAlloc] :
llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs,
privateVarAllocations)) {
+ if (!llvmPrivateVarAlloc)
+ // to be handled inside the task
+ continue;
+
llvm::Expected<llvm::Value *> privateVarOrErr =
initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
blockArg, llvmPrivateVarAlloc, initBlock);
@@ -1975,12 +2009,45 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
auto bodyCB = [&](InsertPointTy allocaIP,
InsertPointTy codegenIP) -> llvm::Error {
+ // Save the alloca insertion point on ModuleTranslation stack for use in
+ // nested regions.
+ LLVM::ModuleTranslation::SaveStack<OpenMPAllocaStackFrame> frame(
+ moduleTranslation, allocaIP);
+
+ // translate the body of the task:
builder.restoreIP(codegenIP);
+
+ llvm::BasicBlock *privInitBlock = nullptr;
+ for (auto [blockArg, privDecl, mlirPrivVar] :
+ llvm::zip_equal(privateBlockArgs, privateDecls, mlirPrivateVars)) {
+ if (privatizerReadsSourceVariable(privDecl))
+ // This is handled before the task executes
+ continue;
+
+ auto codegenInsertionPt = builder.saveIP();
+ llvm::Type *llvmAllocType =
+ moduleTranslation.convertType(privDecl.getType());
+ builder.SetInsertPoint(allocaIP.getBlock()->getTerminator());
+ llvm::Value *llvmPrivateVar = builder.CreateAlloca(
+ llvmAllocType, /*ArraySize=*/nullptr, "omp.private.alloc");
+
+ llvm::Expected<llvm::Value *> privateVarOrError =
+ initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
+ blockArg, llvmPrivateVar, privInitBlock);
+ if (auto err = privateVarOrError.takeError())
+ return err;
+ moduleTranslation.mapValue(blockArg, privateVarOrError.get());
+ builder.restoreIP(codegenInsertionPt);
+ }
+
// Find and map the addresses of each variable within the task context
// structure
taskStructMgr.createGEPsToPrivateVars(llvmPrivateVars);
for (auto [blockArg, llvmPrivateVar] :
llvm::zip_equal(privateBlockArgs, llvmPrivateVars)) {
+ if (!llvmPrivateVar)
+ // This was handled above
+ continue;
// Fix broken pass-by-value case for Fortran character boxes
if (!mlir::isa<LLVM::LLVMPointerType>(blockArg.getType())) {
llvmPrivateVar = builder.CreateLoad(
diff --git a/mlir/test/Target/LLVMIR/openmp-llvm.mlir b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
index b8a5d36a2f024..f25ba4aa3c8dc 100644
--- a/mlir/test/Target/LLVMIR/openmp-llvm.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
@@ -2795,9 +2795,10 @@ llvm.func @par_task_(%arg0: !llvm.ptr {fir.bindc_name = "a"}) {
// CHECK: call i32 @__kmpc_omp_task({{.*}}, ptr %[[TASK_ALLOC]])
// CHECK: define internal void @[[task_outlined_fn]](i32 %[[GLOBAL_TID_VAL:.*]], ptr %[[STRUCT_ARG:.*]])
// CHECK: %[[LOADED_STRUCT_PTR:.*]] = load ptr, ptr %[[STRUCT_ARG]], align 8
-// CHECK: %[[GEP_STRUCTARG:.*]] = getelementptr { ptr, ptr }, ptr %[[LOADED_STRUCT_PTR]], i32 0, i32 0
+// CHECK: %[[GEP_STRUCTARG:.*]] = getelementptr { ptr }, ptr %[[LOADED_STRUCT_PTR]], i32 0, i32 0
// CHECK: %[[LOADGEP_STRUCTARG:.*]] = load ptr, ptr %[[GEP_STRUCTARG]], align 8
-// CHECK: call void ({{.*}}) @__kmpc_fork_call({{.*}}, ptr @[[parallel_outlined_fn:.+]], ptr %[[LOADGEP_STRUCTARG]])
+// CHEKC: %[[NEW_STRUCTARG:.*]] = alloca { ptr }, align 8
+// CHECK: call void ({{.*}}) @__kmpc_fork_call({{.*}}, ptr @[[parallel_outlined_fn:.+]],
// CHECK: define internal void @[[parallel_outlined_fn]]
// -----
diff --git a/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir b/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir
index 78cbda5de67d7..f7a8b970f5f80 100644
--- a/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-task-privatization.mlir
@@ -36,12 +36,11 @@ llvm.func @task_privatization_test() {
// CHECK: br label %omp.private.init
// CHECK: omp.private.init:
// CHECK: %[[VAL_5:.*]] = tail call ptr @malloc(i64 ptrtoint (ptr getelementptr ([[STRUCT_KMP_PRIVATES_T:.*]], ptr null, i32 1) to i64))
-// CHECK: %[[VAL_7:.*]] = getelementptr { i32, i32 }, ptr %[[VAL_5]], i32 0, i32 0
-// CHECK: %[[VAL_8:.*]] = getelementptr { i32, i32 }, ptr %[[VAL_5]], i32 0, i32 1
+// CHECK: %[[VAL_7:.*]] = getelementptr { i32 }, ptr %[[VAL_5]], i32 0, i32 0
// CHECK: br label %omp.private.copy
// CHECK: omp.private.copy:
// CHECK: %[[VAL_10:.*]] = load i32, ptr %[[VAL_1]], align 4
-// CHECK: store i32 %[[VAL_10]], ptr %[[VAL_8]], align 4
+// CHECK: store i32 %[[VAL_10]], ptr %[[VAL_7]], align 4
// CHECK: br label %omp.task.start
// CHECK: omp.task.start:
// CHECK: br label %codeRepl
@@ -63,14 +62,14 @@ llvm.func @task_privatization_test() {
// CHECK: %[[OMP_TASK_CONEXT_PTR_PTR_PTR:.*]] = load ptr, ptr %[[OMP_TASK_CONTEXT_PTR_PTR_PTR_PTR]], align 8
// CHECK: %[[OMP_TASK_CONTEXT_PTR_PTR:.*]] = getelementptr { ptr }, ptr %[[OMP_TASK_CONTEXT_PTR_PTR_PTR:.*]], i32 0, i32 0
// CHECK: %[[OMP_TASK_CONTEXT_PTR:.*]] = load ptr, ptr %[[OMP_TASK_CONTEXT_PTR_PTR:.*]], align 8
+// CHECK: %[[OMP_PRIVATE_ALLOC:.*]] = alloca i32, align 4
// CHECK: br label %[[VAL_18:.*]]
// CHECK: task.body: ; preds = %[[VAL_19:.*]]
-// CHECK: %[[VAL_20:.*]] = getelementptr { i32, i32 }, ptr %[[OMP_TASK_CONTEXT_PTR]], i32 0, i32 0
-// CHECK: %[[VAL_22:.*]] = getelementptr { i32, i32 }, ptr %[[OMP_TASK_CONTEXT_PTR]], i32 0, i32 1
+// CHECK: %[[VAL_20:.*]] = getelementptr { i32 }, ptr %[[OMP_TASK_CONTEXT_PTR]], i32 0, i32 0
// CHECK: br label %[[VAL_23:.*]]
// CHECK: omp.task.region: ; preds = %[[VAL_18]]
-// CHECK: %[[VAL_24:.*]] = load i32, ptr %[[VAL_22]], align 4
-// CHECK: store i32 %[[VAL_24]], ptr %[[VAL_20]], align 4
+// CHECK: %[[VAL_24:.*]] = load i32, ptr %[[VAL_20]], align 4
+// CHECK: store i32 %[[VAL_24]], ptr %[[OMP_PRIVATE_ALLOC]], align 4
// CHECK: br label %[[VAL_25:.*]]
// CHECK: omp.region.cont: ; preds = %[[VAL_23]]
// CHECK: tail call void @free(ptr %[[OMP_TASK_CONTEXT_PTR]])
>From 3683d4178097c71b044548be67795b4f4d3df997 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Wed, 5 Feb 2025 09:39:33 +0000
Subject: [PATCH 03/12] Add methods to operation to test if the mold arg is
read
---
.../lib/Lower/OpenMP/DataSharingProcessor.cpp | 2 +-
mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td | 15 ++++++++++++--
.../OpenMP/OpenMPToLLVMIRTranslation.cpp | 20 +++----------------
3 files changed, 17 insertions(+), 20 deletions(-)
diff --git a/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp b/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
index d725dfd3e94f3..6b0d783fb8c30 100644
--- a/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
+++ b/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
@@ -594,7 +594,7 @@ void DataSharingProcessor::doPrivatize(const semantics::Symbol *sym,
sym, cannotHaveNonDefaultLowerBounds);
// TODO: currently there are false positives from dead uses of the mold
// arg
- if (!result.getInitMoldArg().getUses().empty())
+ if (result.initReadsFromMold())
mightHaveReadHostSym.insert(sym);
}
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index 2d8e022190f62..ecff73f44b89a 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -146,13 +146,24 @@ def PrivateClauseOp : OpenMP_Op<"private", [IsolatedFromAbove, RecipeInterface]>
return region.empty() ? nullptr : region.getArgument(0);
}
+ /// Returns true if the init region might read from the mold argument
+ bool initReadsFromMold() {
+ BlockArgument moldArg = getInitMoldArg();
+ return moldArg ? !moldArg.use_empty() : false;
+ }
+
+ /// Returns true if any region of this privatizer might read from the mold
+ /// argument
+ bool readsFromMold() {
+ return initReadsFromMold() || !getCopyRegion().empty();
+ }
+
/// needsMap returns true if the value being privatized should additionally
/// be mapped to the target region using a MapInfoOp. This is most common
/// when an allocatable is privatized. In such cases, the descriptor is used
/// in privatization and needs to be mapped on to the device.
bool needsMap() {
- BlockArgument moldArg = getInitMoldArg();
- return moldArg ? !moldArg.use_empty() : false;
+ return initReadsFromMold();
}
/// Get the type for arguments to nested regions. This should
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 8adaa68e3937d..83597bfe413e9 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1767,20 +1767,6 @@ buildDependData(std::optional<ArrayAttr> dependKinds, OperandRange dependVars,
}
}
-static bool privatizerReadsSourceVariable(omp::PrivateClauseOp &priv) {
- if (priv.getDataSharingType() == omp::DataSharingClauseType::FirstPrivate)
- return true;
-
- Region &initRegion = priv.getInitRegion();
- if (initRegion.empty())
- return false;
-
- BlockArgument sourceVariable = priv.getInitMoldArg();
- if (!sourceVariable)
- return false;
- return !sourceVariable.use_empty();
-}
-
namespace {
/// TaskContextStructManager takes care of creating and freeing a structure
/// containing information needed by the task body to execute.
@@ -1833,7 +1819,7 @@ void TaskContextStructManager::generateTaskContextStruct() {
for (omp::PrivateClauseOp &privOp : privateDecls) {
// Skip private variables which can safely be allocated and initialised
// inside of the task
- if (!privatizerReadsSourceVariable(privOp))
+ if (!privOp.readsFromMold())
continue;
Type mlirType = privOp.getType();
privateVarTypes.push_back(moduleTranslation.convertType(mlirType));
@@ -1865,7 +1851,7 @@ void TaskContextStructManager::createGEPsToPrivateVars(
llvm::Value *zero = builder.getInt32(0);
unsigned i = 0;
for (auto privDecl : privateDecls) {
- if (!privatizerReadsSourceVariable(privDecl)) {
+ if (!privDecl.readsFromMold()) {
// Handle this inside of the task so we don't pass unnessecary vars in
llvmPrivateVars.push_back(nullptr);
continue;
@@ -2020,7 +2006,7 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
llvm::BasicBlock *privInitBlock = nullptr;
for (auto [blockArg, privDecl, mlirPrivVar] :
llvm::zip_equal(privateBlockArgs, privateDecls, mlirPrivateVars)) {
- if (privatizerReadsSourceVariable(privDecl))
+ if (privDecl.readsFromMold())
// This is handled before the task executes
continue;
>From 7391b7b5145bc1f45726ea61d500325f1241eeca Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Wed, 5 Feb 2025 09:39:59 +0000
Subject: [PATCH 04/12] Fix comment
---
.../LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 83597bfe413e9..e5f263716efbf 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1779,10 +1779,9 @@ class TaskContextStructManager {
privateDecls{privateDecls} {}
/// Creates a heap allocated struct containing space for each private
- /// variable. Returns nullptr if there are is no struct needed. Invariant:
- /// privateVarTypes, privateDecls, and the elements of the structure should
- /// all have the same order (although privateDecls which do not read from the
- /// mold argument are skipped).
+ /// variable. Invariant: privateVarTypes, privateDecls, and the elements of
+ /// the structure should all have the same order (although privateDecls which
+ /// do not read from the mold argument are skipped).
void generateTaskContextStruct();
/// Create GEPs to access each member of the structure representing a private
>From 682d511d0b8389a048eda03bf4c11fc5136c954b Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Wed, 5 Feb 2025 10:00:29 +0000
Subject: [PATCH 05/12] Make logic clearer
---
.../LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index e5f263716efbf..d2f7b6820910c 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1954,9 +1954,11 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
for (auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVarAlloc] :
llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs,
privateVarAllocations)) {
- if (!llvmPrivateVarAlloc)
+ if (!privDecl.readsFromMold())
// to be handled inside the task
continue;
+ assert(llvmPrivateVarAlloc &&
+ "reads from mold so shouldn't have been skipped");
llvm::Expected<llvm::Value *> privateVarOrErr =
initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
>From c517052b9d13ac2212309af7379cb269d71a0b65 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Wed, 5 Feb 2025 15:48:58 +0000
Subject: [PATCH 06/12] Move llvm private vars into task context struct manager
---
.../OpenMP/OpenMPToLLVMIRTranslation.cpp | 28 +++++++++++++------
1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index d2f7b6820910c..eb93261c4d34d 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1470,7 +1470,7 @@ static LogicalResult
copyFirstPrivateVars(llvm::IRBuilderBase &builder,
LLVM::ModuleTranslation &moduleTranslation,
SmallVectorImpl<mlir::Value> &mlirPrivateVars,
- SmallVectorImpl<llvm::Value *> &llvmPrivateVars,
+ ArrayRef<llvm::Value *> llvmPrivateVars,
SmallVectorImpl<omp::PrivateClauseOp> &privateDecls) {
// Apply copy region for firstprivate.
bool needsFirstprivate =
@@ -1788,11 +1788,15 @@ class TaskContextStructManager {
/// variable, adding them to llvmPrivateVars. Null values are added where
/// private decls were skipped so that the ordering continues to match the
/// private decls.
- void createGEPsToPrivateVars(SmallVectorImpl<llvm::Value *> &llvmPrivateVars);
+ void createGEPsToPrivateVars();
/// De-allocate the task context structure.
void freeStructPtr();
+ MutableArrayRef<llvm::Value *> getLLVMPrivateVars() {
+ return llvmPrivateVars;
+ }
+
llvm::Value *getStructPtr() { return structPtr; }
private:
@@ -1803,6 +1807,10 @@ class TaskContextStructManager {
/// The type of each member of the structure, in order.
SmallVector<llvm::Type *> privateVarTypes;
+ /// LLVM values for each private variable, or null if that private variable is
+ /// not included in the task context structure
+ SmallVector<llvm::Value *> llvmPrivateVars;
+
/// A pointer to the structure containing context for this task.
llvm::Value *structPtr = nullptr;
/// The type of the structure
@@ -1838,14 +1846,14 @@ void TaskContextStructManager::generateTaskContextStruct() {
"omp.task.context_ptr");
}
-void TaskContextStructManager::createGEPsToPrivateVars(
- SmallVectorImpl<llvm::Value *> &llvmPrivateVars) {
+void TaskContextStructManager::createGEPsToPrivateVars() {
if (!structPtr) {
assert(privateVarTypes.empty());
return;
}
// Create GEPs for each struct member and initialize llvmPrivateVars to point
+ llvmPrivateVars.clear();
llvmPrivateVars.reserve(privateVarTypes.size());
llvm::Value *zero = builder.getInt32(0);
unsigned i = 0;
@@ -1941,7 +1949,6 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
builder.SetInsertPoint(initBlock->getTerminator());
// Create task variable structure
- llvm::SmallVector<llvm::Value *> privateVarAllocations;
taskStructMgr.generateTaskContextStruct();
// GEPs so that we can initialize the variables. Don't use these GEPs inside
// of the body otherwise it will be the GEP not the struct which is fowarded
@@ -1949,11 +1956,11 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
// stack-allocated (by OpenMPIRBuilder) structure which is not safe for tasks
// which may not be executed until after the current stack frame goes out of
// scope.
- taskStructMgr.createGEPsToPrivateVars(privateVarAllocations);
+ taskStructMgr.createGEPsToPrivateVars();
for (auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVarAlloc] :
llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs,
- privateVarAllocations)) {
+ taskStructMgr.getLLVMPrivateVars())) {
if (!privDecl.readsFromMold())
// to be handled inside the task
continue;
@@ -1988,7 +1995,8 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
// firstprivate copy region
setInsertPointForPossiblyEmptyBlock(builder, copyBlock);
if (failed(copyFirstPrivateVars(builder, moduleTranslation, mlirPrivateVars,
- privateVarAllocations, privateDecls)))
+ taskStructMgr.getLLVMPrivateVars(),
+ privateDecls)))
return llvm::failure();
// Set up for call to createTask()
@@ -2029,7 +2037,9 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
// Find and map the addresses of each variable within the task context
// structure
- taskStructMgr.createGEPsToPrivateVars(llvmPrivateVars);
+ taskStructMgr.createGEPsToPrivateVars();
+ llvm::copy(taskStructMgr.getLLVMPrivateVars(),
+ std::back_inserter(llvmPrivateVars));
for (auto [blockArg, llvmPrivateVar] :
llvm::zip_equal(privateBlockArgs, llvmPrivateVars)) {
if (!llvmPrivateVar)
>From 9604d0b7adbaa59a4f1bf7c765b910abb2339988 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Thu, 6 Feb 2025 09:57:01 +0000
Subject: [PATCH 07/12] Fix 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 eb93261c4d34d..5f1f936957a22 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1852,7 +1852,7 @@ void TaskContextStructManager::createGEPsToPrivateVars() {
return;
}
- // Create GEPs for each struct member and initialize llvmPrivateVars to point
+ // Create GEPs for each struct member
llvmPrivateVars.clear();
llvmPrivateVars.reserve(privateVarTypes.size());
llvm::Value *zero = builder.getInt32(0);
>From 5bfe525faa30fafefee90382ea7a81dbee138e0e Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Thu, 6 Feb 2025 09:57:39 +0000
Subject: [PATCH 08/12] Reserve the correct size
---
.../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 5f1f936957a22..0e1f002486691 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1854,7 +1854,7 @@ void TaskContextStructManager::createGEPsToPrivateVars() {
// Create GEPs for each struct member
llvmPrivateVars.clear();
- llvmPrivateVars.reserve(privateVarTypes.size());
+ llvmPrivateVars.reserve(privateDecls.size());
llvm::Value *zero = builder.getInt32(0);
unsigned i = 0;
for (auto privDecl : privateDecls) {
>From b18b1faab2d395b6c4b5f7e684b6d557e7a3c29b Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Thu, 6 Feb 2025 10:02:08 +0000
Subject: [PATCH 09/12] Update charbox comment
---
.../LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 0e1f002486691..e79cba0867630 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1976,7 +1976,11 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
llvm::IRBuilderBase::InsertPointGuard guard(builder);
builder.SetInsertPoint(builder.GetInsertBlock()->getTerminator());
- // TODO: this is a bit of a hack for Fortran character boxes
+ // TODO: this is a bit of a hack for Fortran character boxes.
+ // Character boxes are passed by value into the init region and then the
+ // initialized character box is yielded by value. Here we need to store the
+ // yielded value into the private allocation, and load the private
+ // allocation to match the type expected by region block arguments.
if ((privateVarOrErr.get() != llvmPrivateVarAlloc) &&
!mlir::isa<LLVM::LLVMPointerType>(blockArg.getType())) {
builder.CreateStore(privateVarOrErr.get(), llvmPrivateVarAlloc);
>From 5f40731f84c51fe591a5f89937c9bd3896b3dd26 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Thu, 6 Feb 2025 10:03:27 +0000
Subject: [PATCH 10/12] Rename llvmPrivateVars to llvmPrivateVarGEPs
---
.../OpenMP/OpenMPToLLVMIRTranslation.cpp | 20 +++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index e79cba0867630..d1f6862cac9e9 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1793,8 +1793,8 @@ class TaskContextStructManager {
/// De-allocate the task context structure.
void freeStructPtr();
- MutableArrayRef<llvm::Value *> getLLVMPrivateVars() {
- return llvmPrivateVars;
+ MutableArrayRef<llvm::Value *> getLLVMPrivateVarGEPs() {
+ return llvmPrivateVarGEPs;
}
llvm::Value *getStructPtr() { return structPtr; }
@@ -1809,7 +1809,7 @@ class TaskContextStructManager {
/// LLVM values for each private variable, or null if that private variable is
/// not included in the task context structure
- SmallVector<llvm::Value *> llvmPrivateVars;
+ SmallVector<llvm::Value *> llvmPrivateVarGEPs;
/// A pointer to the structure containing context for this task.
llvm::Value *structPtr = nullptr;
@@ -1853,19 +1853,19 @@ void TaskContextStructManager::createGEPsToPrivateVars() {
}
// Create GEPs for each struct member
- llvmPrivateVars.clear();
- llvmPrivateVars.reserve(privateDecls.size());
+ llvmPrivateVarGEPs.clear();
+ llvmPrivateVarGEPs.reserve(privateDecls.size());
llvm::Value *zero = builder.getInt32(0);
unsigned i = 0;
for (auto privDecl : privateDecls) {
if (!privDecl.readsFromMold()) {
// Handle this inside of the task so we don't pass unnessecary vars in
- llvmPrivateVars.push_back(nullptr);
+ llvmPrivateVarGEPs.push_back(nullptr);
continue;
}
llvm::Value *iVal = builder.getInt32(i);
llvm::Value *gep = builder.CreateGEP(structTy, structPtr, {zero, iVal});
- llvmPrivateVars.push_back(gep);
+ llvmPrivateVarGEPs.push_back(gep);
i += 1;
}
}
@@ -1960,7 +1960,7 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
for (auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVarAlloc] :
llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs,
- taskStructMgr.getLLVMPrivateVars())) {
+ taskStructMgr.getLLVMPrivateVarGEPs())) {
if (!privDecl.readsFromMold())
// to be handled inside the task
continue;
@@ -1999,7 +1999,7 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
// firstprivate copy region
setInsertPointForPossiblyEmptyBlock(builder, copyBlock);
if (failed(copyFirstPrivateVars(builder, moduleTranslation, mlirPrivateVars,
- taskStructMgr.getLLVMPrivateVars(),
+ taskStructMgr.getLLVMPrivateVarGEPs(),
privateDecls)))
return llvm::failure();
@@ -2042,7 +2042,7 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
// Find and map the addresses of each variable within the task context
// structure
taskStructMgr.createGEPsToPrivateVars();
- llvm::copy(taskStructMgr.getLLVMPrivateVars(),
+ llvm::copy(taskStructMgr.getLLVMPrivateVarGEPs(),
std::back_inserter(llvmPrivateVars));
for (auto [blockArg, llvmPrivateVar] :
llvm::zip_equal(privateBlockArgs, llvmPrivateVars)) {
>From 193623e504d73c678ea49df83c5ce44877c28b32 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Mon, 24 Feb 2025 11:21:43 +0000
Subject: [PATCH 11/12] Fix skatrak's comments
---
mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td | 2 +-
.../OpenMP/OpenMPToLLVMIRTranslation.cpp | 40 +++++++++++--------
2 files changed, 25 insertions(+), 17 deletions(-)
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index ecff73f44b89a..f5a8a7ba04375 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -149,7 +149,7 @@ def PrivateClauseOp : OpenMP_Op<"private", [IsolatedFromAbove, RecipeInterface]>
/// Returns true if the init region might read from the mold argument
bool initReadsFromMold() {
BlockArgument moldArg = getInitMoldArg();
- return moldArg ? !moldArg.use_empty() : false;
+ return moldArg && !moldArg.use_empty();
}
/// Returns true if any region of this privatizer might read from the mold
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index d1f6862cac9e9..ab368d883d565 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1360,9 +1360,8 @@ static llvm::Expected<llvm::Value *> initPrivateVar(
llvm::Value *llvmPrivateVar, llvm::BasicBlock *privInitBlock,
llvm::DenseMap<Value, Value> *mappedPrivateVars = nullptr) {
Region &initRegion = privDecl.getInitRegion();
- if (initRegion.empty()) {
+ if (initRegion.empty())
return llvmPrivateVar;
- }
// map initialization region block arguments
llvm::Value *nonPrivateVar = findAssociatedValue(
@@ -1412,8 +1411,8 @@ initPrivateVars(llvm::IRBuilderBase &builder,
builder, moduleTranslation, privDecl, mlirPrivVar, blockArg,
llvmPrivateVar, privInitBlock, mappedPrivateVars);
- if (auto err = privVarOrErr.takeError())
- return err;
+ if (!privVarOrErr)
+ return privVarOrErr.takeError();
llvmPrivateVar = privVarOrErr.get();
moduleTranslation.mapValue(blockArg, llvmPrivateVar);
@@ -2017,13 +2016,15 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
builder.restoreIP(codegenIP);
llvm::BasicBlock *privInitBlock = nullptr;
- for (auto [blockArg, privDecl, mlirPrivVar] :
- llvm::zip_equal(privateBlockArgs, privateDecls, mlirPrivateVars)) {
+ llvmPrivateVars.resize(privateBlockArgs.size());
+ for (auto [i, zip] : llvm::enumerate(llvm::zip_equal(
+ privateBlockArgs, privateDecls, mlirPrivateVars))) {
+ auto [blockArg, privDecl, mlirPrivVar] = zip;
+ // This is handled before the task executes
if (privDecl.readsFromMold())
- // This is handled before the task executes
continue;
- auto codegenInsertionPt = builder.saveIP();
+ llvm::IRBuilderBase::InsertPointGuard guard(builder);
llvm::Type *llvmAllocType =
moduleTranslation.convertType(privDecl.getType());
builder.SetInsertPoint(allocaIP.getBlock()->getTerminator());
@@ -2036,18 +2037,25 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
if (auto err = privateVarOrError.takeError())
return err;
moduleTranslation.mapValue(blockArg, privateVarOrError.get());
- builder.restoreIP(codegenInsertionPt);
+ llvmPrivateVars[i] = privateVarOrError.get();
+ }
+
+ taskStructMgr.createGEPsToPrivateVars();
+ for (auto [i, llvmPrivVar] :
+ llvm::enumerate(taskStructMgr.getLLVMPrivateVarGEPs())) {
+ if (!llvmPrivVar) {
+ assert(llvmPrivateVars[i] && "This is added in the loop above");
+ continue;
+ }
+ llvmPrivateVars[i] = llvmPrivVar;
}
// Find and map the addresses of each variable within the task context
// structure
- taskStructMgr.createGEPsToPrivateVars();
- llvm::copy(taskStructMgr.getLLVMPrivateVarGEPs(),
- std::back_inserter(llvmPrivateVars));
- for (auto [blockArg, llvmPrivateVar] :
- llvm::zip_equal(privateBlockArgs, llvmPrivateVars)) {
- if (!llvmPrivateVar)
- // This was handled above
+ for (auto [blockArg, llvmPrivateVar, privateDecl] :
+ llvm::zip_equal(privateBlockArgs, llvmPrivateVars, privateDecls)) {
+ // This was handled above.
+ if (!privateDecl.readsFromMold())
continue;
// Fix broken pass-by-value case for Fortran character boxes
if (!mlir::isa<LLVM::LLVMPointerType>(blockArg.getType())) {
>From 18daec335c15aadfec1ba5c13fdecc64bfa2f755 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Wed, 26 Feb 2025 17:32:23 +0000
Subject: [PATCH 12/12] Fix comments I missed
---
.../Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index ab368d883d565..5035551dd6023 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1960,8 +1960,8 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
for (auto [privDecl, mlirPrivVar, blockArg, llvmPrivateVarAlloc] :
llvm::zip_equal(privateDecls, mlirPrivateVars, privateBlockArgs,
taskStructMgr.getLLVMPrivateVarGEPs())) {
+ // To be handled inside the task.
if (!privDecl.readsFromMold())
- // to be handled inside the task
continue;
assert(llvmPrivateVarAlloc &&
"reads from mold so shouldn't have been skipped");
@@ -1969,8 +1969,8 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
llvm::Expected<llvm::Value *> privateVarOrErr =
initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
blockArg, llvmPrivateVarAlloc, initBlock);
- if (auto err = privateVarOrErr.takeError())
- return handleError(std::move(err), *taskOp.getOperation());
+ if (!privateVarOrErr)
+ return handleError(privateVarOrErr, *taskOp.getOperation());
llvm::IRBuilderBase::InsertPointGuard guard(builder);
builder.SetInsertPoint(builder.GetInsertBlock()->getTerminator());
@@ -2034,8 +2034,8 @@ convertOmpTaskOp(omp::TaskOp taskOp, llvm::IRBuilderBase &builder,
llvm::Expected<llvm::Value *> privateVarOrError =
initPrivateVar(builder, moduleTranslation, privDecl, mlirPrivVar,
blockArg, llvmPrivateVar, privInitBlock);
- if (auto err = privateVarOrError.takeError())
- return err;
+ if (!privateVarOrError)
+ return privateVarOrError.takeError();
moduleTranslation.mapValue(blockArg, privateVarOrError.get());
llvmPrivateVars[i] = privateVarOrError.get();
}
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