[MLIR][OpenMP] Handle privatization for global values in MLIR->LLVM translation #104407
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@llvm/pr-subscribers-flang-openmp @llvm/pr-subscribers-mlir Author: Kareem Ergawy (ergawy) ChangesFix for #102939. The issues occurs because the CodeExtractor component only collect inputs This commit attempts to fix the issue by adding a flag to the Full diff: https://github.com/llvm/llvm-project/pull/104407.diff 6 Files Affected:
diff --git a/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90 b/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90
index 833976ff284a86..5f09371bbaba2e 100644
--- a/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90
+++ b/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90
@@ -57,6 +57,5 @@ end program compilation_to_obj
! LLVM: @[[GLOB_VAR:[^[:space:]]+]]t = internal global
! LLVM: define internal void @_QQmain..omp_par
-! LLVM: %[[LOCAL_VAR:.*]] = alloca { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] }, align 8
-! LLVM-NEXT: %[[GLOB_VAL:.*]] = load { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] }, ptr @[[GLOB_VAR]]t, align 8
-! LLVM-NEXT: store { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] } %[[GLOB_VAL]], ptr %[[LOCAL_VAR]], align 8
+! LLVM: %[[GLOB_VAL:.*]] = load { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] }, ptr @[[GLOB_VAR]]t, align 8
+! LLVM-NEXT: store { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] } %[[GLOB_VAL]], ptr %{{.*}}, align 8
diff --git a/llvm/include/llvm/Transforms/Utils/CodeExtractor.h b/llvm/include/llvm/Transforms/Utils/CodeExtractor.h
index 333ed6774d6c7e..9fd5f52d212519 100644
--- a/llvm/include/llvm/Transforms/Utils/CodeExtractor.h
+++ b/llvm/include/llvm/Transforms/Utils/CodeExtractor.h
@@ -198,7 +198,8 @@ class CodeExtractorAnalysisCache {
/// sets, before extraction occurs. These modifications won't have any
/// significant impact on the cost however.
void findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
- const ValueSet &Allocas) const;
+ const ValueSet &Allocas,
+ bool CollectGlobalInputs = false) const;
/// Check if life time marker nodes can be hoisted/sunk into the outline
/// region.
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
index 83fec194d73904..6df68d36e0c20a 100644
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -1542,7 +1542,9 @@ IRBuilder<>::InsertPoint OpenMPIRBuilder::createParallel(
BasicBlock *CommonExit = nullptr;
SetVector<Value *> Inputs, Outputs, SinkingCands, HoistingCands;
Extractor.findAllocas(CEAC, SinkingCands, HoistingCands, CommonExit);
- Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands);
+
+ Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands,
+ /*CollectGlobalInputs=*/true);
LLVM_DEBUG(dbgs() << "Before privatization: " << *OuterFn << "\n");
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index 94c7f161fc4c73..2c4a98134b91f8 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -644,14 +644,17 @@ bool CodeExtractor::isEligible() const {
}
void CodeExtractor::findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
- const ValueSet &SinkCands) const {
+ const ValueSet &SinkCands,
+ bool CollectGlobalInputs) const {
for (BasicBlock *BB : Blocks) {
// If a used value is defined outside the region, it's an input. If an
// instruction is used outside the region, it's an output.
for (Instruction &II : *BB) {
for (auto &OI : II.operands()) {
Value *V = OI;
- if (!SinkCands.count(V) && definedInCaller(Blocks, V))
+ if (!SinkCands.count(V) &&
+ (definedInCaller(Blocks, V) ||
+ (CollectGlobalInputs && llvm::isa<llvm::GlobalVariable>(V))))
Inputs.insert(V);
}
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 458d05d5059db7..75133ec82cc9f0 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1444,12 +1444,43 @@ convertOmpParallel(omp::ParallelOp opInst, llvm::IRBuilderBase &builder,
auto privateVars = opInst.getPrivateVars();
auto privateSyms = opInst.getPrivateSyms();
+ // Try to find a privatizer that corresponds to the LLVM value being
+ // prvatized.
for (auto [privVar, privatizerAttr] :
llvm::zip_equal(privateVars, *privateSyms)) {
// Find the MLIR private variable corresponding to the LLVM value
// being privatized.
llvm::Value *llvmPrivVar = moduleTranslation.lookupValue(privVar);
- if (llvmPrivVar != &vPtr)
+
+ // Check if the LLVM value being privatized matches the LLVM value
+ // mapped to privVar. In some cases, this is not trivial ...
+ auto isMatch = [](llvm::Value *vPtr, llvm::Value *llvmPrivVar) {
+ // If both values are trivially equal, we found a match.
+ if (llvmPrivVar == nullptr)
+ return false;
+
+ if (llvmPrivVar == vPtr)
+ return true;
+
+ auto *vPtrLoad = llvm::dyn_cast_if_present<llvm::LoadInst>(vPtr);
+
+ if (vPtrLoad == nullptr)
+ return false;
+
+ // Otherwise, we check if both vPtr and llvmPrivVar refer to the
+ // same memory (through a load/store pair).
+ for (auto &use : llvmPrivVar->uses()) {
+ auto *llvmPrivVarStore =
+ llvm::dyn_cast_if_present<llvm::StoreInst>(use.getUser());
+ if (llvmPrivVarStore && (vPtrLoad->getPointerOperand() ==
+ llvmPrivVarStore->getPointerOperand()))
+ return true;
+ }
+
+ return false;
+ };
+
+ if (!isMatch(&vPtr, llvmPrivVar))
continue;
SymbolRefAttr privSym = llvm::cast<SymbolRefAttr>(privatizerAttr);
diff --git a/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir b/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir
index 65ae98b2a74c6e..02ce6b5b19ceaf 100644
--- a/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir
@@ -114,3 +114,91 @@ omp.private {type = firstprivate} @multi_block.privatizer : !llvm.ptr alloc {
llvm.store %arg2, %arg3 : f32, !llvm.ptr
omp.yield(%arg3 : !llvm.ptr)
}
+
+// -----
+
+// Verifies fix for https://github.com/llvm/llvm-project/issues/102935.
+//
+// The issue happens since we previously failed to match MLIR values to their
+// corresponding LLVM values in some cases (e.g. char strings with non-const
+// length).
+llvm.func @non_const_len_char_test(%n: !llvm.ptr {fir.bindc_name = "n"}) {
+ %n_val = llvm.load %n : !llvm.ptr -> i64
+ %orig_alloc = llvm.alloca %n_val x i8 {bindc_name = "str"} : (i64) -> !llvm.ptr
+ %orig_val = llvm.mlir.undef : !llvm.struct<(ptr, i64)>
+ %orig_val_init = llvm.insertvalue %orig_alloc, %orig_val[0] : !llvm.struct<(ptr, i64)>
+ omp.parallel private(@non_const_len_char %orig_val_init -> %priv_arg : !llvm.struct<(ptr, i64)>) {
+ %dummy = llvm.extractvalue %priv_arg[0] : !llvm.struct<(ptr, i64)>
+ omp.terminator
+ }
+ llvm.return
+}
+
+omp.private {type = firstprivate} @non_const_len_char : !llvm.struct<(ptr, i64)> alloc {
+^bb0(%orig_val: !llvm.struct<(ptr, i64)>):
+ %str_len = llvm.extractvalue %orig_val[1] : !llvm.struct<(ptr, i64)>
+ %priv_alloc = llvm.alloca %str_len x i8 {bindc_name = "str", pinned} : (i64) -> !llvm.ptr
+ %priv_val = llvm.mlir.undef : !llvm.struct<(ptr, i64)>
+ %priv_val_init = llvm.insertvalue %priv_alloc, %priv_val[0] : !llvm.struct<(ptr, i64)>
+ omp.yield(%priv_val_init : !llvm.struct<(ptr, i64)>)
+} copy {
+^bb0(%orig_val: !llvm.struct<(ptr, i64)>, %priv_val: !llvm.struct<(ptr, i64)>):
+ llvm.call @foo() : () -> ()
+ omp.yield(%priv_val : !llvm.struct<(ptr, i64)>)
+}
+
+llvm.func @foo()
+
+// CHECK-LABEL: @non_const_len_char_test..omp_par({{.*}})
+// CHECK-NEXT: omp.par.entry:
+// Verify that we found the privatizer by checking that we properly inlined the
+// bodies of the alloc and copy regions.
+// CHECK: %[[STR_LEN:.*]] = extractvalue { ptr, i64 } %{{.*}}, 1
+// CHECK: %{{.*}} = alloca i8, i64 %[[STR_LEN]], align 1
+// CHECK: call void @foo()
+
+// -----
+
+// Verifies fix for https://github.com/llvm/llvm-project/issues/102939.
+//
+// The issues occurs because the CodeExtractor component only collect inputs
+// (to the parallel regions) that are defined in the same function in which the
+// parallel regions is present. Howerver, this is problematic because if we are
+// privatizing a global value (e.g. a `target` variable which is emitted as a
+// global), then we miss finding that input and we do not privatize the
+// variable.
+
+omp.private {type = firstprivate} @global_privatizer : !llvm.ptr alloc {
+^bb0(%arg0: !llvm.ptr):
+ %0 = llvm.mlir.constant(1 : i64) : i64
+ %1 = llvm.alloca %0 x f32 {bindc_name = "global", pinned} : (i64) -> !llvm.ptr
+ omp.yield(%1 : !llvm.ptr)
+} copy {
+^bb0(%arg0: !llvm.ptr, %arg1: !llvm.ptr):
+ %0 = llvm.load %arg0 : !llvm.ptr -> f32
+ llvm.store %0, %arg1 : f32, !llvm.ptr
+ omp.yield(%arg1 : !llvm.ptr)
+}
+
+llvm.func @global_accessor() {
+ %global_addr = llvm.mlir.addressof @global : !llvm.ptr
+ omp.parallel private(@global_privatizer %global_addr -> %arg0 : !llvm.ptr) {
+ %1 = llvm.mlir.constant(3.140000e+00 : f32) : f32
+ llvm.store %1, %arg0 : f32, !llvm.ptr
+ omp.terminator
+ }
+ llvm.return
+}
+
+llvm.mlir.global internal @global() {addr_space = 0 : i32} : f32 {
+ %0 = llvm.mlir.zero : f32
+ llvm.return %0 : f32
+}
+
+// CHECK-LABEL: @global_accessor..omp_par({{.*}})
+// CHECK-NEXT: omp.par.entry:
+// Verify that we found the privatizer by checking that we properly inlined the
+// bodies of the alloc and copy regions.
+// CHECK: %[[PRIV_ALLOC:.*]] = alloca float, i64 1, align 4
+// CHECK: %[[GLOB_VAL:.*]] = load float, ptr @global, align 4
+// CHECK: store float %[[GLOB_VAL]], ptr %[[PRIV_ALLOC]], align 4
|
|
@llvm/pr-subscribers-flang-fir-hlfir Author: Kareem Ergawy (ergawy) ChangesFix for #102939. The issues occurs because the CodeExtractor component only collect inputs This commit attempts to fix the issue by adding a flag to the Full diff: https://github.com/llvm/llvm-project/pull/104407.diff 6 Files Affected:
diff --git a/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90 b/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90
index 833976ff284a86..5f09371bbaba2e 100644
--- a/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90
+++ b/flang/test/Lower/OpenMP/delayed-privatization-allocatable-firstprivate.f90
@@ -57,6 +57,5 @@ end program compilation_to_obj
! LLVM: @[[GLOB_VAR:[^[:space:]]+]]t = internal global
! LLVM: define internal void @_QQmain..omp_par
-! LLVM: %[[LOCAL_VAR:.*]] = alloca { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] }, align 8
-! LLVM-NEXT: %[[GLOB_VAL:.*]] = load { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] }, ptr @[[GLOB_VAR]]t, align 8
-! LLVM-NEXT: store { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] } %[[GLOB_VAL]], ptr %[[LOCAL_VAR]], align 8
+! LLVM: %[[GLOB_VAL:.*]] = load { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] }, ptr @[[GLOB_VAR]]t, align 8
+! LLVM-NEXT: store { ptr, i64, i32, i8, i8, i8, i8, [1 x [3 x i64]] } %[[GLOB_VAL]], ptr %{{.*}}, align 8
diff --git a/llvm/include/llvm/Transforms/Utils/CodeExtractor.h b/llvm/include/llvm/Transforms/Utils/CodeExtractor.h
index 333ed6774d6c7e..9fd5f52d212519 100644
--- a/llvm/include/llvm/Transforms/Utils/CodeExtractor.h
+++ b/llvm/include/llvm/Transforms/Utils/CodeExtractor.h
@@ -198,7 +198,8 @@ class CodeExtractorAnalysisCache {
/// sets, before extraction occurs. These modifications won't have any
/// significant impact on the cost however.
void findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
- const ValueSet &Allocas) const;
+ const ValueSet &Allocas,
+ bool CollectGlobalInputs = false) const;
/// Check if life time marker nodes can be hoisted/sunk into the outline
/// region.
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
index 83fec194d73904..6df68d36e0c20a 100644
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -1542,7 +1542,9 @@ IRBuilder<>::InsertPoint OpenMPIRBuilder::createParallel(
BasicBlock *CommonExit = nullptr;
SetVector<Value *> Inputs, Outputs, SinkingCands, HoistingCands;
Extractor.findAllocas(CEAC, SinkingCands, HoistingCands, CommonExit);
- Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands);
+
+ Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands,
+ /*CollectGlobalInputs=*/true);
LLVM_DEBUG(dbgs() << "Before privatization: " << *OuterFn << "\n");
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index 94c7f161fc4c73..2c4a98134b91f8 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -644,14 +644,17 @@ bool CodeExtractor::isEligible() const {
}
void CodeExtractor::findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
- const ValueSet &SinkCands) const {
+ const ValueSet &SinkCands,
+ bool CollectGlobalInputs) const {
for (BasicBlock *BB : Blocks) {
// If a used value is defined outside the region, it's an input. If an
// instruction is used outside the region, it's an output.
for (Instruction &II : *BB) {
for (auto &OI : II.operands()) {
Value *V = OI;
- if (!SinkCands.count(V) && definedInCaller(Blocks, V))
+ if (!SinkCands.count(V) &&
+ (definedInCaller(Blocks, V) ||
+ (CollectGlobalInputs && llvm::isa<llvm::GlobalVariable>(V))))
Inputs.insert(V);
}
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 458d05d5059db7..75133ec82cc9f0 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -1444,12 +1444,43 @@ convertOmpParallel(omp::ParallelOp opInst, llvm::IRBuilderBase &builder,
auto privateVars = opInst.getPrivateVars();
auto privateSyms = opInst.getPrivateSyms();
+ // Try to find a privatizer that corresponds to the LLVM value being
+ // prvatized.
for (auto [privVar, privatizerAttr] :
llvm::zip_equal(privateVars, *privateSyms)) {
// Find the MLIR private variable corresponding to the LLVM value
// being privatized.
llvm::Value *llvmPrivVar = moduleTranslation.lookupValue(privVar);
- if (llvmPrivVar != &vPtr)
+
+ // Check if the LLVM value being privatized matches the LLVM value
+ // mapped to privVar. In some cases, this is not trivial ...
+ auto isMatch = [](llvm::Value *vPtr, llvm::Value *llvmPrivVar) {
+ // If both values are trivially equal, we found a match.
+ if (llvmPrivVar == nullptr)
+ return false;
+
+ if (llvmPrivVar == vPtr)
+ return true;
+
+ auto *vPtrLoad = llvm::dyn_cast_if_present<llvm::LoadInst>(vPtr);
+
+ if (vPtrLoad == nullptr)
+ return false;
+
+ // Otherwise, we check if both vPtr and llvmPrivVar refer to the
+ // same memory (through a load/store pair).
+ for (auto &use : llvmPrivVar->uses()) {
+ auto *llvmPrivVarStore =
+ llvm::dyn_cast_if_present<llvm::StoreInst>(use.getUser());
+ if (llvmPrivVarStore && (vPtrLoad->getPointerOperand() ==
+ llvmPrivVarStore->getPointerOperand()))
+ return true;
+ }
+
+ return false;
+ };
+
+ if (!isMatch(&vPtr, llvmPrivVar))
continue;
SymbolRefAttr privSym = llvm::cast<SymbolRefAttr>(privatizerAttr);
diff --git a/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir b/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir
index 65ae98b2a74c6e..02ce6b5b19ceaf 100644
--- a/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-firstprivate.mlir
@@ -114,3 +114,91 @@ omp.private {type = firstprivate} @multi_block.privatizer : !llvm.ptr alloc {
llvm.store %arg2, %arg3 : f32, !llvm.ptr
omp.yield(%arg3 : !llvm.ptr)
}
+
+// -----
+
+// Verifies fix for https://github.com/llvm/llvm-project/issues/102935.
+//
+// The issue happens since we previously failed to match MLIR values to their
+// corresponding LLVM values in some cases (e.g. char strings with non-const
+// length).
+llvm.func @non_const_len_char_test(%n: !llvm.ptr {fir.bindc_name = "n"}) {
+ %n_val = llvm.load %n : !llvm.ptr -> i64
+ %orig_alloc = llvm.alloca %n_val x i8 {bindc_name = "str"} : (i64) -> !llvm.ptr
+ %orig_val = llvm.mlir.undef : !llvm.struct<(ptr, i64)>
+ %orig_val_init = llvm.insertvalue %orig_alloc, %orig_val[0] : !llvm.struct<(ptr, i64)>
+ omp.parallel private(@non_const_len_char %orig_val_init -> %priv_arg : !llvm.struct<(ptr, i64)>) {
+ %dummy = llvm.extractvalue %priv_arg[0] : !llvm.struct<(ptr, i64)>
+ omp.terminator
+ }
+ llvm.return
+}
+
+omp.private {type = firstprivate} @non_const_len_char : !llvm.struct<(ptr, i64)> alloc {
+^bb0(%orig_val: !llvm.struct<(ptr, i64)>):
+ %str_len = llvm.extractvalue %orig_val[1] : !llvm.struct<(ptr, i64)>
+ %priv_alloc = llvm.alloca %str_len x i8 {bindc_name = "str", pinned} : (i64) -> !llvm.ptr
+ %priv_val = llvm.mlir.undef : !llvm.struct<(ptr, i64)>
+ %priv_val_init = llvm.insertvalue %priv_alloc, %priv_val[0] : !llvm.struct<(ptr, i64)>
+ omp.yield(%priv_val_init : !llvm.struct<(ptr, i64)>)
+} copy {
+^bb0(%orig_val: !llvm.struct<(ptr, i64)>, %priv_val: !llvm.struct<(ptr, i64)>):
+ llvm.call @foo() : () -> ()
+ omp.yield(%priv_val : !llvm.struct<(ptr, i64)>)
+}
+
+llvm.func @foo()
+
+// CHECK-LABEL: @non_const_len_char_test..omp_par({{.*}})
+// CHECK-NEXT: omp.par.entry:
+// Verify that we found the privatizer by checking that we properly inlined the
+// bodies of the alloc and copy regions.
+// CHECK: %[[STR_LEN:.*]] = extractvalue { ptr, i64 } %{{.*}}, 1
+// CHECK: %{{.*}} = alloca i8, i64 %[[STR_LEN]], align 1
+// CHECK: call void @foo()
+
+// -----
+
+// Verifies fix for https://github.com/llvm/llvm-project/issues/102939.
+//
+// The issues occurs because the CodeExtractor component only collect inputs
+// (to the parallel regions) that are defined in the same function in which the
+// parallel regions is present. Howerver, this is problematic because if we are
+// privatizing a global value (e.g. a `target` variable which is emitted as a
+// global), then we miss finding that input and we do not privatize the
+// variable.
+
+omp.private {type = firstprivate} @global_privatizer : !llvm.ptr alloc {
+^bb0(%arg0: !llvm.ptr):
+ %0 = llvm.mlir.constant(1 : i64) : i64
+ %1 = llvm.alloca %0 x f32 {bindc_name = "global", pinned} : (i64) -> !llvm.ptr
+ omp.yield(%1 : !llvm.ptr)
+} copy {
+^bb0(%arg0: !llvm.ptr, %arg1: !llvm.ptr):
+ %0 = llvm.load %arg0 : !llvm.ptr -> f32
+ llvm.store %0, %arg1 : f32, !llvm.ptr
+ omp.yield(%arg1 : !llvm.ptr)
+}
+
+llvm.func @global_accessor() {
+ %global_addr = llvm.mlir.addressof @global : !llvm.ptr
+ omp.parallel private(@global_privatizer %global_addr -> %arg0 : !llvm.ptr) {
+ %1 = llvm.mlir.constant(3.140000e+00 : f32) : f32
+ llvm.store %1, %arg0 : f32, !llvm.ptr
+ omp.terminator
+ }
+ llvm.return
+}
+
+llvm.mlir.global internal @global() {addr_space = 0 : i32} : f32 {
+ %0 = llvm.mlir.zero : f32
+ llvm.return %0 : f32
+}
+
+// CHECK-LABEL: @global_accessor..omp_par({{.*}})
+// CHECK-NEXT: omp.par.entry:
+// Verify that we found the privatizer by checking that we properly inlined the
+// bodies of the alloc and copy regions.
+// CHECK: %[[PRIV_ALLOC:.*]] = alloca float, i64 1, align 4
+// CHECK: %[[GLOB_VAL:.*]] = load float, ptr @global, align 4
+// CHECK: store float %[[GLOB_VAL]], ptr %[[PRIV_ALLOC]], align 4
|
ergawy
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ergawy
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|
|
||
| Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands, | ||
| /*CollectGlobalInputs=*/true); | ||
|
|
||
| Inputs.remove_if([&](Value *I) { | ||
| if (auto *GV = dyn_cast_if_present<GlobalVariable>(I)) | ||
| return GV->getValueType() == OpenMPIRBuilder::Ident; | ||
|
|
||
| return false; | ||
| }); |
There was a problem hiding this comment.
Tbh, I do not know if this is cleanest or best approach to solve this issue. To get a better understanding of the problem, please take a look at the new test added in openmp-firstprivate.mlir below as well as the 2 linked issues: #102939 and #102949.
Let me know if you disagree with the solution and/or have a better suggestion.
ergawy
requested review from
tblah,
kiranchandramohan,
jdoerfert and
bhandarkar-pranav
| Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands, | ||
| /*CollectGlobalInputs=*/true); | ||
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| Inputs.remove_if([&](Value *I) { |
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Would it not be better to NOT add the global value in the first place, if it's an OpenMPIRBuilder::Ident? You already do isa in the code below, so doing a GV = dyn_cast_if_present instead and follow that with a getValueType != OpenMPIRBuilder::Ident?
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The problem with that is:
OpenMPIRBuilder::Identare created and maintained by the functions of theOpenMPIRBuilder. So I think it would be preferable to keep the knowledge of these structs within the builder.- The
CodeExtractoris not OpenMP-related and I think it would better not to leak any non-related OpenMP-details to it.
Of course it is better not to add something and then remove it. But I think it logically isolates things better this way.
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@Leporacanthicus is it fine with you merging this PR? Let me know if you do not agree with my reply above.
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…ranslation Fix for llvm#102939. The issues occurs because the CodeExtractor component only collect inputs (to the parallel regions) that are defined in the same function in which the parallel regions is present. Howerver, this is problematic because if we are privatizing a global value (e.g. a `target` variable which is emitted as a global), then we miss finding that input and we do not privatize the variable. This commit attempts to fix the issue by adding a flag to the CodeExtractor so that we can collect global inputs.
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/179/builds/4972 Here is the relevant piece of the build log for the reference |
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…ranslation (llvm#104407) Potential fix for llvm#102939 and llvm#102949. The issues occurs because the CodeExtractor component only collect inputs (to the parallel regions) that are defined in the same function in which the parallel regions is present. Howerver, this is problematic because if we are privatizing a global value (e.g. a `target` variable which is emitted as a global), then we miss finding that input and we do not privatize the variable. This commit attempts to fix the issue by adding a flag to the CodeExtractor so that we can collect global inputs.
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…ranslation (llvm#104407) Potential fix for llvm#102939 and llvm#102949. The issues occurs because the CodeExtractor component only collect inputs (to the parallel regions) that are defined in the same function in which the parallel regions is present. Howerver, this is problematic because if we are privatizing a global value (e.g. a `target` variable which is emitted as a global), then we miss finding that input and we do not privatize the variable. This commit attempts to fix the issue by adding a flag to the CodeExtractor so that we can collect global inputs.
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Potential fix for #102939 and #102949.
The issues occurs because the CodeExtractor component only collect inputs (to the parallel regions) that are defined in the same function in which the parallel regions is present. Howerver, this is problematic because if we are privatizing a global value (e.g. a
targetvariable which is emitted as a global), then we miss finding that input and we do not privatize the variable.This commit attempts to fix the issue by adding a flag to the CodeExtractor so that we can collect global inputs.