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[flang][OpenMP] Add alias analysis for omp private #113566

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Merged
DominikAdamski merged 5 commits into from
Nov 5, 2024
Merged

[flang][OpenMP] Add alias analysis for omp private #113566

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8a6bcdc
[flang][OpenMP] Add alias analysis for omp private
DominikAdamski Oct 21, 2024
362cf24
refactor
DominikAdamski Oct 25, 2024
14808d9
Extend alias analysis for other OpenMP operations
DominikAdamski Oct 25, 2024
a027f1d
applied remarks
DominikAdamski Oct 28, 2024
a0f2424
Merge branch 'main' into aa_omp_private
DominikAdamski Nov 5, 2024
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75 changes: 61 additions & 14 deletions flang/lib/Optimizer/Analysis/AliasAnalysis.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -372,6 +372,17 @@ getAttrsFromVariable(fir::FortranVariableOpInterface var) {
return attrs;
}

static std::optional<omp::BlockArgOpenMPOpInterface>
getOpenMPBlockArgInterface(Operation *op) {
std::optional<omp::BlockArgOpenMPOpInterface> blockArgOpenMPOpInterface;
if (!op)
return blockArgOpenMPOpInterface;
if (llvm::isa<omp::TargetOp>(op) || llvm::isa<omp::ParallelOp>(op)) {
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@tblah tblah Oct 24, 2024

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Why not return the block args interface for other operation types (where the dyn_cast succeeds)?

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@DominikAdamski DominikAdamski Oct 25, 2024

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Fixed.

blockArgOpenMPOpInterface = dyn_cast<omp::BlockArgOpenMPOpInterface>(op);
}
return blockArgOpenMPOpInterface;
}

AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v,
bool getInstantiationPoint) {
auto *defOp = v.getDefiningOp();
Expand Down Expand Up @@ -470,20 +481,56 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v,
breakFromLoop = true;
})
.Case<hlfir::DeclareOp, fir::DeclareOp>([&](auto op) {
// If declare operation is inside omp target region,
// continue alias analysis outside the target region
if (auto targetOp =
llvm::dyn_cast<omp::TargetOp>(op->getParentOp())) {
auto argIface = cast<omp::BlockArgOpenMPOpInterface>(*targetOp);
for (auto [opArg, blockArg] : llvm::zip_equal(
targetOp.getMapVars(), argIface.getMapBlockArgs())) {
if (blockArg == op.getMemref()) {
omp::MapInfoOp mapInfo =
llvm::cast<omp::MapInfoOp>(opArg.getDefiningOp());
v = mapInfo.getVarPtr();
defOp = v.getDefiningOp();
return;
}
auto argIface = getOpenMPBlockArgInterface(op->getParentOp());
if (argIface) {
Value ompValArg;
llvm::TypeSwitch<Operation *>(op->getParentOp())
.template Case<omp::TargetOp>([&](auto targetOp) {
// If declare operation is inside omp target region,
// continue alias analysis outside the target region
for (auto [opArg, blockArg] :
llvm::zip_equal(targetOp.getMapVars(),
(*argIface).getMapBlockArgs())) {
if (blockArg == op.getMemref()) {
omp::MapInfoOp mapInfo =
llvm::cast<omp::MapInfoOp>(opArg.getDefiningOp());
ompValArg = mapInfo.getVarPtr();
break;
}
}
})
.template Case<omp::ParallelOp>([&](auto parallelOp) {
// TODO private clause can be part of multiple
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@tblah tblah Oct 24, 2024

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I imagine it should be possible to write this generically to work on any operation with an OpenMPBlockArgInterface. If the operation does not yet support delayed privatisation the private syms should be empty.

Reductions also work in the same way as delayed privatization (but don't feel that has to be done in this PR).

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@DominikAdamski DominikAdamski Oct 25, 2024

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Fixed -> extended support for alias analysis for private clause for different operations even if Flang does not fully support private clause for all of these operations.

// OpenMP directives( target, simd, etc.)
// We should extend alias analysis when Flang
// will handle private clause for different than parallel
// directives.
if (!parallelOp.getPrivateSyms().has_value())
return;
for (auto [opSym, blockArg] :
llvm::zip_equal(*parallelOp.getPrivateSyms(),
(*argIface).getPrivateBlockArgs())) {
if (blockArg == op.getMemref()) {
omp::PrivateClauseOp privateOp =
SymbolTable::lookupNearestSymbolFrom<
omp::PrivateClauseOp>(parallelOp,
cast<SymbolRefAttr>(opSym));
privateOp.walk([&](omp::YieldOp yieldOp) {
llvm::TypeSwitch<Operation *>(
yieldOp.getResults()[0].getDefiningOp())
.template Case<fir::DeclareOp, hlfir::DeclareOp>(
[&](auto declOp) {
ompValArg = declOp.getMemref();
});
});
return;
}
}
});
if (ompValArg) {
v = ompValArg;
defOp = ompValArg.getDefiningOp();
return;
}
}
auto varIf = llvm::cast<fir::FortranVariableOpInterface>(defOp);
Expand Down
121 changes: 121 additions & 0 deletions flang/test/Analysis/AliasAnalysis/alias-analysis-omp-teams-distribute-private.mlir
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Original file line number Diff line number Diff line change
@@ -0,0 +1,121 @@
// Use --mlir-disable-threading so that the AA queries are serialized
// as well as its diagnostic output.
// RUN: fir-opt %s -pass-pipeline='builtin.module(func.func(test-fir-alias-analysis))' -split-input-file --mlir-disable-threading 2>&1 | FileCheck %s

// Fortran code:
//
// program main
// integer :: arrayA(10,10)
// integer :: tmp(2)
// integer :: i,j
// !$omp teams distribute parallel do private(tmp)
// do j = 1, 10
// do i = 1,10
// tmp = [i,j]
// arrayA = tmp(1)
// end do
// end do
// end program main

// CHECK-LABEL: Testing : "_QQmain"
// CHECK-DAG: tmp_private_array#0 <-> unnamed_array#0: NoAlias
// CHECK-DAG: tmp_private_array#1 <-> unnamed_array#0: NoAlias
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@jeanPerier jeanPerier Oct 25, 2024

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Can you add a positive case? I understand NoAlias is what matter from an optimization point of view, but MayAlias is the most important to prove from a correctness point of view, so I think it is always good to add both negative and positive test cases here.

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@DominikAdamski DominikAdamski Nov 5, 2024

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Done


omp.private {type = private} @_QFEi_private_ref_i32 : !fir.ref<i32> alloc {
^bb0(%arg0: !fir.ref<i32>):
%0 = fir.alloca i32 {bindc_name = "i", pinned, uniq_name = "_QFEi"}
%1:2 = hlfir.declare %0 {uniq_name = "_QFEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
omp.yield(%1#0 : !fir.ref<i32>)
}
omp.private {type = private} @_QFEj_private_ref_i32 : !fir.ref<i32> alloc {
^bb0(%arg0: !fir.ref<i32>):
%0 = fir.alloca i32 {bindc_name = "j", pinned, uniq_name = "_QFEj"}
%1:2 = hlfir.declare %0 {uniq_name = "_QFEj"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
omp.yield(%1#0 : !fir.ref<i32>)
}
omp.private {type = private} @_QFEtmp_private_ref_2xi32 : !fir.ref<!fir.array<2xi32>> alloc {
^bb0(%arg0: !fir.ref<!fir.array<2xi32>>):
%c2 = arith.constant 2 : index
%0 = fir.alloca !fir.array<2xi32> {bindc_name = "tmp", pinned, uniq_name = "_QFEtmp"}
%1 = fir.shape %c2 : (index) -> !fir.shape<1>
%2:2 = hlfir.declare %0(%1) {uniq_name = "_QFEtmp"} : (!fir.ref<!fir.array<2xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<2xi32>>, !fir.ref<!fir.array<2xi32>>)
omp.yield(%2#0 : !fir.ref<!fir.array<2xi32>>)
}
func.func @_QQmain() attributes {fir.bindc_name = "main"} {
%0 = fir.address_of(@_QFEarraya) : !fir.ref<!fir.array<10x10xi32>>
%c10 = arith.constant 10 : index
%c10_0 = arith.constant 10 : index
%1 = fir.shape %c10, %c10_0 : (index, index) -> !fir.shape<2>
%2:2 = hlfir.declare %0(%1) {uniq_name = "_QFEarraya"} : (!fir.ref<!fir.array<10x10xi32>>, !fir.shape<2>) -> (!fir.ref<!fir.array<10x10xi32>>, !fir.ref<!fir.array<10x10xi32>>)
%3 = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFEi"}
%4:2 = hlfir.declare %3 {uniq_name = "_QFEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
%5 = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFEj"}
%6:2 = hlfir.declare %5 {uniq_name = "_QFEj"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
%c2 = arith.constant 2 : index
%7 = fir.alloca !fir.array<2xi32> {bindc_name = "tmp", uniq_name = "_QFEtmp"}
%8 = fir.shape %c2 : (index) -> !fir.shape<1>
%9:2 = hlfir.declare %7(%8) {uniq_name = "_QFEtmp"} : (!fir.ref<!fir.array<2xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<2xi32>>, !fir.ref<!fir.array<2xi32>>)
omp.teams {
omp.parallel private(@_QFEtmp_private_ref_2xi32 %9#0 -> %arg0, @_QFEj_private_ref_i32 %6#0 -> %arg1, @_QFEi_private_ref_i32 %4#0 -> %arg2 : !fir.ref<!fir.array<2xi32>>, !fir.ref<i32>, !fir.ref<i32>) {
%c2_1 = arith.constant 2 : index
%10 = fir.shape %c2_1 : (index) -> !fir.shape<1>
%11:2 = hlfir.declare %arg0(%10) {uniq_name = "_QFEtmp", test.ptr = "tmp_private_array"} : (!fir.ref<!fir.array<2xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<2xi32>>, !fir.ref<!fir.array<2xi32>>)
%12:2 = hlfir.declare %arg1 {uniq_name = "_QFEj"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
%13:2 = hlfir.declare %arg2 {uniq_name = "_QFEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
%c1_i32 = arith.constant 1 : i32
%c10_i32 = arith.constant 10 : i32
%c1_i32_2 = arith.constant 1 : i32
omp.distribute {
omp.wsloop {
omp.loop_nest (%arg3) : i32 = (%c1_i32) to (%c10_i32) inclusive step (%c1_i32_2) {
fir.store %arg3 to %12#1 : !fir.ref<i32>
%c1_i32_3 = arith.constant 1 : i32
%14 = fir.convert %c1_i32_3 : (i32) -> index
%c10_i32_4 = arith.constant 10 : i32
%15 = fir.convert %c10_i32_4 : (i32) -> index
%c1 = arith.constant 1 : index
%16 = fir.convert %14 : (index) -> i32
%17:2 = fir.do_loop %arg4 = %14 to %15 step %c1 iter_args(%arg5 = %16) -> (index, i32) {
fir.store %arg5 to %13#1 : !fir.ref<i32>
%c2_5 = arith.constant 2 : index
%c1_6 = arith.constant 1 : index
%c1_7 = arith.constant 1 : index
%18 = fir.allocmem !fir.array<2xi32> {bindc_name = ".tmp.arrayctor", uniq_name = ""}
%19 = fir.shape %c2_5 : (index) -> !fir.shape<1>
%20:2 = hlfir.declare %18(%19) {uniq_name = ".tmp.arrayctor"} : (!fir.heap<!fir.array<2xi32>>, !fir.shape<1>) -> (!fir.heap<!fir.array<2xi32>>, !fir.heap<!fir.array<2xi32>>)
%21 = fir.load %13#0 : !fir.ref<i32>
%22 = arith.addi %c1_6, %c1_7 : index
%23 = hlfir.designate %20#0 (%c1_6) : (!fir.heap<!fir.array<2xi32>>, index) -> !fir.ref<i32>
hlfir.assign %21 to %23 : i32, !fir.ref<i32>
%24 = fir.load %12#0 : !fir.ref<i32>
%25 = hlfir.designate %20#0 (%22) : (!fir.heap<!fir.array<2xi32>>, index) -> !fir.ref<i32>
hlfir.assign %24 to %25 : i32, !fir.ref<i32>
%true = arith.constant true
%26 = hlfir.as_expr %20#0 move %true {test.ptr = "unnamed_array"} : (!fir.heap<!fir.array<2xi32>>, i1) -> !hlfir.expr<2xi32>
hlfir.assign %26 to %11#0 : !hlfir.expr<2xi32>, !fir.ref<!fir.array<2xi32>>
hlfir.destroy %26 : !hlfir.expr<2xi32>
%c1_8 = arith.constant 1 : index
%27 = hlfir.designate %11#0 (%c1_8) : (!fir.ref<!fir.array<2xi32>>, index) -> !fir.ref<i32>
%28 = fir.load %27 : !fir.ref<i32>
hlfir.assign %28 to %2#0 : i32, !fir.ref<!fir.array<10x10xi32>>
%29 = arith.addi %arg4, %c1 : index
%30 = fir.convert %c1 : (index) -> i32
%31 = fir.load %13#1 : !fir.ref<i32>
%32 = arith.addi %31, %30 : i32
fir.result %29, %32 : index, i32
}
fir.store %17#1 to %13#1 : !fir.ref<i32>
omp.yield
}
} {omp.composite}
} {omp.composite}
omp.terminator
} {omp.composite}
omp.terminator
}
return
}
fir.global internal @_QFEarraya : !fir.array<10x10xi32> {
%0 = fir.zero_bits !fir.array<10x10xi32>
fir.has_value %0 : !fir.array<10x10xi32>
}
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