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[flang] Support fir.pack_array in FIR alias analysis. (#131946)

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`fir.pack_array` is just a pass-through op for the process
of finding the source in FIR alias analysis (as defined in #127147).
This commit is contained in:
Slava Zakharin
2025-04-21 08:59:41 -07:00
committed by GitHub
parent 93b74f7178
commit 86a03367bf
2 changed files with 51 additions and 0 deletions
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8
flang/lib/Optimizer/Analysis/AliasAnalysis.cpp
View File

@@ -542,6 +542,14 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v,
v = op->getOperand(0); v = op->getOperand(0);
defOp = v.getDefiningOp(); defOp = v.getDefiningOp();
}) })
.Case<fir::PackArrayOp>([&](auto op) {
// The packed array is not distinguishable from the original
// array, so skip PackArrayOp and track further through
// the array operand.
v = op.getArray();
defOp = v.getDefiningOp();
approximateSource = true;
})
.Case<fir::BoxAddrOp>([&](auto op) { .Case<fir::BoxAddrOp>([&](auto op) {
v = op->getOperand(0); v = op->getOperand(0);
defOp = v.getDefiningOp(); defOp = v.getDefiningOp();

43
flang/test/Analysis/AliasAnalysis/alias-analysis-pack-array.fir Normal file
View File

@@ -0,0 +1,43 @@
// Test alias analysis queries for dummy arguments wired
// through fir.pack_array.
// fir.pack_array is a pass-through operation for FIR alias analysis.
// RUN: fir-opt %s --test-fir-alias-analysis -split-input-file --mlir-disable-threading 2>&1 | FileCheck %s
// The two pointers referencing two different maybe repacked
// versions of the original dummy arguments do not alias:
// CHECK-DAG: test1_y_repack(1)#0 <-> test1_x_repack(1)#0: NoAlias
// CHECK-DAG: test1_x_orig(1)#0 <-> test1_y_orig(1)#0: NoAlias
// Repacked dummy does not alias with another original dummy:
// CHECK-DAG: test1_y_repack(1)#0 <-> test1_x_orig(1)#0: NoAlias
// CHECK-DAG: test1_x_repack(1)#0 <-> test1_y_orig(1)#0: NoAlias
// Repacked dummy may alias with its original:
// CHECK-DAG: test1_x_repack(1)#0 <-> test1_x_orig(1)#0: MayAlias
// CHECK-DAG: test1_y_repack(1)#0 <-> test1_y_orig(1)#0: MayAlias
// Ideally, these should report MustAlias, but MayAlias
// may work as well:
// CHECK-DAG: test1_y_repack(1)#0 <-> test1_y_repack2(1)#0: MayAlias
// CHECK-DAG: test1_x_repack(1)#0 <-> test1_x_repack2(1)#0: MayAlias
func.func @_QFtest1(%arg0: !fir.box<!fir.array<?xf32>> {fir.bindc_name = "x"}, %arg1: !fir.box<!fir.array<?xf32>> {fir.bindc_name = "y"}) {
%c1 = arith.constant 1 : index
%0 = fir.dummy_scope : !fir.dscope
%1 = fir.pack_array %arg0 heap whole : (!fir.box<!fir.array<?xf32>>) -> !fir.box<!fir.array<?xf32>>
%2:2 = hlfir.declare %1 dummy_scope %0 {uniq_name = "_QFtest1Ex"} : (!fir.box<!fir.array<?xf32>>, !fir.dscope) -> (!fir.box<!fir.array<?xf32>>, !fir.box<!fir.array<?xf32>>)
%3 = fir.pack_array %arg1 heap whole : (!fir.box<!fir.array<?xf32>>) -> !fir.box<!fir.array<?xf32>>
%4:2 = hlfir.declare %3 dummy_scope %0 {uniq_name = "_QFtest1Ey"} : (!fir.box<!fir.array<?xf32>>, !fir.dscope) -> (!fir.box<!fir.array<?xf32>>, !fir.box<!fir.array<?xf32>>)
%5 = fir.box_addr %4#0 {test.ptr = "test1_y_repack(1)"} : (!fir.box<!fir.array<?xf32>>) -> !fir.ref<f32>
%52 = fir.box_addr %4#0 {test.ptr = "test1_y_repack2(1)"} : (!fir.box<!fir.array<?xf32>>) -> !fir.ref<f32>
%6 = fir.load %5 : !fir.ref<f32>
%7 = fir.box_addr %2#0 {test.ptr = "test1_x_repack(1)"} : (!fir.box<!fir.array<?xf32>>) -> !fir.ref<f32>
%72 = fir.box_addr %2#0 {test.ptr = "test1_x_repack2(1)"} : (!fir.box<!fir.array<?xf32>>) -> !fir.ref<f32>
hlfir.assign %6 to %7 : f32, !fir.ref<f32>
fir.unpack_array %3 to %arg1 heap : !fir.box<!fir.array<?xf32>>
fir.unpack_array %1 to %arg0 heap : !fir.box<!fir.array<?xf32>>
%8 = fir.box_addr %arg0 {test.ptr = "test1_x_orig(1)"} : (!fir.box<!fir.array<?xf32>>) -> !fir.ref<f32>
%9 = fir.box_addr %arg1 {test.ptr = "test1_y_orig(1)"} : (!fir.box<!fir.array<?xf32>>) -> !fir.ref<f32>
return
}