[flang-commits] [flang] [flang][openacc] Do not loose attributes on folding (PR #80516)

[via flang-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-openacc

Author: Valentin Clement (バレンタイン クレメン) (clementval)

<details>
<summary>Changes</summary>

hlfir.declare introduce some boxes that can be later optimized away. The OpenACC lowering is currently setting some attributes on FIR operations to track declare variables. When the boxes are optimized away these attributes are lost. This patch propagate OpenACC attributes from box_addr op to the defining op of the folding result. 

---
Full diff: https://github.com/llvm/llvm-project/pull/80516.diff


2 Files Affected:

- (modified) flang/lib/Optimizer/Dialect/FIROps.cpp (+16-1) 
- (added) flang/test/Fir/OpenACC/propagate-attr-folding.fir (+39) 


``````````diff
diff --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
index f826f2566b897..96a676149203d 100644
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -20,6 +20,7 @@
 #include "flang/Optimizer/Support/Utils.h"
 #include "mlir/Dialect/CommonFolders.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/Dialect/OpenACC/OpenACC.h"
 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"
 #include "mlir/IR/Attributes.h"
 #include "mlir/IR/BuiltinAttributes.h"
@@ -36,6 +37,18 @@ namespace {
 #include "flang/Optimizer/Dialect/CanonicalizationPatterns.inc"
 } // namespace
 
+static void propagateAttributes(mlir::Operation *fromOp,
+                                mlir::Operation *toOp) {
+  if (!fromOp || !toOp)
+    return;
+
+  for (mlir::NamedAttribute attr : fromOp->getAttrs()) {
+    if (attr.getName().str().rfind(
+            mlir::acc::OpenACCDialect::getDialectNamespace(), 0) == 0)
+      toOp->setAttr(attr.getName().str(), attr.getValue());
+  }
+}
+
 /// Return true if a sequence type is of some incomplete size or a record type
 /// is malformed or contains an incomplete sequence type. An incomplete sequence
 /// type is one with more unknown extents in the type than have been provided
@@ -626,8 +639,10 @@ mlir::OpFoldResult fir::BoxAddrOp::fold(FoldAdaptor adaptor) {
   if (auto *v = getVal().getDefiningOp()) {
     if (auto box = mlir::dyn_cast<fir::EmboxOp>(v)) {
       // Fold only if not sliced
-      if (!box.getSlice() && box.getMemref().getType() == getType())
+      if (!box.getSlice() && box.getMemref().getType() == getType()) {
+        propagateAttributes(getOperation(), box.getMemref().getDefiningOp());
         return box.getMemref();
+      }
     }
     if (auto box = mlir::dyn_cast<fir::EmboxCharOp>(v))
       if (box.getMemref().getType() == getType())
diff --git a/flang/test/Fir/OpenACC/propagate-attr-folding.fir b/flang/test/Fir/OpenACC/propagate-attr-folding.fir
new file mode 100644
index 0000000000000..f84269f5fef26
--- /dev/null
+++ b/flang/test/Fir/OpenACC/propagate-attr-folding.fir
@@ -0,0 +1,39 @@
+// RUN: fir-opt %s --opt-bufferization | FileCheck %s 
+
+// Check that OpenACC attributes are propagated to the defining operations when
+// fir.box_addr is folded in bufferization optimization.
+
+func.func @_QPsub1(%arg0: !fir.ref<!fir.array<?x?xf32>> {fir.bindc_name = "a"}, %arg1: !fir.ref<i32> {fir.bindc_name = "n1"}, %arg2: !fir.ref<i32> {fir.bindc_name = "n2"}) {
+  %c1 = arith.constant 1 : index
+  %c0 = arith.constant 0 : index
+  %0 = fir.declare %arg1 {uniq_name = "_QFsub1En1"} : (!fir.ref<i32>) -> !fir.ref<i32>
+  %1 = fir.declare %arg2 {uniq_name = "_QFsub1En2"} : (!fir.ref<i32>) -> !fir.ref<i32>
+  %2 = fir.load %0 : !fir.ref<i32>
+  %3 = fir.convert %2 : (i32) -> index
+  %4 = arith.cmpi sgt, %3, %c0 : index
+  %5 = arith.select %4, %3, %c0 : index
+  %6 = fir.load %1 : !fir.ref<i32>
+  %7 = fir.convert %6 : (i32) -> index
+  %8 = arith.cmpi sgt, %7, %c0 : index
+  %9 = arith.select %8, %7, %c0 : index
+  %10 = fir.shape %5, %9 : (index, index) -> !fir.shape<2>
+  %11 = fir.declare %arg0(%10) {acc.declare = #acc.declare<dataClause =  acc_present>, uniq_name = "_QFsub1Ea"} : (!fir.ref<!fir.array<?x?xf32>>, !fir.shape<2>) -> !fir.ref<!fir.array<?x?xf32>>
+  %12 = fir.embox %11(%10) : (!fir.ref<!fir.array<?x?xf32>>, !fir.shape<2>) -> !fir.box<!fir.array<?x?xf32>>
+  %13:3 = fir.box_dims %12, %c0 : (!fir.box<!fir.array<?x?xf32>>, index) -> (index, index, index)
+  %14 = arith.subi %13#1, %c1 : index
+  %15 = acc.bounds lowerbound(%c0 : index) upperbound(%14 : index) extent(%13#1 : index) stride(%13#2 : index) startIdx(%c1 : index) {strideInBytes = true}
+  %16 = arith.muli %13#2, %13#1 : index
+  %17:3 = fir.box_dims %12, %c1 : (!fir.box<!fir.array<?x?xf32>>, index) -> (index, index, index)
+  %18 = arith.subi %17#1, %c1 : index
+  %19 = acc.bounds lowerbound(%c0 : index) upperbound(%18 : index) extent(%17#1 : index) stride(%16 : index) startIdx(%c1 : index) {strideInBytes = true}
+  %20 = acc.present varPtr(%11 : !fir.ref<!fir.array<?x?xf32>>) bounds(%15, %19) -> !fir.ref<!fir.array<?x?xf32>> {name = "a"}
+  %21 = acc.declare_enter dataOperands(%20 : !fir.ref<!fir.array<?x?xf32>>)
+  acc.declare_exit token(%21)
+  return
+}
+
+// CHECK-LABEL: func.func @_QPsub1(
+// CHECK-SAME: %[[ARG0:.*]]: !fir.ref<!fir.array<?x?xf32>> {fir.bindc_name = "a"}
+// CHECK: %[[DECL:.*]] = fir.declare %[[ARG0]](%{{.*}}) {acc.declare = #acc.declare<dataClause =  acc_present>, uniq_name = "_QFsub1Ea"} : (!fir.ref<!fir.array<?x?xf32>>, !fir.shape<2>) -> !fir.ref<!fir.array<?x?xf32>>
+// CHECK: %[[PRES:.*]] = acc.present varPtr(%[[DECL]] : !fir.ref<!fir.array<?x?xf32>>) bounds(%{{.*}}, %{{.*}}) -> !fir.ref<!fir.array<?x?xf32>> {name = "a"}
+// CHECK: %{{.*}} = acc.declare_enter dataOperands(%[[PRES]] : !fir.ref<!fir.array<?x?xf32>>)

``````````

</details>


https://github.com/llvm/llvm-project/pull/80516