[flang][acc] Fix mappableTy.generateAccBounds to correctly handle dynamic-sized arrays (#155666)

We currently see the misuse of the `upperbound` operand for the
`acc::DataBoundsOp` generation in `generateSeqTyAccBounds`. This PR
keeps setting `lowerbound` to zero for all cases and adjusts
`upperbound` to be `extent - 1`.

Author: khaki3

flang/lib/Optimizer/OpenACC/Support/FIROpenACCTypeInterfaces.cpp

@@ -271,8 +271,6 @@ generateSeqTyAccBounds(fir::SequenceType seqType, mlir::Value var,
             mlir::Value extent = val;
             mlir::Value upperbound =
                 mlir::arith::SubIOp::create(builder, loc, extent, one);
-            upperbound = mlir::arith::AddIOp::create(builder, loc, lowerbound,
-                                                     upperbound);
             mlir::Value stride = one;
             if (strideIncludeLowerExtent) {
               stride = cummulativeExtent;

flang/test/Fir/OpenACC/openacc-mappable.fir

@@ -62,17 +62,26 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<f16 = dense<16> : vector<2xi64>,
   // CHECK: Visiting: %{{.*}} = acc.copyin varPtr(%{{.*}} : !fir.ref<!fir.array<?xf32>>) -> !fir.ref<!fir.array<?xf32>> {name = "arr1", structured = false}
   // CHECK: Pointer-like and Mappable: !fir.ref<!fir.array<?xf32>>
   // CHECK: Type category: array
-  // CHECK: Bound[0]: %{{.*}} = acc.bounds lowerbound(%c0{{.*}} : index) upperbound(%{{.*}} : index) extent(%{{.*}} : index) stride(%c1{{.*}} : index) startIdx(%c1{{.*}} : index)
+  // CHECK: Shape: %{{.*}} = fir.shape %[[EXTENT1:.*]] : (index) -> !fir.shape<1>
+  // CHECK: Bound[0]: %{{.*}} = acc.bounds lowerbound(%[[LB1:.*]] : index) upperbound(%[[UB1:.*]] : index) extent(%{{.*}} : index) stride(%c1{{.*}} : index) startIdx(%c1{{.*}} : index)
+  // CHECK: Lower bound: %[[LB1]] = arith.constant 0 : index
+  // CHECK: Upper bound: %[[UB1]] = arith.subi %[[EXTENT1]], %c1{{.*}} : index
 
   // CHECK: Visiting: %{{.*}} = acc.copyin varPtr(%{{.*}} : !fir.ref<!fir.array<?xf32>>) -> !fir.ref<!fir.array<?xf32>> {name = "arr2", structured = false}
   // CHECK: Pointer-like and Mappable: !fir.ref<!fir.array<?xf32>>
   // CHECK: Type category: array
-  // CHECK: Bound[0]: %{{.*}} = acc.bounds lowerbound(%c0{{.*}} : index) upperbound(%{{.*}} : index) extent(%{{.*}} : index) stride(%c1{{.*}} : index) startIdx(%c2{{.*}} : index)
+  // CHECK: Shape: %{{.*}} = fir.shape_shift %c2{{.*}}, %[[EXTENT2:.*]] : (index, index) -> !fir.shapeshift<1>
+  // CHECK: Bound[0]: %{{.*}} = acc.bounds lowerbound(%[[LB2:.*]] : index) upperbound(%[[UB2:.*]] : index) extent(%{{.*}} : index) stride(%c1{{.*}} : index) startIdx(%c2{{.*}} : index)
+  // CHECK: Lower bound: %[[LB2]] = arith.constant 0 : index
+  // CHECK: Upper bound: %[[UB2]] = arith.subi %[[EXTENT2]], %c1{{.*}} : index
 
   // CHECK: Visiting: %{{.*}} = acc.copyin varPtr(%{{.*}} : !fir.ref<!fir.array<10xf32>>) -> !fir.ref<!fir.array<10xf32>> {name = "arr3", structured = false}
   // CHECK: Pointer-like and Mappable: !fir.ref<!fir.array<10xf32>>
   // CHECK: Type category: array
   // CHECK: Size: 40
   // CHECK: Offset: 0
-  // CHECK: Bound[0]: %{{.*}} = acc.bounds lowerbound(%c0{{.*}} : index) upperbound(%{{.*}} : index) extent(%c10{{.*}} : index) stride(%c1{{.*}} : index) startIdx(%c1{{.*}} : index)
+  // CHECK: Shape: %{{.*}} = fir.shape %[[EXTENT3:.*]] : (index) -> !fir.shape<1>
+  // CHECK: Bound[0]: %{{.*}} = acc.bounds lowerbound(%[[LB3:.*]] : index) upperbound(%[[UB3:.*]] : index) extent(%c10{{.*}} : index) stride(%c1{{.*}} : index) startIdx(%c1{{.*}} : index)
+  // CHECK: Lower bound: %[[LB3]] = arith.constant 0 : index
+  // CHECK: Upper bound: %[[UB3]] = arith.subi %[[EXTENT3]], %c1{{.*}} : index
 }

flang/test/lib/OpenACC/TestOpenACCInterfaces.cpp

@@ -15,6 +15,7 @@
 #include "mlir/Support/LLVM.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/HLFIR/HLFIRDialect.h"
+#include "flang/Optimizer/HLFIR/HLFIROps.h"
 #include "flang/Optimizer/Support/DataLayout.h"
 
 using namespace mlir;
@@ -99,11 +100,23 @@ struct TestFIROpenACCInterfaces
             }
           }
 
+          if (auto declareOp =
+                  dyn_cast_if_present<hlfir::DeclareOp>(var.getDefiningOp())) {
+            llvm::errs() << "\t\tShape: " << declareOp.getShape() << "\n";
+          }
+
           builder.setInsertionPoint(op);
           auto bounds = mappableTy.generateAccBounds(acc::getVar(op), builder);
           if (!bounds.empty()) {
             for (auto [idx, bound] : llvm::enumerate(bounds)) {
-              llvm::errs() << "\t\tBound[" << idx << "]: " << bound << "\n";
+              if (auto boundOp = dyn_cast_if_present<acc::DataBoundsOp>(
+                      bound.getDefiningOp())) {
+                llvm::errs() << "\t\tBound[" << idx << "]: " << bound << "\n";
+                llvm::errs()
+                    << "\t\tLower bound: " << boundOp.getLowerbound() << "\n";
+                llvm::errs()
+                    << "\t\tUpper bound: " << boundOp.getUpperbound() << "\n";
+              }
             }
           }
         }