diff --git a/flang/lib/Lower/OpenACC.cpp b/flang/lib/Lower/OpenACC.cpp
--- a/flang/lib/Lower/OpenACC.cpp
+++ b/flang/lib/Lower/OpenACC.cpp
@@ -107,7 +107,7 @@
              const std::list<Fortran::parser::SectionSubscript> &subscripts,
              std::stringstream &asFortran, const Fortran::parser::Name &name) {
   int dimension = 0;
-  mlir::Type i64Ty = builder.getI64Type();
+  mlir::Type idxTy = builder.getIndexType();
   mlir::Type boundTy = builder.getType<mlir::acc::DataBoundsType>();
   llvm::SmallVector<mlir::Value> bounds;
   for (const auto &subscript : subscripts) {
@@ -121,7 +121,7 @@
       if (lower) {
         lval = Fortran::semantics::GetIntValue(lower);
         if (lval) {
-          lbound = builder.createIntegerConstant(loc, i64Ty, *lval);
+          lbound = builder.createIntegerConstant(loc, idxTy, *lval - 1);
           asFortran << *lval;
         } else {
           TODO(loc, "non constant lower bound in array section");
@@ -132,7 +132,7 @@
       if (upper) {
         uval = Fortran::semantics::GetIntValue(upper);
         if (uval) {
-          ubound = builder.createIntegerConstant(loc, i64Ty, *uval);
+          ubound = builder.createIntegerConstant(loc, idxTy, *uval - 1);
           asFortran << *uval;
         } else {
           TODO(loc, "non constant upper bound in array section");
@@ -151,13 +151,15 @@
           }
         }
       }
+      mlir::Value one = builder.createIntegerConstant(loc, idxTy, 1);
       if (!ubound) {
         fir::ExtendedValue x = converter.getSymbolExtendedValue(*name.symbol);
-        extent = fir::factory::readExtent(builder, loc, x, dimension);
+        mlir::Value ext = fir::factory::readExtent(builder, loc, x, dimension);
+        extent = builder.create<mlir::arith::SubIOp>(loc, ext, one);
       }
       mlir::Value empty;
       mlir::Value bound = builder.create<mlir::acc::DataBoundsOp>(
-          loc, boundTy, lbound, ubound, extent, empty, false, empty);
+          loc, boundTy, lbound, ubound, extent, empty, false, one);
       bounds.push_back(bound);
       ++dimension;
     }
diff --git a/flang/test/Lower/OpenACC/acc-enter-data.f90 b/flang/test/Lower/OpenACC/acc-enter-data.f90
--- a/flang/test/Lower/OpenACC/acc-enter-data.f90
+++ b/flang/test/Lower/OpenACC/acc-enter-data.f90
@@ -88,32 +88,43 @@
 !CHECK: acc.enter_data wait_devnum(%[[WAIT6]] : i32) wait(%[[WAIT4]], %[[WAIT5]] : i32, i32) dataOperands(%[[CREATE_A]] : !fir.ref<!fir.array<10x10xf32>>)
 
   !$acc enter data copyin(a(1:10,1:5))
-!CHECK: %[[LB1:.*]] = arith.constant 1 : i64
-!CHECK: %[[UB1:.*]] = arith.constant 10 : i64
-!CHECK: %[[BOUND1:.*]] = acc.bounds lowerbound(%[[LB1]] : i64) upperbound(%[[UB1]] : i64)
-!CHECK: %[[LB2:.*]] = arith.constant 1 : i64
-!CHECK: %[[UB2:.*]] = arith.constant 5 : i64
-!CHECK: %[[BOUND2:.*]] = acc.bounds lowerbound(%[[LB2]] : i64) upperbound(%[[UB2]] : i64)
+!CHECK: %[[LB1:.*]] = arith.constant 0 : index
+!CHECK: %[[UB1:.*]] = arith.constant 9 : index
+!CHECK: %[[BOUND1:.*]] = acc.bounds lowerbound(%[[LB1]] : index) upperbound(%[[UB1]] : index) startIdx(%c1{{.*}} : index)
+!CHECK: %[[LB2:.*]] = arith.constant 0 : index
+!CHECK: %[[UB2:.*]] = arith.constant 4 : index
+!CHECK: %[[BOUND2:.*]] = acc.bounds lowerbound(%[[LB2]] : index) upperbound(%[[UB2]] : index) startIdx(%c1{{.*}} : index) 
 !CHECK: %[[COPYIN_A:.*]] = acc.copyin varPtr(%[[A]] : !fir.ref<!fir.array<10x10xf32>>) bounds(%[[BOUND1]], %[[BOUND2]]) -> !fir.ref<!fir.array<10x10xf32>> {name = "a(1:10,1:5)", structured = false}
 !CHECK: acc.enter_data dataOperands(%[[COPYIN_A]] : !fir.ref<!fir.array<10x10xf32>>)
 
   !$acc enter data copyin(a(1:,1:5))
-!CHECK: %[[LB1:.*]] = arith.constant 1 : i64
-!CHECK: %[[BOUND1:.*]] = acc.bounds   lowerbound(%[[LB1]] : i64) extent(%[[EXTENT_C10]] : index)
-!CHECK: %[[LB2:.*]] = arith.constant 1 : i64
-!CHECK: %[[UB2:.*]] = arith.constant 5 : i64
-!CHECK: %[[BOUND2:.*]] = acc.bounds   lowerbound(%[[LB2]] : i64) upperbound(%[[UB2]] : i64)
-!CHECK: %[[COPYIN_A:.*]] = acc.copyin varPtr(%[[A]] : !fir.ref<!fir.array<10x10xf32>>)   bounds(%[[BOUND1]], %[[BOUND2]]) -> !fir.ref<!fir.array<10x10xf32>> {name = "a(1:,1:5)", structured = false}
+!CHECK: %[[LB1:.*]] = arith.constant 0 : index
+!CHECK: %[[EXTENT:.*]] = arith.subi %[[EXTENT_C10:.*]], %c1{{.*}} : index 
+!CHECK: %[[BOUND1:.*]] = acc.bounds   lowerbound(%[[LB1]] : index) extent(%[[EXTENT]] : index)  startIdx(%c1{{.*}} : index)
+!CHECK: %[[LB2:.*]] = arith.constant 0 : index
+!CHECK: %[[UB2:.*]] = arith.constant 4 : index
+!CHECK: %[[BOUND2:.*]] = acc.bounds lowerbound(%[[LB2]] : index) upperbound(%[[UB2]] : index)  startIdx(%c1{{.*}} : index)
+!CHECK: %[[COPYIN_A:.*]] = acc.copyin varPtr(%[[A]] : !fir.ref<!fir.array<10x10xf32>>) bounds(%[[BOUND1]], %[[BOUND2]]) -> !fir.ref<!fir.array<10x10xf32>> {name = "a(1:,1:5)", structured = false}
 !CHECK: acc.enter_data   dataOperands(%[[COPYIN_A]] : !fir.ref<!fir.array<10x10xf32>>)
 
   !$acc enter data copyin(a(:10,1:5))
-!CHECK: %[[UB1:.*]] = arith.constant 10 : i64
-!CHECK: %[[BOUND1:.*]] = acc.bounds   upperbound(%[[UB1]] : i64)
-!CHECK: %[[LB2:.*]] = arith.constant 1 : i64
-!CHECK: %[[UB2:.*]] = arith.constant 5 : i64
-!CHECK: %[[BOUND2:.*]] = acc.bounds   lowerbound(%[[LB2]] : i64) upperbound(%[[UB2]] : i64)
-!CHECK: %[[COPYIN_A:.*]] = acc.copyin varPtr(%[[A]] : !fir.ref<!fir.array<10x10xf32>>)   bounds(%[[BOUND1]], %[[BOUND2]]) -> !fir.ref<!fir.array<10x10xf32>> {name = "a(:10,1:5)", structured = false}
-!CHECK: acc.enter_data   dataOperands(%[[COPYIN_A]] : !fir.ref<!fir.array<10x10xf32>>)
+!CHECK: %[[UB1:.*]] = arith.constant 9 : index
+!CHECK: %[[BOUND1:.*]] = acc.bounds   upperbound(%[[UB1]] : index)
+!CHECK: %[[LB2:.*]] = arith.constant 0 : index
+!CHECK: %[[UB2:.*]] = arith.constant 4 : index
+!CHECK: %[[BOUND2:.*]] = acc.bounds lowerbound(%[[LB2]] : index) upperbound(%[[UB2]] : index)  startIdx(%c1{{.*}} : index)
+!CHECK: %[[COPYIN_A:.*]] = acc.copyin varPtr(%[[A]] : !fir.ref<!fir.array<10x10xf32>>) bounds(%[[BOUND1]], %[[BOUND2]]) -> !fir.ref<!fir.array<10x10xf32>> {name = "a(:10,1:5)", structured = false}
+!CHECK: acc.enter_data dataOperands(%[[COPYIN_A]] : !fir.ref<!fir.array<10x10xf32>>)
+
+  !$acc enter data copyin(a(:,:))
+!CHECK: %[[C1:.*]] = arith.constant 1 : index
+!CHECK: %[[EXT:.*]] = arith.subi %c10{{.*}}, %[[C1]] : index
+!CHECK: %[[BOUND1:.*]] = acc.bounds extent(%[[EXT]] : index) startIdx(%[[C1]] : index)
+!CHECK: %[[C1:.*]] = arith.constant 1 : index
+!CHECK: %[[EXT:.*]] = arith.subi %c10{{.*}}, %[[C1]] : index
+!CHECK: %[[BOUND2:.*]] = acc.bounds extent(%[[EXT]] : index) startIdx(%[[C1]] : index)
+!CHECK: %[[COPYIN_A:.*]] = acc.copyin varPtr(%[[A]] : !fir.ref<!fir.array<10x10xf32>>) bounds(%[[BOUND1]], %[[BOUND2]]) -> !fir.ref<!fir.array<10x10xf32>> {name = "a(:,:)", structured = false}
+!CHECK: acc.enter_data dataOperands(%[[COPYIN_A]] : !fir.ref<!fir.array<10x10xf32>>)
 
 end subroutine acc_enter_data
 
@@ -125,10 +136,10 @@
 !CHECK-SAME:    %[[A:.*]]: !fir.ref<!fir.array<10xf32>> {fir.bindc_name = "a"}
 
   !$acc enter data create(a(5:10))
-!CHECK: %[[LB1:.*]] = arith.constant 5 : i64
-!CHECK: %[[UB1:.*]] = arith.constant 10 : i64
-!CHECK: %[[BOUND1:.*]] = acc.bounds lowerbound(%[[LB1]] : i64) upperbound(%[[UB1]] : i64)
-!CHECK: %[[CREATE1:.*]] = acc.create varPtr(%[[A]] : !fir.ref<!fir.array<10xf32>>)   bounds(%[[BOUND1]]) -> !fir.ref<!fir.array<10xf32>> {name = "a(5:10)", structured = false}
-!CHECK: acc.enter_data   dataOperands(%[[CREATE1]] : !fir.ref<!fir.array<10xf32>>)
+!CHECK: %[[LB1:.*]] = arith.constant 4 : index
+!CHECK: %[[UB1:.*]] = arith.constant 9 : index
+!CHECK: %[[BOUND1:.*]] = acc.bounds lowerbound(%[[LB1]] : index) upperbound(%[[UB1]] : index)  startIdx(%c1{{.*}} : index)
+!CHECK: %[[CREATE1:.*]] = acc.create varPtr(%[[A]] : !fir.ref<!fir.array<10xf32>>) bounds(%[[BOUND1]]) -> !fir.ref<!fir.array<10xf32>> {name = "a(5:10)", structured = false}
+!CHECK: acc.enter_data dataOperands(%[[CREATE1]] : !fir.ref<!fir.array<10xf32>>)
 
 end subroutine