Index: flang/test/Lower/OpenMP/simd.f90
===================================================================
--- flang/test/Lower/OpenMP/simd.f90
+++ flang/test/Lower/OpenMP/simd.f90
@@ -89,3 +89,40 @@
   end do
   !$OMP END SIMD
 end subroutine
+
+!CHECK-LABEL: func @_QPsimdloop_with_collapse_clause
+!CHECK: %[[VAL_0:.*]] = fir.alloca i32 {adapt.valuebyref}
+!CHECK: %[[VAL_1:.*]] = fir.alloca i32 {adapt.valuebyref}
+!CHECK: %[[LOWER_I:.*]] = arith.constant 1 : i32
+!CHECK: %[[UPPER_I:.*]] = fir.load %[[PARAM_ARG:.*]] : !fir.ref<i32>
+!CHECK: %[[STEP_I:.*]] = arith.constant 1 : i32
+!CHECK: %[[LOWER_J:.*]] = arith.constant 1 : i32
+!CHECK: %[[UPPER_J:.*]] = fir.load %[[PARAM_ARG:.*]] : !fir.ref<i32>
+!CHECK: %[[STEP_J:.*]] = arith.constant 1 : i32
+! CHECK-LABEL:   omp.simdloop   for  (
+! CHECK:                         %[[ARG_0:.*]], %[[ARG_1:.*]]) : i32 = (
+! CHECK:                         %[[LOWER_I]],
+! CHECK:                         %[[LOWER_J]]) to (
+! CHECK:                         %[[UPPER_I]],
+! CHECK:                         %[[UPPER_J]]) inclusive step (
+! CHECK:                         %[[STEP_I]],
+! CHECK:                         %[[STEP_J]]) {
+! CHECK:           fir.store %[[ARG_0]] to %[[VAL_1]] : !fir.ref<i32>
+! CHECK:           fir.store %[[ARG_1]] to %[[VAL_0]] : !fir.ref<i32>
+! CHECK:           fir.call @_QPfoo(%[[VAL_1]]) : (!fir.ref<i32>) -> ()
+! CHECK:           fir.call @_QPbar(%[[VAL_0]]) : (!fir.ref<i32>) -> ()
+! CHECK:           omp.yield
+! CHECK:         }
+! CHECK:         return
+
+subroutine simdloop_with_collapse_clause(n)
+integer :: i, j, n
+  !$OMP SIMD collapse(2)
+  do i = 1, n
+    do j = 1, n
+      call foo(i)
+      call bar(j)
+    end do
+  end do
+  !$OMP END SIMD
+end subroutine
Index: mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
===================================================================
--- mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -412,6 +412,9 @@
     The body region can contain any number of blocks. The region is terminated
     by "omp.yield" instruction without operands.
 
+    Collapsed loops are represented by the simd-loop having a list of indices,
+    bounds and steps where the size of the list is equal to the collapse value.
+
     When an if clause is present and evaluates to false, the preferred number of
     iterations to be executed concurrently is one, regardless of whether
     a simdlen clause is specified.