Fortran/OpenMP: Fix detecting not perfectly nested loops

This is a backport for master of commit
57dd9f3bfca8bb752c630431dc033c761e2ad382.

gcc/fortran/ChangeLog:

	* openmp.c (resolve_omp_do): Detect not perfectly
	nested loop with innermost collapse.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/collapse1.f90: Add dg-error.
	* gfortran.dg/gomp/collapse2.f90: New test.

diff --git a/gcc/fortran/ChangeLog.omp b/gcc/fortran/ChangeLog.omp
index d68db5ba0a3d6beda94c50baf56ae22dc3ae6a89..e64bf823ca672fcb0136d0aabdd987cdce4a2e50 100644 (file)
--- a/gcc/fortran/ChangeLog.omp
+++ b/gcc/fortran/ChangeLog.omp
@@ -1,3 +1,11 @@
+2020-08-18  Kwok Cheung Yeung  <kcy@codesourcery.com>
+
+       Backport from mainline
+       2020-08-04  Tobias Burnus  <tobias@codesourcery.com>
+
+       * openmp.c (resolve_omp_do): Detect not perfectly
+       nested loop with innermost collapse.
+
 2020-08-18  Kwok Cheung Yeung  <kcy@codesourcery.com>
 
        Backport from mainline

diff --git a/gcc/fortran/openmp.c b/gcc/fortran/openmp.c
index d9b110fb75a783d603353eb01acaaedfa6f61f8e..9d13863f1885a3cc13a46bab7d97b91de845a492 100644 (file)
--- a/gcc/fortran/openmp.c
+++ b/gcc/fortran/openmp.c
@@ -5907,8 +5907,6 @@ resolve_omp_do (gfc_code *code)
              do_code2 = do_code2->block->next;
            }
        }
-      if (i == collapse)
-       break;
       for (c = do_code->next; c; c = c->next)
        if (c->op != EXEC_NOP && c->op != EXEC_CONTINUE)
          {
@@ -5916,7 +5914,7 @@ resolve_omp_do (gfc_code *code)
                       name, &c->loc);
            break;
          }
-      if (c)
+      if (i == collapse || c)
        break;
       do_code = do_code->block;
       if (do_code->op != EXEC_DO && do_code->op != EXEC_DO_WHILE)

diff --git a/gcc/testsuite/ChangeLog.omp b/gcc/testsuite/ChangeLog.omp
index 9838d848eb46c989a18df777bce9597e0c44b4ac..19395cfff330d52918c28cb470460bb52a29cf71 100644 (file)
--- a/gcc/testsuite/ChangeLog.omp
+++ b/gcc/testsuite/ChangeLog.omp
@@ -1,3 +1,11 @@
+2020-08-18  Kwok Cheung Yeung  <kcy@codesourcery.com>
+
+       Backport from mainline
+       2020-08-04  Tobias Burnus  <tobias@codesourcery.com>
+
+       * gfortran.dg/gomp/collapse1.f90: Add dg-error.
+       * gfortran.dg/gomp/collapse2.f90: New test.
+
 2020-08-18  Kwok Cheung Yeung  <kcy@codesourcery.com>
 
        Backport from mainline

diff --git a/gcc/testsuite/gfortran.dg/gomp/collapse1.f90 b/gcc/testsuite/gfortran.dg/gomp/collapse1.f90
index f16a780ad9948da5a027e8ee42b5e1655e82f9e5..1a06eaba82372708bed694cee8e5fccc613bf155 100644 (file)
--- a/gcc/testsuite/gfortran.dg/gomp/collapse1.f90
+++ b/gcc/testsuite/gfortran.dg/gomp/collapse1.f90
@@ -31,7 +31,7 @@ subroutine collapse1
     do i = 1, 3
       do j = 4, 6
       end do
-      k = 4
+      k = 4  ! { dg-error "loops not perfectly nested" }
     end do
   !$omp parallel do collapse(2)
     do i = 1, 3

diff --git a/gcc/testsuite/gfortran.dg/gomp/collapse2.f90 b/gcc/testsuite/gfortran.dg/gomp/collapse2.f90
new file mode 100644 (file)
index 0000000..1ab934e
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/gomp/collapse2.f90
@@ -0,0 +1,32 @@
+program p
+   integer :: i, j, k
+   real :: x
+   !$omp parallel do collapse(3)
+   do i = 1, 8
+      do j = 1, 8
+        do k = 1, 8
+        end do
+        x = 5  ! { dg-error "loops not perfectly nested" }
+      end do
+   end do
+   !$omp parallel do ordered(3)
+   do i = 1, 8
+      do j = 1, 8
+        do k = 1, 8
+        end do
+      end do
+      x = 5  ! { dg-error "loops not perfectly nested" }
+   end do
+   !$omp parallel do collapse(2)  ! { dg-error "not enough DO loops for collapsed" }
+   do i = 1, 8
+      x = 5
+      do j = 1, 8
+      end do
+   end do
+   !$omp parallel do ordered(2)  ! { dg-error "not enough DO loops for collapsed" }
+   do i = 1, 8
+      x = 5
+      do j = 1, 8
+      end do
+   end do
+end