Hi!
Currently if a target* pragma appears within a target region, GCC successfully
compiles such code (with a warning). But the binary fails at run-time, since it
tries to call GOMP_target* functions on target.
The spec says: "If a target, target update, or target data construct appears
within a target region then the behavior is unspecified."
I see 2 options to make the behavior more user-friendly:
1. To return an error at compile-time.
2. To check at run-time in libgomp whether GOMP_target* is called on target, and
perform target-fallback if so.
If we will select option #1, the patch is ready.
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index eaad52a..ae8b90a 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -2682,8 +2682,14 @@ check_omp_nesting_restrictions (gimple stmt, omp_context
*ctx)
}
break;
case GIMPLE_OMP_TARGET:
- for (; ctx != NULL; ctx = ctx->outer)
- if (is_targetreg_ctx (ctx))
+ {
+ bool target_p = false;
+ if (cgraph_node::get (current_function_decl)->offloadable)
+ target_p = true;
+ for (; ctx != NULL && !target_p; ctx = ctx->outer)
+ if (is_targetreg_ctx (ctx))
+ target_p = true;
+ if (target_p)
{
const char *name;
switch (gimple_omp_target_kind (stmt))
@@ -2693,9 +2699,11 @@ check_omp_nesting_restrictions (gimple stmt, omp_context
*ctx)
case GF_OMP_TARGET_KIND_UPDATE: name = "target update"; break;
default: gcc_unreachable ();
}
- warning_at (gimple_location (stmt), 0,
- "%s construct inside of target region", name);
+ error_at (gimple_location (stmt),
+ "%s construct inside of target region", name);
+ return false;
}
+ }
break;
default:
break;
diff --git a/gcc/testsuite/c-c++-common/gomp/nesting-error-1.c
b/gcc/testsuite/c-c++-common/gomp/nesting-error-1.c
new file mode 100644
index 0000000..ff6a75e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/nesting-error-1.c
@@ -0,0 +1,23 @@
+extern int i;
+
+void
+f_omp_target (void)
+{
+#pragma omp target
+ {
+#pragma omp target /* { dg-error "target construct inside of target region" }
*/
+ ;
+#pragma omp target data /* { dg-error "target data construct inside of target
region" } */
+ ;
+#pragma omp target update to(i) /* { dg-error "target update construct inside
of target region" } */
+
+#pragma omp parallel
+ {
+#pragma omp target /* { dg-error "target construct inside of target region" }
*/
+ ;
+#pragma omp target data /* { dg-error "target data construct inside of target
region" } */
+ ;
+#pragma omp target update to(i) /* { dg-error "target update construct inside
of target region" } */
+ }
+ }
+}
diff --git a/gcc/testsuite/c-c++-common/gomp/nesting-warn-1.c
b/gcc/testsuite/c-c++-common/gomp/nesting-warn-1.c
deleted file mode 100644
index c39dd49..0000000
--- a/gcc/testsuite/c-c++-common/gomp/nesting-warn-1.c
+++ /dev/null
@@ -1,23 +0,0 @@
-extern int i;
-
-void
-f_omp_target (void)
-{
-#pragma omp target
- {
-#pragma omp target /* { dg-warning "target construct inside of target region"
} */
- ;
-#pragma omp target data /* { dg-warning "target data construct inside of
target region" } */
- ;
-#pragma omp target update to(i) /* { dg-warning "target update construct
inside of target region" } */
-
-#pragma omp parallel
- {
-#pragma omp target /* { dg-warning "target construct inside of target region"
} */
- ;
-#pragma omp target data /* { dg-warning "target data construct inside of
target region" } */
- ;
-#pragma omp target update to(i) /* { dg-warning "target update construct
inside of target region" } */
- }
- }
-}
diff --git a/gcc/testsuite/gfortran.dg/gomp/target3.f90
b/gcc/testsuite/gfortran.dg/gomp/target3.f90
index 53a9682..e451548 100644
--- a/gcc/testsuite/gfortran.dg/gomp/target3.f90
+++ b/gcc/testsuite/gfortran.dg/gomp/target3.f90
@@ -4,9 +4,18 @@
subroutine foo (r)
integer :: i, r
!$omp target
- !$omp target teams distribute parallel do reduction (+: r) ! { dg-warning
"target construct inside of target region" }
+ !$omp target teams distribute parallel do reduction (+: r) ! { dg-error
"target construct inside of target region" }
do i = 1, 10
r = r + 1
end do
!$omp end target
end subroutine
+
+subroutine bar (r)
+ !$omp declare target
+ integer :: i, r
+ !$omp target teams distribute parallel do reduction (+: r) ! { dg-error
"target construct inside of target region" }
+ do i = 1, 10
+ r = r + 1
+ end do
+end subroutine
-- Ilya
