Hi!
If sections construct has all section directives non-fallthru, as in
the attached testcase, including the case where they can be all or some of
them cancelled, we generate too large argument for GOMP_sections_start,
so if there are more threads than section directives (including the implicit
first) in the sections construct, we can __builtin_trap ().
Fixed thusly, tested on x86_64-linux and i686-linux, committed to trunk/4.8.
2013-09-19 Jakub Jelinek <ja...@redhat.com>
* omp-low.c (expand_omp_sections): Always pass len - 1 to
GOMP_sections_start, even if !exit_reachable.
libgomp/
* testsuite/libgomp.c/sections-2.c: New test.
--- gcc/omp-low.c.jj 2013-09-19 09:15:08.000000000 +0200
+++ gcc/omp-low.c 2013-09-19 12:59:49.325031241 +0200
@@ -6862,8 +6862,7 @@ expand_omp_sections (struct omp_region *
{
/* If we are not inside a combined parallel+sections region,
call GOMP_sections_start. */
- t = build_int_cst (unsigned_type_node,
- exit_reachable ? len - 1 : len);
+ t = build_int_cst (unsigned_type_node, len - 1);
u = builtin_decl_explicit (BUILT_IN_GOMP_SECTIONS_START);
stmt = gimple_build_call (u, 1, t);
}
--- libgomp/testsuite/libgomp.c/sections-2.c.jj 2013-09-19 13:06:46.138913032
+0200
+++ libgomp/testsuite/libgomp.c/sections-2.c 2013-09-19 13:07:00.250841349
+0200
@@ -0,0 +1,29 @@
+/* { dg-do run } */
+
+#include <stdlib.h>
+#include <unistd.h>
+
+__attribute__((noinline, noclone, noreturn))
+void
+foo ()
+{
+ sleep (4);
+ exit (0);
+}
+
+int
+main ()
+{
+ #pragma omp parallel
+ {
+ #pragma omp sections
+ {
+ foo ();
+ #pragma omp section
+ foo ();
+ #pragma omp section
+ foo ();
+ }
+ }
+ return 0;
+}
Jakub
