https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68756
--- Comment #3 from Arseny Solokha <asolokha at gmx dot com> ---
The following observations were made w/ gcc-6.0.0-alpha20151220 snapshot.
isl fails w/
> isl-0.15/isl_ctx.c:227: Assertion "ctx->ref > 0" failed
when compiling the following snippet w/ the same options as above:
int s9;
int id[2];
void
aj(void)
{
int l6, p0, dg, it, gs = 0;
for (it = 0; it < 2; ++it) {
--gs;
for (s9 = 0; s9 < 2; ++s9) {
if (gs != 0)
break;
for (dg = 0; dg < 2; ++dg)
for (p0 = 0; p0 < 2; ++p0)
for (l6 = 0; l6 < 2; ++l6)
id[l6] = 0;
}
}
}
After moving s9 declarations into aj() cc1 starts to segfault w/ a new
backtrace:
--- qtcykola.c 2015-12-22 17:00:04.827862358 +0700
+++ eu1fk1op.c 2015-12-22 17:00:39.119531288 +0700
@@ -1,9 +1,9 @@
-int s9;
int id[2];
void
aj(void)
{
+ int s9;
int l6, p0, dg, it, gs = 0;
for (it = 0; it < 2; ++it) {
--gs;
#0 0x000003fff7eefeca in isl_map_dim () from /usr/lib64/libisl.so.15
#1 0x00000000011c3a0a in
translate_isl_ast_to_gimple::get_max_schedule_dimensions(scop*) ()
#2 0x00000000011c3ad9 in
translate_isl_ast_to_gimple::generate_isl_schedule(scop*) ()
#3 0x00000000011c5924 in translate_isl_ast_to_gimple::scop_to_isl_ast(scop*,
std::map<isl_id*, tree_node*, std::less<isl_id*>,
std::allocator<std::pair<isl_id* const, tree_node*> > >&) ()
#4 0x00000000011c9012 in graphite_regenerate_ast_isl(scop*) ()
#5 0x00000000011c0366 in graphite_transform_loops() ()
[trimmed]
Further minimization of these two new testcases yield the same failure as in
#c0.
Another question is, why segfaults in libisl.so aren't propagated to cc1 and,
eventually, to a driver?
