I'm writing a set of tests for functionality of GCC generic vectors.
Several very large tests result in internal compiler errors or seg
faults because a type node that is reused has been garbage-collected.
I'll leave it to someone who understands the garbage collector to
figure out how to fix this.
The node in question is allocated in build_word_node_vector_type.
It's easier to detect the problem with the following patch:
--- tree-complex.c.orig 2004-10-12 14:43:10.574920072 -0700
+++ tree-complex.c 2004-10-12 14:43:50.232015984 -0700
@@ -521,7 +521,10 @@ build_word_mode_vector_type (int nunits)
if (!innertype)
innertype = lang_hooks.types.type_for_mode (word_mode, 1);
else if (last_nunits == nunits)
- return last;
+ {
+ gcc_assert (TREE_CODE (last) == VECTOR_TYPE);
+ return last;
+ }
/* We build a new type, but we canonicalize it nevertheless,
because it still saves some memory. */
... and by forcing garbage collection to happen frequently, like so.
laptop% /home/janis/tools/gcc-mline-20041012/bin/gcc -c --param ggc-min-expand=0
--param ggc-min-heapsize=0 bug1.c
bug1.c: In function 'vsub':
bug1.c:17: internal compiler error: in build_word_mode_vector_type, at
/tree-complex.c:525
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
This happens for me on powerpc64-unknown-linux-gnu and i686-pc-linux-gnu
using today's mainline sources, with the patch above to detect the
problem more quickly.
--
Summary: vector type node used after garbage-collected
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: janis187 at us dot ibm dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17957
