This patch prevents two Invalid read of size 8 and one
Invalid write of size 8 warnings when cc1 is run under valgrind. What
happens here is that we firstly allocate 0B
ebb_data.path = XNEWVEC (struct branch_path,
PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH));
(in fact, XNEWVEC always allocates at least 1B--but still it's not enough),
then in cse_find_path we have (path_size is 0)
if (path_size == 0)
data->path[path_size++].bb = first_bb;
so we immediately have invalid write and moreover path_size increments,
thus we call cse_find_path again, then we get the invalid reads.
So fixed by guarding the write with PARAM_MAX_CSE_PATH_LENGTH > 0.
Alternatively, we can bump the minimum of that param, as usual ;)
Bootstrapped/regtested on x86_64-linux, ok for trunk/4.8?
2013-04-08 Marek Polacek <[email protected]>
PR tree-optimization/48762
* cse.c (cse_find_path): Require PARAM_MAX_CSE_PATH_LENGTH be > 0.
--- gcc/cse.c.mp 2013-04-08 13:19:15.082670099 +0200
+++ gcc/cse.c 2013-04-08 13:19:29.014713914 +0200
@@ -6166,7 +6166,7 @@ cse_find_path (basic_block first_bb, str
}
/* If the path was empty from the beginning, construct a new path. */
- if (path_size == 0)
+ if (path_size == 0 && PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH) > 0)
data->path[path_size++].bb = first_bb;
else
{
Marek
