On Tue, 19 Feb 2013, Jakub Jelinek wrote:
> Hi!
>
> On the following patch gcc ICEs because malloc memory is corrupted.
> The problem is that const_val array is allocated at the start of the pass,
> but during the execution of ccp some new SSA_NAMEs are created
> (update_call_from_tree if I remember well).
>
> The following patch fixes that by making const_val a vector instead of
> array, and growing it when needed.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ick. This happens from calling fold_stmt during substitute_and_fold,
a place where increasing the lattice isn't useful. So I'd prefer
the same fix as present in VRP for this issue, simply return VARYING
for out-of-bound accesses. Same issue is latent for copyprop.
I'm testing the following.
Richard.
2013-02-20 Richard Biener <rguent...@suse.de>
Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/56396
* tree-ssa-ccp.c (n_const_val): New static variable.
(get_value): Return NULL for SSA names we don't have a lattice
entry for.
(ccp_initialize): Initialize n_const_val.
* tree-ssa-copy.c (n_copy_of): New static variable.
(init_copy_prop): Initialize n_copy_of.
(get_value): Return NULL_TREE for SSA names we don't have a
lattice entry for.
* gcc.dg/pr56396.c: New testcase.
Index: gcc/tree-ssa-ccp.c
===================================================================
*** gcc/tree-ssa-ccp.c (revision 196167)
--- gcc/tree-ssa-ccp.c (working copy)
*************** typedef struct prop_value_d prop_value_t
*** 162,167 ****
--- 162,168 ----
memory reference used to store (i.e., the LHS of the assignment
doing the store). */
static prop_value_t *const_val;
+ static unsigned n_const_val;
static void canonicalize_float_value (prop_value_t *);
static bool ccp_fold_stmt (gimple_stmt_iterator *);
*************** get_value (tree var)
*** 295,301 ****
{
prop_value_t *val;
! if (const_val == NULL)
return NULL;
val = &const_val[SSA_NAME_VERSION (var)];
--- 296,303 ----
{
prop_value_t *val;
! if (const_val == NULL
! || SSA_NAME_VERSION (var) >= n_const_val)
return NULL;
val = &const_val[SSA_NAME_VERSION (var)];
*************** ccp_initialize (void)
*** 713,719 ****
{
basic_block bb;
! const_val = XCNEWVEC (prop_value_t, num_ssa_names);
/* Initialize simulation flags for PHI nodes and statements. */
FOR_EACH_BB (bb)
--- 715,722 ----
{
basic_block bb;
! n_const_val = num_ssa_names;
! const_val = XCNEWVEC (prop_value_t, n_const_val);
/* Initialize simulation flags for PHI nodes and statements. */
FOR_EACH_BB (bb)
Index: gcc/tree-ssa-copy.c
===================================================================
*** gcc/tree-ssa-copy.c (revision 196167)
--- gcc/tree-ssa-copy.c (working copy)
*************** struct prop_value_d {
*** 280,285 ****
--- 280,286 ----
typedef struct prop_value_d prop_value_t;
static prop_value_t *copy_of;
+ static unsigned n_copy_of;
/* Return true if this statement may generate a useful copy. */
*************** init_copy_prop (void)
*** 664,670 ****
{
basic_block bb;
! copy_of = XCNEWVEC (prop_value_t, num_ssa_names);
FOR_EACH_BB (bb)
{
--- 665,672 ----
{
basic_block bb;
! n_copy_of = num_ssa_names;
! copy_of = XCNEWVEC (prop_value_t, n_copy_of);
FOR_EACH_BB (bb)
{
*************** init_copy_prop (void)
*** 728,734 ****
static tree
get_value (tree name)
{
! tree val = copy_of[SSA_NAME_VERSION (name)].value;
if (val && val != name)
return val;
return NULL_TREE;
--- 730,739 ----
static tree
get_value (tree name)
{
! tree val;
! if (SSA_NAME_VERSION (name) >= n_copy_of)
! return NULL_TREE;
! val = copy_of[SSA_NAME_VERSION (name)].value;
if (val && val != name)
return val;
return NULL_TREE;
Index: gcc/testsuite/gcc.dg/pr56396.c
===================================================================
*** gcc/testsuite/gcc.dg/pr56396.c (revision 0)
--- gcc/testsuite/gcc.dg/pr56396.c (working copy)
***************
*** 0 ****
--- 1,22 ----
+ /* PR tree-optimization/56396 */
+ /* { dg-do compile } */
+ /* { dg-options "-O2 -fpic -g" } */
+
+ struct S { char *s; int z; };
+ struct T { int t; } *c, u;
+ void bar (int, const char *);
+
+ inline void *
+ foo (void *x, char *y, int z)
+ {
+ struct S s;
+ char b[256];
+ s.s = b;
+ s.z = __builtin___sprintf_chk (s.s, 1, __builtin_object_size (s.s, 2),
"Require");
+ if (s.z < 0)
+ bar (u.t | c->t, "rls");
+ if (foo (x, s.s, s.z))
+ {
+ }
+ return (void *) 0;
+ }
