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authorPaolo Bonzini <bonzini@gnu.org>2009-01-28 08:02:31 +0000
committerPaolo Bonzini <bonzini@gcc.gnu.org>2009-01-28 08:02:31 +0000
commit89ebafc6cdbfe4f67d017844f50b3810fd9e1399 (patch)
tree3cd192be101ee3c3c1d45220682f7ba74918cf0b /gcc/tree-ssa-structalias.c
parentbef3c57babac2e7ff368cb226a962644575c22e0 (diff)
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re PR tree-optimization/38984 (NULL pointers always considered distinct by PTA, even with -fno-delete-null-pointer-checks)
gcc: 2009-01-28 Paolo Bonzini <bonzini@gnu.org> PR tree-optimization/38984 * tree-ssa-structalias.c (get_constraints_for_1): Do not use the nothing_id variable if -fno-delete-null-pointer-checks. gcc/testsuite: 2009-01-28 Paolo Bonzini <bonzini@gnu.org> PR tree-optimization/38984 * gcc.dg/pr38984.c: New XFAILed testcase. From-SVN: r143721
Diffstat (limited to 'gcc/tree-ssa-structalias.c')
-rw-r--r--gcc/tree-ssa-structalias.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index cae478a..21566bb 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -3044,8 +3044,14 @@ get_constraint_for_1 (tree t, VEC (ce_s, heap) **results, bool address_p)
happens below, since it will fall into the default case. The only
case we know something about an integer treated like a pointer is
when it is the NULL pointer, and then we just say it points to
- NULL. */
- if (TREE_CODE (t) == INTEGER_CST
+ NULL.
+
+ Do not do that if -fno-delete-null-pointer-checks though, because
+ in that case *NULL does not fail, so it _should_ alias *anything.
+ It is not worth adding a new option or renaming the existing one,
+ since this case is relatively obscure. */
+ if (flag_delete_null_pointer_checks
+ && TREE_CODE (t) == INTEGER_CST
&& integer_zerop (t))
{
temp.var = nothing_id;