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| author | Paolo Bonzini <bonzini@gnu.org> | 2009-01-28 08:02:31 +0000 |
|---|---|---|
| committer | Paolo Bonzini <bonzini@gcc.gnu.org> | 2009-01-28 08:02:31 +0000 |
| commit | 89ebafc6cdbfe4f67d017844f50b3810fd9e1399 (patch) | |
| tree | 3cd192be101ee3c3c1d45220682f7ba74918cf0b /gcc | |
| parent | bef3c57babac2e7ff368cb226a962644575c22e0 (diff) | |
| download | gcc-89ebafc6cdbfe4f67d017844f50b3810fd9e1399.zip gcc-89ebafc6cdbfe4f67d017844f50b3810fd9e1399.tar.gz gcc-89ebafc6cdbfe4f67d017844f50b3810fd9e1399.tar.bz2 | |
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')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr38984.c | 19 | ||||
| -rw-r--r-- | gcc/tree-ssa-structalias.c | 10 |
4 files changed, 38 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 5300a86..2727cc2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +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. + 2009-01-28 Uros Bizjak <ubizjak@gmail.com> PR target/38988 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 8f1ceb8..7721a56 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2009-01-28 Paolo Bonzini <bonzini@gnu.org> + + PR tree-optimization/38984 + * gcc.dg/pr38984.c: New XFAILed testcase. + 2009-01-27 Paolo Carlini <paolo.carlini@oracle.com> PR c++/37554 diff --git a/gcc/testsuite/gcc.dg/pr38984.c b/gcc/testsuite/gcc.dg/pr38984.c new file mode 100644 index 0000000..0ba7273 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr38984.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-delete-null-pointer-checks -fdump-tree-optimized" } + * */ + +int f(int *p) +{ + int a = *p; + int *null = 0; + *null = 5; + return *p == a; +} + +/* Currently fails because of PR38985. */ + +/* { dg-final { scan-tree-dump-times " = \\\*p" 2 "optimized" { xfail *-*-* } } } */ +/* { dg-final { scan-tree-dump-not "return 1" "optimized" { xfail *-*-* } } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ + + 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; |