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| author | Richard Biener <rguenther@suse.de> | 2016-08-15 09:56:00 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-08-15 09:56:00 +0000 |
| commit | e4969090b68ff266b29c86b6aebec25812666fc4 (patch) | |
| tree | c23c379cf6e756837d03ce0db535edbb68acd4cc /gcc | |
| parent | 980bd53780025944008dbcd89caeed8d6e782715 (diff) | |
| download | gcc-e4969090b68ff266b29c86b6aebec25812666fc4.zip gcc-e4969090b68ff266b29c86b6aebec25812666fc4.tar.gz gcc-e4969090b68ff266b29c86b6aebec25812666fc4.tar.bz2 | |
re PR tree-optimization/73434 (Wrong code with casting, branches and aliasing)
2016-08-15 Richard Biener <rguenther@suse.de>
PR tree-optimization/73434
* tree-ssa-sccvn.c (vn_reference_maybe_forwprop_address): Preserve
TBAA info on the base when forwarding a non-invariant address.
* gcc.dg/torture/pr73434.c: New testcase.
From-SVN: r239471
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr73434.c | 19 | ||||
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 12 |
4 files changed, 42 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 32e9439..4e6ffb4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-08-15 Richard Biener <rguenther@suse.de> + + PR tree-optimization/73434 + * tree-ssa-sccvn.c (vn_reference_maybe_forwprop_address): Preserve + TBAA info on the base when forwarding a non-invariant address. + 2016-08-15 Jakub Jelinek <jakub@redhat.com> * dwarf2out.c (struct checksum_attributes): Add diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 6fa7c1f..fc25482 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-08-15 Richard Biener <rguenther@suse.de> + + PR tree-optimization/73434 + * gcc.dg/torture/pr73434.c: New testcase. + 2016-08-15 Jakub Jelinek <jakub@redhat.com> PR tree-optimization/72824 diff --git a/gcc/testsuite/gcc.dg/torture/pr73434.c b/gcc/testsuite/gcc.dg/torture/pr73434.c new file mode 100644 index 0000000..624e0c6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr73434.c @@ -0,0 +1,19 @@ +/* { dg-do run } */ + +typedef struct { unsigned char x; } A; +typedef struct { unsigned char x; } B; + +int idx = 0; + +A objs[1] = {{0}}; + +int main() +{ + B *b = (B*)&objs[idx]; + b->x++; + if (b->x) + b->x = 0; + if (b->x) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index e889d60..21b3d56 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -1225,6 +1225,18 @@ vn_reference_maybe_forwprop_address (vec<vn_reference_op_s> *ops, { auto_vec<vn_reference_op_s, 32> tem; copy_reference_ops_from_ref (TREE_OPERAND (addr, 0), &tem); + /* Make sure to preserve TBAA info. The only objects not + wrapped in MEM_REFs that can have their address taken are + STRING_CSTs. */ + if (tem.length () >= 2 + && tem[tem.length () - 2].opcode == MEM_REF) + { + vn_reference_op_t new_mem_op = &tem[tem.length () - 2]; + new_mem_op->op0 = fold_convert (TREE_TYPE (mem_op->op0), + new_mem_op->op0); + } + else + gcc_assert (tem.last ().opcode == STRING_CST); ops->pop (); ops->pop (); ops->safe_splice (tem); |