diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2008-11-17 20:58:52 +0000 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2008-11-17 20:58:52 +0000 |
| commit | ba6b10e3505f55abe1e9764932b06d1898f354dd (patch) | |
| tree | 2fda85eef94cf204f819a91ac43fc189c8adafb3 | |
| parent | 0265d301dab7f232f3f2b4846d3c93cd11b1a678 (diff) | |
PR middle-end/38140
* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): If
propagating x = &a into *x = b, add a cast if not useless
type conversion or don't optimize if another stmt would be
needed.
* gcc.dg/pr38140.c: New test.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@141949 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr38140.c | 10 | ||||
| -rw-r--r-- | gcc/tree-ssa-forwprop.c | 27 |
4 files changed, 44 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a916993a799..ff382751044 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2008-11-17 Jakub Jelinek <jakub@redhat.com> + + PR middle-end/38140 + * tree-ssa-forwprop.c (forward_propagate_addr_expr_1): If + propagating x = &a into *x = b, add a cast if not useless + type conversion or don't optimize if another stmt would be + needed. + 2008-11-17 Uros Bizjak <ubizjak@gmail.com> PR middle-end/37908 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0c0dc1d0a5c..00b7cef1442 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2008-11-17 Jakub Jelinek <jakub@redhat.com> + + PR middle-end/38140 + * gcc.dg/pr38140.c: New test. + 2008-11-17 Jack Howarth <howarth@bromo.med.uc.edu> PR testsuite/38099 diff --git a/gcc/testsuite/gcc.dg/pr38140.c b/gcc/testsuite/gcc.dg/pr38140.c new file mode 100644 index 00000000000..35f6010089e --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr38140.c @@ -0,0 +1,10 @@ +/* PR middle-end/38140 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-strict-aliasing" } */ + +int foo (void *x) +{ + int (*fn) (int); + *(void **)&fn = x; + return fn (6); +} diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 5626b103429..333ef828473 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -721,13 +721,28 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs, && TREE_OPERAND (lhs, 0) == name && may_propagate_address_into_dereference (def_rhs, lhs)) { - *lhsp = unshare_expr (TREE_OPERAND (def_rhs, 0)); - fold_stmt_inplace (use_stmt); - tidy_after_forward_propagate_addr (use_stmt); + bool valid = true; + if (lhsp == gimple_assign_lhs_ptr (use_stmt) + && !useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (def_rhs, 0)), + TREE_TYPE (rhs)) + && !CONVERT_EXPR_CODE_P (rhs_code)) + { + if (rhs_code == SSA_NAME) + gimple_assign_set_rhs_code (use_stmt, NOP_EXPR); + else + valid = false; + } + if (valid) + { + *lhsp = unshare_expr (TREE_OPERAND (def_rhs, 0)); + fold_stmt_inplace (use_stmt); + tidy_after_forward_propagate_addr (use_stmt); - /* Continue propagating into the RHS if this was not the only use. */ - if (single_use_p) - return true; + /* Continue propagating into the RHS if this was not the only + use. */ + if (single_use_p) + return true; + } } /* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR |