diff options
Diffstat (limited to 'gcc/tree-outof-ssa.c')
| -rw-r--r-- | gcc/tree-outof-ssa.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/gcc/tree-outof-ssa.c b/gcc/tree-outof-ssa.c index 65c74d310a4..c6aa812bc17 100644 --- a/gcc/tree-outof-ssa.c +++ b/gcc/tree-outof-ssa.c @@ -1659,8 +1659,23 @@ find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb) { if (tab->version_info[SSA_NAME_VERSION (def)]) { - /* Mark expression as replaceable unless stmt is volatile. */ - if (!ann->has_volatile_ops) + bool same_root_var = false; + tree def2; + ssa_op_iter iter2; + + /* See if the root variables are the same. If they are, we + do not want to do the replacement to avoid problems with + code size, see PR tree-optimization/17549. */ + FOR_EACH_SSA_TREE_OPERAND (def2, stmt, iter2, SSA_OP_DEF) + if (SSA_NAME_VAR (def) == SSA_NAME_VAR (def2)) + { + same_root_var = true; + break; + } + + /* Mark expression as replaceable unless stmt is volatile + or DEF sets the same root variable as STMT. */ + if (!ann->has_volatile_ops && !same_root_var) mark_replaceable (tab, def); else finish_expr (tab, SSA_NAME_VERSION (def), false); |