diff options
Diffstat (limited to 'gcc-4.8/gcc/tree-ssa-phiprop.c')
| -rw-r--r-- | gcc-4.8/gcc/tree-ssa-phiprop.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/gcc-4.8/gcc/tree-ssa-phiprop.c b/gcc-4.8/gcc/tree-ssa-phiprop.c index 4da181487..36b47d7f0 100644 --- a/gcc-4.8/gcc/tree-ssa-phiprop.c +++ b/gcc-4.8/gcc/tree-ssa-phiprop.c @@ -307,6 +307,12 @@ propagate_with_phi (basic_block bb, gimple phi, struct phiprop_d *phivn, gimple def_stmt; tree vuse; + /* Only replace loads in blocks that post-dominate the PHI node. That + makes sure we don't end up speculating loads. */ + if (!dominated_by_p (CDI_POST_DOMINATORS, + bb, gimple_bb (use_stmt))) + continue; + /* Check whether this is a load of *ptr. */ if (!(is_gimple_assign (use_stmt) && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME @@ -378,6 +384,7 @@ tree_ssa_phiprop (void) size_t n; calculate_dominance_info (CDI_DOMINATORS); + calculate_dominance_info (CDI_POST_DOMINATORS); n = num_ssa_names; phivn = XCNEWVEC (struct phiprop_d, n); @@ -395,6 +402,8 @@ tree_ssa_phiprop (void) bbs.release (); free (phivn); + free_dominance_info (CDI_POST_DOMINATORS); + return 0; } |