diff options
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index 7787da8..ce84048 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -1106,10 +1106,13 @@ record_equivalences_from_phis (basic_block bb) { gphi_iterator gsi; - for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); ) { gphi *phi = gsi.phi (); + /* We might eliminate the PHI, so advance GSI now. */ + gsi_next (&gsi); + tree lhs = gimple_phi_result (phi); tree rhs = NULL; size_t i; @@ -1159,9 +1162,26 @@ record_equivalences_from_phis (basic_block bb) this, since this is a true assignment and not an equivalence inferred from a comparison. All uses of this ssa name are dominated by this assignment, so unwinding just costs time and space. */ - if (i == gimple_phi_num_args (phi) - && may_propagate_copy (lhs, rhs)) - set_ssa_name_value (lhs, rhs); + if (i == gimple_phi_num_args (phi)) + { + if (may_propagate_copy (lhs, rhs)) + set_ssa_name_value (lhs, rhs); + else if (virtual_operand_p (lhs)) + { + gimple *use_stmt; + imm_use_iterator iter; + use_operand_p use_p; + /* For virtual operands we have to propagate into all uses as + otherwise we will create overlapping life-ranges. */ + FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) + FOR_EACH_IMM_USE_ON_STMT (use_p, iter) + SET_USE (use_p, rhs); + if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) + SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1; + gimple_stmt_iterator tmp_gsi = gsi_for_stmt (phi); + remove_phi_node (&tmp_gsi, true); + } + } } } |