diff options
Diffstat (limited to 'gcc/gimple-ssa-strength-reduction.c')
| -rw-r--r-- | gcc/gimple-ssa-strength-reduction.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/gcc/gimple-ssa-strength-reduction.c b/gcc/gimple-ssa-strength-reduction.c index 9a53bf7..edb1afc 100644 --- a/gcc/gimple-ssa-strength-reduction.c +++ b/gcc/gimple-ssa-strength-reduction.c @@ -1882,6 +1882,7 @@ replace_mult_candidate (slsr_cand_t c, tree basis_name, double_int bump) gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt); gimple_set_location (copy_stmt, gimple_location (c->cand_stmt)); gsi_replace (&gsi, copy_stmt, false); + c->cand_stmt = copy_stmt; if (dump_file && (dump_flags & TDF_DETAILS)) stmt_to_print = copy_stmt; } @@ -2179,6 +2180,18 @@ phi_add_costs (gimple phi, slsr_cand_t c, int one_add_cost) int cost = 0; slsr_cand_t phi_cand = base_cand_from_table (gimple_phi_result (phi)); + /* If we work our way back to a phi that isn't dominated by the hidden + basis, this isn't a candidate for replacement. Indicate this by + returning an unreasonably high cost. It's not easy to detect + these situations when determining the basis, so we defer the + decision until now. */ + basic_block phi_bb = gimple_bb (phi); + slsr_cand_t basis = lookup_cand (c->basis); + basic_block basis_bb = gimple_bb (basis->cand_stmt); + + if (phi_bb == basis_bb || !dominated_by_p (CDI_DOMINATORS, phi_bb, basis_bb)) + return COST_INFINITE; + for (i = 0; i < gimple_phi_num_args (phi); i++) { tree arg = gimple_phi_arg_def (phi, i); @@ -3226,6 +3239,7 @@ replace_one_candidate (slsr_cand_t c, unsigned i, tree basis_name) gimple_stmt_iterator gsi = gsi_for_stmt (c->cand_stmt); gimple_set_location (copy_stmt, gimple_location (c->cand_stmt)); gsi_replace (&gsi, copy_stmt, false); + c->cand_stmt = copy_stmt; if (dump_file && (dump_flags & TDF_DETAILS)) stmt_to_print = copy_stmt; @@ -3238,6 +3252,7 @@ replace_one_candidate (slsr_cand_t c, unsigned i, tree basis_name) NULL_TREE); gimple_set_location (cast_stmt, gimple_location (c->cand_stmt)); gsi_replace (&gsi, cast_stmt, false); + c->cand_stmt = cast_stmt; if (dump_file && (dump_flags & TDF_DETAILS)) stmt_to_print = cast_stmt; |