diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp index e242e4fbccd..3e3aeca1f8e 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp @@ -118,24 +118,25 @@ can_coalesce_vars(brw::fs_live_variables *live_intervals, if (!live_intervals->vars_interfere(var_from, var_to)) return true; - /* We know that the live ranges of A (var_from) and B (var_to) - * interfere because of the ->vars_interfere() call above. If the end - * of B's live range is after the end of A's range, then we know two - * things: - * - the start of B's live range must be in A's live range (since we - * already know the two ranges interfere, this is the only remaining - * possibility) - * - the interference isn't of the form we're looking for (where B is - * entirely inside A) - */ - if (live_intervals->end[var_to] > live_intervals->end[var_from]) + int start_to = live_intervals->start[var_to]; + int end_to = live_intervals->end[var_to]; + int start_from = live_intervals->start[var_from]; + int end_from = live_intervals->end[var_from]; + + /* Variables interfere and one line range isn't a subset of the other. */ + if ((end_to > end_from && start_from < start_to) || + (end_from > end_to && start_to < start_from)) return false; + int start_ip = MIN2(start_to, start_from); int scan_ip = -1; foreach_in_list(fs_inst, scan_inst, instructions) { scan_ip++; + if (scan_ip < start_ip) + continue; + if (scan_inst->is_control_flow()) return false; |