diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp | 91 |
1 files changed, 47 insertions, 44 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 ca9376f8a77..5c16798d68b 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_register_coalesce.cpp @@ -65,6 +65,51 @@ is_coalesce_candidate(const fs_inst *inst, const int *virtual_grf_sizes) return true; } +static bool +can_coalesce_vars(brw::fs_live_variables *live_intervals, + const exec_list *instructions, const fs_inst *inst, + int var_to, int var_from) +{ + if (live_intervals->vars_interfere(var_from, var_to) && + !inst->dst.equals(inst->src[0])) { + + /* 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]) + return false; + + int scan_ip = -1; + + foreach_list(n, instructions) { + fs_inst *scan_inst = (fs_inst *)n; + scan_ip++; + + if (scan_inst->is_control_flow()) + return false; + + if (scan_ip <= live_intervals->start[var_to]) + continue; + + if (scan_ip > live_intervals->end[var_to]) + break; + + if (scan_inst->dst.equals(inst->dst) || + scan_inst->dst.equals(inst->src[0])) + return false; + } + } + + return true; +} + bool fs_visitor::register_coalesce() { @@ -87,50 +132,8 @@ fs_visitor::register_coalesce() int var_from = live_intervals->var_from_reg(&inst->src[0]); int var_to = live_intervals->var_from_reg(&inst->dst); - if (live_intervals->vars_interfere(var_from, var_to) && - !inst->dst.equals(inst->src[0])) { - - /* 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]) - continue; - - bool overwritten = false; - int scan_ip = -1; - - foreach_list(n, &this->instructions) { - fs_inst *scan_inst = (fs_inst *)n; - scan_ip++; - - if (scan_inst->is_control_flow()) { - overwritten = true; - break; - } - - if (scan_ip <= live_intervals->start[var_to]) - continue; - - if (scan_ip > live_intervals->end[var_to]) - break; - - if (scan_inst->dst.equals(inst->dst) || - scan_inst->dst.equals(inst->src[0])) { - overwritten = true; - break; - } - } - - if (overwritten) - continue; - } + if (!can_coalesce_vars(live_intervals, &instructions, inst, var_to, var_from)) + continue; if (reg_from != inst->src[0].reg) { reg_from = inst->src[0].reg; |