diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.cpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index bc49ee8fe0d..11a5a4aceff 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -466,6 +466,7 @@ public: void assign_regs_trivial(); void calculate_live_intervals(); bool propagate_constants(); + bool register_coalesce(); bool dead_code_eliminate(); bool virtual_grf_interferes(int a, int b); void generate_code(); @@ -2719,6 +2720,84 @@ fs_visitor::dead_code_eliminate() } bool +fs_visitor::register_coalesce() +{ + bool progress = false; + + foreach_iter(exec_list_iterator, iter, this->instructions) { + fs_inst *inst = (fs_inst *)iter.get(); + + if (inst->opcode != BRW_OPCODE_MOV || + inst->predicated || + inst->saturate || + inst->dst.file != GRF || inst->src[0].file != GRF || + inst->dst.type != inst->src[0].type) + continue; + + /* Found a move of a GRF to a GRF. Let's see if we can coalesce + * them: check for no writes to either one until the exit of the + * program. + */ + bool interfered = false; + exec_list_iterator scan_iter = iter; + scan_iter.next(); + for (; scan_iter.has_next(); scan_iter.next()) { + fs_inst *scan_inst = (fs_inst *)scan_iter.get(); + + if (scan_inst->opcode == BRW_OPCODE_DO || + scan_inst->opcode == BRW_OPCODE_WHILE || + scan_inst->opcode == BRW_OPCODE_ENDIF) { + interfered = true; + iter = scan_iter; + break; + } + + if (scan_inst->dst.file == GRF) { + if (scan_inst->dst.reg == inst->dst.reg && + (scan_inst->dst.reg_offset == inst->dst.reg_offset || + scan_inst->opcode == FS_OPCODE_TEX)) { + interfered = true; + break; + } + if (scan_inst->dst.reg == inst->src[0].reg && + (scan_inst->dst.reg_offset == inst->src[0].reg_offset || + scan_inst->opcode == FS_OPCODE_TEX)) { + interfered = true; + break; + } + } + } + if (interfered) { + continue; + } + + /* Rewrite the later usage to point at the source of the move to + * be removed. + */ + for (exec_list_iterator scan_iter = iter; scan_iter.has_next(); + scan_iter.next()) { + fs_inst *scan_inst = (fs_inst *)scan_iter.get(); + + for (int i = 0; i < 3; i++) { + if (scan_inst->src[i].file == GRF && + scan_inst->src[i].reg == inst->dst.reg && + scan_inst->src[i].reg_offset == inst->dst.reg_offset) { + scan_inst->src[i].reg = inst->src[0].reg; + scan_inst->src[i].reg_offset = inst->src[0].reg_offset; + scan_inst->src[i].abs |= inst->src[0].abs; + scan_inst->src[i].negate ^= inst->src[0].negate; + } + } + } + + inst->remove(); + progress = true; + } + + return progress; +} + +bool fs_visitor::virtual_grf_interferes(int a, int b) { int start = MAX2(this->virtual_grf_def[a], this->virtual_grf_def[b]); @@ -3047,6 +3126,7 @@ brw_wm_fs_emit(struct brw_context *brw, struct brw_wm_compile *c) v.calculate_live_intervals(); progress = v.propagate_constants() || progress; + progress = v.register_coalesce() || progress; progress = v.dead_code_eliminate() || progress; } while (progress); |