| /* |
| * Copyright © 2013 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include "brw_fs.h" |
| #include "brw_fs_live_variables.h" |
| #include "brw_cfg.h" |
| |
| /** @file brw_fs_saturate_propagation.cpp |
| * |
| * Implements a pass that propagates the SAT modifier from a MOV.SAT into the |
| * instruction that produced the source of the MOV.SAT, thereby allowing the |
| * MOV's src and dst to be coalesced and the MOV removed. |
| * |
| * For instance, |
| * |
| * ADD tmp, src0, src1 |
| * MOV.SAT dst, tmp |
| * |
| * would be transformed into |
| * |
| * ADD.SAT tmp, src0, src1 |
| * MOV dst, tmp |
| */ |
| |
| static bool |
| opt_saturate_propagation_local(fs_visitor *v, bblock_t *block) |
| { |
| bool progress = false; |
| int ip = block->end_ip + 1; |
| |
| foreach_inst_in_block_reverse(fs_inst, inst, block) { |
| ip--; |
| |
| if (inst->opcode != BRW_OPCODE_MOV || |
| !inst->saturate || |
| inst->dst.file != VGRF || |
| inst->dst.type != inst->src[0].type || |
| inst->src[0].file != VGRF || |
| inst->src[0].abs) |
| continue; |
| |
| int src_var = v->live_intervals->var_from_reg(inst->src[0]); |
| int src_end_ip = v->live_intervals->end[src_var]; |
| |
| bool interfered = false; |
| foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst) { |
| if (scan_inst->overwrites_reg(inst->src[0])) { |
| if (scan_inst->is_partial_write() || |
| (scan_inst->dst.type != inst->dst.type && |
| !scan_inst->can_change_types())) |
| break; |
| |
| if (scan_inst->saturate) { |
| inst->saturate = false; |
| progress = true; |
| } else if (src_end_ip == ip || inst->dst.equals(inst->src[0])) { |
| if (scan_inst->can_do_saturate()) { |
| if (scan_inst->dst.type != inst->dst.type) { |
| scan_inst->dst.type = inst->dst.type; |
| for (int i = 0; i < scan_inst->sources; i++) { |
| scan_inst->src[i].type = inst->dst.type; |
| } |
| } |
| |
| if (inst->src[0].negate) { |
| if (scan_inst->opcode == BRW_OPCODE_MUL) { |
| scan_inst->src[0].negate = !scan_inst->src[0].negate; |
| inst->src[0].negate = false; |
| } else if (scan_inst->opcode == BRW_OPCODE_MAD) { |
| scan_inst->src[0].negate = !scan_inst->src[0].negate; |
| scan_inst->src[1].negate = !scan_inst->src[1].negate; |
| inst->src[0].negate = false; |
| } else if (scan_inst->opcode == BRW_OPCODE_ADD) { |
| if (scan_inst->src[1].file == IMM) { |
| if (!brw_negate_immediate(scan_inst->src[1].type, |
| &scan_inst->src[1].as_brw_reg())) { |
| break; |
| } |
| } else { |
| scan_inst->src[1].negate = !scan_inst->src[1].negate; |
| } |
| scan_inst->src[0].negate = !scan_inst->src[0].negate; |
| inst->src[0].negate = false; |
| } else { |
| break; |
| } |
| } |
| |
| scan_inst->saturate = true; |
| inst->saturate = false; |
| progress = true; |
| } |
| } |
| break; |
| } |
| for (int i = 0; i < scan_inst->sources; i++) { |
| if (scan_inst->src[i].file == VGRF && |
| scan_inst->src[i].nr == inst->src[0].nr && |
| scan_inst->src[i].reg_offset == inst->src[0].reg_offset) { |
| if (scan_inst->opcode != BRW_OPCODE_MOV || |
| !scan_inst->saturate || |
| scan_inst->src[0].abs || |
| scan_inst->src[0].negate || |
| scan_inst->src[0].abs != inst->src[0].abs || |
| scan_inst->src[0].negate != inst->src[0].negate) { |
| interfered = true; |
| break; |
| } |
| } |
| } |
| |
| if (interfered) |
| break; |
| } |
| } |
| |
| return progress; |
| } |
| |
| bool |
| fs_visitor::opt_saturate_propagation() |
| { |
| bool progress = false; |
| |
| calculate_live_intervals(); |
| |
| foreach_block (block, cfg) { |
| progress = opt_saturate_propagation_local(this, block) || progress; |
| } |
| |
| /* Live intervals are still valid. */ |
| |
| return progress; |
| } |