From 947c828d5cbffe9640ac63103a6223112eeff27f Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Thu, 12 Dec 2013 00:30:16 -0800 Subject: [PATCH] i965/fs: Add a saturation propagation optimization pass. Transforms, for example, mul vgrf3, vgrf2, vgrf1 mov.sat vgrf4, vgrf3 into mul.sat vgrf3, vgrf2, vgrf1 mov vgrf4, vgrf3 which gives register_coalescing an opportunity to remove the MOV instruction. total instructions in shared programs: 1515039 -> 1504634 (-0.69%) instructions in affected programs: 798586 -> 788181 (-1.30%) GAINED: 0 LOST: 4 Reviewed-by: Jordan Justen --- src/mesa/drivers/dri/i965/Makefile.sources | 1 + src/mesa/drivers/dri/i965/brw_fs.cpp | 1 + src/mesa/drivers/dri/i965/brw_fs.h | 1 + .../dri/i965/brw_fs_saturate_propagation.cpp | 104 ++++++++++++++++++ 4 files changed, 107 insertions(+) create mode 100644 src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources index a3fb4172edc..4c5a2a0b20b 100644 --- a/src/mesa/drivers/dri/i965/Makefile.sources +++ b/src/mesa/drivers/dri/i965/Makefile.sources @@ -63,6 +63,7 @@ i965_FILES = \ brw_fs_live_variables.cpp \ brw_fs_peephole_predicated_break.cpp \ brw_fs_reg_allocate.cpp \ + brw_fs_saturate_propagation.cpp \ brw_fs_sel_peephole.cpp \ brw_fs_vector_splitting.cpp \ brw_fs_visitor.cpp \ diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 1e6c3e0b1d0..d7301dd0a12 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -3362,6 +3362,7 @@ fs_visitor::run() progress = dead_code_eliminate_local() || progress; progress = opt_peephole_sel() || progress; progress = dead_control_flow_eliminate(this) || progress; + progress = opt_saturate_propagation() || progress; progress = register_coalesce() || progress; progress = compute_to_mrf() || progress; } while (progress); diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h index 2ccb8c4585d..9c5c13ae393 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.h +++ b/src/mesa/drivers/dri/i965/brw_fs.h @@ -371,6 +371,7 @@ public: void try_replace_with_sel(); bool opt_peephole_sel(); bool opt_peephole_predicated_break(); + bool opt_saturate_propagation(); void emit_bool_to_cond_code(ir_rvalue *condition); void emit_if_gen6(ir_if *ir); void emit_unspill(fs_inst *inst, fs_reg reg, uint32_t spill_offset, diff --git a/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp new file mode 100644 index 00000000000..9c2e4512578 --- /dev/null +++ b/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp @@ -0,0 +1,104 @@ +/* + * 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 + */ + +static bool +opt_saturate_propagation_local(fs_visitor *v, bblock_t *block) +{ + bool progress = false; + int ip = block->start_ip; + + for (fs_inst *inst = (fs_inst *)block->start; + inst != block->end->next; + inst = (fs_inst *) inst->next) { + ip++; + + if (inst->opcode != BRW_OPCODE_MOV || + inst->dst.file != GRF || + !inst->saturate) + continue; + + int src_var = v->live_intervals->var_from_reg(&inst->src[0]); + int src_end_ip = v->live_intervals->end[src_var]; + if (src_end_ip > ip && !inst->dst.equals(inst->src[0])) + continue; + + int scan_ip = ip; + bool interfered = false; + for (fs_inst *scan_inst = (fs_inst *) inst->prev; + scan_inst != block->start->prev; + scan_inst = (fs_inst *) scan_inst->prev) { + scan_ip--; + + if (scan_inst->dst.file == GRF && + scan_inst->dst.reg == inst->src[0].reg && + scan_inst->dst.reg_offset == inst->src[0].reg_offset) { + if (scan_inst->can_do_saturate()) { + scan_inst->saturate = true; + inst->saturate = false; + progress = true; + } + break; + } + for (int i = 0; i < 3; i++) { + if (scan_inst->src[i].file == GRF && + scan_inst->src[i].reg == inst->src[0].reg && + scan_inst->src[i].reg_offset == inst->src[0].reg_offset) { + interfered = true; + break; + } + } + + if (interfered) + break; + } + } + + return progress; +} + +bool +fs_visitor::opt_saturate_propagation() +{ + bool progress = false; + + calculate_live_intervals(); + + cfg_t cfg(&instructions); + + for (int b = 0; b < cfg.num_blocks; b++) { + progress = opt_saturate_propagation_local(this, cfg.blocks[b]) + || progress; + } + + if (progress) + invalidate_live_intervals(); + + return progress; +} -- 2.30.2