| /* |
| * Copyright © 2014 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. |
| * |
| * Authors: |
| * Jason Ekstrand (jason@jlekstrand.net) |
| * |
| */ |
| |
| #include "nir.h" |
| |
| /* |
| * This pass lowers the neg, abs, and sat operations to source modifiers on |
| * ALU operations to make things nicer for the backend. It's just much |
| * easier to not have them when we're doing optimizations. |
| */ |
| |
| static void |
| alu_src_consume_abs(nir_alu_src *src) |
| { |
| src->abs = true; |
| } |
| |
| static void |
| alu_src_consume_negate(nir_alu_src *src) |
| { |
| /* If abs is set on the source, the negate goes away */ |
| if (!src->abs) |
| src->negate = !src->negate; |
| } |
| |
| static bool |
| nir_lower_to_source_mods_block(nir_block *block, |
| nir_lower_to_source_mods_flags options) |
| { |
| bool progress = false; |
| |
| nir_foreach_instr(instr, block) { |
| if (instr->type != nir_instr_type_alu) |
| continue; |
| |
| nir_alu_instr *alu = nir_instr_as_alu(instr); |
| |
| bool lower_abs = (nir_op_infos[alu->op].num_inputs < 3) || |
| (options & nir_lower_triop_abs); |
| |
| for (unsigned i = 0; i < nir_op_infos[alu->op].num_inputs; i++) { |
| if (!alu->src[i].src.is_ssa) |
| continue; |
| |
| if (alu->src[i].src.ssa->parent_instr->type != nir_instr_type_alu) |
| continue; |
| |
| nir_alu_instr *parent = nir_instr_as_alu(alu->src[i].src.ssa->parent_instr); |
| |
| if (parent->dest.saturate) |
| continue; |
| |
| switch (nir_alu_type_get_base_type(nir_op_infos[alu->op].input_types[i])) { |
| case nir_type_float: |
| if (!(options & nir_lower_float_source_mods)) |
| continue; |
| if (parent->op != nir_op_fabs && parent->op != nir_op_fneg) |
| continue; |
| break; |
| case nir_type_int: |
| if (!(options & nir_lower_int_source_mods)) |
| continue; |
| if (parent->op != nir_op_iabs && parent->op != nir_op_ineg) |
| continue; |
| break; |
| default: |
| continue; |
| } |
| |
| /* We can only do a rewrite if the source we are copying is SSA. |
| * Otherwise, moving the read might invalidly reorder reads/writes |
| * on a register. |
| */ |
| if (!parent->src[0].src.is_ssa) |
| continue; |
| |
| if (!lower_abs && (parent->op == nir_op_fabs || |
| parent->op == nir_op_iabs)) |
| continue; |
| |
| nir_instr_rewrite_src(instr, &alu->src[i].src, parent->src[0].src); |
| |
| /* Apply any modifiers that come from the parent opcode */ |
| if (parent->op == nir_op_fneg || parent->op == nir_op_ineg) |
| alu_src_consume_negate(&alu->src[i]); |
| if (parent->op == nir_op_fabs || parent->op == nir_op_iabs) |
| alu_src_consume_abs(&alu->src[i]); |
| |
| /* Apply modifiers from the parent source */ |
| if (parent->src[0].negate) |
| alu_src_consume_negate(&alu->src[i]); |
| if (parent->src[0].abs) |
| alu_src_consume_abs(&alu->src[i]); |
| |
| for (int j = 0; j < 4; ++j) { |
| if (!nir_alu_instr_channel_used(alu, i, j)) |
| continue; |
| alu->src[i].swizzle[j] = parent->src[0].swizzle[alu->src[i].swizzle[j]]; |
| } |
| |
| if (list_is_empty(&parent->dest.dest.ssa.uses) && |
| list_is_empty(&parent->dest.dest.ssa.if_uses)) |
| nir_instr_remove(&parent->instr); |
| |
| progress = true; |
| } |
| |
| /* We've covered sources. Now we're going to try and saturate the |
| * destination if we can. |
| */ |
| |
| if (!alu->dest.dest.is_ssa) |
| continue; |
| |
| /* We can only saturate float destinations */ |
| if (nir_alu_type_get_base_type(nir_op_infos[alu->op].output_type) != |
| nir_type_float) |
| continue; |
| |
| if (!(options & nir_lower_float_source_mods)) |
| continue; |
| |
| if (!list_is_empty(&alu->dest.dest.ssa.if_uses)) |
| continue; |
| |
| bool all_children_are_sat = true; |
| nir_foreach_use(child_src, &alu->dest.dest.ssa) { |
| assert(child_src->is_ssa); |
| nir_instr *child = child_src->parent_instr; |
| if (child->type != nir_instr_type_alu) { |
| all_children_are_sat = false; |
| continue; |
| } |
| |
| nir_alu_instr *child_alu = nir_instr_as_alu(child); |
| if (child_alu->src[0].negate || child_alu->src[0].abs) { |
| all_children_are_sat = false; |
| continue; |
| } |
| |
| if (child_alu->op != nir_op_fsat) { |
| all_children_are_sat = false; |
| continue; |
| } |
| } |
| |
| if (!all_children_are_sat) |
| continue; |
| |
| alu->dest.saturate = true; |
| progress = true; |
| |
| nir_foreach_use(child_src, &alu->dest.dest.ssa) { |
| assert(child_src->is_ssa); |
| nir_alu_instr *child_alu = nir_instr_as_alu(child_src->parent_instr); |
| |
| child_alu->op = nir_op_mov; |
| child_alu->dest.saturate = false; |
| /* We could propagate the dest of our instruction to the |
| * destinations of the uses here. However, one quick round of |
| * copy propagation will clean that all up and then we don't have |
| * the complexity. |
| */ |
| } |
| } |
| |
| return progress; |
| } |
| |
| static bool |
| nir_lower_to_source_mods_impl(nir_function_impl *impl, |
| nir_lower_to_source_mods_flags options) |
| { |
| bool progress = false; |
| |
| nir_foreach_block(block, impl) { |
| progress |= nir_lower_to_source_mods_block(block, options); |
| } |
| |
| if (progress) |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| |
| return progress; |
| } |
| |
| bool |
| nir_lower_to_source_mods(nir_shader *shader, |
| nir_lower_to_source_mods_flags options) |
| { |
| bool progress = false; |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl) { |
| progress |= nir_lower_to_source_mods_impl(function->impl, options); |
| } |
| } |
| |
| return progress; |
| } |
