/* * 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; }