diff options
Diffstat (limited to 'src/compiler/nir/nir_lower_to_source_mods.c')
| -rw-r--r-- | src/compiler/nir/nir_lower_to_source_mods.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_lower_to_source_mods.c b/src/compiler/nir/nir_lower_to_source_mods.c new file mode 100644 index 00000000000..6c4e1f0d3f3 --- /dev/null +++ b/src/compiler/nir/nir_lower_to_source_mods.c @@ -0,0 +1,196 @@ +/* + * 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 bool +nir_lower_to_source_mods_block(nir_block *block, void *state) +{ + nir_foreach_instr(block, instr) { + if (instr->type != nir_instr_type_alu) + continue; + + nir_alu_instr *alu = nir_instr_as_alu(instr); + + 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_op_infos[alu->op].input_types[i]) { + case nir_type_float: + if (parent->op != nir_op_fmov) + continue; + break; + case nir_type_int: + if (parent->op != nir_op_imov) + 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; + + nir_instr_rewrite_src(instr, &alu->src[i].src, parent->src[0].src); + if (alu->src[i].abs) { + /* abs trumps both neg and abs, do nothing */ + } else { + alu->src[i].negate = (alu->src[i].negate != parent->src[0].negate); + alu->src[i].abs |= parent->src[0].abs; + } + + 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_empty(&parent->dest.dest.ssa.uses) && + list_empty(&parent->dest.dest.ssa.if_uses)) + nir_instr_remove(&parent->instr); + } + + switch (alu->op) { + case nir_op_fsat: + alu->op = nir_op_fmov; + alu->dest.saturate = true; + break; + case nir_op_ineg: + alu->op = nir_op_imov; + alu->src[0].negate = !alu->src[0].negate; + break; + case nir_op_fneg: + alu->op = nir_op_fmov; + alu->src[0].negate = !alu->src[0].negate; + break; + case nir_op_iabs: + alu->op = nir_op_imov; + alu->src[0].abs = true; + alu->src[0].negate = false; + break; + case nir_op_fabs: + alu->op = nir_op_fmov; + alu->src[0].abs = true; + alu->src[0].negate = false; + break; + default: + break; + } + + /* 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_op_infos[alu->op].output_type != nir_type_float) + continue; + + if (!list_empty(&alu->dest.dest.ssa.if_uses)) + continue; + + bool all_children_are_sat = true; + nir_foreach_use(&alu->dest.dest.ssa, child_src) { + 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 && + !(child_alu->op == nir_op_fmov && child_alu->dest.saturate)) { + all_children_are_sat = false; + continue; + } + } + + if (!all_children_are_sat) + continue; + + alu->dest.saturate = true; + + nir_foreach_use(&alu->dest.dest.ssa, child_src) { + assert(child_src->is_ssa); + nir_instr *child = child_src->parent_instr; + assert(child->type == nir_instr_type_alu); + nir_alu_instr *child_alu = nir_instr_as_alu(child); + + child_alu->op = nir_op_fmov; + 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 true; +} + +static void +nir_lower_to_source_mods_impl(nir_function_impl *impl) +{ + nir_foreach_block(impl, nir_lower_to_source_mods_block, NULL); +} + +void +nir_lower_to_source_mods(nir_shader *shader) +{ + nir_foreach_function(shader, function) { + if (function->impl) + nir_lower_to_source_mods_impl(function->impl); + } +} |