From ea811b7868d4039499dddf53c109cf0b9da98967 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 27 Mar 2015 14:18:11 -0700 Subject: [PATCH] nir: Add a lowering pass for texture projectors. Not much hardware wants them these days, and it might give us a chance to do CSE or algebraic at the NIR level. Reviewed-by: Jason Ekstrand --- src/glsl/Makefile.sources | 1 + src/glsl/nir/nir.h | 1 + src/glsl/nir/nir_lower_tex_projector.c | 142 +++++++++++++++++++++++++ 3 files changed, 144 insertions(+) create mode 100644 src/glsl/nir/nir_lower_tex_projector.c diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources index b56fa2608ea..ffce706fa22 100644 --- a/src/glsl/Makefile.sources +++ b/src/glsl/Makefile.sources @@ -37,6 +37,7 @@ NIR_FILES = \ nir/nir_lower_phis_to_scalar.c \ nir/nir_lower_samplers.cpp \ nir/nir_lower_system_values.c \ + nir/nir_lower_tex_projector.c \ nir/nir_lower_to_source_mods.c \ nir/nir_lower_vars_to_ssa.c \ nir/nir_lower_var_copies.c \ diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h index 24deb82d2e7..6e2aa97d498 100644 --- a/src/glsl/nir/nir.h +++ b/src/glsl/nir/nir.h @@ -1601,6 +1601,7 @@ void nir_lower_samplers(nir_shader *shader, struct gl_program *prog); void nir_lower_system_values(nir_shader *shader); +void nir_lower_tex_projector(nir_shader *shader); void nir_lower_atomics(nir_shader *shader); void nir_lower_to_source_mods(nir_shader *shader); diff --git a/src/glsl/nir/nir_lower_tex_projector.c b/src/glsl/nir/nir_lower_tex_projector.c new file mode 100644 index 00000000000..6327b23f6a5 --- /dev/null +++ b/src/glsl/nir/nir_lower_tex_projector.c @@ -0,0 +1,142 @@ +/* + * Copyright © 2015 Broadcom + * + * 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. + */ + +/* + * This lowering pass converts the coordinate division for texture projection + * to be done in ALU instructions instead of asking the texture operation to + * do so. + */ + +#include "nir.h" +#include "nir_builder.h" + +static nir_ssa_def * +channel(nir_builder *b, nir_ssa_def *def, int c) +{ + return nir_swizzle(b, def, (unsigned[4]){c, c, c, c}, 1, false); +} + +static bool +nir_lower_tex_projector_block(nir_block *block, void *void_state) +{ + nir_builder *b = void_state; + + nir_foreach_instr_safe(block, instr) { + if (instr->type != nir_instr_type_tex) + continue; + + nir_tex_instr *tex = nir_instr_as_tex(instr); + nir_builder_insert_before_instr(b, &tex->instr); + + /* Find the projector in the srcs list, if present. */ + int proj_index; + for (proj_index = 0; proj_index < tex->num_srcs; proj_index++) { + if (tex->src[proj_index].src_type == nir_tex_src_projector) + break; + } + if (proj_index == tex->num_srcs) + continue; + nir_ssa_def *inv_proj = + nir_frcp(b, nir_ssa_for_src(b, tex->src[proj_index].src, 1)); + + /* Walk through the sources projecting the arguments. */ + for (int i = 0; i < tex->num_srcs; i++) { + switch (tex->src[i].src_type) { + case nir_tex_src_coord: + case nir_tex_src_comparitor: + break; + default: + continue; + } + nir_ssa_def *unprojected = + nir_ssa_for_src(b, tex->src[i].src, nir_tex_instr_src_size(tex, i)); + nir_ssa_def *projected = nir_fmul(b, unprojected, inv_proj); + + /* Array indices don't get projected, so make an new vector with the + * coordinate's array index untouched. + */ + if (tex->is_array && tex->src[i].src_type == nir_tex_src_coord) { + switch (tex->coord_components) { + case 4: + projected = nir_vec4(b, + channel(b, projected, 0), + channel(b, projected, 1), + channel(b, projected, 2), + channel(b, unprojected, 3)); + break; + case 3: + projected = nir_vec3(b, + channel(b, projected, 0), + channel(b, projected, 1), + channel(b, unprojected, 2)); + break; + case 2: + projected = nir_vec2(b, + channel(b, projected, 0), + channel(b, unprojected, 1)); + break; + default: + unreachable("bad texture coord count for array"); + break; + } + } + + nir_instr_rewrite_src(&tex->instr, + &tex->src[i].src, + nir_src_for_ssa(projected)); + } + + /* Now move the later tex sources down the array so that the projector + * disappears. + */ + nir_src dead = {.is_ssa = false, .ssa = NULL}; + nir_instr_rewrite_src(&tex->instr, &tex->src[proj_index].src, dead); + memmove(&tex->src[proj_index], + &tex->src[proj_index + 1], + (tex->num_srcs - proj_index) * sizeof(*tex->src)); + tex->num_srcs--; + } + + return true; +} + +static void +nir_lower_tex_projector_impl(nir_function_impl *impl) +{ + nir_builder b; + nir_builder_init(&b, impl); + + nir_foreach_block(impl, nir_lower_tex_projector_block, &b); + + nir_metadata_preserve(impl, nir_metadata_block_index | + nir_metadata_dominance); +} + +void +nir_lower_tex_projector(nir_shader *shader) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_lower_tex_projector_impl(overload->impl); + } +} -- 2.30.2