diff options
Diffstat (limited to 'src/compiler/nir/nir_lower_ssbo.c')
| -rw-r--r-- | src/compiler/nir/nir_lower_ssbo.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_lower_ssbo.c b/src/compiler/nir/nir_lower_ssbo.c new file mode 100644 index 00000000000..ab22317caf3 --- /dev/null +++ b/src/compiler/nir/nir_lower_ssbo.c @@ -0,0 +1,162 @@ +/* + * Copyright © 2019 Collabora, Ltd. + * + * 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 (Collabora): + * Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> + */ + +#include "nir.h" +#include "nir_builder.h" + +/* + * Lowers SSBOs to globals, for hardware that lack native SSBO support. When + * lowering, *_ssbo_* instructions will become *_global_* instructions, + * augmented with load_ssbo_address. + * + * DOES NOT PERFORM BOUNDS CHECKING. DO NOT USE IN PRODUCTION ON UNTRUSTED + * CONTEXTS INCLUDING WEBGL 2. + */ + +static nir_intrinsic_op +lower_ssbo_op(nir_intrinsic_op op) +{ + switch (op) { + case nir_intrinsic_load_ssbo: + return nir_intrinsic_load_global; + + case nir_intrinsic_store_ssbo: + return nir_intrinsic_store_global; + + default: + unreachable("Invalid SSBO op"); + } +} + +/* Like SSBO property sysvals, though SSBO index may be indirect. C.f. + * nir_load_system_value */ + +static inline nir_ssa_def * +nir_load_ssbo_prop(nir_builder *b, nir_intrinsic_op op, + nir_src *idx, unsigned bitsize) +{ + nir_intrinsic_instr *load = nir_intrinsic_instr_create(b->shader, op); + load->num_components = 1; + nir_src_copy(&load->src[0], idx, load); + nir_ssa_dest_init(&load->instr, &load->dest, 1, bitsize, NULL); + nir_builder_instr_insert(b, &load->instr); + return &load->dest.ssa; +} + +#define nir_ssbo_prop(b, prop, index, bitsize) \ + nir_load_ssbo_prop(b, nir_intrinsic_##prop, index, bitsize) + +static nir_ssa_def * +lower_ssbo_instr(nir_builder *b, nir_intrinsic_instr *intr) +{ + nir_intrinsic_op op = lower_ssbo_op(intr->intrinsic); + bool is_store = op == nir_intrinsic_store_global; + + /* We have to calculate the address: + * + * &(SSBO[offset]) = &SSBO + offset + */ + + nir_src index = intr->src[is_store ? 1 : 0]; + nir_src *offset_src = nir_get_io_offset_src(intr); + nir_ssa_def *offset = nir_ssa_for_src(b, *offset_src, 1); + + nir_ssa_def *address = + nir_iadd(b, + nir_ssbo_prop(b, load_ssbo_address, &index, 64), + nir_u2u64(b, offset)); + + /* Create the replacement intrinsic */ + + nir_intrinsic_instr *global = + nir_intrinsic_instr_create(b->shader, op); + + global->num_components = intr->num_components; + global->src[is_store ? 1 : 0] = nir_src_for_ssa(address); + + if (is_store) { + nir_src_copy(&global->src[0], &intr->src[0], global); + nir_intrinsic_set_write_mask(global, nir_intrinsic_write_mask(intr)); + } else { + nir_ssa_dest_init(&global->instr, &global->dest, + intr->dest.ssa.num_components, + intr->dest.ssa.bit_size, NULL); + } + + nir_builder_instr_insert(b, &global->instr); + return is_store ? NULL : &global->dest.ssa; +} + +static bool +should_lower_ssbo_instr(const nir_instr *instr) +{ + if (instr->type != nir_instr_type_intrinsic) + return false; + + const nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + + switch (intr->intrinsic) { + case nir_intrinsic_load_ssbo: + case nir_intrinsic_store_ssbo: + return true; + default: + return false; + } + + return false; +} + +bool +nir_lower_ssbo(nir_shader *shader) +{ + bool progress = false; + + nir_foreach_function(function, shader) { + nir_function_impl *impl = function->impl; + nir_builder b; + nir_builder_init(&b, impl); + + nir_foreach_block(block, impl) { + nir_foreach_instr_safe(instr, block) { + if (!should_lower_ssbo_instr(instr)) continue; + progress = true; + b.cursor = nir_before_instr(instr); + + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + nir_ssa_def *replace = lower_ssbo_instr(&b, intr); + + if (replace) { + nir_ssa_def_rewrite_uses(&intr->dest.ssa, + nir_src_for_ssa(replace)); + } + + nir_instr_remove(instr); + } + } + } + + return progress; +} |